CN1797986A - Multi-antenna transmitting/receiving processing method obtaining suboptimized channe/capacity and device thereof - Google Patents

Abstract

Time division duplexing (TDD) operation mode is adopted in system to adapt MIMO channel. Power is distributed evenly for multiple transmitting antennae at transmitting end without need of updating transmission pre filtering array V and dynamic power distribution. Two processing methods are adopted at tramnstting end: (1) based on minimal principle of mean square deviation of transmitting and receiving signal, first method gives minimal mean-square error (MMSE) solution of received filtering array U; (2) using simple lowest mean square (LMS) adaptive algorithm, second method obtains U in order to track change of channel, and to reduce amount of calculation. Simplified transmitting and receiving process obtains suboptimal MIMO capacity, and reduces influence on capacity caused by error of estimating channel.

Description

Obtain many antenna transmission and the receiving handling method and the device of suboptimum channel capacity

Technical field

The present invention relates to a kind of many antennas of low complex degree MIMO transmission, receiving and processing device and method that in wireless communication system, obtains the suboptimum channel capacity.Particularly, relate to the time become under the fading channel environment, the emission of multi-aerial radio communication system, method for processing received signal and device, can utilize simplification emission, receive to handle and obtain suboptimum MIMO capacity and reduce the influence of channel estimation errors capacity.

Background technology

Along with the fusion gradually of wireless network and internet, people are more and more higher to the requirement of the type of radio communication service and quality.For satisfying the requirement of radio multimedium and high speed data transfers, need the Development of New Generation wireless communication system.Wherein use multiple-input and multiple-output (MIMO) technology of multi-antenna array (MEA) to be subjected to extensive concern in transmission and receiving terminal.

Adopt the MIMO technology can obtain the space division multiplexing gain, when reception antenna during more than or equal to number of transmit antennas, mimo channel capacity and number of transmit antennas are linear under the Rayleigh decline, increase power system capacity greatly need not to expend under the condition of excess power and bandwidth, can significantly improve link quality simultaneously.

In multiaerial system, studying more at present is space division multiplexing and Space Time Coding two classes.The former is by improving system's speed at the every different symbol of antenna emission, and the latter improves system's bit error rate by introducing coding redundancy at the transmission intersymbol of different antennae.The two all is to carry out channel estimating earlier at receiving terminal, then the time that receives is deciphered to recover bit stream, and channel estimation errors will influence systematic function, and error is bigger under the time varying channel environment especially.Simultaneously, they all do not utilize the channel information of transmitting terminal, so do not obtain the system optimal capacity.

Recently, the MIMO OFDM technology that many antennas input and output (MIMO) and OFDM (OFDM) combine is subjected to extensive concern.

The MIMO ofdm system that MIMO and OFDM combine has the advantage of the two, and it is modulated by OFDM, and frequency selectivity MIMO fading channel is resolved into one group of parallel flat fading channel, utilizes MIMO again, has improved power system capacity.

G.J.Foschini, in 1996 at Bell Labs Tech.J., vol.1, the article of delivering on the 41-59 page or leaf that is entitled as " Layered space-time architecture for wireless communication in afading environment when using multi-element antennas ", and I.E.Telatar, in 1999 at Eur.Trans.Tel., vol.10, no.6, Nov./Dec.1999 has disclosed the research to many antennas mimo channel in the article that is entitled as " the capacity C apacity of multi-antennaGaussian channels of many antennas Gaussian channel " that the 585-595 page or leaf is delivered.Wherein show if transmitter, receiver known channel transmission matrix, can resolve into the single output of a plurality of single inputs of parallel independent (SISO) channel to mimo channel by characteristic value decomposition SVD, then each subchannel is carried out power division according to " water filling " (WF:Water Filling) principle, thereby can obtain optimum Shannon (Shannon) capacity.But under time varying channel, transmitting terminal and receiving terminal can not obtain the correct estimation of channel usually simultaneously.Therefore, consider that engineering is used and channel the time become characteristics, need to study low complex degree and transmission, receiving handling method that can obtain the MIMO capacity.

In the MIMO transmission system based on singular value decomposition (SVD), by sending, accept filter and the SVD processing, mimo channel is broken down into one group of parallel independent subchannel.At this moment, utilize the WF algorithm that each subchannel is carried out the optimum capacity that power division can obtain mimo channel.Studies show that, after SNR is increased to certain value, adopt the WF algorithm can not make channel capacity continue to increase.Because along with the raising of SNR, channel fading reduces, power division no longer is a major issue that influences capacity.

Simultaneously,, need to estimate channel gain matrix, because the time varying characteristic of wireless channel is estimated comparatively difficulty of these parameters exactly for obtaining transmission, the battle array that accepts filter.Even after estimating these parameters, transmission pre-filtering battle array is fed back to transmitting terminal will be increased overhead and bring error.Transmitting terminal power division, adjustment pre-filtering battle array will correspondingly change the battle array that accepts filter.Consider the influence of these factors, need a kind of emission, reception treatment technology of low complex degree.Simultaneously, compare with optimum capacity, it can guarantee within the less permissible range of being lost in of power system capacity.

Summary of the invention

The object of the present invention is to provide the transmission with lower complexity, receiving system and method in a kind of multi-aerial radio communication system, use these apparatus and method can under the time varying channel environment, obtain the influence that the suboptimum capacity also overcomes channel estimation errors preferably.

In order to realize purpose of the present invention, according to an aspect of the present invention, a kind of method that obtains the suboptimum capacity in many antennas multiple-input and multiple-output (MIMO) system is provided, comprise step: at transmitting terminal, to each the transmitting antenna uniform distribution transmitted power in a plurality of transmitting antennas, the baseband signalling after the concurrent warp let-off carrier modulation; At receiving terminal, receive the carrier signal of described a plurality of antenna transmission and down-convert to baseband signalling by a plurality of reception antennas; Baseband signalling through frequency conversion is carried out timing and Frequency Synchronization; From the synchronous symbol of process, estimate channel gain battle array H; Utilize Minimum Mean Square Error (MMSE) algorithm to find the solution to accept filter matrix U to import many output capacities to obtain suboptimum.

According to another aspect of the present invention, a kind of method that obtains the suboptimum capacity in many antennas multiple-input and multiple-output (MIMO) system is provided, comprise step: at transmitting terminal, to each the transmitting antenna uniform distribution transmitted power in a plurality of transmitting antennas, the baseband signalling after the concurrent warp let-off carrier modulation; At receiving terminal, receive the carrier signal of described a plurality of antenna transmission and down-convert to baseband signalling by a plurality of reception antennas; Baseband signalling through frequency conversion is carried out timing and Frequency Synchronization; From the synchronous symbol of process, estimate channel gain battle array H; Utilize lowest mean square (LSE) algorithm to find the solution to accept filter matrix U to import many output capacities to obtain suboptimum.

According to a further aspect of the invention, provide a kind of device that obtains the suboptimum capacity in many antennas multiple-input and multiple-output (MIMO) system, comprising: power distribution unit is used for each the transmitting antenna uniform distribution transmitted power to a plurality of transmitting antennas; A plurality of receiving systems are used to receive the carrier signal of described a plurality of antenna transmission and down-convert to baseband signalling; Synchronizer is used for the baseband signalling through frequency conversion is carried out timing and Frequency Synchronization; Channel estimating apparatus is used for from estimate channel gain battle array H through synchronous symbol; The Minimum Mean Square Error device that accepts filter utilizes Minimum Mean Square Error (MMSE) algorithm to find the solution to accept filter matrix U to import many output capacities to obtain suboptimum.

According to a further aspect of the invention, a kind of device that obtains the suboptimum capacity in many antennas multiple-input and multiple-output (MIMO) system is provided, comprise: power distribution unit, be used for each transmitting antenna uniform distribution transmitted power, the baseband signalling after the concurrent warp let-off carrier modulation to a plurality of transmitting antennas; A plurality of receiving systems are used to receive the carrier signal of described a plurality of antenna transmission and down-convert to baseband signalling; Synchronizer is used for the baseband signalling through frequency conversion is carried out timing and Frequency Synchronization; Channel estimating apparatus is used for from estimate channel gain battle array H through synchronous symbol; The lowest mean square device that accepts filter utilizes lowest mean square (LSE) algorithm to find the solution and accepts filter matrix U to obtain suboptimum multiple-input and multiple-output capacity.

Thought of the present invention is the transmitting terminal uniform distribution power at multiple antenna communication, and receiving terminal is dynamically adjusted the matrix that accepts filter with acquisition channel suboptimum capacity according to MMSE and adaptive algorithm, and reduces the complexity of channel estimation errors influence and Project Realization.

Description of drawings

By reading and understanding the detailed description of the preferred embodiment of the present invention being done below with reference to accompanying drawing, these and other objects of the present invention, feature and advantage will be become apparent.Wherein:

Figure 1A and 1B are the transmitter of multiaerial system of prior art and the block diagram of receiver structure;

Fig. 2 is the schematic diagram of expression SVD technology;

Fig. 3 is the transmitter of the expression mimo system that obtains optimum capacity and the block diagram of receiver structure;

Fig. 4 is the schematic diagram that is illustrated in the SVD under the TDD mode of operation;

Fig. 5 A and 5B are mimo system that expression obtains the suboptimum capacity be used to obtain the to accept filter transmitter and the receiver structure block diagrams of Minimum Mean Square Error of gust U;

Fig. 6 A and 6B are mimo system that expression obtains the suboptimum capacity be used to obtain the to accept filter transmitter and the receiver structure block diagrams of lowest mean square of gust U;

Fig. 7 A to Fig. 7 C is the schematic diagram of expression MIMO capacity;

Fig. 8 is the schematic diagram that there is the MIMO capacity under the situation of channel estimation errors and TX3-RX3 in expression.

Embodiment

With reference to the accompanying drawings embodiments of the invention are described in detail, having omitted in the description process is unnecessary details and function for the present invention, obscures to prevent that the understanding of the present invention from causing.

In order to understand the present invention better, structure and its operation of many antennas mimo system transmitter and receiver are described with reference to figure 1 at first.What Figure 1A and 1B represented is that N is installed _tTransmit antennas and N _rThe space division multiplexing mimo system model of root reception antenna.

Shown in Figure 1A, the transmitter of many antennas mimo system comprises serial/parallel converter 11a, channel encoder 12a, interleaver 13a, modulator 14a, prefilter (V) 15a, pilot frequency sequence module 16a, and transmitter module (1 ... N _t) 17a.Shown in Figure 1B, receiver comprises parallel/serial converter 11b, decoder 12b, deinterleaver 13b, demodulator 14b, signal detector 15b, (U) 16b that accepts filter, channel estimator 17b, synchronization module 18b, and receiver module (1 ... N _t) 19b.

Operation below in conjunction with Figure 1A and 1B explanation space division multiplexing mimo system.Serial/parallel converter 11a is multiplexed into N to the bit stream of input _tIndividual symbol substream.At the Zhi Luduan of each antenna, adopt channel encoder 12a that bit stream input, the serial/parallel conversion of process is carried out chnnel coding with antinoise.After this, utilize interleaver 13a that the data of channel encoder 12a output are carried out interleaving treatment with reduction bit stream correlation, and the bit stream after will handling offer modulator 14a.Modulator 14a is modulated to symbols streams with the bit stream of interleaver 13a output.Pre-filtering (emission filtering) device 15a carries out many antenna transmission Signal Pretreatment to the symbols streams of modulation.Then, in symbols streams to be sent, insert the pilot frequency sequence that is used for timing and channel estimating by pilot frequency sequence module 16a, and offer emission (TX) module 17a.Then, transmitter module 17a launches the OFDM baseband signalling that obtains after carrier modulation.

At receiving terminal, receive and offer synchronization module 18b after (RX) module 19b down-converts to baseband signalling to the OFDM carrier signal that receives.Synchronization module 18b carries out timing, Frequency Synchronization to symbol.The synchronous sign estimation of channel estimator 17b diameter goes out the channel gain battle array.The function of receiving filter (U) 16b is corresponding with prefilter 15a.Signal detector 15b carries out the symbol detection of mimo system, then by demodulator 14b to after testing symbol demodulation.Deinterleaver 13b carries out deinterleaving to the bit stream of demodulator 14b output, by decoder 12b the bit stream of deinterleaving is deciphered then.At last, parallel/serial transducer 11b is many antennas bit stream translation a serial output information bit stream.

Below the bit stream in this operating process is described.

Suppose to transmit into $x={\left[\begin{array}{ccc}{x}_1& \·\·\·& x_{N_t}\end{array}\right]}^T,$ Become x=Vx after pre-filtering V pre-filtering, the signal after the channel H transmission is represented by following expression (1):

y＝H x+ w＝HVx+ w (1)

Wherein $\stackrel{\&OverBar;}{w}={\left[\begin{array}{ccc}{\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="A20041010207000211.png,A20041010207000212.png"\; state="\{\{state\}\}">w</figure-callout>}}_1& \&CenterDot;\&CenterDot;\&CenterDot;& w_{N_r}\end{array}\right]}^T$ Be the white Gauss noise vector.

Through the filtered signal vector of receiving filter (U) 16b $y={\left[\begin{array}{ccc}{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="A20041010207000211.png,A20041010207000212.png"\; state="\{\{state\}\}">y</figure-callout>}}_1& \&CenterDot;\&CenterDot;\&CenterDot;& y_{N_r}\end{array}\right]}^T,$ And the expression formula above the substitution (1) obtains following expression (2)

y＝U ^Hy＝U ^H(HVx+ w) (2)

Wherein V is emission pre-filtering battle array, and U is for accepting filter battle array, and " T " represents transposition, the Hermite transposition of " H " representing matrix.Channel matrix

Middle element h _IjBe the channel fading coefficient of transmitting antenna i to reception antenna j, it is independent Gaussian random variable again.If the covariance matrix R of noise vector w _{W w}=E (w w ^H) be the multiple of unit matrix, promptly $R_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}={\mathrm{\&sigma;}}_{\stackrel{\&OverBar;}{w}}^{2}I,$ I is a unit matrix, then can be directly from expression formula (1) processing; If the covariance matrix R of noise vector w _{W w}=E (w w ^H) not the multiple of unit matrix, then need in expression formula (1), multiply by R _{W w} ^-1/2The decorrelation noise, thus expression formula (3) obtained, that is:

$R_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}\stackrel{\&OverBar;}{y}=R_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}H\stackrel{\&OverBar;}{x}+R_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}\stackrel{\&OverBar;}{w}---\left(3\right)$

The transmitting power of establishing every antenna now is P _i, total emission power is P _T, satisfying the power constraint condition $E\left[x^{H}x\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_i\&le;P_T$ Situation under, in order to obtain the optimum capacity of mimo channel, channel matrix is carried out characteristic value decomposition, obtain H=U Λ V ^H, as Fig. 2.Matrix U, V satisfy UU ^H=I, VV ^H=I; Diagonal matrix Λ=diag (λ ₁λ ₂λ _k), λ ₁＞λ ₂＞...＞λ _kBe the characteristic value of H, substitution expression formula (3) obtains the output of receiving filter 16b and is represented by following expression (4).

y＝U ^H(UΛV ^H)(Vx)+U ^Hw＝Λx+w (4)

Noise in the formula

The channel capacity of mimo system generally is expressed as: $C={\log }_2\left[\det (I+\frac{\mathrm{SNR}}{N_t}H{H}^H)\right],$ Wherein det () expression is asked determinant to matrix, and SNR is the output signal-to-noise ratio of every reception antenna.Utilize the system's closed-loop capacity after SVD decomposes to represent by following expression (5).

$C=\underset{i=1}{\overset{K}{\mathrm{\&Sigma;}}}{\log }_2(1+\frac{P_i}{{\mathrm{\&sigma;}}_w^2}{\mathrm{\&lambda;}}_i^2)---\left(5\right)$

Wherein K is the order of channel matrix, K≤min (N _r, N _t), $P_i={(\mathrm{\&mu;}-{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="A20041010207000261.png,A20041010207000262.png"\; state="\{\{state\}\}">w</figure-callout>}}^2/{\mathrm{\&lambda;}}_i^2)}^{+},$ μ satisfies $\underset{i=1}{\overset{K}{\mathrm{\&Sigma;}}}{(\mathrm{\&mu;}-{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="A20041010207000261.png,A20041010207000262.png"\; state="\{\{state\}\}">w</figure-callout>}}^2/{\mathrm{\&lambda;}}_i^2)}^{+}=P_T,{\left(x\right)}^{+}$ Be defined as max{x, 0}.

From top calculating process as can be seen, through sending, accept filter and the SVD processing, mimo channel is broken down into one group of parallel independent subchannel.At this moment, utilize WF (water filling) algorithm that each subchannel is carried out power division, can obtain the optimum capacity of mimo channel.

Fig. 3 shows the mimo system structure chart that can obtain optimum capacity.As shown in Figure 3, the transmitting terminal that can obtain the mimo system of optimum capacity comprises serial/parallel converter 31a, channel encoder 32a, interleaver 33a, modulator 34a, prefilter (V) 35a, pilot frequency sequence module 36a, and transmitter module (1 ... N _t) 37a; Receiving terminal comprises parallel/serial converter 31b, decoder 32b, deinterleaver 33b, demodulator 34b, signal detector 35b, receiving filter (U) 36b, channel estimator 37b, synchronization module 38b, receiver module (1 ... N _t) 39b, and power division module 30 and SVD module 40.

The following describes the operation of the mimo system that can obtain optimum capacity.At transmitting terminal, serial/parallel converter 31a is multiplexed with N to incoming bit stream _tIndividual symbol substream.At each antenna branch end, adopt encoder 32a that the bit stream of input is carried out chnnel coding with antinoise.After this, utilize interleaver 33a that the data of channel encoder 32a output are carried out interleaving treatment with reduction bit stream correlation, and the bit stream after will handling offer modulator 34a.Modulator 34a is modulated to symbols streams with the bit stream of interleaver 33a output.Pre-filtering (emission filtering) device 35a is to handling the pre-filtering battle array obtain to many antenna transmission Signal Pretreatment according to channel matrix being carried out SVD.Then, in symbols streams to be sent, insert the pilot frequency sequence that is used for timing and channel estimating by pilot frequency sequence module 36a.Power division module 30 is carried out power division according to channel gain to every antenna, and offers emission (TX) module 37a.Then, transmitter module 37a launches the OFDM baseband signalling that obtains after carrier modulation.

At receiving terminal, RX module 39b down-converts to the OFDM carrier signal that receives baseband signalling and outputs to synchronization module 38b.Synchronization module 38b carries out timing and Frequency Synchronization to the baseband signalling of input.Then, go out channel gain battle array H according to the sign estimation that is timed with Frequency Synchronization, channel gain battle array H is fed back to transmitting terminal by the based on feedback link of forming by SVD module 40 and power division module 30 by channel estimator 37b.40 couples of H of SVD module carry out characteristic value decomposition with obtain pre-filtering battle array U, the characteristic value of accept filter gust V and H, and the characteristic value of the H that characterizes channel gain is fed to power division module 30 by based on feedback link.The function of receiving filter 36b is corresponding with the function of prefilter 35a, and it utilizes U to handle to received signal.Signal detector 35b carries out the symbol detection of mimo system, carries out symbol demodulation by demodulator 34b then, and demodulation result is outputed to deinterleaver 33b.Deinterleaver 33b carries out deinterleaving to the output bit flow from demodulator 34b.After this, decoder 32b deciphers the bit stream of deinterleaving.At last, be many antennas bit stream translation serial output information bit stream by parallel/serial transducer 31b.

The principle of water filling (WF) algorithm is to the little big transmitting power of channel allocation of decay, gives decay the big little power of channel allocation.Studies show that, after SNR is increased to certain value, adopt the WF algorithm can not make channel capacity continue to increase.Because along with the raising of SNR, channel fading reduces, power division no longer is a major issue that influences capacity.Therefore, need to study the technology that improves the MIMO capacity from other angle.

For obtaining Shannon (Shannon) capacity of mimo channel, when channel matrix is carried out the SVD decomposition, need estimate channel matrix and noise covariance battle array.Because the time varying characteristic of wireless channel is estimated comparatively difficulty of these parameters exactly.After receiving terminal estimates these parameters, need feed back to transmitting terminal to it, this can increase overhead and bring error.At transmitting terminal, power division and change pre-filtering battle array will correspondingly dynamically be adjusted the battle array that accepts filter.

Consider the influence of these factors, the present invention proposes TDD (time division duplex) mimo system of low complex degree, and it has following characteristics:

Adopt the TDD working method, do not need feedback channel;

To every transmitting antenna uniform distribution power;

The MMSE that receiving terminal solves gust U that accepts filter separates or utilizes adaptive algorithm to upgrade gust U that accepts filter.

Use above method, reduced overhead, can obtain the suboptimum capacity simultaneously, below this is elaborated.

As shown in Figure 4, under the TDD mode of operation, the channel condition information (CSI) that transmitter can utilize the former frame that receives to estimate.Compare with feedback system, the TDD mode has been utilized the mutual benefit of wireless channel, and up link and down link utilize same Channel Transmission matrix, the down link (U that accepts filter ^H) can be used as up link pre-filtering (U ^H), need not extra feedback channel, reduced overhead.But, the renewal rate that its requirement is used for the pilot frequency sequence of channel estimating is higher than feedback system, be applicable in low Doppler frequency shift channel circumstance or the short frame system, and mimo system often is applied to provide under the low speed mobile environment high-rate service, so it adopts the TDD mode comparatively suitable.

By aforementioned content as can be known, though the SVD method can obtain optimum capacity, its shortcoming is to be difficult to practicability.For this reason, wish to seek to obtain the simple sending, receiving method and the device of suboptimum capacity.The battle array of launching, accept filter is different with utilizing simultaneously in the SVD method, has proposed among the present invention every transmitting antenna uniform distribution power, that is, the emission filtering matrix is a unit matrix, seeks optimum simultaneously and accepts filter battle array to realize optimal detection.In other words, find the solution the Minimum Mean Square Error (MMSE) of gust U that accepts filter in the expression formula (6) and separate, make the mean square deviation minimum of transmission, received signal.

ε＝E[|x-U ^Hy| ²] (6)

Expression formula (6) is launched to obtain

$\mathrm{\&epsiv;}=R_{\mathrm{xx}}-2\mathrm{real}\left(R_{\stackrel{\&OverBar;}{y}x}^{H}U\right)+U^H{R}_{\stackrel{\&OverBar;}{\mathrm{yy}}}U$

R wherein _Xx=E[|x| ²], R _Yx=E[yx ^H], R _Yy=E[yy ^H], the MMSE that tries to achieve U thus separates by following expression (7) and represents.

$U=R_{\stackrel{\&OverBar;}{\mathrm{yy}}}^{-1}{R}_{\stackrel{\&OverBar;}{y}x}---\left(7\right)$

Utilize following formula

R _yy ＝E[ yy ^H]＝E[(HVx+ w)(HVx+ w) ^H]＝HVR _xxVH+R _{w? w} ，

R _yx ＝E[ yx ^H]＝E[(HVx+ w)x ^H]＝HVR _xx，

R _xx＝E[xx ^H]，

Abbreviation U gets

$U=R_{\stackrel{\&OverBar;}{\mathrm{yy}}}^{-1}{R}_{\stackrel{\&OverBar;}{y}x}={({\mathrm{HVR}}_{\mathrm{xx}}{V}^H{H}^H+R_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}})}^{-1}{\mathrm{HVR}}_{\mathrm{xx}}$

$=R_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}{(R_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}{\mathrm{HVR}}_{\mathrm{xx}}{V}^H{H}^H{R}_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}+I)}^{-1}{R}_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}{\mathrm{HVR}}_{\mathrm{xx}}$

Make R _{W w} ^-1/2The SVD of H is U _wΛ _wV _w, establish V _w=V then has

$U=R_{\mathrm{ww}}^{-1/2}{(U_w{\mathrm{\&Lambda;}}_w{R}_{\mathrm{XX}}{\mathrm{\&Lambda;}}_w^H{U}_w^H+I)}^{-1}{U}_w{\mathrm{\&Lambda;}}_w{R}_{\mathrm{xx}}$

$=R_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}{U}_{\stackrel{\&OverBar;}{w}}{({\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}{R}_{\mathrm{xx}}{\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}^H+I)}^{-1}{\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}{R}_{\mathrm{xx}}$

So obtain expression formula (8)

$U^H\stackrel{\&OverBar;}{y}=R_{\mathrm{xx}}{\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}^H{({\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}{R}_{\mathrm{xx}}{\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}^H+I)}^{-1}{U}_{\stackrel{\&OverBar;}{w}}^H{R}_{\stackrel{\&OverBar;}{w}\stackrel{\&OverBar;}{w}}^{-1/2}\stackrel{\&OverBar;}{y}---\left(8\right)$

In this formula, utilize R earlier _{W w} ^-1/2It is relevant to multiply by the y denoising, multiply by U again _w ^HObtain parallel sub-channels, compare with formula (3), this formula contains the tolerance factor, i.e. a diagonal matrix $R_{\mathrm{xx}}{\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}^H{({\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}{R}_{\mathrm{xx}}{\mathrm{\&Lambda;}}_{\stackrel{\&OverBar;}{w}}^H+I)}^{-1}.$ Say the two equivalence in essence.Therefore, if transmitting terminal adopts optimum pre-filtering battle array, the battle array that accepts filter adopts the Minimum Mean Square Error of U to separate, also can be the same with the SVD technology, obtain the optimum capacity of mimo system.

As previously mentioned, consider the realizability of mimo system, in the proposition method, transmitting terminal does not adopt optimum pre-filtering battle array, but to every antenna uniform distribution power.The battle array that accepts filter adopts the Minimum Mean Square Error of U to separate, and it can obtain suboptimum MIMO capacity.Though this method is different with the SVD method, but utilized its transmission, thought accepts filter, and the Minimum Mean Square Error detection from the Channel Transmission matrix is different again with directly, and simple lowest mean square poor reception is only considered input, and does not have the influence of consideration to power system capacity.

Illustrate according to one embodiment of the invention below with reference to Fig. 5 A and 5B, can obtain the structure chart of the mimo system of suboptimum capacity.Shown in Fig. 5 A, the transmitting terminal of mimo system comprises serial/parallel converter 51a according to an embodiment of the invention, channel encoder 52a, interleaver 53a, modulator 54a, prefilter (V) 55a, pilot frequency sequence module 56a, and transmitter module (1 ... N _t) 57a and even power division module 58a.Shown in Fig. 5 B, the receiving terminal of the mimo system of present embodiment comprises parallel/serial converter 51b, decoder 52b, deinterleaver 53b, demodulator 54b, Minimum Mean Square Error receiving filter (U) 56b, channel estimator 57b, synchronization module 58b, receiver module (1 ... N _t) 59b.

The following describes the operation of the mimo system that can obtain the suboptimum capacity.At transmitting terminal, serial/parallel converter 51a is multiplexed with N to incoming bit stream _tIndividual symbol substream at each antenna branch end, adopts channel encoder 52a that the bit stream of input is carried out chnnel coding with antinoise.After this, utilize interleaver 53a that the data of channel encoder 52a output are carried out interleaving treatment with reduction bit stream correlation, and the bit stream after will handling offer modulator 54a.Modulator 54a is modulated to symbols streams with the bit stream of interleaver 53a output.Prefilter 55a utilizes unit matrix that many antenna transmission signal is carried out preliminary treatment (at this, the prefilter 55a that draws for sake of comparison can save this module, because it does not change characteristics of signals in reality is implemented).Pilot frequency sequence module 56a inserts in sending symbols streams and is used for regularly and the pilot frequency sequence of channel estimating.Power division module 58a carries out uniform power to every antenna and distributes.After this, the TX module is launched the OFDM baseband signalling that obtains after carrier modulation.

At receiving terminal, RX module 59b down-converts to the OFDM carrier signal that receives baseband signalling and offers synchronization module 58b.Synchronization module 58b carries out timing and Frequency Synchronization to the symbol of input.Channel estimator 57b is from estimating channel gain battle array H through the synchronous symbol.Minimum Mean Square Error (MMSE) receiving filter 56b utilizes the MMSE criterion to carry out Filtering Processing to received signal, finds the solution gust U that accepts filter, and filtered signal is input to demodulator 54b.After this, demodulator 54b carries out demodulation to symbol, by deinterleaver 53b the bit stream that demodulator 54b exports is carried out deinterleaving then.The bit stream of decoder 52b after to deinterleaving deciphered.At last, be many antennas bit stream translation serial output information bit stream by parallel/serial transducer 51b.

See that from expression formula (7) and (8) of explanation the amount of calculation of separating according to the MMSE that asks U of first embodiment of the invention is bigger.

For reducing complexity, according to another embodiment of the invention, further propose to adopt simple lowest mean square (LMS) algorithm to find the solution formula (6), its iterative process is represented by following expression 9:

U(k+1)＝U(k)+2μ y(k)[x(k)-y(k)] ^H (9)

μ in the following formula＞0 is a step factor, if μ＜1/E[| y (k) | ²], E[U (k) then] converge to MMSE and separate.

Fig. 6 A and 6B show according to a further embodiment of the invention, adopt lowest mean square (LMS) structure chart receiving filter, that can obtain the mimo system of suboptimum capacity at receiving terminal.As shown in Figure 6A, identical according to the configuration of the transmitting terminal of the mimo system of present embodiment with the transmitting terminal shown in Fig. 5 A, comprise serial/parallel converter 61a, channel encoder 62a, interleaver 63a, modulator 64a, prefilter (V) 65a, pilot frequency sequence module 66a, and transmitter module (1 ... N _t) 67a and even power division module 68a.Shown in Fig. 6 B, the receiving terminal of the mimo system of present embodiment comprises parallel/serial converter 61b, decoder 62b, deinterleaver 63b, demodulator 64b, LMS receiving filter (U) 66b, channel estimator 67b, synchronization module 68b, receiver module (1 ... N _t) 69b.

The following describes according to operation present embodiment, that can obtain the mimo system of suboptimum capacity.At transmitting terminal, serial/parallel converter 61a is multiplexed with N to incoming bit stream _tIndividual symbol substream at each antenna branch end, adopts channel encoder 62a that the bit stream of input is carried out chnnel coding with antinoise.After this, utilize interleaver 63a that the data of channel encoder 62a output are carried out interleaving treatment with reduction bit stream correlation, and the bit stream after will handling offer modulator 64a.Modulator 64a is modulated to symbols streams with the bit stream of interleaver 63a output.Prefilter 65a utilizes unit matrix that many antenna transmission signal is carried out preliminary treatment (at this, the prefilter 65a that draws for sake of comparison can save this module in reality is implemented, because it does not change characteristics of signals).Pilot frequency sequence module 66a inserts in sending symbols streams and is used for regularly and the pilot frequency sequence of channel estimating.Power division module 68a carries out uniform power to every antenna and distributes.After this, TX module 67a launches the OFDM baseband signalling that obtains after carrier modulation.

At receiving terminal, RX module 69b down-converts to the OFDM carrier signal that receives baseband signalling and offers synchronization module 68b.Synchronization module 68b carries out timing and Frequency Synchronization to the symbol of input.Channel estimator 67b is from estimating channel gain battle array H through the synchronous symbol.Lowest mean square (LMS) receiving filter 66b utilizes the LMS criterion to carry out Filtering Processing to received signal, finds the solution gust U that accepts filter, and filtered signal is input to demodulator 64b.After this, demodulator 64b carries out demodulation to symbol, by deinterleaver 63b the bit stream that demodulator 64b exports is carried out deinterleaving then.The bit stream of decoder 62b after to deinterleaving deciphered.At last, be many antennas bit stream translation serial output information bit stream by parallel/serial transducer 61b.

The difference of the mimo system of the optimum capacity of acquisition shown in Figure 3 and the mimo system of the acquisition suboptimum capacity shown in Fig. 5 and 6 is:

1) there is based on feedback link in the mimo system of the optimum capacity of acquisition shown in Figure 3, and pre-filtering battle array, channel gain (characteristic value) that the channel matrix that it obtains channel estimating carries out after SVD decomposes feed back to transmitting terminal; And not having feedback device in the mimo system of the acquisition suboptimum capacity shown in Fig. 5 and 6, complexity is lower;

2) pre-(transmissions) the filtering matrix V of the mimo system of the optimum capacity of acquisition shown in Figure 3 and gust SVD decomposition by channel matrix H that accepts filter obtain, and according to the transmitting power of every antenna of channel gain dynamic assignment; And the filtering matrix of the mimo system of the acquisition suboptimum capacity shown in Fig. 5 and 6 is unit matrix, promptly to every antenna uniform distribution power, accepts filter and adopts MMSE and LMS algorithm to handle respectively.

Can calculate the power system capacity that adopts method of the present invention to obtain from top expression formula (2), the signal that accepts filter is:

y＝U ^HHVx+U ^Hw＝ Hx+U ^Hw

Definition H=U ^HHV is then provided the signal to noise ratio (snr) of i subchannel by following expression (10).

${\mathrm{SNR}}_i=\frac{{\left|{\stackrel{\&OverBar;}{h}}_{\mathrm{ii}}\right|}^{2}E\left[{\left|x_i\right|}^2\right]}{\underset{i\&NotEqual;j}{\mathrm{\&Sigma;}}{\left|{\stackrel{\&OverBar;}{h}}_{\mathrm{ij}}\right|}^{2}E\left[{\left|x_i\right|}^2\right]+\underset{j}{\mathrm{\&Sigma;}}{\left|u_{\mathrm{ij}}\right|}^{2}E\left[{\left|w_j\right|}^2\right]}---\left(10\right)$

According to the general expression formula of mimo channel capacity, obtain the channel capacity that expression formula (11) provides and be,

$C=\underset{i}{\mathrm{\&Sigma;}}{\log }_2(1+{\mathrm{SNR}}_i)---\left(11\right)$

Equally, method of the present invention can be promoted and be used for the MIMO ofdm system, at this moment need calculate the SNR of each empty frequency subchannel, calculates the capacity of each empty frequency subchannel again, calculates the system channel capacity at last.In addition, though preamble only be illustrated for simplicity at single user.In fact, method of the present invention can be used for multi-user MIMO system equally.

In the discussion in front, all suppose the channel estimating perfection.In fact, always there is certain channel estimation errors, especially all the more so in the time varying channel environment.The influence of channel estimation errors is discussed below.

Signaling channel evaluated error battle array is Δ H, and the channel matrix that then has evaluated error is H _e=H+ Δ H, its SVD then are U _eΛ _eV _e ^HIf V _e=V+ Δ V, U _e=U+ Δ U, then $V_e^H{H}_e^H{H}_e{V}_e={\mathrm{\&Lambda;}}_e^2={\mathrm{\&Lambda;}}^2+{\mathrm{\&Delta;\&Lambda;}}^2,$ Further can release $V_e^H(H_e^H{H}_e-H^{H}H)V_e={\mathrm{\&Delta;\&Lambda;}}^2,$ | Δ Λ ²|=| H ^HΔ H+ Δ H ^HH+ Δ H ^HΔ H| under the high SNR condition, ignores Δ H ^HΔ H, | Δ Λ ²|=2|H ^HΔ H| obtains the evaluated error upper bound that following expression (12) is represented thus.

|ΔΛ ²|≤2|H||ΔH| (12)

Though this upper bound is to derive from the SVD that can obtain optimum capacity, because of method of the present invention can obtain the suboptimum capacity, so it also is the upper bound that the present invention proposes method.

Verified that by emulation experiment the present invention proposes the performance of method.Fig. 7 A to 7C shows the simulation result under the situation of the transmission of varying number and reception antenna.Wherein Fig. 7 A is the correlation curve figure that the quantity of transmitting antenna and reception antenna is respectively mimo system capacity under 2 the situation.Fig. 7 B is the correlation curve figure that the quantity of transmitting antenna and reception antenna is respectively the mimo system capacity under 3 the situation.Fig. 7 C is the correlation curve figure that the quantity of transmitting antenna and reception antenna is respectively the mimo system capacity under 4 the situation.

Be noted that in Fig. 7 A to 7C, the simulation parameter of employing is as follows: each element of channel matrix H is a unit gain, submits to independent Rayleigh fading; Doppler frequency shift is 40Hz, is equivalent to the walking speed under the 5.7GHz frequency range; The noise of every reception antenna end is obeyed I.I.D and is distributed, and power ${\mathrm{\&sigma;}}_w^2=0.02;$ Average total power P _T=1; Channel estimation errors power is 0.01.Fig. 7 A to 7C is along with the time changes, three kinds of channel capacities that (that is, water flood described above (WF), MMSE and LMS) distinct methods obtains.Can see, (TX2-RX2 under the situation of difference transmission, reception antenna quantity, TX3-RX3, TX4-RX4), the WF method can obtain optimum capacity, and the MMSE of U separates and takes second place, the LMS of U separates and takes second place, but the Changing Pattern of the capacity of three kinds of method acquisitions is more consistent, and the MMSE of proposition, LMS method be track channel change better, conforms to aforementioned analysis; Along with the increase of antenna number, distinct methods obtains capacity difference and becomes big.Method of the present invention more is applicable under the less situation of antenna amount, as TX2-RX2, and TX3-RX3 etc.

Fig. 8 is illustrated in when having channel estimation errors, sends and the quantity of reception antenna is respectively channel capacity under 3 the situation.Compare with Fig. 7 B with same antenna quantity, as can be seen, because algorithm has adaptive ability, channel estimation errors is not obvious to the influence of capacity.

The method according to this invention and device in the even power division of transmitting terminal, need not to upgrade transmission pre-filtering battle array V and dynamic assignment transmitting power.Receiving terminal is found the solution gust U that accepts filter according to certain criterion and algorithm, thereby has simplified emission, reception processing, can obtain suboptimum MIMO capacity.This system adopts the TDD working method, and it has utilized the mutual benefit of wireless channel, need not the additional feedback channel, has reduced overhead, and suitable with mimo channel.

Invention has been described in conjunction with the preferred embodiments above.It should be appreciated by those skilled in the art that under the situation that does not break away from the spirit and scope of the present invention, can carry out various other change, replacement and interpolations.Therefore, scope of the present invention should not be understood that to be limited to above-mentioned specific embodiment, and should be limited by claims.

Claims (22)

1. method that obtains the suboptimum capacity in many antennas multiple-input and multiple-output (MIMO) system comprises step:

At transmitting terminal, to each the transmitting antenna uniform distribution transmitted power in a plurality of transmitting antennas, the baseband signalling after the concurrent warp let-off carrier modulation;

At receiving terminal, receive the carrier signal of described a plurality of antenna transmission and down-convert to baseband signalling by a plurality of reception antennas;

Baseband signalling through frequency conversion is carried out timing and Frequency Synchronization;

From the synchronous symbol of process, estimate channel gain battle array H;

Utilize Minimum Mean Square Error (MMSE) algorithm to find the solution to accept filter matrix U to import many output capacities to obtain suboptimum.

2. method according to claim 1 wherein also is included in transmitting terminal and utilizes unit matrix to being carried out the step of pre-filtering by the signal of many antenna transmission.

3. method according to claim 1 and 2 is wherein utilized Minimum Mean Square Error to find the solution separating by following expression of the matrix U that accepts filter and is represented

$U=R_{\stackrel{\&OverBar;}{\mathrm{yy}}}^{-1}{R}_{\stackrel{\&OverBar;}{y}x},$

Wherein $R_{\stackrel{\&OverBar;}{y}x}=E\left[{\stackrel{\&OverBar;}{y}x}^H\right],$ $R_{\stackrel{\&OverBar;}{\mathrm{yy}}}=E\left[{\stackrel{\&OverBar;}{\mathrm{yy}}}^H\right],$ $x=$ ${\left[\begin{array}{ccc}{x}_1& \&CenterDot;\&CenterDot;\&CenterDot;& {x_N}_r\end{array}\right]}^T$ For transmitting, after the pre-filtering x=vx, y is the signal after the channel H transmission, the battle array that accepts filter is handled a signal vector that recovers the back and is $y={\left[\begin{array}{ccc}{y}_1& \&CenterDot;\&CenterDot;\&CenterDot;& {y_N}_r\end{array}\right]}^T,$ " T " represents transposition, " H ' in distress close (Hermite) transposition of representing matrix.

4. method according to claim 1 wherein also comprises the following steps: at transmitting terminal

Incoming bit stream is carried out serial/parallel conversion, it is multiplexed with the symbol substream of each the antenna branch end in a plurality of antennas;

Bit stream to input carries out chnnel coding with antinoise;

Bit stream through chnnel coding is carried out interleaving treatment to reduce the bit stream correlation;

Bit stream after will interweaving is modulated to symbols streams; With

In sending symbols streams, insert and be used for regularly and the pilot frequency sequence of channel estimating.

5. method according to claim 1 wherein also comprises the following steps: at receiving terminal

The symbol that utilizes lms algorithm to find the solution to accept filter matrix U is carried out demodulation;

Bit stream through demodulation is carried out deinterleaving;

Bit stream after the deinterleaving is deciphered; With

Bit stream through decoding is carried out parallel/serial conversion, is many antennas bit stream translation serial output information bit stream.

6. according to any one the described method in the claim 1 to 5, wherein said many antennas multi-input multi-output system is the duplicating multi-antenna orthogonal frequency division radio multi-media communicating system.

7. method that obtains the suboptimum capacity in many antennas multiple-input and multiple-output (MIMO) system comprises step:

At transmitting terminal, to each the transmitting antenna uniform distribution transmitted power in a plurality of transmitting antennas, the baseband signalling after the concurrent warp let-off carrier modulation;

At receiving terminal, receive the carrier signal of described a plurality of antenna transmission and down-convert to baseband signalling by a plurality of reception antennas;

Baseband signalling through frequency conversion is carried out timing and Frequency Synchronization;

From the synchronous symbol of process, estimate channel gain battle array H;

Utilize lowest mean square (LSE) algorithm to find the solution to accept filter matrix U to import many output capacities to obtain suboptimum.

8. method according to claim 7 wherein also is included in transmitting terminal and utilizes unit matrix to being carried out the step of pre-filtering by the signal of many antenna transmission.

9. according to claim 7 or 8 described methods, wherein utilize lowest mean square to find the solution separating of the matrix U that accepts filter, the iterative process of U is

U(k+1)＝U(k)+2μ y(k)[x(k)-y(k)] ^H

In the superincumbent expression formula, μ＞0 is a step factor, if μ＜1/E[| y (k) | ²], E[U (k) then] converge to separating of its Minimum Mean Square Error.

10. method according to claim 7 wherein also comprises the following steps: at transmitting terminal

Incoming bit stream is carried out serial/parallel conversion, it is multiplexed with the symbol substream of each the antenna branch end in a plurality of antennas;

Bit stream to input carries out chnnel coding with antinoise;

Bit stream through chnnel coding is carried out interleaving treatment to reduce the bit stream correlation;

Bit stream after will interweaving is modulated to symbols streams; With

In sending symbols streams, insert and be used for regularly and the pilot frequency sequence of channel estimating.

11. method according to claim 7 wherein also comprises the following steps: at receiving terminal

The symbol that utilizes least mean square algorithm to find the solution to accept filter matrix U is carried out demodulation;

Bit stream through demodulation is carried out deinterleaving;

Bit stream after the deinterleaving is deciphered; With

Bit stream through decoding is carried out parallel/serial conversion, is many antennas bit stream translation serial output information bit stream.

12. according to any one the described method in the claim 7 to 11, wherein said many antennas multi-input multi-output system is the duplicating multi-antenna orthogonal frequency division radio multi-media communicating system.

13. a device that obtains the suboptimum capacity in many antennas multiple-input and multiple-output (MIMO) system comprises:

Power distribution unit is used for each the transmitting antenna uniform distribution transmitted power to a plurality of transmitting antennas;

A plurality of receiving systems are used to receive the carrier signal of described a plurality of antenna transmission and down-convert to baseband signalling;

Synchronizer is used for the baseband signalling through frequency conversion is carried out timing and Frequency Synchronization;

Channel estimating apparatus is used for from estimate channel gain battle array H through synchronous symbol;

The Minimum Mean Square Error device that accepts filter utilizes Minimum Mean Square Error (MMSE) algorithm to find the solution to accept filter matrix U to import many output capacities to obtain suboptimum.

14. device according to claim 13 wherein also is included in transmitting terminal and utilizes unit matrix to being carried out the device of pre-filtering by the signal of many antenna transmission.

15. device according to claim 13 wherein also comprises at transmitting terminal:

Serial/parallel conversion equipment is used for incoming bit stream is carried out serial/parallel conversion, and it is multiplexed with the symbol substream of each the antenna branch end in a plurality of antennas;

A plurality of channel coding devices carry out chnnel coding with antinoise to the bit stream of importing;

A plurality of interlaced devices carry out interleaving treatment to reduce the bit stream correlation to the bit stream through chnnel coding;

A plurality of modulating devices are used for the bit stream after interweaving is modulated to symbols streams; With

The pilot frequency sequence module is used for sending the pilot frequency sequence that the symbols streams insertion is used for timing and channel estimating.

16. device according to claim 13 wherein also comprises the following steps: at receiving terminal

A plurality of demodulating equipments carry out demodulation to the symbol that utilizes lms algorithm to find the solution to accept filter matrix U;

A plurality of de-interleaving apparatus are used for the bit stream through demodulation is carried out deinterleaving;

A plurality of code translators are used for the bit stream after the deinterleaving is deciphered; With

Parallel/serial conversion equipment carries out parallel/serial conversion to the bit stream through decoding, is many antennas bit stream translation serial output information bit stream.

17. according to any one the described device in the claim 13 to 16, wherein said many antennas multi-input multi-output system is the duplicating multi-antenna orthogonal frequency division radio multi-media communicating system.

18. a device that obtains the suboptimum capacity in many antennas multiple-input and multiple-output (MIMO) system comprises:

Power distribution unit is used for each the transmitting antenna uniform distribution transmitted power to a plurality of transmitting antennas, the baseband signalling after the concurrent warp let-off carrier modulation;

A plurality of receiving systems are used to receive the carrier signal of described a plurality of antenna transmission and down-convert to baseband signalling;

Synchronizer is used for the baseband signalling through frequency conversion is carried out timing and Frequency Synchronization;

Channel estimating apparatus is used for from estimate channel gain battle array H through synchronous symbol;

The lowest mean square device that accepts filter utilizes lowest mean square (LSE) algorithm to find the solution and accepts filter matrix U to obtain suboptimum multiple-input and multiple-output capacity.

19. device according to claim 18 wherein also is included in transmitting terminal and utilizes unit matrix to being carried out the device of pre-filtering by the signal of many antenna transmission.

20. device according to claim 18 wherein also comprises at transmitting terminal:

Serial/parallel conversion equipment is used for incoming bit stream is carried out serial/parallel conversion, and it is multiplexed with the symbol substream of each the antenna branch end in a plurality of antennas;

A plurality of channel coding devices carry out chnnel coding with antinoise to the bit stream of importing;

A plurality of interlaced devices carry out interleaving treatment to reduce the bit stream correlation to the bit stream through chnnel coding;

A plurality of modulating devices are used for the bit stream after interweaving is modulated to symbols streams; With

The pilot frequency sequence module is used for sending the pilot frequency sequence that the symbols streams insertion is used for timing and channel estimating.

21. device according to claim 18 wherein also comprises the following steps: at receiving terminal

A plurality of demodulating equipments carry out demodulation to the symbol that utilizes least mean square algorithm to find the solution to accept filter matrix U;

A plurality of de-interleaving apparatus are used for the bit stream through demodulation is carried out deinterleaving;

A plurality of code translators are used for the bit stream after the deinterleaving is deciphered; With

Parallel/serial conversion equipment carries out parallel/serial conversion to the bit stream through decoding, is many antennas bit stream translation serial output information bit stream.

22. according to any one the described device in the claim 18 to 21, wherein said many antennas multi-input multi-output system is the duplicating multi-antenna orthogonal frequency division radio multi-media communicating system.

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