WO1998035463A2 - Method for frequency division duplex communications - Google Patents
Method for frequency division duplex communications Download PDFInfo
- Publication number
- WO1998035463A2 WO1998035463A2 PCT/US1998/002250 US9802250W WO9835463A2 WO 1998035463 A2 WO1998035463 A2 WO 1998035463A2 US 9802250 W US9802250 W US 9802250W WO 9835463 A2 WO9835463 A2 WO 9835463A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- base station
- tdma
- receive path
- wireless signal
- diversity
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/0001—Arrangements for dividing the transmission path
- H04L5/0003—Two-dimensional division
- H04L5/0005—Time-frequency
- H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A), DMT
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/10—Polarisation diversity; Directional diversity
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/02—Arrangements for detecting or preventing errors in the information received by diversity reception
- H04L1/06—Arrangements for detecting or preventing errors in the information received by diversity reception using space diversity
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/02—Channels characterised by the type of signal
- H04L5/023—Multiplexing of multicarrier modulation signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/14—Two-way operation using the same type of signal, i.e. duplex
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/14—Two-way operation using the same type of signal, i.e. duplex
- H04L5/143—Two-way operation using the same type of signal, i.e. duplex for modulated signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/14—Two-way operation using the same type of signal, i.e. duplex
- H04L5/1469—Two-way operation using the same type of signal, i.e. duplex using time-sharing
- H04L5/1484—Two-way operation using the same type of signal, i.e. duplex using time-sharing operating bytewise
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0652—Synchronisation among time division multiple access [TDMA] nodes, e.g. time triggered protocol [TTP]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
Definitions
- This invention involves improvements to communications systems and methods in a wireless, frequency division duplex communications system.
- Wireless communications systems such as cellular and personal communications systems, operate over limited spectral bandwidths. They must make highly efficient use of the scarce bandwidth resource to provide good service to a large population of users. Examples of such communications systems that deal with high user demand and scarce bandwidth resources are wireless communications systems, such as cellular and personal communications systems.
- TDMA Time Division Multiple Access
- CDMA Code Division Multiple Access
- SDMA Space Division Multiple Access
- FDMA Frequency Division Multiple Access
- the Time Division Multiple Access (TDMA) protocol sends information from a multiplicity of users on one assigned frequency bandwidth by time division multiplexing the information from the various users.
- time division multiplexing particular time slots are devoted to specific users. Knowledge of the time slot during which any specific information is transmitted, permits the separation and reconstruction of each user's message at the receiving end of the communication channel.
- CDMA Code Division Multiple Access
- the Code Division Multiple Access (CDMA) protocol uses a unique code to distinguish each user's data signal from other users' data signals. Knowledge of the unique code with which any specific information is transmitted, permits the separation and reconstruction of each user's message at the receiving end of the communication channel.
- CDMA protocols classified by modulation: direct sequence (or pseudo-noise), frequency hopping, time hopping, and hybrid systems.
- direct sequence or pseudo-noise
- frequency hopping frequency hopping
- time hopping time hopping
- hybrid systems time hopping
- the Direct Sequence CDMA (DS-CDMA) protocol spreads a user's data signal over a wide portion of the frequency spectrum by modulating the data signal with a unique code signal that is of higher bandwidth than the data signal.
- the frequency of the code signal is chosen to be much larger than the frequency of the data signal.
- the data signal is directly modulated by the by the code signal and the resulting encoded data signal modulates a single, wideband carrier that continuously covers a wide frequency range.
- the receiver uses a locally generated version of the user's unique code signal to demodulate the received signal and obtain a reconstructed data signal. The receiver is thus able to extract the user's data signal from a modulated carrier that bears many other users' data signals.
- the Frequency Hopping Spread Spectrum (FHSS) protocol uses a unique code to change a value of the narrowband carrier frequency for successive bursts of the user's data signal.
- the value of the carrier frequency varies in time over a wide range of the frequency spectrum in accordance with the unique code.
- SSMA Spread Spectrum Multiple Access
- CDMA protocols such as DS-CDMA and FHSS that use a relatively wide frequency range over which to distribute a relatively narrowband data signal.
- the Time Hopping CDMA (T ⁇ -CDMA) protocol uses a single, narrow bandwidth, carrier frequency to send bursts of the user's data at intervals determined by the user's unique code.
- Hybrid CDMA systems include all CDMA systems that employ a combination of two or more CDMA protocols, such as direct sequence / frequency hopping (DS/FH), direct sequence / time hopping (DS/TH), frequency hopping / time hopping (FH TH), and direct sequence / frequency hopping / time hopping (DS/FH/TH).
- the Space Division Multiple Access (SDMA) transmission protocol forms directed beams of energy whose radiation patterns do not overlap spatially with each other, to communicate with users at different locations.
- Adaptive antenna arrays can be driven in phased patterns to simultaneously steer energy in the direction of selected receivers.
- the other multiplexing schemes can be reused in each of the separately directed beams.
- the specific codes used in CDMA can be transmitted in two different beams. Accordingly, if the beams do not overlap each other, different users can be assigned the same code as long as they do not receive the same beam.
- the Frequency Division Multiple Access (FDMA) protocol services a multiplicity of users over one frequency band by devoting particular frequency slots to specific users, i.e., by frequency division multiplexing the information associated with different users. Knowledge of the frequency slot in which any specific information resides permits reconstruction of each user's information at the receiving end of the communication channel.
- FDMA Frequency Division Multiple Access
- Orthogonal Frequency Division Multiplexing addresses a problem that is faced, for example, when pulsed signals are transmitted in an FDMA format.
- OFDM Orthogonal Frequency Division Multiplexing
- the limited time duration of such signals inherently broadens the bandwidth of the signal in frequency space. Accordingly, different frequency channels may significantly overlap, defeating the use of frequency as a user-identifying-parameter, the principle upon which FDMA is based.
- pulsed information that is transmitted on specific frequencies can be separated, in accordance with OFDM principles, despite the fact that the frequency channels overlap due to the limited time duration of the signals.
- OFDM requires a specific relationship between the data rate and the carrier frequencies.
- the total signal frequency band is divided into N frequency sub-channels, each of which has the same data rate 1/T. These data streams are then multiplexed onto a multiplicity of carriers that are separated in frequency by 1 T. Multiplexing signals under these constraints results in each carrier having a frequency response that has zeroes at multiples of 1 T. Therefore, there is no interference between the various carrier channels, despite the fact that the channels overlap each other because of the broadening associated with the data rate.
- OFDM is disclosed, for example, by Chang in Bell Sys. Tech. Jour., Vol. 45, pp. 1775-1796, Dec. 1966, and in U.S. Patent No. 4,488,445.
- Parallel Data Transmission is a technique related to FDMA. It is also referred to as Multitone Transmission (MT), Discrete Multitone Transmission (DMT) or Multi- Carrier Transmission (MCT).
- Parallel Data Transmission has significant calculational advantages over simple FDMA.
- each user's information is divided and transmitted over different frequencies, or "tones", rather than over a single frequency, as in standard FDMA.
- input data at NF bits per second are grouped into blocks of N bits at a data rate of F bits per second. N carriers or "tones" are then used to transmit these bits, each carrier transmitting F bits per second.
- the carriers can be spaced in accordance with the principles of OFDM.
- Both the phase and the amplitude of the carrier can be varied to represent the signal in multitone transmission. Accordingly, multitone transmission can be implemented with M-ary digital modulation schemes.
- M-ary modulation scheme two or more bits are grouped together to form symbols and one of the M possible signals is transmitted during each symbol period.
- M-ary digital modulation schemes include Phase Shift Keying (PSK), Frequency Shift Keying (FSK), and higher order Quadrature Amplitude Modulation (QAM).
- PSK Phase Shift Keying
- FSK Frequency Shift Keying
- QAM Quadrature Amplitude Modulation
- a signal is represented by the phase and amplitude of a carrier wave.
- high order QAM a multitude of points can be distinguished on a amplitude/phase plot. For example, in 64-ary QAM, 64 such points can be distinguished.
- a six-bit sequence of data symbols can, for example, be modulated onto a carrier in 64-ary QAM by transmitting only one value set of phase and amplitude, out of the possible 64 such sets.
- the invention enables high quality PCS communications in environments where adjacent PCS service bands operate with out-of-band harmonics that would otherwise interfere with the system's operation.
- the highly bandwidth-efficient communications method combines a form of time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations.
- the invention provides excellent fade resistance.
- the invention enables changing a user's available bandwidth on demand by assigning additional TDMA slots during the user's session.
- TDD, FDD, TDMA, and OFDM are combined to enable a base station to efficiently communicate with many remote stations.
- the method includes the step of receiving at the base station a first incoming wireless signal comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station during a first time division multiple access (TDMA) interval.
- the method includes the step of receiving at the base station a second incoming wireless signal comprising a plurality of second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a second remote station during the first time division multiple access (TDMA) interval.
- the first and second stations accordingly have different sets of discrete frequency tones that are orthogonal frequency division multiplexed.
- the method includes the step of receiving at the base station a third incoming wireless signal comprising a plurality of the first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a third remote station during a second time division multiple access (TDMA) interval.
- the first and third stations accordingly are time division multiplexed by sharing the same set of discrete frequency tones in different TDMA intervals.
- the method includes the step of receiving at the base station a fourth incoming wireless signal comprising a plurality of the second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a fourth remote station during the second time division multiple access (TDMA) interval.
- the second and fourth stations accordingly are time division multiplexed by sharing the same set of discrete frequency tones in different TDMA intervals.
- the method includes the step of transmitting at the base station the first outgoing wireless signal comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to the first remote station during a third time division multiple access (TDMA) interval.
- the first remote station and the base station accordingly are time division duplexed (TDD) by transmitting their respective signals at different TDMA intervals.
- the first remote station and the base station accordingly are frequency division duplexed (FDD) by transmitting their respective signals on different sets of discrete frequency tones in different frequency bands.
- TDD time division duplexed
- FDD frequency division duplexed
- the method includes the step of transmitting at the base station the second outgoing wireless signal comprising a plurality of fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the second remote station during the third time division multiple access (TDMA) interval.
- the second remote station and the base station accordingly are time division duplexed (TDD) by transmitting their respective signals at different TDMA intervals.
- the second remote station and the base station accordingly are frequency division duplexed (FDD) by transmitting their respective signals on different sets of discrete frequency tones in different frequency bands.
- TDD time division duplexed
- FDD frequency division duplexed
- the method includes the step of transmitting at the base station the third outgoing wireless signal comprising the plurality of the third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the third remote station during a fourth time division multiple access (TDMA) interval.
- the third remote station and the base station accordingly are time division duplexed (TDD) by transmitting their respective signals at different TDMA intervals.
- the third remote station and the base station accordingly are frequency division duplexed (FDD) by transmitting their respective signals on different sets of discrete frequency tones in different frequency bands.
- the method includes the step of transmitting at the base station the fourth outgoing wireless signal comprising the plurality of the fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the fourth remote station during the fourth time division multiple access (TDMA) interval.
- the fourth remote station and the base station accordingly are time division duplexed (TDD) by transmitting their respective signals at different TDMA intervals.
- the fourth remote station and the base station accordingly are frequency division duplexed (FDD) by transmitting their respective signals on different sets of discrete frequency tones in different frequency bands.
- TDD time division duplexed
- FDD frequency division duplexed
- TDD, FDD, TDMA, OFDM, and space diversity are combined to enable a base station to efficiently communicate with many remote stations.
- the spreading weights enable the base station to steer the signals it transmits to remote stations that are have a sufficient geographic separation from one another.
- the despreading weights enable the base station to steer the receive sensitivity of the base station toward the sources of signals transmits by remote stations that have a sufficient geographic separation from one another.
- the method includes the step of receiving at the base station a first incoming wireless signal comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station at a first geographic location during a first time division multiple access (TDMA) interval. Then the method includes the step of receiving at the base station a second incoming wireless signal comprising a plurality of the first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a second remote station at a second geographic location during the first time division multiple access (TDMA) interval.
- TDMA time division multiple access
- the method includes the step of spatially despreading the first and second incoming signals received at the base station by using spatial despreading weights. Spatial diversity is provided because the despreading weights enable the base station to steer the receive sensitivity of the base station toward the first remote station and the second remote station, respectively.
- the method performs the step of spatially spreading a first and second outgoing wireless signals at the base station by using spatial spreading weights. Then the method includes the step of transmitting at the base station the first outgoing wireless signal comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to the first remote station at the first geographic location during a third time division multiple access (TDMA) interval. Then the method includes the step of transmitting at the base station the second outgoing wireless signal comprising a plurality of the third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the second frequency
- OFDM orthogonal frequency division multiplexed
- TDMA time division multiple access
- TDD, FDD, TDMA, OFDM, and polarization diversity are combined to enable a base station to efficiently communicate with many remote stations. This is possible because the antenna at the base station and the antennas at the remote stations are designed to distinguish orthogonally polarized signals. Signals exchanged between the base station and a first remote station are polarized in one direction, and signals exchanged between the base station and a second remote station are polarized in an orthogonal direction.
- the method includes the step of receiving at the base station a first incoming wireless signal polarized in a first polarization direction comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station during a first time division multiple access (TDMA) interval. Then the method includes the step of receiving at the base station a second incoming wireless signal polarized in a second polarization direction comprising a plurality of the first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a second remote station during the first time division multiple access (TDMA) interval.
- TDMA time division multiple access
- the method includes the step of distinguishing the first and second incoming signals received at the base station by detecting the first and second polarization directions.
- Polarization diversity is provided because signals exchanged between the base station and the first remote station are polarized in one direction, and signals exchanged between the base station and the second remote station are polarized in an orthogonal direction.
- the method includes the step of forming a first and second outgoing wireless signals at the base station by polarizing them in the first and second polarization directions, respectively. Then the method includes the step of transmitting at the base station the first outgoing wireless signal polarized in the first polarization direction comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to the first remote station at the first geographic location during a third time division multiple access (TDMA) interval.
- OFDM orthogonal frequency division multiplexed
- the method includes the step of transmitting at the base station the second outgoing wireless signal polarized in the second polarization direction comprising a plurality of the third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the second remote station at the second geographic location during the third time division multiple access (TDMA) interval.
- Polarization diversity is provided because signals exchanged between the base station and the first remote station are polarized in one direction, and signals exchanged between the base station and the second remote station are polarized in an orthogonal direction.
- TDD, FDD, TDMA, OFDM, spatial diversity, and polarization diversity are combined to enable a base station to efficiently communicate with many remote stations.
- the resulting invention makes highly efficient use of scarce bandwidth resources to provide good service to a large population of users.
- the invention has advantageous applications in the field of wireless communications, such as cellular communications or personal communications, where bandwidth is scarce compared to the number of the users and their needs. Such applications may be effected in mobile, fixed, or minimally mobile systems. However, the invention may be advantageously applied to other, non-wireless, communications systems as well.
- Figure 1 is an architectural diagram of the PWAN FDD system, including remote stations communicating with a base station.
- Figure 1.1 is a diagram of PWAN Airlink RF Band Organization
- Figure 1.2 is a diagram of Physical Channels.
- Figure 1.3 is a diagram of PWAN Physical Layer Framing Structure
- Figure 1.4 is a diagram of Details of TDMA Slot Parameters
- Figure 1.5 is a diagram of A PWAN 64 kbit/s data channel
- Figure 1.6 is a diagram of Functional Block Diagram of Base transmitter for a single traffic channel in rate 3/4 16 QAM mode.
- Figure 1.7 is a diagram of The block diagram for Base CLC/BRC transmissions
- Figure 1.8 is a diagram of Gray-coded mapping for the QPSK modulation on the CLC/BRCchannel.
- Figure 1.9 is a diagram of The demultiplexing of a CLC BRC message on two consequent TDMA frames
- Figure 1.10 is a diagram of The Functional Block Diagram of Base receiver for a single traffic channel in rate 3/4 16 QAM mode
- Figure 1.11 is a diagram of The Functional Block Diagram of Base receiver for a CAC Figure 1.12 is a diagram of Functional Block Diagram of RU transmitter for a single traffic channel in rate 3/4 16 QAM mode
- Figure 1.13 is a diagram of The block diagram for RU CAC transmissions
- Figure 1.14 is a diagram of The demultiplexing of a CAC message on two consequent TDMA frames.
- Figure 1.15 is a diagram of The Functional Block Diagram of RU receiver for a single traffic channel in rate 3/4 16 QAM mode
- Figure 1.16 is a diagram of The baseband representation of the RU CLC/BRC receiver
- Figure 2.1 is a diagram of Functional Block Diagram of Base transmitter for a single traffic channel in rate 3/4 16 QAM mode.
- Figure 2.2 is a diagram of The Functional Block Diagram of Base receiver for a single traffic channel in rate 3/4 16 QAM mode
- Figure 3.1 is a diagram of Forward beam pattern and its effect on RU RSSI
- Figure 3.2 is a diagram of Forward beam pattern altered to accomodate incoming RU
- Figure 4.1 is a diagram of Processing Diagram
- Figure 4.2 is a diagram of Signals as seen at the Base station
- Figure 4.3 is a diagram of Delay Compensation in action
- FIGURE 1 is an architectural diagram of the frequency division duplex (FDD) personal wireless access network (PWAN) system, in accordance with the invention.
- the system employs the method of the invention that combines time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations.
- TDD time division duplex
- FDD frequency division duplex
- TDMA time division multiple access
- OFDM orthogonal frequency division multiplexing
- spatial diversity and polarization diversity
- Figure 1 provides an overview of how the invention combines TDD, FDD, TDMA, and OFDM to enable the base station Z to efficiently communicate with many remote stations U, V, W, and X.
- the base station Z receives a first incoming wireless signal 10 comprising a plurality of first discrete frequency tones F2 that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from the first remote station U during a first time division multiple access (TDMA) interval.
- TDMA time division multiple access
- the base station Z receives a second incoming wireless signal 12 comprising a plurality of second discrete frequency tones F4 that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a second remote station W during the first time division multiple access (TDMA) interval.
- the first and second stations U and W accordingly have different sets of discrete frequency tones F2 and F4, that are orthogonal frequency division multiplexed.
- the base station Z in Figure 1 receives a third incoming wireless signal 14 comprising a plurality of the first discrete frequency tones F2 that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a third remote station V during a second time division multiple access (TDMA) interval.
- the first and second TDMA intervals are part of the same TDMA frame, as is shown in Figure 1.5.
- the first and third stations U and V accordingly are time division multiplexed by sharing the same set of discrete frequency tones F2 in different TDMA intervals.
- the base station Z in Figure 1 receives a fourth incoming wireless signal 16 comprising a plurality of the second discrete frequency tones F4 that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a fourth remote station X during the second time division multiple access (TDMA) interval.
- the second and fourth stations W and X accordingly are time division multiplexed by sharing the same set of discrete frequency tones F4 in different TDMA intervals.
- the base station Z in Figure 1 transmits the first outgoing wireless signal 18 comprising a plurality of third discrete frequency tones FI that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to the first remote station U during a third time division multiple access (TDMA) interval.
- the first remote station U and the base station Z accordingly are time division duplexed (TDD) by transmitting their respective signals 10 and 18 at different TDMA intervals.
- the first, second, third, and fourth TDMA intervals occur at mutually different times, as is shown in Figure 1.5.
- the first remote station U and the base station Z accordingly are frequency division duplexed (FDD) by transmitting their respective signals 10 and 18 on different sets of discrete frequency tones F2 and FI in different frequency bands.
- FDD frequency division duplexed
- the base station Z in Figure 1 transmits the second outgoing wireless signal 20 comprising a plurality of fourth discrete frequency tones F3 that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the second remote station W during the third time division multiple access (TDMA) interval.
- the second remote station W and the base station Z accordingly are time division duplexed (TDD) by transmitting their respective signals 12 and 20 at different TDMA intervals.
- the second remote station W and the base station Z accordingly are frequency division duplexed (FDD) by transmitting their respective signals 12 and 20 on different sets of discrete frequency tones F4 and F3 in different frequency bands.
- the base station Z in Figure 1 transmits the third outgoing wireless signal 22 comprising the plurality of the third discrete frequency tones FI that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the third remote station V during a fourth time division multiple access (TDMA) interval.
- the third remote station V and the base station Z accordingly are time division duplexed (TDD) by transmitting their respective signals 14 and 22 at different TDMA intervals.
- the third remote station V and the base station Z accordingly are frequency division duplexed (FDD) by transmitting their respective signals 14 and 22 on different sets of discrete frequency tones F2 and FI in different frequency bands.
- the base station Z in Figure 1 transmits the fourth outgoing wireless signal 24 comprising the plurality of the fourth discrete frequency tones F3 that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the fourth remote station X during the fourth time division multiple access (TDMA) interval.
- the fourth remote station X and the base station Z accordingly are time division duplexed (TDD) by transmitting their respective signals 16 and 24 at different TDMA intervals.
- the fourth remote station X and the base station Z accordingly are frequency division duplexed (FDD) by transmitting their respective signals 16 and 24 on different sets of discrete frequency tones F4 and F3 in different frequency bands.
- Figure 1 shows another embodiment of the invention, wherein TDD, FDD, TDMA, OFDM, and space diversity are combined to enable the base station to efficiently communicate with many remote stations.
- the spreading weights enable the base station Z to steer the signals it transmits to remote stations U and V that are have a sufficient geographic separation from one another.
- the despreading weights enable the base station Z to steer the receive sensitivity of the base station toward the sources of signals transmitted by remote stations U and V that have a sufficient geographic separation from one another.
- remote stations U and V share the same discrete frequency tones FI and F2 and the same TDMA interval.
- the base station Z in Figure 1 receives a first incoming wireless signal 10 comprising a plurality of first discrete frequency tones F2 that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from the first remote station U at a first geographic location during a first time division multiple access (TDMA) interval.
- OFDM orthogonal frequency division multiplexed
- the base station Z in Figure 1 receives a second incoming wireless signal 14 comprising a plurality of the first discrete frequency tones F2 that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from the second remote station V at a second geographic location during the same, first time division multiple access (TDMA) interval.
- the base station Z in Figure 1 spatially despreads the first and second incoming signals 10 and 14 received at the base station Z by using spatial despreading weights. Spatial diversity is provided because the despreading weights enable the base station Z to steer the receive sensitivity of the base station toward the first remote station U and the second remote station V, respectively.
- the base station Z in Figure 1 spatially spreads a first and second outgoing wireless signals 18 and 22 at the base station by using spatial spreading weights. Then the base station Z in Figure 1, transmits the first outgoing wireless signal 18 comprising a plurality of third discrete frequency tones FI that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to the first remote station U at the first geographic location during a third time division multiple access (TDMA) interval.
- OFDM orthogonal frequency division multiplexed
- the base station Z in Figure 1 transmits the second outgoing wireless signal 22 comprising a plurality of the third discrete frequency tones FI that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the second remote station V at the second geographic location during the same, third time division multiple access (TDMA) interval. Spatial diversity is provided because the spreading weights enable the base station Z to steer the signals it transmits to the first and second remote stations U and V, respectively.
- OFDM orthogonal frequency division multiplexed
- FIG. 1 shows still another embodiment of the invention, wherein TDD, FDD, TDMA, OFDM, and polarization diversity are combined to enable the base station Z to efficiently communicate with many remote stations U, V, W, and X.
- the antenna A, B, C, or D at the base station Z and the antennas at the remote stations U, V, W, and X are designed to distinguish orthogonally polarized signals.
- Signals exchanged between the base station Z and a first remote station U are polarized in one direction, and signals exchanged between the base station Z and a second remote station V are polarized in an orthogonal direction.
- remote stations U and V share the same discrete frequency tones FI and F2 and the same TDMA interval.
- the base station Z in Figure 1 receives a first incoming wireless signal 10 polarized in a first polarization direction comprising a plurality of first discrete frequency tones F2 that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from the first remote station U during a first time division multiple access (TDMA) interval.
- the base station Z in Figure 1 receives a second incoming wireless signal 14 polarized in a second polarization direction comprising a plurality of the first discrete frequency tones F2 that are orthogonal frequency division multiplexed (OFDM) in the first frequency band from a second remote station V during the first time division multiple access (TDMA) interval.
- the base station Z in Figure 1 distinguishes the first and second incoming signals 10 and 14 received at the base station by detecting the first and second polarization directions.
- Polarization diversity is provided because signals exchanged between the base station Z and the first remote station U are polarized in one direction, and signals exchanged between the base station Z and the second remote station V are polarized in an orthogonal direction.
- the base station Z in Figure 1 forms a first and second outgoing wireless signals 18and 22 at the base station by polarizing them in the first and second polarization directions, respectively. Then the base station Z in Figure 1, transmits the first outgoing wireless signal 18 polarized in the first polarization direction comprising a plurality of third discrete frequency tones FI that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to the first remote station U at the first geographic location during a third time division multiple access (TDMA) interval.
- OFDM orthogonal frequency division multiplexed
- the base station Z in Figure 1 transmits the second outgoing wireless signal 22 polarized in the second polarization direction comprising a plurality of the third discrete frequency tones FI that are orthogonal frequency division multiplexed (OFDM) in the second frequency band to the second remote station V at the second geographic location during the third time division multiple access (TDMA) interval.
- Polarization diversity is provided because signals exchanged between the base station Z and the first remote station U are polarized in one direction, and signals exchanged between the base station Z and the second remote station V are polarized in an orthogonal direction.
- TDD, FDD, TDMA, OFDM, spatial diversity, and polarization diversity are combined to enable a base station Z to efficiently communicate with many remote stations U, V, W, and X.
- the resulting invention makes highly efficient use of scarce bandwidth resources to provide good service to a large population of users.
- the PWAN system has a total of 3200 discrete tones (carriers) equally spaced in 10 MHZ of available bandwidth in the range of 1850 to 1990 MHZ.
- the spacing between the tones is 3.125 kHz.
- the total set of tones are numbered consecutively form 0 to 3199 starting from the lowest frequency tone.
- the tones are used to carry traffic messages and overhead messages between the base station and the plurality of remote units.
- the PWAN system uses overhead tones to establish synchronization and to pass control information between the base station and the remote units.
- a Common Link Channel (CLC) is used by the base to transmit control information to the Remote Units.
- a Common Access Channel (CAC) is used to transmit messages from the Remote Unit to the Base. There is one grouping of tones assigned to each channel. These overhead channels are used in common by all of the remote units when they are exchanging control messages with the base station.
- Pilot tones are designated as pilots distributed throughout the frequency band. Pilot tones carry known data patterns that enable an accurate channel estimation.
- the series of pilot tones, having known amplitudes and phases, have a known level and are spaced apart by approximately 30 KHz to provide an accurate representation of the channel response (i.e., the amplitude and phase distortion introduced by the communication channel characteristics) over the entire transmission band.
- the PWAN FDD system uses a TDMA structure to provide various data rates, and to allow a hybrid FDD/TDD technique at the remote station (RU).
- FDD is used in the sense that the Base and the RU transmit and receive on two separate bands, and the TDD is used to indicate that for a given connection both the Base and the RU transmit and receive on different TDMA slots. This has no effect on the overall system capacity, and is only a measure for simplifying the RU design; i.e, to ensure that a duplexer is not needed at the RU.
- the total bandwidth allocation for the airlink of the PWAN Network is 10 MHZ in the PCS spectrum which is in the range of 1850 to 1990 MHZ.
- the total bandwidth is divided into two 5 MHZ bands called the Lower RF Band and the Upper RF Band.
- the separation between the lowest frequency in the Lower RF Band and the lowest frequency in the Upper RF Band (DF) is 80 MHZ.
- the base frequency (fbase) for the PWAN Network is defined as the lowest frequency of the Lower RF Band which depends on the specific PCS frequency band.
- the PWAN frequency assignment consists of a lower and an upper frequency band.
- the spacing between the tones is 3.125 kHz.
- the total set of tones are numbered consecutively from 0 to 3199 starting from the lowest frequency tone.
- Ti is the frequency of the ith tone:
- T, f b ⁇ pent + ⁇ F + — f + i - ⁇ f 1600 ⁇ i ⁇ 3l99
- T. f Ml , - S0C 0 -H (i - S • 3.125 kHz 1600 ⁇ ⁇ ⁇ 3199
- the set of 3200 tones is the Tone Space.
- the tones in the Tone Space are used for two functions: transmission of bearer data, and transmission of overhead data.
- the tones used for the transmission of bearer data are the Bearer Tones, and the tones dedicated to pilot channels are the Overhead Tones.
- the bearer tones are divided into 160 Physical Channels which consist of 80 Forward Physical Channels (FPC) and 80 reverse Physical Channels (RPC). Some of these channels are unavailable because they must be used as a guardband between PWAN and other services in the neighboring bands.
- Each of the Physical channels contains 18 Tones as shown in Figure 1.2.
- the mapping of tones into the ith FPCi, and the ith RPCi is shown in Table 1.1 and Table 1.2 respectively.
- the overhead tones are used for the following channels:
- These channels may use any set of the 160 overhead tones.
- the following equation shows the mapping of overhead tones:
- RCC(i) T 16 , ;0 ⁇
- the framing structure is shown in Figure 1.3.
- the smallest unit of time shown in this figure is a TDMA Slot.
- 8 TDMA slots constitute a TDMA frame.
- 16 TDMA frames make a multiframe, and 32 multiframes make a superframe.
- Frame synchronization is performed at the superframe level.
- the multiframe boundary is determined from the superframe boundary.
- a PWAN bearer channel uses a single physical channel with 18 tones separated by 3.125 kHz. The bandwidth occupancy of a bearer channel is therefore 56.25 kHz. Bearer channels may be used to carry traffic or control (access and broadcast) information.
- the PWAN traffic channels may carry between 16 kbit s to 64 kbit/s of information depending on the number of TDMA slots assigned to them.
- a 16 kbit/s PWAN traffic channel uses one TDMA slot per TDMA frame, a 32 kbit/s channel uses 2 TDMA slots per frame, and a 64 kbit s channel uses 4 TMDA slots per TDMA frame, as shown in Figure 1.5.
- Figure 1.5 assumes that there is no space division multiple access. However, it may be possible to support more than one user on a given TDMA slot, if the users are geographically separated and the transceiver can take advantage of that separation to form spatial beams.
- PWAN may use various coded modulation schemes (rates). Under benign channel conditions, an efficient high rate code may be used. If conditions get worse, a low rate, coded modulation scheme is used. This is especially important considering the high availability requirements for a wireless local loop system. As an example, we consider the use of a bandwidth efficient rate 3/4 16 QAM scheme. Lower rate codes can also be used.
- the Base transmits information to multiple RUs in its cell.
- This section describes the transmission formats for a 16 kbit/s to 64 kbit/s traffic channel, together with a 1 kbit/s to 4 kbit s Link Control Channel (LCC) from the Base to a single RU.
- the 16 kbit/s link is achieved by assigning one TDMA slot per TDMA frame.
- the TDMA frame is 3 s long, thus the effective data rate is 16 kbit/s times the number of TDMA slots per TDMA frame. For higher data rates, the process described in this section is repeated in every applicable TDMA slot.
- the Binary Source delivers 48 bits of data in one TDMA slot.
- the bit to octal conversion block converts the binary sequence into a sequence of 3-bit symbols.
- the symbol sequence is converted into a 16 element vector.
- One symbol from the Link Control Channel (LCC) is added to form a 17 element vector.
- LCC Link Control Channel
- the vector is trellis encoded.
- the trellis encoding starts with the most significant symbol (first element of the vector) and is continued sequentially until the last element of the vector (the LCC symbol).
- the output of the trellis encoder is a 17 element vector where each element is a signal within the set of 16QAM constellation signals.
- a known pilot symbol is added to form an 18 element vector, with the pilot as the first element of this vector.
- the resulting vector is to be transmitted over 8 different antennas.
- the elements of the vector are weighted according to the antenna element through which they are transmitted. The description of how these weights can be derived is found in Section 2.
- the 18 symbols destined for each antenna are then placed in the inverse DFT frequency bins (corresponding to the physical channel) where they are converted into the time domain.
- the symbols are mapped into tones on the ith forward physical channel FPCi.
- the mapping of the common link channel (CLC) / broadcast channel (BRC) symbols into tones is shown in Table 1-4.
- the digital samples are converted to analog, RF converted and sent to the corresponding antenna element (0 to 7) for transmission over the air.
- Figure 1.6 is a Functional Block Diagram of Base transmitter for a single traffic channel in rate 3/4 16 QAM mode.
- the block diagram for the CLC/BRC transmissions is shown in Figure 1.7.
- the generation of CLC/BRC information is represented by a binary source that generates 72 bits of data for every CLC/BRC transmission.
- the 72 bit sequence is RS encoded using a shortened Reed Solomon RS (63, 35) code to generate a 40 RS symbol sequence (or equivalently a 240 bit sequence).
- the 240 bit sequence is then quadrature phase shift key (QPSK) modulated where every two bits are mapped onto a constellation point according to the Gray mapping shown in Figure 1.8.
- the output of the QPSK modulator is a 120 symbol sequence (S0-S119).
- the QPSK symbols are interleaved with 24 pilot symbols (P0-P23), where for every 5 data symbols, a pilot is inserted. This results in a 144 symbol sequence.
- the sequence is then time demultiplexed into 8, 18 element vectors for transmission over 8 TDMA slots (in two TDMA frames) as shown in Figure 1.9.
- a given 18 element vector is transmitted over 8 different antennas.
- the elements of the vector are weighted according to the antenna element through which they are transmitted. The description of how these weights can be derived is found in Section 2.
- the 18 symbols destined for each antenna are then placed in the inverse DFT frequency bins (corresponding to the physical channel) where they are converted into the time domain.
- the digital samples are converted to analog, RF converted and sent to the corresponding antenna element (0 to 7) for transmission over the air.
- Table 1.4 shows a mapping of symbols onto tones for CLC/BRC transmissions on the ith physical channel.
- Figure 1.10 shows the block diagram of the Base receiver for a traffic channel.
- the Base receives signals on all its 8 antennas.
- the signals are down-converted, digitally sampled, and transformed back into frequency domain using Discrete Fourier Transform (DFT).
- DFT Discrete Fourier Transform
- the appropriate tones are selected using a demultiplexer.
- the tones from all the antennas are then sent to a despreader.
- the despreader weights all the tones from a given antenna by a given weight which can be calculated as described in Section 2, and then adds all the tones from different antennas (addition of 8, 18 element vectors).
- the resulting 18 element vector is then sent to an equalizer where each element of the vector is multiplied by a phase correction factor, and the pilot symbol is stripped off the sequence.
- the remaining 17 symbols are sent to the trellis decoder which delivers 16 symbols (48 bits) of traffic data, and 1 symbol (3 bits) of LCC data.
- Figure 1.10 is a Functional Block Diagram of Base receiver for a single traffic channel in rate 3/4 16 QAM mode.
- CACs Common Access Channels
- Figure 1.11 shows the block diagram of the Base receiver for a CAC.
- the Base receives signals on all its 8 antennas.
- the signals are down-converted, digitally sampled, and transformed back into frequency domain using Discrete Fourier Transform (DFT).
- DFT Discrete Fourier Transform
- the appropriate tones are selected using a demultiplexer.
- the tones from all the antennas are then sent to a despreader.
- the despreader weights all the tones from a given antenna by a given weight which can be calculated as described in Section 2, and then adds all the tones from different antennas (addition of 8, 18 element vectors).
- the resulting 18 tones are sent to an equalizer where each tone is multiplied by a phase correction factor, and the 9 pilot symbols are stripped off the sequence.
- the 9 element vector is then QPSK demodulated. Since each element of the vector is a QPSK symbol representing two bits of information, the demodulator outputs 18 bits of information.
- the time multiplexer collects the symbols received in 8 consecutive TDMA slots to form 144 bits of RS encoded information hence forming a 24 RS symbol block (every RS symbol is 6 bits long).
- the RS block is then decoded to produce 12 RS symbols or 72 bits of the original CAC information transmitted from the RU.
- Figure l. l l is a Functional Block Diagram of Base receiver for a CAC.
- the RU transmits information to the single Base in its cell.
- This section describes the transmission formats for a 16 kbit/s to 64 kbit/s traffic channel, together with a 1 kbit/s to 4 kbit/s Link Control Channel (LCC) from an RU to its Base.
- the 16 kbit s link is achieved by assigning one TDMA slot per frame. For higher data rates, the process described in this section is repeated in every applicable TDMA slot. For example, for the 64 kbit/s link, 4 TDMA slots per frame need to be assigned.
- the block diagram for the RU transmitter in Figure 1.12 shows the processing of data for one TDMA slot.
- the Binary Source delivers 48 bits of data in one TDMA slot.
- the bit to octal conversion block converts the binary sequence into a sequence of 3 -bit symbols.
- the symbol sequence is converted into a 16 element vector.
- One symbol from the Link Control Channel (LCC) is then added to form a 17 element vector.
- LCC Link Control Channel
- the vector is trellis encoded.
- the output of the trellis encoder is another 17 element vector where each element is a signal within the set of 16QAM constellation signals.
- a known pilot symbol is then added to form an 18 element vector.
- the 18 elements are placed in the inverse DFT frequency bins (corresponding to the physical channel) where they are converted into the time domain.
- the digital samples are converted to analog, RF converted and sent to antenna for transmission over the air.
- Figure 1.12 is a Functional Block Diagram of RU transmitter for a single traffic channel in rate 3/4 16 QAM mode.
- CACs Common Access Channels
- the block diagram for the RU CAC transmissions is shown in Figure 1.13.
- the generation of CAC information is represented by a binary source that generates 72 bits of data for every CAC transmission.
- the 72 bit sequence is RS encoded using a shortened Reed Solomon RS (63, 35) code to generate a 24 RS symbol sequence (or equivalently a 114 bit sequence).
- the 114 bit sequence is QPSK modulated where every two bits are mapped onto a constellation point according to Gray mapping.
- the output of the QPSK modulator is therefore a 72 symbol sequence (S0-S71).
- the QPSK symbols are interleaved with 72 known pilot symbols (P0-P71), where for every data symbol, a pilot is inserted. This results in a 144 symbol sequence.
- the sequence is time demultiplexed into 8, 18 element vectors for transmission over 8 TDMA slots (in two TDMA frames) as shown in Figure 1.14.
- FIG. 15 shows the block diagram of the RU receiver.
- the RU receives a signal on its antenna.
- the signals are down-converted, digitally sampled, and transformed back into frequency domain using Discrete Fourier Transform (DFT).
- DFT Discrete Fourier Transform
- the appropriate tones are selected using a demultiplexer.
- the 18 tones are sent to an equalizer where each tone is multiplied by a phase correction factor, and the pilot symbol is stripped off the sequence.
- the remaining 17 symbols are sent to the trellis decoder which delivers 16 symbols (48 bits) of traffic data, and 1 symbol (3 bits) of LCC data.
- Figure 1.15 shows the Functional Block Diagram of RU receiver for a single traffic channel in rate 3/4 16 QAM mode.
- Figure 1.16 is a block diagram representation of baseband processing in the CLC/BRC receiver.
- the RU receives a time domain signal through its antenna.
- the signal is down-converted, digitally sampled, and transformed back into frequency domain using Discrete Fourier Transform (DFT).
- DFT Discrete Fourier Transform
- the appropriate tones for the CLC/BRC are selected using a demultiplexer.
- the 18 tones are sent to an equalizer where each tone is multiplied by a phase correction factor, and the 3 pilot symbols are then stripped off.
- the remaining 15 elements are then QPSK demodulated.
- the demodulator outputs 30 bits of information.
- the time multiplexer collects the data in 8 consecutive TDMA slots to form 240 bits of RS encoded information hence forming a 40 RS symbol block (every RS symbol is 6 bits long).
- the RS block is then decoded to produce 12 RS symbols or 72 bits of the original CLC/BRC information transmitted from the Base.
- Spatial processing is incorporated into the PWAN physical layer to provide enhanced capacity and an improved grade of service. These are achieved through spatial isolation for frequency reuse and through the suppression of co-channel interferers.
- FDD frequency division duplex
- reciprocity in the channel is not achievable. Therefore, different beamforming strategies are needed on the forward and reverse channels.
- Spatial processing at the Remote Unit is optional and offers a potential means of gaining spatial degrees of freedom for further increases in capacity.
- the primary functions present in any beamforming system will be described for both the forward and reverse links. They include the application of the beamforming weights, weight computation, adaptation, and incorporation of the reference pilots.
- This assumption can be examined analytically in the context of the observation time-bandwidth product for the Base station antenna aperture. It can also be tested through observation of the mismatch present in the beam pattern across the frequency band of interest.
- the observation-time interval for an antenna aperture is defined as the time required for a plane waveform to travel completely across the antenna aperture. This is a function of the signal angle-of-arrival.
- the observation time-bandwidth product (TBWP) is the product of the observation interval and the signal bandwidth. For an array to be considered narrowband, the TBWP should be much less than 1 for all angles of arrival.
- Equation 2.1 and Equation 2.2 describe this calculation, where Td is the observation time interval, BW is the signal bandwidth (112.5 kHz), N is the number of array elements (8), and c is the speed of light.
- Td (Element Spacing * sin(angle-of-arrival))/c)*(N-l)
- beamforming is employed to provide isolation between spatially separated RUs.
- beamforming is based on direction-of-arrival estimates derived from received RU transmissions.
- spatial isolation is provided by data combining at the antenna aperture itself for a continuous fixed beampattern.
- Figure 2.1 A functional representation of a single traffic channel for the Base transmitter is presented in Figure 2.1. This section will address those components of the Base transmitter that directly implement the spatial processing functions; the Spreader block shaded in Figure 2.1 and the antenna array.
- Figure 2.1 is a Functional Block Diagram of Base transmitter for a single traffic channel in rate 3/4 16 QAM mode.
- the antenna array for the Base transmitter consists of N sensors that transmit spatially weighted signals from each array element. This array is configured in a hemispherical geometry with either uniform or non-uniform element spacing.
- Beamforming in the forward direction is achieved by applying a complex weight matrix, W, composed of weight vectors corresponding to each user, such that the transmitted signal is reinforced in the direction of the desired RU(s) and attenuated for all other transmit directions.
- W a complex weight matrix
- Equation 2.3 represents a matrix multiplication of the baseband tone data, Y, by the weight matrix, W, to produce the tone data to be modulated and transmitted, X.
- the Spreader block within the Base transmitter provides the matrix of spatial weights, W, for application to the tone data to be transmitted.
- This matrix may be derived by one of several methods; from data-independent fixed beam weights derived from the spatial separation of the antenna array aperture, by real-time, adaptive, computation of statistically optimum beam weights derived from second order statistics of the data received over the antenna array aperture, or by receiving either type of weight through an interface from another Base subsystem.
- Each method of weight derivation implies certain advantages with regard to spatial isolation, co-channel interference rejection, and system processing complexity.
- Data independent fixed beam weights place the least real-time computational burden on the baseband subsystem, since these weights can be pre-calculated and tabularized for look-up on a per call basis at real-time.
- Data-independent weights provide spatial isolation between downlink transmissions for spatial division multiple access (SDMA) but, will not steer nulls for direct suppression of co-channel interferers.
- SDMA spatial division multiple access
- suppression of these interferers is inherent in the spatial isolation provided by the mainlobe-to-sidelobe ratio, but the advantages (spatial resolution and increased attenuation) of adaptively steering nulls directly at a co-channel interferers are not available.
- Statistically optimum beamforming weights provide direct suppression of co- channel interferers, but require increased processing power and cause increased latency due to convergence times in the weight calculation. It should also be noted that in FDD systems, direction of arrival (DOA) estimation will not provide the transmit beamformer with accurate estimates of multipath components due to the independence of channel effects over the wide frequency separation of the forward and reverse bands. This implies that the transmit beamfomer will only be able to null fixed line of sight (LOS) transmissions from interfering RUs. Another significant benefit to this approach, however, is the increased resolution of the mainbeam, thus providing enhanced spatial resolution over data-independent weights.
- DOA direction of arrival
- the weight matrix, W must be periodically updated. This update is required to track changes in the forward link channel as well as individual links continuously being torn down and set up over that channel. For data independent weights, channel tracking does not apply and the weight update is based on a per call basis. For statistically optimum weights, the update interval is based on the rate of adaptation derived from the channel statistics (time-bandwidth product and channel stationarity.) 2.3.1.5 Reference Signal
- the Base will transmit reference link maintenance pilots (LMPs) to provide a phase reference for coherent demodulation and an estimate of the desired signal for beamform error estimation.
- Reference signals are transmitted on both the forward link and on the reverse link. This allows the Base to make a measurement of mean-square error (MSE) for use in deriving an optimal beamform solution on the reverse link without relying on direction-of-arrival estimation.
- MSE mean-square error
- Apriori knowledge of the angle-of-arrival for RU transmissions is required to steer transmit beams at the desired signals on a call-by-call basis. This information must be gathered through DOA estimation techniques.
- RU baseband spatial processing techniques perform spatial processing at the array aperture to form a continuous beam.
- beamforming is employed to provide isolation between spatially separated RUs and to provide suppression of co-channel interferers.
- no apriori knowledge of the angle-of-arrival of RU transmissions is required but, rather, reference signal adaptive beamforming is employed.
- the antenna array for the Base receiver consists of N sensors that sample waveforms impinging on the array aperture at each array element. This array is configured in a hemispherical geometry with either uniform or non-uniform element spacing.
- Equation 2.4 represents a matrix multiplication of the baseband tone data, X, by the weight matrix, W, to produce the despread tone data,Y.
- the Depreader block within the Base receiver provides the matrix of spatial weights, W, for application to the received data.
- This matrix may be derived by one of several methods; from data-independent fixed beam weights derived from the spatial separation of the antenna array aperture, by real-time, adaptive, computation of statistically optimum beam weights derived from second-order statistics received over the antenna array aperture, or by receiving either type of weight through an interface from another Base subsystem.
- Data independent fixed beam weights place the least real-time computational burden on the baseband subsystem, since these weights can be pre-calculated and tabularized for look-up on a per call basis at real-time.
- Data-independent weights provide spatial isolation between uplink transmissions for spatial division multiple access (SDMA) but, do not steer nulls for direct suppression of co-channel interferers. however, suppression of these interferers is inherent in the spatial isolation provided by the mainlobe-to-sidelobe ratio, but the advantages (spatial resolution and increased attenuation) of adaptively steering nulls directly at a co-channel interferers is not available.
- SDMA spatial division multiple access
- Statistically optimum beamforming weights provide direct suppression of co- channel interferers, but require increased processing power and cause increased latency due to convergence times in the weight calculation.
- the weight matrix, W must be periodically updated. This update is required to track changes in the reverse link channel as well as individual links continuously being torn down and set up over the channel. For data independent weights, channel tracking does not apply and the weight update is based on a per call basis. For statistically optimum weights, the update interval is based on the rate of adaptation derived from the channel statistics (time-bandwidth product and channel stationarity.) 2.4.1.5 Direction-of-Arrival Estimation
- direction-of-arrival estimation is performed on the received data set for application on the forward link.
- This information allows the Base transmit beamformer to steer beams at the intended RU and, for statistically optimum weights, nulls at interfering RUs.
- no tracking of the angle-of-arrival estimate is necessary since the source RUs are fixed in space.
- these angle-of-arrival estimates have the disadvantage of being independent across PCS bands so that they will not track multipath effects.
- the Base will transmit reference link maintenance pilots (LMPs) to provide a phase reference for coherent demodulation and an estimate of the desired signal for beamform error estimation.
- Reference signals are transmitted on both the forward link and on the reverse link. This allows the Base to make a measurement of mean-square error (MSE) for use in deriving an optimal beamform solution on the reverse link without relying on direction-of-arrival estimation.
- MSE mean-square error
- RU baseband spatial processing techniques RU perform spatial processing at the array aperture to form a continuous beam.
- the channel allocation algorithm needs to know information concerning the capabilities of each active and new RU. If future equipments operate over different IF bandwidths then the channel allocation algorithm needs to know what each equipment can support.
- the RlFs support a 1 MHz operating bandwidth. This allows operation over any of 16 channels.
- the base searches a data base containing the required information about the RU for the channel allocation algorithm e.g. frequency (IF), bandwidth (BW), number of bearer (B) channels supported, type(s) of voice coding supported, etc.
- IF frequency
- BW bandwidth
- B number of bearer
- type(s) of voice coding supported etc.
- DOA Direction of Arrival
- DOA the DOA for each RU.
- the channel allocation algorithm needs to know the DOA of every RU involved in an active call and the DO As of any new RUs.
- the RUs In order for the best channel to be chosen, the RUs must make measurements on some number of channels and report the results to the base station for use in selecting the best channel for an RU when a link is established. These measurements include RSSI and SINR. Table 3.1 shows a gross look at how received signal strength indicator (RSSI) and signal to interference ratio (SINR) information could be used to assign channels to incoming RUs.
- RSSI received signal strength indicator
- SINR signal to interference ratio
- the SINR measurements are used.
- a low SINR value indicates high levels of noise and interference on the channel.
- a high SINR value indicates a clear signal from the serving base. So for the situation shown in Figure 3.1 the RU would report significant RSSI with fairly high SINR. If the DOA of the incoming RU was far enough away from the established RU then there is enough information to know that the forward beam pattern can be squinted to accomodate the incoming RU on that channel as shown in Figure 3.2. As a first cut it seems that the three pieces of data can be combined into a channel candidacy assessment factor (CAF). The three desirable situations are: large separation in DOA, small RSSI, and high SINR. So an equation to quantify the candidacy of channel n is
- CAF(n) fDOA(n) + fRSSI(n) - fSINR(n)
- Equation 3.1 assesses the DOA information. The maximum separation possible is 180 degrees. So a larger difference in DOA will cause the first term to be smaller.
- the second term of Equation 3.1 assesses the RSSI measurement. The noise floor of the receiver is -133 dBm. This is the ideal measurement indicating no activity on that channel, so any value greater than -133 dB biases the CAF away from ideal.
- the third term of Equation 3.1 includes the effects of channel SINR. A larger value of SLNRRU gives a better CAF since it means the energy seen by the RU is from the serving base. Likewise a larger SINRBase means there is less interference from RUs in other cells on that channel.
- RSSI(2) -95 dBm
- SINRRU(2) 4.5 dB.
- CAF(2) (180 - 1133 - 42
- ) + (133 - 95) - 0.5(4.5 + 13) 118.25
- the RU measured the same RSSI on both channels.
- the DOA of the existing RU on channel 1 was slightly better than the DOA of the existing RU on channel 2.
- the base's SINR measurement for channel 1 was slightly better than the measurement for channel 2.
- the measurement that made the biggest difference in this case was the RU SINR.
- the RUs and base In order to effectively measure SINR, the RUs and base must have a sense of whether or not a signal belongs to a given cell. Without any such mechanisms a SINR measurement would be the same for a signal of a given RSSI level from the serving base as it would be for a signal from a neighboring base with the same RSSI value.
- a way to differentiate signals in different cells is to encode the reference pilots on the traffic channels with different phases or sequence of phases which would be derived from the Base Station Offset Code.
- meas_rpts which is sent on the broadcast channel of each base stating how many channel measurements an RU will send to the base when a traffic connection is to be established.
- the RU When a traffic connection is to be established the RU sends the best meas_rpts channel measurements to the base on the SCAC channel.
- the base uses the channel measurements sent by the RU to compute a CAF for each of the candidate channels in the set sent by the RU.
- the base requests the next best set of meas_rpts measurements from the RU.
- the base repeats steps 4 through 6 until either an acceptable channel is found and is then used or the list of candidate channels is exhausted at which point the call is blocked.
- the remote unit When the remote unit (RU) is initialized and begins receiving transmissions from its Base, the time of arrival of the waveform is unknown. Also, the RU Signal Pilots (RSPs) will not likely be within the prescribed FFT bins because the Base oscillator and the RU oscillator are operating at slightly different frequencies.
- the purpose of the synchronization algorithm is to align the RU processing window, or receive gate, with the waveform, and to adjust the RU reference oscillator (VCXO) to operate at the same frequency as the Base oscillator.
- Synchronization is presented as a two-step process.
- acquisition of the synchronization waveform in both time and frequency must occur.
- the RU receive gate is adjusted to contain most of the signal energy, and the RU VCXO is adjusted to eliminate most of the RU-Base frequency disparity.
- Driving the residual frequency offset to zero and maintaining an average frequency offset of zero requires a robust method of frequency estimation, continuously running during RU operation.
- the RU is said to be frequency-locked to the base. Maintaining the zero frequency error is the function of the frequency-tracking step, which runs continuously in the background.
- the phase-locked loop (PLL) is capable of tracking time-varying phase immersed in noise, and is thus an effective frequency estimator for tracking RU-Base frequency errors.
- the PLL is the implementation of the optimal; i.e., maximum likelihood, carrier phase estimator.
- RU synchronization is performed at initialization of the RU, or whenever synchronization is lost.
- the time requirements for achieving initial synchronization are not as critical as for the case when the RU has to reestablish frequency lock after sleep mode.
- RU battery life is the critical issue in keeping resync time at a minimum.
- Time and frequency bandwidth are the resources that determine how long it takes to achieve frequency lock.
- Channel effects and noise must be averaged out in the estimation of time delay and frequency offsets; one can either average over time, or over frequency, to mitigate these effects.
- a balance must be struck between use of the available bandwidth and the time constraints determined by the system requirements.
- the proposed synchronization algorithm does not assume a particular model for the data channel configuration. That is, no particular tone mapping of the pilot waveforms, or RU signal pilots (RSPs), is assumed.
- the RSPs can comprise the overhead tones of a data channel, be in a separate synchronization channel, or constitute part of a message framing structure.
- the ultimate objective of synchronization is to achieve time and frequency lock for demodulation of data.
- Precise alignment of the RU receive time gate with the data burst, and frequency lock of the RU oscillator with the Base is required for orthogonality of the FFT bin data, and hence, for reliable demodulation.
- Synchronization relies upon a multiple step procedure in which coarse adjustments are made in time and frequency, then fine adjustments are made in time and frequency to system specifications.
- the steps, labeled coarse time alignment, coarse frequency alignment, fine time alignment, and frequency tracking, are outlined below.
- Coarse Time Alignment The waveform must be within the receive gate for determination of the RSPs in frequency. Coarse time alignment is achieved with a filter matched to the frequency-offset waveform.
- a phase-locked loop drives the residual frequency offset to zero and continuously adjusts the RU VCXO to keep the average frequency difference at zero.
- Fine Time Alignment This aligns the waveform with the RU receive gate to within the final required accuracy.
- Figure 4.1 shows the methods used to accomplish the objective of each processing step. Except for the frequency tracking stage, matched filtering constitutes the primary tool for time and frequency acquisition. Realization of the matched filter differs in each step, but the concept is identical.
- Coarse time alignment uses a filter impulse response that is matched to the frequency-offset waveform.
- Coarse frequency alignment uses a bank of filters to estimate the frequency offset.
- the final time alignment step uses a single filter that is tuned to the exact specified frequency. 4.2 Delay Compensation
- a RU When a RU is installed, it needs to know when to transmit its signals in relation to the signals received from the Base station so that its signal will arrive at the base station at the same time as the signals from the other RUs.
- the Base station measures the difference between the expected time of arrival and the actual time of arrival of the RU signals. It then transmits this measurement information to the RU so it can advance or delay the time that it sends signals to the Base station.
- Figure 4.2 shows the signals that appear at the Base station. The Base station expects to see the signals from the RU arrive 55 us after it transmits its last burst.
- the 4.3 shows the signals that appear at the Base and the RU. Before the RU is compensated, the signals it transmits arrive at the Base at a different time to the signals transmitted by the other RUs. The Base measures the delay and transmits the measurement to the RU. The RU then adjusts the time of transmission to compensate for the delay.
- Delay compensation can be performed upon installation and also at every call setup.
- the Delay Compensation calculation routine examines the average signal power in the signals used for the delay calculations and if they are above a certain threshold then a delay compensation measurement is made.
- Figure 4.3 shows the Delay Compensation in action.
- Delay compensation relies on measuring the phase of pilot tones called delay compensation pilots (DCPs).
- DCPs delay compensation pilots
- the RU transmits the DCPs to the base station with each DCP having the same phase shift. If the RU has been compensated properly the DCP tones arrive at the base station in phase with each other. If the signal from the RU is delayed then each of the DCP tones experiences a phase shift, which is proportional to the DCP frequency.
- the Base measures the phase of each DCP and uses linear regression to fit the phases to a straight line. The slope of this line is proportional to the delay. A slope of zero indicates that no delay compensation is needed, whereas a nonzero slope means that the signal is arriving too early (or late) and the RU needs to delay (or advance) transmission of its signal.
- phase measurements will corrupt the phase measurements. This can be mitigated by averaging the phase measurements over frequency (over DCPs) and over time (over successive data bursts).
- Diversity is a communication receiver technique that exploits the random nature of radio propagation by finding highly uncorrelated signal paths for communication. Diversity decisions are made by the receiver. If one radio path undergoes a deep fade, another independent path may have a strong signal. By having more than one path to select from, both the instantaneous and average signal to noise ratios at the receiver may be improved.
- multiple base station or remote station receiving antennas are used to provide diversity reception.
- Frequency diversity transmits information on more than one carrier frequency
- Time diversity repeatedly transmits information at time spacings that exceed the coherence time of the channel, so that multiple repetitions of the signal will be received with independent fading conditions.
- Selection diversity m demodulators are used to provide m diversity branches
- the receiver branch having the highest instantaneous SNR is connected to the demodulator.
- the m signals are scanned in a fixed sequence until one is found to be above a predetermined threshold.
- the branch weights are all set to unity but the signals from each branch are co-phased to provide equal gain combining diversity.
- frequency diversity is used to mitigate fading, it is not the sole means. In an FDD-based system in which the coherence bandwidth may exceed the available bandwidth, the effectiveness of frequency diversity is not sufficient to avoid fading. Receiving on orthogonal polarization components is used as a complementary means to combat fading. Polarization diversity is used in the PWAN system. 5.1 Frequency Diversity
- the maximum frequency separation possible in an 8 x 2 (spatial x frequency) implementation for the 5 MHZ band is 2.5 MHZ.
- the frequency separation must exceed the channel coherence bandwidth to minimize the likelihood that both carriers are simultaneously faded.
- the coherence bandwidths corresponding to correlations of 90% and 50% between frequencies are typically used for roughly characterizing the channel.
- An estimate of the coherence bandwidth at the 0.90 correlation level is given by Eq :
- Table 5.1 lists as a function of correlation level and upper and lower bounds on rms delay spreads measured at PCS bands including both line of sight and non-line of sight paths.
- the data presented here is not intended as the definitive measure of the coherence bandwidths expected in the PWAN deployment. Rather, it is intended to show that given the uncertainties in the environment, the coherence bandwidth can easily exceed the available system bandwidth for frequency diversity. Given this, another mechanism, such as polarization, must be considered for diversity.
- Polarization diversity exploits the tendency of multipath to spill energy from a transmitted polarization component into the orthogonal polarization component. For example, a transmitter may emit a vertically polarized component, but the receiver would receive energy in both the vertical and horizontal polarization components. If fading affects one component and not the other, then the signal could still be received in a polarization diverse system.
- Polarization diversity for 900 MHZ and 1800 MHZ systems can provide a diversity gain comparable to horizontal spatial diversity gain.
- Polarization diversity is used in conjunction with or in lieu of frequency diversity.
- the correlation between fading of the horizontal and vertical polarization components in multipath is significantly less than 0.70 95% of the time. Correlation values are less than 0.10
- Polarization diversity receive systems can provide performance improvement over a single linear polarization channel in a strong multipath environment. The performance is comparable with that provided by a horizontal spatial diversity system.
- Maximal ratio combining of the polarization branches is generally assumed in the papers. This provides the best performance compared to selection diversity and equal gain combining. Compared with selection diversity, maximal ratio combining can provide as much as a 3 dB gain benefit in mitigating multipath effects.
- the typical cross-polarization level is about -10 dB relative to the polarization level of the transmitting antenna.
- the orthogonal polarization components may be sufficiently decorrelated to provide protection against multipath fading. (However, the high degree of cross- polarization that makes diversity possible works against polarization as an interference suppression mechanism.)
- the implementation scenario for polarization diversity in the PWAN system is the following:
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE69837595T DE69837595T2 (en) | 1997-02-06 | 1998-02-03 | COMMUNICATION PROCESS COMBINED OF FDD, TDD, TDMA, OFDM, POLARIZATION AND SPACE DIVERSITY |
EP98908475A EP0951763B1 (en) | 1997-02-06 | 1998-02-03 | Method for combined fdd, tdd, tdma, ofdm, polarization and spatial diversity communication |
JP53489998A JP3967385B2 (en) | 1997-02-06 | 1998-02-03 | Frequency division duplex communication method |
CA002278852A CA2278852C (en) | 1997-02-06 | 1998-02-03 | Method for frequency division duplex communications |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/796,584 | 1997-02-06 | ||
US08/796,584 US5933421A (en) | 1997-02-06 | 1997-02-06 | Method for frequency division duplex communications |
Publications (2)
Publication Number | Publication Date |
---|---|
WO1998035463A2 true WO1998035463A2 (en) | 1998-08-13 |
WO1998035463A3 WO1998035463A3 (en) | 1999-04-22 |
Family
ID=25168559
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1998/002250 WO1998035463A2 (en) | 1997-02-06 | 1998-02-03 | Method for frequency division duplex communications |
Country Status (6)
Country | Link |
---|---|
US (8) | US5933421A (en) |
EP (4) | EP1786137B1 (en) |
JP (1) | JP3967385B2 (en) |
CA (1) | CA2278852C (en) |
DE (2) | DE69841701D1 (en) |
WO (1) | WO1998035463A2 (en) |
Cited By (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000079722A1 (en) * | 1999-06-23 | 2000-12-28 | At & T Wireless Services, Inc. | Ofdm fixed wireless system |
EP1107481A2 (en) * | 1999-12-10 | 2001-06-13 | Lucent Technologies Inc. | A system for statistically multiplexing real-time and non-real-time voice and data traffic in a wireless system |
EP1107477A2 (en) * | 1999-12-01 | 2001-06-13 | Alcatel Canada Inc. | Physical layer interface system and method for a wireless communication system |
EP1127416A1 (en) * | 1998-10-19 | 2001-08-29 | Motorola, Inc. | Method and system for combining orthogonal transmit diversity and adaptive array techniques in a wireless communications system |
DE10009284A1 (en) * | 2000-02-28 | 2001-08-30 | Nokia Multimedia Terminals Oy | Circuit for implementing spatial diversity with digital signal receiver has complex integrated circuit with diversity processor changing between reception paths according to quality criteria |
WO2002009298A2 (en) * | 2000-07-24 | 2002-01-31 | Runcom Communications Ltd. | Wireless interactive system and method |
FR2820257A1 (en) * | 2001-01-26 | 2002-08-02 | Thomson Csf | Gigahertz frequency high capacity radio system having base station with wide band adaptive directive antennas secondary stations sending with secondary stations transmitting/receiving elevated frequencies. |
US6782039B2 (en) | 1997-02-24 | 2004-08-24 | At&T Wireless Services, Inc. | Vertical adaptive antenna array for a discrete multitone spread spectrum communications system |
US6785300B2 (en) | 1997-02-06 | 2004-08-31 | At&T Wireless Services, Inc. | Delay compensation |
EP1606956A2 (en) * | 2003-03-24 | 2005-12-21 | Mobile Satellite Ventures LP | Co-channel wireless communication methods and systems using nonsymmetrical alphabets |
EP1699143A3 (en) * | 1999-03-31 | 2007-05-23 | Alcatel Lucent | Method and arrangement to estimate transmission channel characteristics |
US7626920B2 (en) | 1999-10-22 | 2009-12-01 | Nextnet Wireless, Inc. | Fixed OFDM wireless MAN utilizing CPE having internal antenna |
WO2009145685A1 (en) | 2008-05-28 | 2009-12-03 | Telefonaktiebolaget Lm Ericsson (Publ) | Polarization co-ordination |
EP2207297A1 (en) * | 2001-10-17 | 2010-07-14 | Nortel Networks Limited | Frame structure for OFDM systems |
WO2010097111A1 (en) * | 2009-02-24 | 2010-09-02 | Telefonaktiebolaget Lm Ericsson (Publ) | Clock recovery in a communications network |
EP2296295A2 (en) * | 2000-09-01 | 2011-03-16 | Nortel Networks Limited | Method and apparatus for adaptive time diversity and spatial diversity for OFDM |
US8108004B2 (en) | 2003-03-24 | 2012-01-31 | Atc Technologies, Llc | Co-channel wireless communication methods and systems using relayed wireless communications |
EP1804536A3 (en) * | 2005-12-28 | 2013-05-01 | Samsung Electronics Co., Ltd. | Method of allocating resources using hybrid duplexing technique |
US9088388B2 (en) | 1997-02-06 | 2015-07-21 | At&T Mobility Ii Llc | Method for frequency division duplex communications |
US9780987B2 (en) | 2000-09-01 | 2017-10-03 | Apple Inc. | Adaptive time diversity and spatial diversity for OFDM |
Families Citing this family (361)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7274652B1 (en) * | 2000-06-02 | 2007-09-25 | Conexant, Inc. | Dual packet configuration for wireless communications |
US6201801B1 (en) * | 1994-03-24 | 2001-03-13 | Ericsson Inc. | Polarization diversity phased array cellular base station and associated methods |
JP3286885B2 (en) * | 1995-11-07 | 2002-05-27 | 三菱電機株式会社 | Timing recovery means and diversity communication device |
US6678311B2 (en) | 1996-05-28 | 2004-01-13 | Qualcomm Incorporated | High data CDMA wireless communication system using variable sized channel codes |
US6771590B1 (en) * | 1996-08-22 | 2004-08-03 | Tellabs Operations, Inc. | Communication system clock synchronization techniques |
US6118758A (en) * | 1996-08-22 | 2000-09-12 | Tellabs Operations, Inc. | Multi-point OFDM/DMT digital communications system including remote service unit with improved transmitter architecture |
EP0931388B1 (en) * | 1996-08-29 | 2003-11-05 | Cisco Technology, Inc. | Spatio-temporal processing for communication |
US9134398B2 (en) | 1996-09-09 | 2015-09-15 | Tracbeam Llc | Wireless location using network centric location estimators |
US6236365B1 (en) | 1996-09-09 | 2001-05-22 | Tracbeam, Llc | Location of a mobile station using a plurality of commercial wireless infrastructures |
US7714778B2 (en) | 1997-08-20 | 2010-05-11 | Tracbeam Llc | Wireless location gateway and applications therefor |
US7903029B2 (en) | 1996-09-09 | 2011-03-08 | Tracbeam Llc | Wireless location routing applications and architecture therefor |
WO1998010307A1 (en) | 1996-09-09 | 1998-03-12 | Dennis Jay Dupray | Location of a mobile station |
US6249252B1 (en) | 1996-09-09 | 2001-06-19 | Tracbeam Llc | Wireless location using multiple location estimators |
US6463295B1 (en) | 1996-10-11 | 2002-10-08 | Arraycomm, Inc. | Power control with signal quality estimation for smart antenna communication systems |
US6275543B1 (en) | 1996-10-11 | 2001-08-14 | Arraycomm, Inc. | Method for reference signal generation in the presence of frequency offsets in a communications station with spatial processing |
US7035661B1 (en) * | 1996-10-11 | 2006-04-25 | Arraycomm, Llc. | Power control with signal quality estimation for smart antenna communication systems |
FI970266A (en) * | 1997-01-22 | 1998-07-23 | Nokia Telecommunications Oy | A method of increasing the range of the control channels in a cellular radio system |
US6359923B1 (en) | 1997-12-18 | 2002-03-19 | At&T Wireless Services, Inc. | Highly bandwidth efficient communications |
US6408016B1 (en) * | 1997-02-24 | 2002-06-18 | At&T Wireless Services, Inc. | Adaptive weight update method and system for a discrete multitone spread spectrum communications system |
WO1998037654A2 (en) | 1997-02-24 | 1998-08-27 | At & T Wireless Services, Inc. | Vertical adaptive antenna array for a discrete multitone spread spectrum communications system |
US6128276A (en) | 1997-02-24 | 2000-10-03 | Radix Wireless, Inc. | Stacked-carrier discrete multiple tone communication technology and combinations with code nulling, interference cancellation, retrodirective communication and adaptive antenna arrays |
US7133380B1 (en) * | 2000-01-11 | 2006-11-07 | At&T Corp. | System and method for selecting a transmission channel in a wireless communication system that includes an adaptive array |
US6185258B1 (en) * | 1997-09-16 | 2001-02-06 | At&T Wireless Services Inc. | Transmitter diversity technique for wireless communications |
US6351458B2 (en) * | 1997-09-22 | 2002-02-26 | Matsushita Electric Industrial Co., Ltd. | CDMA cellular wireless communication system |
EP1808969B1 (en) * | 1997-10-31 | 2014-01-01 | AT & T Mobility II, LLC | Maximum likehood detection of concatenated space-time codes for wireless applications with transmitter diversity |
US7184426B2 (en) | 2002-12-12 | 2007-02-27 | Qualcomm, Incorporated | Method and apparatus for burst pilot for a time division multiplex system |
US9118387B2 (en) * | 1997-11-03 | 2015-08-25 | Qualcomm Incorporated | Pilot reference transmission for a wireless communication system |
US6188736B1 (en) * | 1997-12-23 | 2001-02-13 | At&T Wireless Svcs. Inc. | Near-optimal low-complexity decoding of space-time codes for fixed wireless applications |
JP3718337B2 (en) * | 1998-01-08 | 2005-11-24 | 株式会社東芝 | Adaptive variable directional antenna |
DE69916151T2 (en) | 1998-01-30 | 2005-04-21 | Matsushita Electric Ind Co Ltd | Data transmission with a composition of modulation types |
US6643281B1 (en) * | 1998-03-05 | 2003-11-04 | At&T Wireless Services, Inc. | Synchronization preamble method for OFDM waveforms in a communications system |
US6134261A (en) * | 1998-03-05 | 2000-10-17 | At&T Wireless Svcs. Inc | FDD forward link beamforming method for a FDD communications system |
DK1068704T3 (en) | 1998-04-03 | 2012-09-17 | Tellabs Operations Inc | Impulse response shortening filter, with additional spectral constraints, for multi-wave transfer |
US7440498B2 (en) | 2002-12-17 | 2008-10-21 | Tellabs Operations, Inc. | Time domain equalization for discrete multi-tone systems |
US6317466B1 (en) * | 1998-04-15 | 2001-11-13 | Lucent Technologies Inc. | Wireless communications system having a space-time architecture employing multi-element antennas at both the transmitter and receiver |
US6018600A (en) * | 1998-04-15 | 2000-01-25 | Arch Development Corp. | Sampling and reconstruction of signals and images including MR images of multiple regions |
US6947408B1 (en) * | 1998-04-17 | 2005-09-20 | Telcordia Technologies, Inc. | Wireless internet access system and method |
US6615024B1 (en) | 1998-05-01 | 2003-09-02 | Arraycomm, Inc. | Method and apparatus for determining signatures for calibrating a communication station having an antenna array |
US6212172B1 (en) * | 1998-05-08 | 2001-04-03 | Omnipoint Corporation | Filtering method to allow FDD and TDD operation in PCS transreceivers |
US6115370A (en) * | 1998-05-26 | 2000-09-05 | Nera Wireless Broadband Access As | Method and system for protocols for providing voice, data, and multimedia services in a wireless local loop system |
US6144645A (en) * | 1998-05-26 | 2000-11-07 | Nera Wireless Broadband Access As | Method and system for an air interface for providing voice, data, and multimedia services in a wireless local loop system |
US6131012A (en) * | 1998-05-26 | 2000-10-10 | Nera Wireless Broadband Access As | Method and system for a micro-channel bank for providing voice, data, and multimedia services in a wireless local loop system |
US6795424B1 (en) * | 1998-06-30 | 2004-09-21 | Tellabs Operations, Inc. | Method and apparatus for interference suppression in orthogonal frequency division multiplexed (OFDM) wireless communication systems |
US6418316B2 (en) | 1998-08-06 | 2002-07-09 | Harris Corporation | Increasing channel capacity of wireless local loop via polarization diversity antenna distribution scheme |
US7548787B2 (en) | 2005-08-03 | 2009-06-16 | Kamilo Feher | Medical diagnostic and communication system |
US7593481B2 (en) * | 1998-08-31 | 2009-09-22 | Kamilo Feher | CDMA, W-CDMA, 3rd generation interoperable modem format selectable (MFS) systems with GMSK modulated systems |
US8050345B1 (en) | 1999-08-09 | 2011-11-01 | Kamilo Feher | QAM and GMSK systems |
US6122324A (en) * | 1998-09-02 | 2000-09-19 | Burchett, Jr.; Robert Lee | Narrowband simultaneous multibit wireless transmission method |
US6459740B1 (en) * | 1998-09-17 | 2002-10-01 | At&T Wireless Services, Inc. | Maximum ratio transmission |
US8135413B2 (en) | 1998-11-24 | 2012-03-13 | Tracbeam Llc | Platform and applications for wireless location and other complex services |
US7020071B2 (en) * | 1998-11-25 | 2006-03-28 | Lucent Technologies Inc. | Methods and apparatus for wireless communication using orthogonal frequency division multiplexing |
US6442222B1 (en) * | 1998-12-24 | 2002-08-27 | At&T Wireless Services, Inc. | Method for error compensation in an OFDM system with diversity |
US6141393A (en) * | 1999-03-03 | 2000-10-31 | Motorola, Inc. | Method and device for channel estimation, equalization, and interference suppression |
US7133352B1 (en) * | 1999-09-20 | 2006-11-07 | Zion Hadad | Bi-directional communication channel |
US7952511B1 (en) | 1999-04-07 | 2011-05-31 | Geer James L | Method and apparatus for the detection of objects using electromagnetic wave attenuation patterns |
US6600914B2 (en) | 1999-05-24 | 2003-07-29 | Arraycomm, Inc. | System and method for emergency call channel allocation |
US7139592B2 (en) * | 1999-06-21 | 2006-11-21 | Arraycomm Llc | Null deepening for an adaptive antenna based communication station |
US6768714B1 (en) | 1999-06-23 | 2004-07-27 | At&T Wireless Services, Inc. | Methods and apparatus for use in obtaining frequency synchronization in an OFDM communication system |
US6700866B1 (en) | 1999-06-23 | 2004-03-02 | At&T Wireless Services, Inc. | Methods and apparatus for use in obtaining frequency synchronization in an OFDM communication system |
US6940933B1 (en) * | 1999-06-23 | 2005-09-06 | Cingular Wireless Ii, Llc | Apparatus and method for synchronization in a multiple-carrier communications system by observing a phase-frequency relationship of a plurality of pilot signals |
US6788950B1 (en) * | 1999-07-06 | 2004-09-07 | Cisco Technology Inc. | Optimal use of request access TDMA slots for automatic level control |
FR2797131B1 (en) * | 1999-07-29 | 2004-02-20 | Kurtosis Ingenierie | INFORMATION DISTRIBUTION PROCESS |
US6757265B1 (en) | 1999-07-30 | 2004-06-29 | Iospan Wireless, Inc. | Subscriber unit in a hybrid link incorporating spatial multiplexing |
US7027464B1 (en) * | 1999-07-30 | 2006-04-11 | Matsushita Electric Industrial Co., Ltd. | OFDM signal transmission scheme, and OFDM signal transmitter/receiver |
US6067290A (en) | 1999-07-30 | 2000-05-23 | Gigabit Wireless, Inc. | Spatial multiplexing in a cellular network |
WO2001010156A1 (en) * | 1999-07-30 | 2001-02-08 | Iospan Wireless, Inc. | Spatial multiplexing in a cellular network |
US9307407B1 (en) | 1999-08-09 | 2016-04-05 | Kamilo Feher | DNA and fingerprint authentication of mobile devices |
US9373251B2 (en) | 1999-08-09 | 2016-06-21 | Kamilo Feher | Base station devices and automobile wireless communication systems |
US7260369B2 (en) | 2005-08-03 | 2007-08-21 | Kamilo Feher | Location finder, tracker, communication and remote control system |
US9813270B2 (en) | 1999-08-09 | 2017-11-07 | Kamilo Feher | Heart rate sensor and medical diagnostics wireless devices |
US8064409B1 (en) | 1999-08-25 | 2011-11-22 | Qualcomm Incorporated | Method and apparatus using a multi-carrier forward link in a wireless communication system |
US6985432B1 (en) * | 2000-01-28 | 2006-01-10 | Zion Hadad | OFDM communication channel |
EP1286735A1 (en) | 1999-09-24 | 2003-03-05 | Dennis Jay Dupray | Geographically constrained network services |
US6252867B1 (en) * | 1999-09-30 | 2001-06-26 | Motorola, Inc. | Method and apparatus for determining remote unit location using phased array antenna elements |
US6621804B1 (en) * | 1999-10-07 | 2003-09-16 | Qualcomm Incorporated | Method and apparatus for predicting favored supplemental channel transmission slots using transmission power measurements of a fundamental channel |
US6865169B1 (en) * | 1999-11-02 | 2005-03-08 | Ipwireless, Inc. | Cellular wireless internet access system using spread spectrum and internet protocol |
US8117291B1 (en) | 1999-11-02 | 2012-02-14 | Wireless Technology Solutions Llc | Use of internet web technology to register wireless access customers |
US6377636B1 (en) | 1999-11-02 | 2002-04-23 | Iospan Wirless, Inc. | Method and wireless communications system using coordinated transmission and training for interference mitigation |
US8463231B1 (en) | 1999-11-02 | 2013-06-11 | Nvidia Corporation | Use of radius in UMTS to perform accounting functions |
US6873609B1 (en) | 1999-11-02 | 2005-03-29 | Ipwireless, Inc. | Use of internet WEB technology for wireless internet access |
GB9926438D0 (en) * | 1999-11-08 | 2000-01-12 | Nokia Networks Oy | A method of reducing transmission power in a wireless communication system |
US6434129B1 (en) | 1999-12-01 | 2002-08-13 | Nera Wireless Broadband Access As | Method and system for an air interface for providing voice, data, and multimedia services in a wireless local loop system |
US6922445B1 (en) | 1999-12-15 | 2005-07-26 | Intel Corporation | Method and system for mode adaptation in wireless communication |
US6351499B1 (en) | 1999-12-15 | 2002-02-26 | Iospan Wireless, Inc. | Method and wireless systems using multiple antennas and adaptive control for maximizing a communication parameter |
US6298092B1 (en) | 1999-12-15 | 2001-10-02 | Iospan Wireless, Inc. | Methods of controlling communication parameters of wireless systems |
US6377632B1 (en) * | 2000-01-24 | 2002-04-23 | Iospan Wireless, Inc. | Wireless communication system and method using stochastic space-time/frequency division multiplexing |
US6922388B1 (en) * | 2000-02-11 | 2005-07-26 | Lucent Technologies Inc. | Signal construction, detection and estimation for uplink timing synchronization and access control in a multi-access wireless communication system |
US7088765B1 (en) * | 2000-03-15 | 2006-08-08 | Ndsu Research Foundation | Vector calibration system |
US6952454B1 (en) | 2000-03-22 | 2005-10-04 | Qualcomm, Incorporated | Multiplexing of real time services and non-real time services for OFDM systems |
US6473467B1 (en) * | 2000-03-22 | 2002-10-29 | Qualcomm Incorporated | Method and apparatus for measuring reporting channel state information in a high efficiency, high performance communications system |
US6542556B1 (en) * | 2000-03-31 | 2003-04-01 | Nokia Mobile Phones Ltd. | Space-time code for multiple antenna transmission |
US6377819B1 (en) | 2000-04-06 | 2002-04-23 | Iospan Wireless, Inc. | Wireless communication system using joined transmit and receive processing |
US6807146B1 (en) * | 2000-04-21 | 2004-10-19 | Atheros Communications, Inc. | Protocols for scalable communication system using overland signals and multi-carrier frequency communication |
US6442214B1 (en) | 2000-05-19 | 2002-08-27 | Iospan Wireless, Inc. | Diversity transmitter based on linear transform processing of transmitted information |
JP3678119B2 (en) * | 2000-06-01 | 2005-08-03 | 株式会社デンソー | OFDM communication system and base station and terminal used in the communication system |
US10641861B2 (en) | 2000-06-02 | 2020-05-05 | Dennis J. Dupray | Services and applications for a communications network |
US10684350B2 (en) | 2000-06-02 | 2020-06-16 | Tracbeam Llc | Services and applications for a communications network |
US9875492B2 (en) | 2001-05-22 | 2018-01-23 | Dennis J. Dupray | Real estate transaction system |
US7209745B1 (en) | 2000-06-09 | 2007-04-24 | Intel Corporation | Cellular wireless re-use structure that allows spatial multiplexing and diversity communication |
US8363744B2 (en) | 2001-06-10 | 2013-01-29 | Aloft Media, Llc | Method and system for robust, secure, and high-efficiency voice and packet transmission over ad-hoc, mesh, and MIMO communication networks |
JP2002010339A (en) * | 2000-06-23 | 2002-01-11 | Ntt Docomo Inc | Channel assignment method and communication apparatus |
US6396803B2 (en) * | 2000-06-29 | 2002-05-28 | California Amplifier, Inc. | Modulation methods and structures for wireless communication systems and transceivers |
JP4306098B2 (en) * | 2000-06-30 | 2009-07-29 | 株式会社デンソー | Communication device |
US6963619B1 (en) | 2000-07-21 | 2005-11-08 | Intel Corporation | Spatial separation and multi-polarization of antennae in a wireless network |
US6925066B1 (en) * | 2000-07-31 | 2005-08-02 | Lucent Technologies Inc. | Methods and apparatus for design, adjustment or operation of wireless networks using multi-stage optimization |
US6937592B1 (en) | 2000-09-01 | 2005-08-30 | Intel Corporation | Wireless communications system that supports multiple modes of operation |
JP2002084251A (en) * | 2000-09-07 | 2002-03-22 | Alps Electric Co Ltd | Ofdm receiving device |
US6400699B1 (en) | 2000-09-12 | 2002-06-04 | Iospan Wireless, Inc. | Transmission scheduler for a multiple antenna wireless cellular network |
US7295509B2 (en) | 2000-09-13 | 2007-11-13 | Qualcomm, Incorporated | Signaling method in an OFDM multiple access system |
US9130810B2 (en) | 2000-09-13 | 2015-09-08 | Qualcomm Incorporated | OFDM communications methods and apparatus |
US6760882B1 (en) * | 2000-09-19 | 2004-07-06 | Intel Corporation | Mode selection for data transmission in wireless communication channels based on statistical parameters |
US6802035B2 (en) * | 2000-09-19 | 2004-10-05 | Intel Corporation | System and method of dynamically optimizing a transmission mode of wirelessly transmitted information |
US6795409B1 (en) | 2000-09-29 | 2004-09-21 | Arraycomm, Inc. | Cooperative polling in a wireless data communication system having smart antenna processing |
US7043259B1 (en) * | 2000-09-29 | 2006-05-09 | Arraycomm, Inc. | Repetitive paging from a wireless data base station having a smart antenna system |
US7072315B1 (en) * | 2000-10-10 | 2006-07-04 | Adaptix, Inc. | Medium access control for orthogonal frequency-division multiple-access (OFDMA) cellular networks |
US6711412B1 (en) | 2000-10-13 | 2004-03-23 | Iospan Wireless, Inc. | Interference mitigation in wireless communications by training of interfering signals |
US6870808B1 (en) * | 2000-10-18 | 2005-03-22 | Adaptix, Inc. | Channel allocation in broadband orthogonal frequency-division multiple-access/space-division multiple-access networks |
US6973098B1 (en) | 2000-10-25 | 2005-12-06 | Qualcomm, Incorporated | Method and apparatus for determining a data rate in a high rate packet data wireless communications system |
US7068683B1 (en) | 2000-10-25 | 2006-06-27 | Qualcomm, Incorporated | Method and apparatus for high rate packet data and low delay data transmissions |
US6567387B1 (en) * | 2000-11-07 | 2003-05-20 | Intel Corporation | System and method for data transmission from multiple wireless base transceiver stations to a subscriber unit |
JP3892221B2 (en) * | 2000-11-17 | 2007-03-14 | 株式会社エヌ・ティ・ティ・ドコモ | Mobile station, base station and communication method |
JP4529281B2 (en) | 2000-12-08 | 2010-08-25 | ソニー株式会社 | Transmitting apparatus, receiving apparatus, and communication system |
US6947748B2 (en) | 2000-12-15 | 2005-09-20 | Adaptix, Inc. | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
CN100456758C (en) * | 2000-12-15 | 2009-01-28 | 昂达博思公司 | Multi-carrier communications with group-based subcarrier allocation |
US6850498B2 (en) * | 2000-12-22 | 2005-02-01 | Intel Corporation | Method and system for evaluating a wireless link |
JP3576099B2 (en) * | 2000-12-22 | 2004-10-13 | 株式会社東芝 | Receiver using smart antenna, receiving method using smart antenna, and beam forming circuit |
US6996418B2 (en) * | 2000-12-29 | 2006-02-07 | Nortel Networks Limited | Apparatus and method for OFDM data communications |
GB0031841D0 (en) * | 2000-12-29 | 2001-02-14 | Nokia Networks Oy | Interference power estimation for adaptive antenna system |
US7164669B2 (en) * | 2001-01-19 | 2007-01-16 | Adaptix, Inc. | Multi-carrier communication with time division multiplexing and carrier-selective loading |
US6940827B2 (en) * | 2001-03-09 | 2005-09-06 | Adaptix, Inc. | Communication system using OFDM for one direction and DSSS for another direction |
US20020136287A1 (en) * | 2001-03-20 | 2002-09-26 | Heath Robert W. | Method, system and apparatus for displaying the quality of data transmissions in a wireless communication system |
US6771706B2 (en) | 2001-03-23 | 2004-08-03 | Qualcomm Incorporated | Method and apparatus for utilizing channel state information in a wireless communication system |
US7088734B2 (en) * | 2001-03-27 | 2006-08-08 | Motorola, Inc. | Slot format and method for increasing random access opportunities in a wireless communication system |
EP1382127A1 (en) * | 2001-03-30 | 2004-01-21 | Matsushita Electric Industrial Co., Ltd. | Combined selective time switching transmission diversity (ststd) method and system |
US20020155811A1 (en) * | 2001-04-18 | 2002-10-24 | Jerry Prismantas | System and method for adapting RF transmissions to mitigate the effects of certain interferences |
US7072312B2 (en) * | 2001-05-14 | 2006-07-04 | Interdigital Technology Corporation | Assigning physical channels of a new user service in a hybrid time division multiple access/code division multiple access communication system |
US7023815B2 (en) * | 2001-05-14 | 2006-04-04 | Interdigital Technology Corporation | Reassigning physical channels of a user service experiencing high interference levels in a hybrid wireless communication system |
US6990118B2 (en) * | 2001-05-14 | 2006-01-24 | Interdigital Technology Corporation | Assigning physical channels to time slot sequences in a hybrid time division multiple access/code division multiple access communication system |
US8082096B2 (en) | 2001-05-22 | 2011-12-20 | Tracbeam Llc | Wireless location routing applications and architecture therefor |
CA2390253A1 (en) * | 2001-06-11 | 2002-12-11 | Unique Broadband Systems, Inc. | Ofdm multiple sub-channel communication system |
US7027523B2 (en) * | 2001-06-22 | 2006-04-11 | Qualcomm Incorporated | Method and apparatus for transmitting data in a time division duplexed (TDD) communication system |
US6751444B1 (en) | 2001-07-02 | 2004-06-15 | Broadstorm Telecommunications, Inc. | Method and apparatus for adaptive carrier allocation and power control in multi-carrier communication systems |
US7088955B2 (en) * | 2001-07-16 | 2006-08-08 | Qualcomm Inc. | Method and apparatus for acquiring and tracking pilots in a CDMA communication system |
US7787531B2 (en) * | 2001-07-26 | 2010-08-31 | Cambridge Broadband Networks Limited | Predistorting of contention signals |
US20030039226A1 (en) * | 2001-08-24 | 2003-02-27 | Kwak Joseph A. | Physical layer automatic repeat request (ARQ) |
JP2003070056A (en) * | 2001-08-28 | 2003-03-07 | Ntt Docomo Inc | Communication-channel setting method, communication control apparatus, and radio communication system |
US7149254B2 (en) * | 2001-09-06 | 2006-12-12 | Intel Corporation | Transmit signal preprocessing based on transmit antennae correlations for multiple antennae systems |
US7336626B1 (en) * | 2001-09-28 | 2008-02-26 | Arraycomm, Inc | Operating time division duplex (TDD) wireless systems in paired spectrum (FDD) allocations |
US7961589B2 (en) * | 2001-09-28 | 2011-06-14 | Intel Corporation | System and related methods for introducing sub-carrier diversity in a wideband communication system |
US20030067890A1 (en) * | 2001-10-10 | 2003-04-10 | Sandesh Goel | System and method for providing automatic re-transmission of wirelessly transmitted information |
US7061854B2 (en) * | 2001-10-15 | 2006-06-13 | Nortel Networks Limited | Efficient OFDM communications with interference immunity |
US7349667B2 (en) * | 2001-10-19 | 2008-03-25 | Texas Instruments Incorporated | Simplified noise estimation and/or beamforming for wireless communications |
US6563885B1 (en) | 2001-10-24 | 2003-05-13 | Texas Instruments Incorporated | Decimated noise estimation and/or beamforming for wireless communications |
US7164649B2 (en) * | 2001-11-02 | 2007-01-16 | Qualcomm, Incorporated | Adaptive rate control for OFDM communication system |
US7023931B2 (en) * | 2001-11-05 | 2006-04-04 | Texas Instruments Incorporated | System and method for soft slicing |
US7336719B2 (en) * | 2001-11-28 | 2008-02-26 | Intel Corporation | System and method for transmit diversity base upon transmission channel delay spread |
SE523685C2 (en) * | 2001-11-29 | 2004-05-11 | Ericsson Telefon Ab L M | TX diversity with two fixed beams |
FR2833784B1 (en) * | 2001-12-18 | 2004-02-13 | Thales Sa | ANTI-JAMMING METHOD FOR A SPREAD SPECTRUM RADIO SIGNAL RECEIVER |
JP2003244761A (en) * | 2002-02-14 | 2003-08-29 | Fujitsu Ltd | Communication apparatus, communication system, and method for setting communication frequency |
US7012978B2 (en) * | 2002-03-26 | 2006-03-14 | Intel Corporation | Robust multiple chain receiver |
US7103325B1 (en) | 2002-04-05 | 2006-09-05 | Nortel Networks Limited | Adaptive modulation and coding |
US7426392B2 (en) * | 2002-05-23 | 2008-09-16 | Intel Corporation | Search receiver using adaptive detection theresholds |
FR2840475B1 (en) * | 2002-05-28 | 2004-08-27 | France Telecom | METHOD FOR DETERMINING A TIME OFFSET AND / OR A SIGNAL POWER, CIRCUIT AND RECEIVING DEVICE |
US7181246B2 (en) * | 2002-06-05 | 2007-02-20 | Neocific, Inc. | Adaptive communications system and method |
US6947740B2 (en) * | 2002-06-13 | 2005-09-20 | Spacecode Llc | Communication satellite in a satellite communication system with high aspect ratio cell arrangement and shared and allocable bandwidth |
US20030235252A1 (en) * | 2002-06-19 | 2003-12-25 | Jose Tellado | Method and system of biasing a timing phase estimate of data segments of a received signal |
US7433347B1 (en) * | 2002-06-28 | 2008-10-07 | Arraycomm, Llc | Broadcast superframe with variable reuse and interference levels for a radio communications system |
US20040004951A1 (en) * | 2002-07-05 | 2004-01-08 | Interdigital Technology Corporation | Method for performing wireless switching |
KR20040017909A (en) * | 2002-08-22 | 2004-03-02 | 광주과학기술원 | Method of Interlaced Frequency Division Duplexing for Duplexing Communication System |
US6993333B2 (en) * | 2003-10-16 | 2006-01-31 | Flarion Technologies, Inc. | Methods and apparatus of improving inter-sector and/or inter-cell handoffs in a multi-carrier wireless communications system |
US20040066739A1 (en) * | 2002-10-07 | 2004-04-08 | Koninklijke Philips Electronics N.V. | Simplified implementation of optimal decoding for COFDM transmitter diversity system |
WO2004042959A1 (en) | 2002-11-04 | 2004-05-21 | Vivato Inc | Directed wireless communication |
US20040116146A1 (en) * | 2002-12-13 | 2004-06-17 | Sadowsky John S. | Cellular system with link diversity feedback |
US6914876B2 (en) * | 2002-12-16 | 2005-07-05 | Motorola, Inc. | Method for dynamic frequency selection |
US8027315B2 (en) * | 2003-02-12 | 2011-09-27 | Nortel Networks Limited | Antenna diversity |
AU2003298440A1 (en) | 2003-02-14 | 2004-09-06 | Nortel Networks Limited | Antenna diversity |
US8811348B2 (en) | 2003-02-24 | 2014-08-19 | Qualcomm Incorporated | Methods and apparatus for generating, communicating, and/or using information relating to self-noise |
CN1871862B (en) * | 2003-02-24 | 2012-03-21 | 高通股份有限公司 | Pilot signals for use in multi-sector cells |
BRPI0407800B1 (en) * | 2003-02-24 | 2017-12-26 | Qualcomm Incorporated | METHOD AND APPARATUS FOR THE IMPROVEMENT OF CHANNEL CONDITION MEASUREMENT IN WIRELESS CELLULAR SYSTEMS |
US7218948B2 (en) | 2003-02-24 | 2007-05-15 | Qualcomm Incorporated | Method of transmitting pilot tones in a multi-sector cell, including null pilot tones, for generating channel quality indicators |
US9544860B2 (en) * | 2003-02-24 | 2017-01-10 | Qualcomm Incorporated | Pilot signals for use in multi-sector cells |
US9661519B2 (en) | 2003-02-24 | 2017-05-23 | Qualcomm Incorporated | Efficient reporting of information in a wireless communication system |
US7203261B2 (en) * | 2003-04-07 | 2007-04-10 | Qualcomm Incorporated | Phase locked loop for an OFDM system |
US6980839B2 (en) * | 2003-04-30 | 2005-12-27 | Sony Corporation | Apparatus, system and method for use in powering on a remote wireless device |
US7483675B2 (en) * | 2004-10-06 | 2009-01-27 | Broadcom Corporation | Method and system for weight determination in a spatial multiplexing MIMO system for WCDMA/HSDPA |
CN1813429B (en) * | 2003-07-16 | 2011-09-21 | 日本电信电话株式会社 | Optical communication system using optical frequency code, optical transmission device and optical reception device thereof, and reflection type optical communication device |
MXPA06001808A (en) * | 2003-08-20 | 2006-05-04 | Matsushita Electric Ind Co Ltd | Radio communication apparatus and subcarrier assignment method. |
US7221680B2 (en) | 2003-09-02 | 2007-05-22 | Qualcomm Incorporated | Multiplexing and transmission of multiple data streams in a wireless multi-carrier communication system |
US8477809B2 (en) * | 2003-09-02 | 2013-07-02 | Qualcomm Incorporated | Systems and methods for generalized slot-to-interlace mapping |
US8599764B2 (en) * | 2003-09-02 | 2013-12-03 | Qualcomm Incorporated | Transmission of overhead information for reception of multiple data streams |
US8509051B2 (en) * | 2003-09-02 | 2013-08-13 | Qualcomm Incorporated | Multiplexing and transmission of multiple data streams in a wireless multi-carrier communication system |
US7230942B2 (en) * | 2003-10-03 | 2007-06-12 | Qualcomm, Incorporated | Method of downlink resource allocation in a sectorized environment |
US8149766B2 (en) * | 2003-10-03 | 2012-04-03 | Qualcomm Incorporated | Method of downlink resource allocation in a sectorized environment |
US8526412B2 (en) * | 2003-10-24 | 2013-09-03 | Qualcomm Incorporated | Frequency division multiplexing of multiple data streams in a wireless multi-carrier communication system |
KR100686775B1 (en) * | 2003-11-07 | 2007-02-23 | 삼성전자주식회사 | Method for transmitting traffic a indication message in broadband wireless access communication system |
FI20031702A0 (en) * | 2003-11-21 | 2003-11-21 | Nokia Corp | Allocation of multiple carriers for multiple users in a communication system |
US7164740B2 (en) * | 2003-11-21 | 2007-01-16 | Interdigital Technology Corporation | Wireless communication apparatus using fast fourier transforms to create, optimize and incorporate a beam space antenna array in an orthogonal frequency division multiplexing receiver |
US8027417B2 (en) * | 2003-12-19 | 2011-09-27 | Nortel Networks Limited | Interference-weighted communication signal processing systems and methods |
US20050135229A1 (en) * | 2003-12-19 | 2005-06-23 | Molisch Andreas F. | Ultra wide bandwidth receiver with tone grouping and spreading |
DE60314924T2 (en) * | 2003-12-22 | 2008-03-13 | Telefonaktiebolaget Lm Ericsson (Publ) | MEASURING PROCEDURE FOR SPATIAL PROCESSING |
US7656931B2 (en) * | 2003-12-31 | 2010-02-02 | Ut-Battelle, Llc | Hybrid spread spectrum radio system |
TW200629772A (en) * | 2004-01-14 | 2006-08-16 | Interdigital Tech Corp | Method and apparatus for dynamically selecting the best antennas/mode ports for transmission and reception |
KR100818774B1 (en) | 2004-01-29 | 2008-04-03 | 포스데이타 주식회사 | Method and apparatus for overlaying multi-carrier and direct sequence spread spectrum signals in a broadband wireless communication system |
WO2005081439A1 (en) | 2004-02-13 | 2005-09-01 | Neocific, Inc. | Methods and apparatus for multi-carrier communication systems with adaptive transmission and feedback |
US9083436B2 (en) * | 2004-03-05 | 2015-07-14 | Interdigital Technology Corporation | Full duplex communication system using disjoint spectral blocks |
KR100713528B1 (en) * | 2004-03-12 | 2007-05-02 | 삼성전자주식회사 | Apparatus and method for transmitting sub-channel signal in a communication system using orthogonal frequency division multiple access scheme |
US7046617B2 (en) * | 2004-03-22 | 2006-05-16 | Motorola, Inc. | Method and apparatus for an enhanced OFDM system |
US7729233B2 (en) * | 2004-04-14 | 2010-06-01 | Webster Mark A | Dual mode communication systems and methods |
US20050232308A1 (en) * | 2004-04-19 | 2005-10-20 | Texas Instruments Incorporated | Frame alignment and cyclic extension partitioning |
US8588203B2 (en) | 2004-06-04 | 2013-11-19 | Qualcomm Incorporated | Wireless communication system with improved broadcast coverage |
US7492828B2 (en) * | 2004-06-18 | 2009-02-17 | Qualcomm Incorporated | Time synchronization using spectral estimation in a communication system |
US7263335B2 (en) | 2004-07-19 | 2007-08-28 | Purewave Networks, Inc. | Multi-connection, non-simultaneous frequency diversity in radio communication systems |
US7460839B2 (en) | 2004-07-19 | 2008-12-02 | Purewave Networks, Inc. | Non-simultaneous frequency diversity in radio communication systems |
US9137822B2 (en) | 2004-07-21 | 2015-09-15 | Qualcomm Incorporated | Efficient signaling over access channel |
US9148256B2 (en) | 2004-07-21 | 2015-09-29 | Qualcomm Incorporated | Performance based rank prediction for MIMO design |
KR100590486B1 (en) * | 2004-07-29 | 2006-06-19 | 에스케이 텔레콤주식회사 | Method and System for Generating Switching Timing Signal for Separating Transmitting and Receiving Signal in Optical Repeater of Mobile Telecommunication Network Using TDD and ODFM Modulation |
US20060029029A1 (en) * | 2004-08-09 | 2006-02-09 | Jacobsen Eric A | Apparatus and method capable of wireless communication using channel management |
WO2006017850A2 (en) * | 2004-08-12 | 2006-02-16 | Interdigital Technology Corporation | Method and apparatus for reducing antenna correlation |
US20060058027A1 (en) * | 2004-09-14 | 2006-03-16 | Motorola, Inc. | Method and apparatus for carrier frequency estimation and correction for GPS |
US7359449B2 (en) | 2004-10-05 | 2008-04-15 | Kamilo Feher | Data communication for wired and wireless communication |
DE102004049802A1 (en) * | 2004-10-12 | 2006-04-20 | Deutsches Zentrum für Luft- und Raumfahrt e.V. | Method for suppression of spectral sidelobes in transmission systems based on OFDM |
US8503938B2 (en) | 2004-10-14 | 2013-08-06 | Qualcomm Incorporated | Methods and apparatus for determining, communicating and using information including loading factors which can be used for interference control purposes |
AU2005295580A1 (en) * | 2004-10-14 | 2006-04-27 | Qualcomm Incorporated | Methods and apparatus for determining, communicating and using information which can be used for interference control purposes |
EP2427012B1 (en) * | 2004-10-15 | 2016-01-13 | Apple Inc. | Communication resource allocation method |
FR2877166B1 (en) * | 2004-10-27 | 2009-04-10 | Thales Sa | METHOD FOR CHARACTERIZING TRANSMITTERS BY ASSOCIATING PARAMETERS RELATING TO A SAME RADIO-ELECTRIC TRANSMITTER |
US7877064B2 (en) * | 2004-11-01 | 2011-01-25 | General Instrument Corporation | Methods, apparatus and systems for terrestrial wireless broadcast of digital data to stationary receivers |
CA2586278C (en) * | 2004-11-04 | 2011-07-26 | Samsung Electronics Co., Ltd. | Apparatus and method for signal transmission and reception using downlink channel information in a sleep mode in a bwa communication system |
US7573851B2 (en) | 2004-12-07 | 2009-08-11 | Adaptix, Inc. | Method and system for switching antenna and channel assignments in broadband wireless networks |
US9246560B2 (en) | 2005-03-10 | 2016-01-26 | Qualcomm Incorporated | Systems and methods for beamforming and rate control in a multi-input multi-output communication systems |
US9154211B2 (en) | 2005-03-11 | 2015-10-06 | Qualcomm Incorporated | Systems and methods for beamforming feedback in multi antenna communication systems |
US8446892B2 (en) | 2005-03-16 | 2013-05-21 | Qualcomm Incorporated | Channel structures for a quasi-orthogonal multiple-access communication system |
US9520972B2 (en) | 2005-03-17 | 2016-12-13 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US9461859B2 (en) | 2005-03-17 | 2016-10-04 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US9143305B2 (en) | 2005-03-17 | 2015-09-22 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US20080259854A1 (en) * | 2005-03-30 | 2008-10-23 | Matsushita Electric Industrial Co., Ltd. | Communication Terminal Apparatus, Base Station Apparatus, and Resource Assigning Method |
CN101147334B (en) * | 2005-03-30 | 2012-07-18 | 富士通株式会社 | Wireless communication system and wireless communication method |
US7539463B2 (en) * | 2005-03-30 | 2009-05-26 | Intel Corporation | Techniques to enhance diversity for a wireless system |
US9184870B2 (en) | 2005-04-01 | 2015-11-10 | Qualcomm Incorporated | Systems and methods for control channel signaling |
US9408220B2 (en) | 2005-04-19 | 2016-08-02 | Qualcomm Incorporated | Channel quality reporting for adaptive sectorization |
US9036538B2 (en) | 2005-04-19 | 2015-05-19 | Qualcomm Incorporated | Frequency hopping design for single carrier FDMA systems |
JP4719914B2 (en) * | 2005-04-28 | 2011-07-06 | 独立行政法人情報通信研究機構 | TRANSMISSION DEVICE, RECEPTION DEVICE, TRANSMISSION METHOD, RECEPTION METHOD, AND PROGRAM |
US8565194B2 (en) | 2005-10-27 | 2013-10-22 | Qualcomm Incorporated | Puncturing signaling channel for a wireless communication system |
US8611284B2 (en) | 2005-05-31 | 2013-12-17 | Qualcomm Incorporated | Use of supplemental assignments to decrement resources |
US8879511B2 (en) | 2005-10-27 | 2014-11-04 | Qualcomm Incorporated | Assignment acknowledgement for a wireless communication system |
US8462859B2 (en) | 2005-06-01 | 2013-06-11 | Qualcomm Incorporated | Sphere decoding apparatus |
EP1729531A1 (en) * | 2005-06-02 | 2006-12-06 | Alcatel | Method and device for providing static beamforming |
US8599945B2 (en) | 2005-06-16 | 2013-12-03 | Qualcomm Incorporated | Robust rank prediction for a MIMO system |
US9179319B2 (en) | 2005-06-16 | 2015-11-03 | Qualcomm Incorporated | Adaptive sectorization in cellular systems |
US7706248B2 (en) * | 2005-06-29 | 2010-04-27 | Intel Corporation | Multicarrier receiver and method for time-delay compensation in a multi-user uplink |
US7480497B2 (en) * | 2005-06-29 | 2009-01-20 | Intel Corporation | Multicarrier receiver and method for carrier frequency offset correction and channel estimation for receipt of simultaneous transmissions over a multi-user uplink |
US7426199B2 (en) * | 2005-06-29 | 2008-09-16 | Intel Corporation | Wireless communication device and method for reducing carrier frequency offsets over a simultaneous multi-user uplink in a multicarrier communication network |
US8031669B2 (en) * | 2005-07-29 | 2011-10-04 | Nextel Communications Inc. | Systems and methods for increasing base station capacity |
US10009956B1 (en) | 2017-09-02 | 2018-06-26 | Kamilo Feher | OFDM, 3G and 4G cellular multimode systems and wireless mobile networks |
US7280810B2 (en) * | 2005-08-03 | 2007-10-09 | Kamilo Feher | Multimode communication system |
US8885628B2 (en) | 2005-08-08 | 2014-11-11 | Qualcomm Incorporated | Code division multiplexing in a single-carrier frequency division multiple access system |
US9209956B2 (en) | 2005-08-22 | 2015-12-08 | Qualcomm Incorporated | Segment sensitive scheduling |
US20070041457A1 (en) | 2005-08-22 | 2007-02-22 | Tamer Kadous | Method and apparatus for providing antenna diversity in a wireless communication system |
US8644292B2 (en) | 2005-08-24 | 2014-02-04 | Qualcomm Incorporated | Varied transmission time intervals for wireless communication system |
US9136974B2 (en) | 2005-08-30 | 2015-09-15 | Qualcomm Incorporated | Precoding and SDMA support |
US7826416B2 (en) * | 2005-09-21 | 2010-11-02 | Broadcom Corporation | Method and system for a simplified user group selection scheme with finite-rate channel state information feedback for FDD multiuser MIMO downlink transmission |
US8675760B2 (en) * | 2005-09-21 | 2014-03-18 | Broadcom Corporation | Method and system for selecting a user group using hybrid-quantized channel direction information feedbacks from MIMO capable mobile devices |
WO2007037732A1 (en) * | 2005-09-30 | 2007-04-05 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and device for polarization correction in user equipment |
US9191840B2 (en) | 2005-10-14 | 2015-11-17 | Qualcomm Incorporated | Methods and apparatus for determining, communicating and using information which can be used for interference control |
US8989084B2 (en) | 2005-10-14 | 2015-03-24 | Qualcomm Incorporated | Methods and apparatus for broadcasting loading information corresponding to neighboring base stations |
US8477684B2 (en) | 2005-10-27 | 2013-07-02 | Qualcomm Incorporated | Acknowledgement of control messages in a wireless communication system |
US8045512B2 (en) | 2005-10-27 | 2011-10-25 | Qualcomm Incorporated | Scalable frequency band operation in wireless communication systems |
US9144060B2 (en) | 2005-10-27 | 2015-09-22 | Qualcomm Incorporated | Resource allocation for shared signaling channels |
US9225488B2 (en) | 2005-10-27 | 2015-12-29 | Qualcomm Incorporated | Shared signaling channel |
US8582509B2 (en) | 2005-10-27 | 2013-11-12 | Qualcomm Incorporated | Scalable frequency band operation in wireless communication systems |
US9225416B2 (en) | 2005-10-27 | 2015-12-29 | Qualcomm Incorporated | Varied signaling channels for a reverse link in a wireless communication system |
US9172453B2 (en) | 2005-10-27 | 2015-10-27 | Qualcomm Incorporated | Method and apparatus for pre-coding frequency division duplexing system |
US9210651B2 (en) | 2005-10-27 | 2015-12-08 | Qualcomm Incorporated | Method and apparatus for bootstraping information in a communication system |
US8693405B2 (en) | 2005-10-27 | 2014-04-08 | Qualcomm Incorporated | SDMA resource management |
US9088384B2 (en) | 2005-10-27 | 2015-07-21 | Qualcomm Incorporated | Pilot symbol transmission in wireless communication systems |
EP1784030B1 (en) * | 2005-11-02 | 2008-04-23 | Alcatel Lucent | Method of using the frequency spectrum of a TDD radio system |
US8582548B2 (en) | 2005-11-18 | 2013-11-12 | Qualcomm Incorporated | Frequency division multiple access schemes for wireless communication |
US7508344B2 (en) * | 2005-11-29 | 2009-03-24 | L-3 Communications Integrated Systems, Lp | Systems and methods for TDOA/FDOA location |
US20070253449A1 (en) | 2005-12-22 | 2007-11-01 | Arnab Das | Methods and apparatus related to determining, communicating, and/or using delay information |
US8514771B2 (en) | 2005-12-22 | 2013-08-20 | Qualcomm Incorporated | Methods and apparatus for communicating and/or using transmission power information |
US9473265B2 (en) | 2005-12-22 | 2016-10-18 | Qualcomm Incorporated | Methods and apparatus for communicating information utilizing a plurality of dictionaries |
US9119220B2 (en) | 2005-12-22 | 2015-08-25 | Qualcomm Incorporated | Methods and apparatus for communicating backlog related information |
US8437251B2 (en) | 2005-12-22 | 2013-05-07 | Qualcomm Incorporated | Methods and apparatus for communicating transmission backlog information |
US9572179B2 (en) | 2005-12-22 | 2017-02-14 | Qualcomm Incorporated | Methods and apparatus for communicating transmission backlog information |
US9451491B2 (en) | 2005-12-22 | 2016-09-20 | Qualcomm Incorporated | Methods and apparatus relating to generating and transmitting initial and additional control information report sets in a wireless system |
US9137072B2 (en) | 2005-12-22 | 2015-09-15 | Qualcomm Incorporated | Methods and apparatus for communicating control information |
US9125092B2 (en) | 2005-12-22 | 2015-09-01 | Qualcomm Incorporated | Methods and apparatus for reporting and/or using control information |
US9148795B2 (en) | 2005-12-22 | 2015-09-29 | Qualcomm Incorporated | Methods and apparatus for flexible reporting of control information |
US9338767B2 (en) | 2005-12-22 | 2016-05-10 | Qualcomm Incorporated | Methods and apparatus of implementing and/or using a dedicated control channel |
US9125093B2 (en) | 2005-12-22 | 2015-09-01 | Qualcomm Incorporated | Methods and apparatus related to custom control channel reporting formats |
US20070149132A1 (en) | 2005-12-22 | 2007-06-28 | Junyl Li | Methods and apparatus related to selecting control channel reporting formats |
KR100891818B1 (en) * | 2006-01-27 | 2009-04-07 | 삼성전자주식회사 | Hybrid multiple access apparatus and method in a mobile communication system |
CN101390356B (en) * | 2006-02-24 | 2013-07-10 | 华为技术有限公司 | Method and apparatus for wireless resource allocation |
US8005175B2 (en) * | 2006-03-17 | 2011-08-23 | Futurewei Technologies, Inc. | Method and apparatus for interference mitigation in an OFDMA-based communication system |
US7957345B2 (en) * | 2006-03-20 | 2011-06-07 | Futurewei Technologies, Inc. | Adaptive HARQ in an OFDMA based communication system |
US20070218915A1 (en) * | 2006-03-20 | 2007-09-20 | Futurewei Technologies, Inc. | Wireless communication resource allocation and related signaling |
US20070243882A1 (en) | 2006-04-12 | 2007-10-18 | Qualcomm Incorporated | Method and apparatus for locating a wireless local area network associated with a wireless wide area network |
CN103152145B (en) | 2006-04-25 | 2016-10-12 | Lg电子株式会社 | The method sending data by utilizing the resource in hybrid automatic request operations |
JP4823756B2 (en) * | 2006-04-27 | 2011-11-24 | 京セラ株式会社 | Mobile communication system, base station apparatus, and frequency allocation method for mobile communication system |
US7760751B2 (en) * | 2006-05-19 | 2010-07-20 | Futurewei Technologies, Inc. | System for supporting consecutive and distributed subcarrier channels in OFDMA networks |
EP1863191B1 (en) * | 2006-06-02 | 2012-03-14 | STMicroelectronics N.V. | Method for managing eventual interferences with antenna switching and corresponding device |
US8369424B2 (en) * | 2006-07-14 | 2013-02-05 | Qualcomm Incorporated | Frequency selective and frequency diversity transmissions in a wireless communication system |
JP2008035285A (en) * | 2006-07-28 | 2008-02-14 | Kyocera Corp | Wireless communication apparatus and wireless communication method |
US8345561B2 (en) | 2006-08-22 | 2013-01-01 | Rueters America Inc. | Time monitor |
US8175032B2 (en) * | 2006-09-08 | 2012-05-08 | Clearwire Ip Holdings Llc | System and method for radio frequency resource allocation |
US20080080406A1 (en) * | 2006-09-29 | 2008-04-03 | Motorola, Inc. | Method and device for increasing capacity of tdd wireless communication systems |
KR100826541B1 (en) | 2006-09-29 | 2008-04-30 | 한국전자통신연구원 | Downlink Radio Resource Allocation Apparatus and Method for Guaranteeing QoS of each Traffic Data in OFDM/SDMA-based Cellular System |
KR100959333B1 (en) * | 2006-09-29 | 2010-05-20 | 삼성전자주식회사 | Apparatus for bidirectional communication using auxiliary band in wireless communication system |
CN101202725A (en) * | 2006-12-11 | 2008-06-18 | 昂达博思公司 | Auto frequency offset compensation in TDD wireless OFDM communication system |
US8135400B2 (en) | 2007-01-19 | 2012-03-13 | Samsung Electronics Co., Ltd. | Method and system for device discovery in wireless communication |
US8503968B2 (en) * | 2007-01-19 | 2013-08-06 | Samsung Electronics Co., Ltd. | Method and system for power saving in wireless communications |
US8179805B2 (en) * | 2007-01-19 | 2012-05-15 | Samsung Electronics Co., Ltd. | Method and system for wireless communication by spatial reuse |
US8699421B2 (en) * | 2007-01-19 | 2014-04-15 | Samsung Electronics Co., Ltd. | Method and system for wireless communication using channel selection and bandwidth reservation |
US8509159B2 (en) * | 2007-01-19 | 2013-08-13 | Samsung Electronics Co., Ltd. | Method and system for wireless communication using out-of-band channels |
WO2008121433A2 (en) * | 2007-01-30 | 2008-10-09 | Georgia Tech Research Corporation | Systems and methods for adaptive polarization transmission |
KR100871229B1 (en) | 2007-03-06 | 2008-12-01 | 삼성전자주식회사 | Radio Over Fiber System and Signal Control Method For Executing Wireless-Communication-Service Hybrid Deplexing Technology Based |
US7764747B2 (en) * | 2007-03-30 | 2010-07-27 | Olympus Corporation | Methods and systems for transmitting and processing pilot signals |
CN103402239B (en) | 2007-04-11 | 2017-07-04 | 奥普蒂斯无线技术有限责任公司 | For the information on reference signal structure of neighbor cell measurement |
US20090175210A1 (en) * | 2007-07-26 | 2009-07-09 | Qualcomm Incorporated | Multiplexing and transmission of multiple data streams in a wireless multi-carrier communication system |
KR101454027B1 (en) * | 2007-08-10 | 2014-10-24 | 한국전자통신연구원 | Time division multiplexing communication system with parallel structure and method for the same |
WO2009022709A1 (en) * | 2007-08-13 | 2009-02-19 | Sharp Kabushiki Kaisha | Radio communication system, radio communication method, radio communication device, reception device, and program |
US8325671B2 (en) * | 2007-09-06 | 2012-12-04 | Qualcomm Incorporated | Methods and apparatus for improved utilization of air link resources in a wireless communications system including a multi-antenna element base station |
US20090067383A1 (en) * | 2007-09-12 | 2009-03-12 | Motorola, Inc. | Method and apparatus for a frequency division duplex communication using a time division duplex modem |
US7626546B2 (en) * | 2007-09-27 | 2009-12-01 | L-3 Communications Integrated Systems L.P. | Methods and systems for detection and location of multiple emitters |
AT506274B1 (en) * | 2007-12-19 | 2016-10-15 | Center Communication Systems Gmbh | METHOD FOR CREATING AND SENDING AT LEAST ONE DATA PACKAGE AND USING HIEFÜR |
US8095083B2 (en) * | 2008-02-20 | 2012-01-10 | Broadcom Corporation | Method and system for multiple shared antenna mobile devices |
WO2009110547A1 (en) | 2008-03-05 | 2009-09-11 | シャープ株式会社 | Communication system, communication device and communication method |
WO2009120701A2 (en) * | 2008-03-24 | 2009-10-01 | Zte U.S.A., Inc. | Dynamic adjustment and signaling of downlink/uplink allocation ratio in lte/tdd systems |
EP2112772B1 (en) * | 2008-04-24 | 2016-08-31 | Alcatel Lucent | Method for reducing interference in a radio network equipment and equipment performing the method |
US8629650B2 (en) | 2008-05-13 | 2014-01-14 | Qualcomm Incorporated | Wireless power transfer using multiple transmit antennas |
US8878393B2 (en) * | 2008-05-13 | 2014-11-04 | Qualcomm Incorporated | Wireless power transfer for vehicles |
WO2009153810A2 (en) * | 2008-06-18 | 2009-12-23 | Centre Of Excellence In Wireless Technology | Precoding for multiple transmission streams in multiple antenna systems |
WO2009153773A1 (en) | 2008-06-19 | 2009-12-23 | Marvell Israel (Misl) Ltd. | Balancing capacity between link directions using variable feedback rates |
US20100002782A1 (en) * | 2008-07-02 | 2010-01-07 | Yutaka Asanuma | Radio communication system and radio communication method |
US8249540B1 (en) | 2008-08-07 | 2012-08-21 | Hypres, Inc. | Two stage radio frequency interference cancellation system and method |
US8854224B2 (en) * | 2009-02-10 | 2014-10-07 | Qualcomm Incorporated | Conveying device information relating to wireless charging |
US9312924B2 (en) | 2009-02-10 | 2016-04-12 | Qualcomm Incorporated | Systems and methods relating to multi-dimensional wireless charging |
US20100201312A1 (en) | 2009-02-10 | 2010-08-12 | Qualcomm Incorporated | Wireless power transfer for portable enclosures |
US9077493B2 (en) * | 2009-04-17 | 2015-07-07 | Intel Mobile Communications GmbH | System and method for establishing a localized single frequency network |
US9118468B2 (en) * | 2009-07-23 | 2015-08-25 | Qualcomm Incorporated | Asynchronous time division duplex operation in a wireless network |
US8811200B2 (en) | 2009-09-22 | 2014-08-19 | Qualcomm Incorporated | Physical layer metrics to support adaptive station-dependent channel state information feedback rate in multi-user communication systems |
US8843076B2 (en) * | 2010-07-06 | 2014-09-23 | Intel Corporation | Device, system and method of wireless communication over a beamformed communication link |
US9538493B2 (en) | 2010-08-23 | 2017-01-03 | Finetrak, Llc | Locating a mobile station and applications therefor |
US9331771B2 (en) * | 2010-09-28 | 2016-05-03 | Aviat U.S., Inc. | Systems and methods for wireless communication using polarization diversity |
US8866672B2 (en) | 2012-04-05 | 2014-10-21 | L-3 Communications Integrated Systems Lp | Cooperative systems and methods for TDOA-based emitter location |
US20140044150A1 (en) * | 2012-08-13 | 2014-02-13 | Redline Communications, Inc. | System and method for interference triggered frequency hopping |
US8824272B2 (en) | 2012-10-09 | 2014-09-02 | The Aerospace Corporation | Resolving co-channel interference between overlapping users using rank selection |
WO2014153237A1 (en) * | 2013-03-14 | 2014-09-25 | Google Inc. | Optimizing packet/frame forwarding or routing in a wireless backhaul transport system |
EP3132580B1 (en) * | 2014-05-08 | 2020-01-08 | Huawei Technologies Co., Ltd. | Channel estimation in wireless communication network node |
DE112015004340T5 (en) | 2014-09-24 | 2017-06-01 | Analog Devices, Inc. | Circuits and systems for multiplexed communication via an isolator |
US20170237180A1 (en) | 2015-09-18 | 2017-08-17 | Anokiwave, Inc. | Laminar Phased Array Antenna |
US9867189B2 (en) * | 2015-09-29 | 2018-01-09 | Newracom, Inc. | Resource allocation indication for multi-user multiple-input-multiple-output (MU-MIMO) orthogonal frequency division multiple access (OFDMA) communication |
CN107026720A (en) * | 2016-01-29 | 2017-08-08 | 华为技术有限公司 | A kind of pilot signal transmission, channel estimation methods and equipment |
US10326576B2 (en) * | 2017-04-28 | 2019-06-18 | Qualcomm Incorporated | Reusing long-term evolution (LTE) reference signals for nested system operations |
US11418971B2 (en) | 2017-12-24 | 2022-08-16 | Anokiwave, Inc. | Beamforming integrated circuit, AESA system and method |
US11496350B2 (en) | 2018-03-27 | 2022-11-08 | University Of South Carolina | Dual-polarization FBMC in wireless communication systems |
US10998640B2 (en) | 2018-05-15 | 2021-05-04 | Anokiwave, Inc. | Cross-polarized time division duplexed antenna |
US10756803B2 (en) * | 2018-07-17 | 2020-08-25 | Blinq Networks Inc. | System, apparatus and method for dynamic carrier aggregation to multi-beam antenna mapping |
EP3955665A4 (en) * | 2019-04-10 | 2022-11-16 | Beijing Xiaomi Mobile Software Co., Ltd. | Resource indication method, and device |
CN110719123B (en) * | 2019-09-21 | 2021-05-04 | 广东石油化工学院 | PLC signal reconstruction method and system using subspace optimization theory |
CN111698187A (en) * | 2019-12-13 | 2020-09-22 | 广东工业大学 | Frequency division multiple access communication method based on harmonic modulation technology |
CN111585045B (en) * | 2020-05-20 | 2022-04-12 | 西安黄河机电有限公司 | Multi-connected domino sparse antenna and arraying method thereof |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5260968A (en) * | 1992-06-23 | 1993-11-09 | The Regents Of The University Of California | Method and apparatus for multiplexing communications signals through blind adaptive spatial filtering |
WO1994013077A1 (en) * | 1992-12-01 | 1994-06-09 | Thomson-Csf | Ofdm transmission with polarization multiplexing |
WO1994019877A1 (en) * | 1993-02-16 | 1994-09-01 | Telefonaktiebolaget Lm Ericsson | Arrangement for telecommunication |
EP0641096A1 (en) * | 1993-08-24 | 1995-03-01 | France Telecom | Method with multiple access by orthogenal frequencies, corresponding central station, remote station, system and their use |
US5410538A (en) * | 1993-11-09 | 1995-04-25 | At&T Corp. | Method and apparatus for transmitting signals in a multi-tone code division multiple access communication system |
EP0653859A1 (en) * | 1993-11-11 | 1995-05-17 | Gpt Limited | Discrete multiple tone transmission on high-speed digital subscriber lines |
EP0685973A2 (en) * | 1994-06-03 | 1995-12-06 | AT&T Corp. | Radio-parts assignment in a mobile cellular communication system |
WO1996036136A1 (en) * | 1995-05-11 | 1996-11-14 | Ericsson Inc. | Method and apparatus for polarization diversity in a base station using antenna arrays |
WO1997001256A1 (en) * | 1995-06-22 | 1997-01-09 | Telefonaktiebolaget Lm Ericsson (Publ) | Adaptive channel allocation in a frequency division multiplexed system |
Family Cites Families (146)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3522540A (en) | 1967-05-01 | 1970-08-04 | Bell Telephone Labor Inc | Energy density mobile fm receiver |
US3641463A (en) | 1970-05-27 | 1972-02-08 | Bell Telephone Labor Inc | Linearity compensation for a voltage-controlled oscillator |
US3633107A (en) | 1970-06-04 | 1972-01-04 | Bell Telephone Labor Inc | Adaptive signal processor for diversity radio receivers |
US3745464A (en) | 1971-12-02 | 1973-07-10 | Bell Telephone Labor Inc | Radio system with feedback for fading compensation |
US3971988A (en) | 1975-03-06 | 1976-07-27 | Bell Telephone Laboratories, Incorporated | AM/FM receiver using spectral parameter estimators |
US4249181A (en) | 1979-03-08 | 1981-02-03 | Bell Telephone Laboratories, Incorporated | Cellular mobile radiotelephone system using tilted antenna radiation patterns |
US4381562A (en) * | 1980-05-01 | 1983-04-26 | Bell Telephone Laboratories, Incorporated | Broadcast type satellite communication systems |
US4383332A (en) | 1980-11-21 | 1983-05-10 | Bell Telephone Laboratories, Incorporated | High capacity digital mobile radio system |
DE3118473A1 (en) * | 1981-05-09 | 1982-11-25 | TE KA DE Felten & Guilleaume Fernmeldeanlagen GmbH, 8500 Nürnberg | METHOD FOR PROCESSING ELECTRICAL SIGNALS WITH A DIGITAL FILTER ARRANGEMENT |
US4412350A (en) | 1981-12-30 | 1983-10-25 | Bell Telephone Laboratories, Incorporated | Method and apparatus for distinguishing between minimum and non-minimum phase fades |
US4495648A (en) | 1982-12-27 | 1985-01-22 | At&T Bell Laboratories | Transmitter power control circuit |
US4510595A (en) | 1983-10-03 | 1985-04-09 | At&T Bell Laboratories | Modified time-division transmission technique for digital mobile radio systems |
US4488445A (en) | 1983-10-28 | 1984-12-18 | Honeywell Inc. | Integrated silicon accelerometer with cross-axis compensation |
CA1226914A (en) | 1984-01-26 | 1987-09-15 | The University Of British Columbia | Modem for pseudo noise communication on a.c. lines |
US5752191A (en) | 1984-09-14 | 1998-05-12 | Accessline Technologies, Inc. | Telephone control system which connects a caller with a subscriber AT A telephone address |
US4726040A (en) * | 1984-10-09 | 1988-02-16 | American Telephone And Telegraph Company, At&T Bell Laboratories | Burst demodulator |
US4644562A (en) * | 1985-08-28 | 1987-02-17 | At&T Company | Combined cross polarization interference cancellation and intersymbol interference equalization for terrestrial digital radio systems |
US4723321A (en) * | 1986-11-07 | 1988-02-02 | American Telephone And Telegraph Company, At&T Bell Laboratories | Techniques for cross-polarization cancellation in a space diversity radio system |
US4789983A (en) | 1987-03-05 | 1988-12-06 | American Telephone And Telegraph Company, At&T Bell Laboratories | Wireless network for wideband indoor communications |
US4893266A (en) * | 1987-06-01 | 1990-01-09 | Motorola, Inc. | Alias tagging time domain to frequency domain signal converter |
US4827499A (en) | 1987-06-12 | 1989-05-02 | American Telephone And Telegraph Company At&T Bell Laboratories | Call control of a distributed processing communications switching system |
JPS6477235A (en) | 1987-09-18 | 1989-03-23 | Fujitsu Ltd | Compensating device for interference between cross-polarized waves |
US4807253A (en) | 1987-11-13 | 1989-02-21 | American Telephone And Telegraph Company, At&T Bell Laboratories | Time-varying trellis-coded modulation formats which are robust in channels with phase variations |
US5056112A (en) * | 1989-07-28 | 1991-10-08 | At&T Bell Laboratories | Interleaving in coded modulation for mobile radio |
US5029185A (en) | 1989-07-28 | 1991-07-02 | At&T Bell Laboratories | Coded modulation for mobile radio |
US5054035A (en) | 1989-12-21 | 1991-10-01 | At&T Bell Laboratories | Digital signal quality evaluation circuit using synchronization patterns |
US5088113A (en) | 1990-01-02 | 1992-02-11 | At&T Bell Laboratories | Diversity coded modulation |
US5048057A (en) | 1990-01-02 | 1991-09-10 | At&T Bell Laboratories | Wireless local area network |
US5084869A (en) | 1990-01-31 | 1992-01-28 | At&T Bell Laboratories | Base station for mobile radio telecommunications systems |
SE465597B (en) | 1990-02-16 | 1991-09-30 | Ericsson Telefon Ab L M | PROCEDURE TO REDUCE THE EFFECT OF BREATHING ON A WHITE RECEIVER WITH AT LEAST TWO ANTENNA |
CA2032325C (en) | 1990-12-14 | 1998-07-07 | Leo Strawczynski | Intra-cell call hand-over in radio communication systems with dynamic channel allocation |
US5226071A (en) | 1990-12-18 | 1993-07-06 | At&T Bell Laboratories | Call path resource allocation in a wireless telecommunications system |
US5136612A (en) | 1990-12-31 | 1992-08-04 | At&T Bell Laboratories | Method and apparatus for reducing effects of multiple access interference in a radio receiver in a code division multiple access communication system |
US5177765A (en) | 1991-06-03 | 1993-01-05 | Spectralink Corporation | Direct-sequence spread-spectrum digital signal acquisition and tracking system and method therefor |
CA2066538C (en) | 1991-07-09 | 1997-12-23 | Brian David Bolliger | Mobile-telephone system call processing arrangement |
US5195090A (en) | 1991-07-09 | 1993-03-16 | At&T Bell Laboratories | Wireless access telephone-to-telephone network interface architecture |
US5361397A (en) | 1991-08-26 | 1994-11-01 | Motorola, Inc. | Communication device and system capable of automatic programmable energizing |
US5319634A (en) | 1991-10-07 | 1994-06-07 | Phoenix Corporation | Multiple access telephone extension systems and methods |
US5592490A (en) | 1991-12-12 | 1997-01-07 | Arraycomm, Inc. | Spectrally efficient high capacity wireless communication systems |
US5515378A (en) | 1991-12-12 | 1996-05-07 | Arraycomm, Inc. | Spatial division multiple access wireless communication systems |
US5367539A (en) * | 1991-12-31 | 1994-11-22 | At&T Bell Laboratories | Digital block processor for processing a plurality of transmission channels in a wireless radiotelephony system |
US5260967A (en) | 1992-01-13 | 1993-11-09 | Interdigital Technology Corporation | CDMA/TDMA spread-spectrum communications system and method |
US5392287A (en) | 1992-03-05 | 1995-02-21 | Qualcomm Incorporated | Apparatus and method for reducing power consumption in a mobile communications receiver |
CA2332405C (en) | 1992-03-26 | 2007-01-23 | Matsushita Electric Industrial Co., Ltd. | Communication system |
US5291475B1 (en) | 1992-03-27 | 1995-06-27 | Motorola Inc | Slot hopped fd/td/cmda |
US5282222A (en) * | 1992-03-31 | 1994-01-25 | Michel Fattouche | Method and apparatus for multiple access between transceivers in wireless communications using OFDM spread spectrum |
MX9301888A (en) | 1992-04-10 | 1993-11-30 | Ericsson Telefon Ab L M | MULTIPLE ACCESS OF TIME DIVISION FOR ACCESS OF A MOBILE IN A MULTIPLE ACCESS SYSTEM OF DIVISION OF CODE. |
US5295138A (en) | 1992-04-21 | 1994-03-15 | Northwest Starscon Limited Partnership | Apparatus and method for optimal frequency planning in frequency division multiplexing transmissions |
US5305353A (en) | 1992-05-29 | 1994-04-19 | At&T Bell Laboratories | Method and apparatus for providing time diversity |
CA2139496A1 (en) | 1992-07-03 | 1994-01-20 | Kurt Seidel | Hair treatment preparations |
EP0578313B1 (en) * | 1992-07-08 | 1998-12-02 | Laboratoires D'electronique Philips S.A.S. | Concatenated coding for OFDM transmission |
US5343473A (en) | 1992-08-07 | 1994-08-30 | International Business Machines Corporation | Method of determining whether to use preempt/resume or alternate protocol for data transmission |
DE9210599U1 (en) * | 1992-08-08 | 1993-12-09 | Bosch Gmbh Robert | Belt sander |
FI91699C (en) | 1992-08-14 | 1994-07-25 | Nokia Telecommunications Oy | Method for transmitting packet format user data in a cellular radio system and mobile station |
US5289464A (en) * | 1992-09-21 | 1994-02-22 | At&T Bell Laboratories | Frequency-multiplexed cellular telephone cell site base station and method of operating the same |
US5613211A (en) | 1992-10-07 | 1997-03-18 | Nippon Steel Corporation | Method of establishing inter base-station synchronization and mobile radio communicaton system using the method |
US5302914A (en) | 1992-10-20 | 1994-04-12 | At&T Bell Laboratories | Method and apparatus for reducing the peak-to-average power in multi-carrier RF communication systems |
US5570349A (en) | 1994-06-07 | 1996-10-29 | Stanford Telecommunications, Inc. | Wireless direct sequence spread spectrum digital cellular telephone system |
DE69327837T2 (en) * | 1992-12-01 | 2000-10-12 | Koninkl Philips Electronics Nv | Subband diversity transmission system |
US5274384A (en) | 1992-12-28 | 1993-12-28 | General Electric Company | Antenna beamformer |
US5289499A (en) | 1992-12-29 | 1994-02-22 | At&T Bell Laboratories | Diversity for direct-sequence spread spectrum systems |
FR2701178A1 (en) | 1993-02-03 | 1994-08-05 | Philips Electronique Lab | Spread spectrum communication system with multiple users. |
DE4303355A1 (en) | 1993-02-05 | 1994-08-11 | Philips Patentverwaltung | Radio system |
US5410740A (en) | 1993-03-24 | 1995-04-25 | Telefonaktiebolaget L M Ericsson | Control of a radio communications system base station |
US5438329A (en) | 1993-06-04 | 1995-08-01 | M & Fc Holding Company, Inc. | Duplex bi-directional multi-mode remote instrument reading and telemetry system |
KR0124379B1 (en) | 1993-07-12 | 1997-12-01 | 김광호 | Digital data receiver |
DE4325190A1 (en) | 1993-07-27 | 1995-02-02 | Siemens Ag | Radio system with frequency optimization |
US5363375A (en) | 1993-07-30 | 1994-11-08 | Bell Communications Research, Inc. | Method and apparatus for synchronizing timing among radio ports in wireless communications systems using hierarchical scheme |
EP0647979B1 (en) | 1993-08-12 | 2002-10-23 | Nortel Networks Limited | Base station antenna arrangement |
US5400322A (en) | 1993-08-20 | 1995-03-21 | Amati Communications Corp. | Updating of bit allocations in a multicarrier modulation transmission system |
US5513215A (en) * | 1993-09-20 | 1996-04-30 | Glenayre Electronics, Inc. | High speed simulcast data system using adaptive compensation |
US5414699A (en) | 1993-09-27 | 1995-05-09 | Motorola, Inc. | Method and apparatus for receiving and decoding communication signals in a CDMA receiver using partial de-correlation |
FI106505B (en) | 1993-09-27 | 2001-02-15 | Nokia Networks Oy | A radio system implementing a wireless subscriber line and a subscriber unit for a radio system |
SE503548C2 (en) | 1993-10-01 | 1996-07-01 | Telia Ab | Device in OFDM multi-user system |
US5481570A (en) | 1993-10-20 | 1996-01-02 | At&T Corp. | Block radio and adaptive arrays for wireless systems |
US5463656A (en) | 1993-10-29 | 1995-10-31 | Harris Corporation | System for conducting video communications over satellite communication link with aircraft having physically compact, effectively conformal, phased array antenna |
JPH07147553A (en) | 1993-11-24 | 1995-06-06 | Sanyo Electric Co Ltd | Frequency hopping communication method and device therefor |
CA2118355C (en) * | 1993-11-30 | 2002-12-10 | Michael James Gans | Orthogonal polarization and time varying offsetting of signals for digital data transmission or reception |
JP2734953B2 (en) | 1993-12-16 | 1998-04-02 | 日本電気株式会社 | CDMA receiver |
US5559789A (en) | 1994-01-31 | 1996-09-24 | Matsushita Electric Industrial Co., Ltd. | CDMA/TDD Radio Communication System |
EP0982908B1 (en) | 1994-05-09 | 2005-03-09 | Victor Company Of Japan, Limited | Reference subcarrier setting for multicarrier transission |
US5657313A (en) | 1994-05-09 | 1997-08-12 | Victor Company Of Japan, Ltd. | Signal transmitting apparatus and signal receiving apparatus using orthogonal frequency division multiplexing |
BR9408595A (en) | 1994-05-23 | 1997-08-19 | Itron Inc | Communication processes between an intermediate and central data terminal between a central data terminal a plurality of intermediate data terminals a plurality of remote cell nodes and a plurality of service modules |
EP1622296A3 (en) | 1994-06-23 | 2006-12-13 | NTT DoCoMo, Inc. | CDMA demodulation circuit and demodulation method |
JP3078177B2 (en) | 1994-07-01 | 2000-08-21 | 三菱電機株式会社 | Wireless device |
US5896412A (en) * | 1994-07-22 | 1999-04-20 | Crossbow, Ltd. | Wireless communication system |
US6081566A (en) | 1994-08-02 | 2000-06-27 | Ericsson, Inc. | Method and apparatus for interference rejection with different beams, polarizations, and phase references |
JP2655092B2 (en) | 1994-08-11 | 1997-09-17 | 日本電気株式会社 | Code division multiplex receiver |
US5719883A (en) * | 1994-09-21 | 1998-02-17 | Lucent Technologies Inc. | Adaptive ARQ/FEC technique for multitone transmission |
US5933478A (en) | 1994-09-28 | 1999-08-03 | Hitachi, Ltd. | Data transfer system and handheld terminal device used therefor |
JP2655108B2 (en) | 1994-12-12 | 1997-09-17 | 日本電気株式会社 | CDMA transceiver |
US5654955A (en) | 1994-12-15 | 1997-08-05 | Stanford Telecommunications, Inc. | Network entry channel for CDMA systems |
US5745860A (en) | 1994-12-16 | 1998-04-28 | Telefonaktiebolaget Lm Ericsson | Method and system of data transmission and reception in a mobile station within a radio telecommunications system |
DE69434174T2 (en) | 1994-12-22 | 2005-06-02 | Alcatel | Processor for carrier recovery |
JP3145003B2 (en) * | 1995-03-23 | 2001-03-12 | 株式会社東芝 | Orthogonal frequency division multiplexing transmission system and transmitter and receiver thereof |
EP0801850A1 (en) | 1995-03-27 | 1997-10-22 | Celsat America, Inc. | Cellular communications power control system |
FR2732490B1 (en) | 1995-03-28 | 1997-04-25 | Thomson Csf | MULTI-SENSOR RECEPTION PROCESS FOR A BASE STATION OF A COMMUNICATION NETWORK EXCHANGING DATA WITH MOBILES, AND DEVICE FOR ITS IMPLEMENTATION |
FI105513B (en) | 1995-05-24 | 2000-08-31 | Nokia Networks Oy | Reception procedure and recipients |
SE504356C2 (en) | 1995-05-31 | 1997-01-20 | Ericsson Telefon Ab L M | Method and apparatus for establishing a connection in a telecommunications system |
US5689502A (en) * | 1995-06-05 | 1997-11-18 | Omnipoint Corporation | Efficient frequency division duplex communication system with interleaved format and timing adjustment control |
US5752202A (en) | 1995-06-07 | 1998-05-12 | Motorola, Inc. | Method of message delivery adapted for a power conservation system |
US5563610A (en) | 1995-06-08 | 1996-10-08 | Metawave Communications Corporation | Narrow beam antenna systems with angular diversity |
ZA965340B (en) | 1995-06-30 | 1997-01-27 | Interdigital Tech Corp | Code division multiple access (cdma) communication system |
JPH0927836A (en) | 1995-07-12 | 1997-01-28 | Uniden Corp | Cordless telephone set with power failure detection function |
US5692006A (en) | 1995-07-31 | 1997-11-25 | Qualcomm Incorporated | Adaptive despreader |
FR2739243B1 (en) | 1995-09-26 | 1997-11-14 | Alcatel Mobile Comm France | CELLULAR MOBILE RADIO COMMUNICATION SYSTEM, BASE STATION, AND CORRESPONDING BASE STATION CONTROL DEVICE |
US5799200A (en) | 1995-09-28 | 1998-08-25 | Emc Corporation | Power failure responsive apparatus and method having a shadow dram, a flash ROM, an auxiliary battery, and a controller |
US5815488A (en) * | 1995-09-28 | 1998-09-29 | Cable Television Laboratories, Inc. | Multiple user access method using OFDM |
US6456610B1 (en) * | 1995-11-07 | 2002-09-24 | Lucent Technologies Inc. | TDM/TDMA wireless telecommunication system with electronic scanning antenna |
CA2252664C (en) * | 1996-04-26 | 2002-04-02 | At&T Corp. | Method and apparatus for data transmission using multiple transmit antennas |
US5802044A (en) | 1996-04-26 | 1998-09-01 | Motorola, Inc. | Multicarrier reverse link timing synchronization system, device and method |
JPH09321665A (en) | 1996-05-24 | 1997-12-12 | Matsushita Electric Ind Co Ltd | Transmitter-receiver |
US5732113A (en) | 1996-06-20 | 1998-03-24 | Stanford University | Timing and frequency synchronization of OFDM signals |
CA2183140C (en) * | 1996-08-12 | 2001-11-20 | Grant Mcgibney | Ofdm timing and frequency recovery system |
US5903554A (en) * | 1996-09-27 | 1999-05-11 | Qualcomm Incorporation | Method and apparatus for measuring link quality in a spread spectrum communication system |
US6122260A (en) * | 1996-12-16 | 2000-09-19 | Civil Telecommunications, Inc. | Smart antenna CDMA wireless communication system |
WO1998035458A1 (en) | 1997-02-06 | 1998-08-13 | At & T Wireless Services, Inc. | Method of synchronizing a remote station with a base station in a discrete multitone spread spectrum communications system |
US5933421A (en) * | 1997-02-06 | 1999-08-03 | At&T Wireless Services Inc. | Method for frequency division duplex communications |
US5907577A (en) | 1997-02-06 | 1999-05-25 | At&T Wireless Services | Delay compensation |
US6501771B2 (en) | 1997-02-11 | 2002-12-31 | At&T Wireless Services, Inc. | Delay compensation |
US6085114A (en) | 1997-02-06 | 2000-07-04 | At&T Wireless Systems Inc. | Remote wireless unit having reduced power operating mode |
US5799000A (en) | 1997-02-06 | 1998-08-25 | At&T Wireless Services, Inc. | Delay compensation |
US5987338A (en) | 1997-02-19 | 1999-11-16 | At&T Wireless Services | Remote wireless unit having reduced power operating mode |
US5943375A (en) | 1997-02-06 | 1999-08-24 | At&T Wireless Services Inc. | Method to indicate synchronization lock of a remote station with a base station |
US5875208A (en) | 1997-02-06 | 1999-02-23 | At&T Wireless Services, Inc | Delay compensation in a discrete multitone spread spectrum communications system |
US5773877A (en) * | 1997-02-07 | 1998-06-30 | Ford Motor Company | Plastic encapsulated IC package and method of designing same |
US6408016B1 (en) | 1997-02-24 | 2002-06-18 | At&T Wireless Services, Inc. | Adaptive weight update method and system for a discrete multitone spread spectrum communications system |
US6128276A (en) | 1997-02-24 | 2000-10-03 | Radix Wireless, Inc. | Stacked-carrier discrete multiple tone communication technology and combinations with code nulling, interference cancellation, retrodirective communication and adaptive antenna arrays |
US5923700A (en) | 1997-02-24 | 1999-07-13 | At & T Wireless | Adaptive weight update method and system for a discrete multitone spread spectrum communications system |
US6584144B2 (en) | 1997-02-24 | 2003-06-24 | At&T Wireless Services, Inc. | Vertical adaptive antenna array for a discrete multitone spread spectrum communications system |
US5896425A (en) | 1997-02-24 | 1999-04-20 | At&T Wireless Services Inc | Non-uniformly spaced tones for synchronization waveform |
US5864543A (en) | 1997-02-24 | 1999-01-26 | At&T Wireless Services, Inc. | Transmit/receive compensation in a time division duplex system |
US6359923B1 (en) | 1997-12-18 | 2002-03-19 | At&T Wireless Services, Inc. | Highly bandwidth efficient communications |
WO1998037654A2 (en) * | 1997-02-24 | 1998-08-27 | At & T Wireless Services, Inc. | Vertical adaptive antenna array for a discrete multitone spread spectrum communications system |
WO1998037638A2 (en) | 1997-02-24 | 1998-08-27 | At & T Wireless Services, Inc. | Highly bandwidth-efficient communications |
US6131016A (en) * | 1997-08-27 | 2000-10-10 | At&T Corp | Method and apparatus for enhancing communication reception at a wireless communication terminal |
US6215777B1 (en) * | 1997-09-15 | 2001-04-10 | Qualcomm Inc. | Method and apparatus for transmitting and receiving data multiplexed onto multiple code channels, frequencies and base stations |
US6351458B2 (en) * | 1997-09-22 | 2002-02-26 | Matsushita Electric Industrial Co., Ltd. | CDMA cellular wireless communication system |
US6198719B1 (en) * | 1998-02-27 | 2001-03-06 | Nortel Networks Limited | Bi-orthogonal code division multiple access system |
US6643281B1 (en) * | 1998-03-05 | 2003-11-04 | At&T Wireless Services, Inc. | Synchronization preamble method for OFDM waveforms in a communications system |
US6134261A (en) * | 1998-03-05 | 2000-10-17 | At&T Wireless Svcs. Inc | FDD forward link beamforming method for a FDD communications system |
JP3406831B2 (en) | 1998-03-19 | 2003-05-19 | 富士通株式会社 | Array antenna system for wireless base station |
US6487235B2 (en) | 1998-08-24 | 2002-11-26 | At&T Wireless Services, Inc. | Delay compensation |
US6017580A (en) * | 1998-08-28 | 2000-01-25 | Lilly Industries, (Usa), Inc. | Silver film incorporating protective insoluble metallic salt precipitate |
US6442222B1 (en) | 1998-12-24 | 2002-08-27 | At&T Wireless Services, Inc. | Method for error compensation in an OFDM system with diversity |
US6510182B1 (en) | 1999-10-25 | 2003-01-21 | Freesystems Pte. Ltd. | Wireless infrared digital audio system |
-
1997
- 1997-02-06 US US08/796,584 patent/US5933421A/en not_active Expired - Lifetime
-
1998
- 1998-02-03 EP EP07103383A patent/EP1786137B1/en not_active Expired - Lifetime
- 1998-02-03 EP EP10181828.4A patent/EP2271022B1/en not_active Expired - Lifetime
- 1998-02-03 WO PCT/US1998/002250 patent/WO1998035463A2/en active IP Right Grant
- 1998-02-03 DE DE69841701T patent/DE69841701D1/en not_active Expired - Lifetime
- 1998-02-03 CA CA002278852A patent/CA2278852C/en not_active Expired - Lifetime
- 1998-02-03 JP JP53489998A patent/JP3967385B2/en not_active Expired - Fee Related
- 1998-02-03 EP EP98908475A patent/EP0951763B1/en not_active Expired - Lifetime
- 1998-02-03 EP EP07103376A patent/EP1791288B1/en not_active Expired - Lifetime
- 1998-02-03 DE DE69837595T patent/DE69837595T2/en not_active Expired - Lifetime
-
1999
- 1999-04-19 US US09/294,174 patent/US6560209B1/en not_active Expired - Lifetime
-
2003
- 2003-03-07 US US10/383,976 patent/US6853629B2/en not_active Expired - Lifetime
-
2004
- 2004-12-22 US US11/022,048 patent/US7450542B2/en not_active Expired - Fee Related
-
2008
- 2008-08-15 US US12/192,705 patent/US7983217B2/en not_active Expired - Fee Related
-
2011
- 2011-05-26 US US13/116,375 patent/US8305990B2/en not_active Expired - Fee Related
-
2012
- 2012-10-30 US US13/663,831 patent/US8693432B2/en not_active Expired - Fee Related
-
2014
- 2014-04-07 US US14/246,272 patent/US9088388B2/en not_active Expired - Fee Related
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5260968A (en) * | 1992-06-23 | 1993-11-09 | The Regents Of The University Of California | Method and apparatus for multiplexing communications signals through blind adaptive spatial filtering |
WO1994013077A1 (en) * | 1992-12-01 | 1994-06-09 | Thomson-Csf | Ofdm transmission with polarization multiplexing |
WO1994019877A1 (en) * | 1993-02-16 | 1994-09-01 | Telefonaktiebolaget Lm Ericsson | Arrangement for telecommunication |
EP0641096A1 (en) * | 1993-08-24 | 1995-03-01 | France Telecom | Method with multiple access by orthogenal frequencies, corresponding central station, remote station, system and their use |
US5410538A (en) * | 1993-11-09 | 1995-04-25 | At&T Corp. | Method and apparatus for transmitting signals in a multi-tone code division multiple access communication system |
EP0653859A1 (en) * | 1993-11-11 | 1995-05-17 | Gpt Limited | Discrete multiple tone transmission on high-speed digital subscriber lines |
EP0685973A2 (en) * | 1994-06-03 | 1995-12-06 | AT&T Corp. | Radio-parts assignment in a mobile cellular communication system |
WO1996036136A1 (en) * | 1995-05-11 | 1996-11-14 | Ericsson Inc. | Method and apparatus for polarization diversity in a base station using antenna arrays |
WO1997001256A1 (en) * | 1995-06-22 | 1997-01-09 | Telefonaktiebolaget Lm Ericsson (Publ) | Adaptive channel allocation in a frequency division multiplexed system |
Non-Patent Citations (6)
Title |
---|
CIMINI L J ET AL.: "OFDM with diversity and coding for high-bit-rate mobile data applications" MOBILE MULTIMEDIA COMMUNICATIONS, PROCEEDINGS OF 3RD INTERNATIONAL WORKSHOP ON MOBILE MULTIMEDIA COMMUNICATIONS, 25 - 27 September 1996, pages 247-254, XP002093338 Princeton, NJ, USA * |
DE BOT P G M: "Antenna Diversity for OFDM Systems" PROCEEDINGS OF THE FOURTEENTH SYMPOSIUM ON INFORMATION THEORY IN THE BENELUX, 17 - 18 May 1993, pages 244-251, XP002093339 Veldhoven, The Netherlands * |
GINER V C: "An Approximate Analysis of TDMA Out-of-Slot Random Access Protocols for Microcellular Mobile Communications" INTERNATIONAL JOURNAL OF WIRELESS INFORMATION NETWORKS, vol. 3, no. 1, January 1996, pages 41-53, XP002077581 Plenum, USA * |
OJANPER[ ET AL.: "FRAMES-hybrid multiple access technology" 1996 IEEE 4TH INTERNATIONAL SYMPOSIUM ON SPREAD SPECTRUM TECHNIQUES, vol. 1, 22 - 25 September 1996, pages 320-324, XP002077020 New York, NY, USA, IEEE, USA * |
ROHLING H ET AL: "PERFORMANCE OF AN OFDM-TDMA MOBILE COMMUNICATION SYSTEM" 1996 IEEE 46TH. VEHICULAR TECHNOLOGY CONFERENCE, MOBILE TECHNOLOGY FOR THE HUMAN RACE ATLANTA, APR. 28 - MAY 1, 1996, vol. 3, no. CONF. 46, 28 April 1996, pages 1589-1593, XP000595799 INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS * |
TAKAHASHI H ET AL: "ANTENNA AND MULTI-CARRIER COMBINED DIVERSITY SYSTEM" IEICE TRANSACTIONS ON COMMUNICATIONS, vol. E79B, no. 9, September 1996, pages 1221-1226, XP000636058 * |
Cited By (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9088388B2 (en) | 1997-02-06 | 2015-07-21 | At&T Mobility Ii Llc | Method for frequency division duplex communications |
US6785300B2 (en) | 1997-02-06 | 2004-08-31 | At&T Wireless Services, Inc. | Delay compensation |
US6782039B2 (en) | 1997-02-24 | 2004-08-24 | At&T Wireless Services, Inc. | Vertical adaptive antenna array for a discrete multitone spread spectrum communications system |
EP1127416A4 (en) * | 1998-10-19 | 2004-08-25 | Motorola Inc | Method and system for combining orthogonal transmit diversity and adaptive array techniques in a wireless communications system |
EP1127416A1 (en) * | 1998-10-19 | 2001-08-29 | Motorola, Inc. | Method and system for combining orthogonal transmit diversity and adaptive array techniques in a wireless communications system |
EP1699143A3 (en) * | 1999-03-31 | 2007-05-23 | Alcatel Lucent | Method and arrangement to estimate transmission channel characteristics |
US7095708B1 (en) | 1999-06-23 | 2006-08-22 | Cingular Wireless Ii, Llc | Methods and apparatus for use in communicating voice and high speed data in a wireless communication system |
WO2000079722A1 (en) * | 1999-06-23 | 2000-12-28 | At & T Wireless Services, Inc. | Ofdm fixed wireless system |
US7633893B2 (en) | 1999-10-22 | 2009-12-15 | Nextnet Wireless, Inc. | Fixed OFDM wireless man utilizing CPE having internal antenna |
US7626920B2 (en) | 1999-10-22 | 2009-12-01 | Nextnet Wireless, Inc. | Fixed OFDM wireless MAN utilizing CPE having internal antenna |
EP1107477A3 (en) * | 1999-12-01 | 2003-07-23 | Alcatel Canada Inc. | Physical layer interface system and method for a wireless communication system |
US7209455B2 (en) | 1999-12-01 | 2007-04-24 | Alcatel Canada Inc. | Physical layer interface system and method for a wireless communication system |
US7835314B2 (en) | 1999-12-01 | 2010-11-16 | Alcatel-Lucent Canada Inc. | Physical layer interface system and method for a wireless communication system |
EP1107477A2 (en) * | 1999-12-01 | 2001-06-13 | Alcatel Canada Inc. | Physical layer interface system and method for a wireless communication system |
EP1107481A3 (en) * | 1999-12-10 | 2010-08-25 | Lucent Technologies Inc. | A system for statistically multiplexing real-time and non-real-time voice and data traffic in a wireless system |
EP1107481A2 (en) * | 1999-12-10 | 2001-06-13 | Lucent Technologies Inc. | A system for statistically multiplexing real-time and non-real-time voice and data traffic in a wireless system |
DE10009284A1 (en) * | 2000-02-28 | 2001-08-30 | Nokia Multimedia Terminals Oy | Circuit for implementing spatial diversity with digital signal receiver has complex integrated circuit with diversity processor changing between reception paths according to quality criteria |
WO2002009298A2 (en) * | 2000-07-24 | 2002-01-31 | Runcom Communications Ltd. | Wireless interactive system and method |
WO2002009298A3 (en) * | 2000-07-24 | 2002-05-02 | Runcom Comm Ltd | Wireless interactive system and method |
EP3373470A1 (en) * | 2000-09-01 | 2018-09-12 | Apple Inc. | Adaptive space-time diversity and spatial multiplexing |
EP2296295A3 (en) * | 2000-09-01 | 2013-12-04 | Apple Inc. | Method and apparatus for adaptive time diversity and spatial diversity for OFDM |
EP2296295A2 (en) * | 2000-09-01 | 2011-03-16 | Nortel Networks Limited | Method and apparatus for adaptive time diversity and spatial diversity for OFDM |
US9780987B2 (en) | 2000-09-01 | 2017-10-03 | Apple Inc. | Adaptive time diversity and spatial diversity for OFDM |
FR2820257A1 (en) * | 2001-01-26 | 2002-08-02 | Thomson Csf | Gigahertz frequency high capacity radio system having base station with wide band adaptive directive antennas secondary stations sending with secondary stations transmitting/receiving elevated frequencies. |
EP2207297A1 (en) * | 2001-10-17 | 2010-07-14 | Nortel Networks Limited | Frame structure for OFDM systems |
EP2267961A2 (en) * | 2001-10-17 | 2010-12-29 | Nortel Networks Limited | OFDM transmitter for symbols of different sizes |
US10595249B2 (en) | 2001-10-17 | 2020-03-17 | Apple Inc. | System access and synchronization methods for MIMO OFDM communications systems and physical layer packet and preamble design |
US8108004B2 (en) | 2003-03-24 | 2012-01-31 | Atc Technologies, Llc | Co-channel wireless communication methods and systems using relayed wireless communications |
EP1606956A4 (en) * | 2003-03-24 | 2011-04-27 | Atc Tech Llc | Co-channel wireless communication methods and systems using nonsymmetrical alphabets |
EP1606956A2 (en) * | 2003-03-24 | 2005-12-21 | Mobile Satellite Ventures LP | Co-channel wireless communication methods and systems using nonsymmetrical alphabets |
EP1804536A3 (en) * | 2005-12-28 | 2013-05-01 | Samsung Electronics Co., Ltd. | Method of allocating resources using hybrid duplexing technique |
EP2283602A4 (en) * | 2008-05-28 | 2016-10-26 | Ericsson Telefon Ab L M | Polarization co-ordination |
WO2009145685A1 (en) | 2008-05-28 | 2009-12-03 | Telefonaktiebolaget Lm Ericsson (Publ) | Polarization co-ordination |
WO2010097111A1 (en) * | 2009-02-24 | 2010-09-02 | Telefonaktiebolaget Lm Ericsson (Publ) | Clock recovery in a communications network |
Also Published As
Publication number | Publication date |
---|---|
EP1786137B1 (en) | 2012-08-15 |
US5933421A (en) | 1999-08-03 |
EP2271022A1 (en) | 2011-01-05 |
DE69837595D1 (en) | 2007-05-31 |
US20030156570A1 (en) | 2003-08-21 |
JP3967385B2 (en) | 2007-08-29 |
EP0951763A2 (en) | 1999-10-27 |
CA2278852C (en) | 2002-04-09 |
JP2001511966A (en) | 2001-08-14 |
EP2271022B1 (en) | 2016-10-19 |
US6853629B2 (en) | 2005-02-08 |
WO1998035463A3 (en) | 1999-04-22 |
US20110222526A1 (en) | 2011-09-15 |
US20080298339A1 (en) | 2008-12-04 |
EP1786137A1 (en) | 2007-05-16 |
US7450542B2 (en) | 2008-11-11 |
CA2278852A1 (en) | 1998-08-13 |
US6560209B1 (en) | 2003-05-06 |
US20140219075A1 (en) | 2014-08-07 |
US8305990B2 (en) | 2012-11-06 |
EP1791288A1 (en) | 2007-05-30 |
US20130051291A1 (en) | 2013-02-28 |
DE69837595T2 (en) | 2008-01-03 |
US9088388B2 (en) | 2015-07-21 |
DE69841701D1 (en) | 2010-07-15 |
EP1791288B1 (en) | 2010-06-02 |
US7983217B2 (en) | 2011-07-19 |
US8693432B2 (en) | 2014-04-08 |
US20050180349A1 (en) | 2005-08-18 |
EP0951763B1 (en) | 2007-04-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9088388B2 (en) | Method for frequency division duplex communications | |
US6621851B1 (en) | Priority messaging method for a discrete multitone spread spectrum communications system | |
US7061969B2 (en) | Vertical adaptive antenna array for a discrete multitone spread spectrum communication system | |
US6600776B1 (en) | Vertical adaptive antenna array for a discrete multitone spread spectrum communications system | |
US6643281B1 (en) | Synchronization preamble method for OFDM waveforms in a communications system | |
US7339978B2 (en) | Adaptive weight update method and system for a discrete multitone spread spectrum communications system | |
WO1998037654A9 (en) | Vertical adaptive antenna array for a discrete multitone spread spectrum communications system | |
CA2503248C (en) | Highly bandwidth-efficient communications | |
MXPA99007160A (en) | Method for frequency division duplex communications |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): CA JP MX |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
AK | Designated states |
Kind code of ref document: A3 Designated state(s): CA JP MX |
|
AL | Designated countries for regional patents |
Kind code of ref document: A3 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
ENP | Entry into the national phase |
Ref document number: 2278852 Country of ref document: CA Ref country code: CA Ref document number: 2278852 Kind code of ref document: A Format of ref document f/p: F |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1998908475 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: PA/a/1999/007160 Country of ref document: MX |
|
ENP | Entry into the national phase |
Ref country code: JP Ref document number: 1998 534899 Kind code of ref document: A Format of ref document f/p: F |
|
WWP | Wipo information: published in national office |
Ref document number: 1998908475 Country of ref document: EP |
|
WWG | Wipo information: grant in national office |
Ref document number: 1998908475 Country of ref document: EP |