United States Patent [19] [ii] Patent Number: 4,567,591
Gray et al. [45] Date of Patent: Jan. 28, 1986
[54] DIGITAL AUDIO SATELLITE TRANSMISSION SYSTEM
[76] Inventors: James S. Gray, 4718 Pine Acres Ct.,
Dunwoody, Ga. 30338; James W.
Chamberlin, 368 Omega Dr.; Alan L.
McBride, 2974 Moore Ave., both of,
Lawrenceville, Ga. 30245; Peter G.
Schreiner, III, 1281 Brockett Rd.,
Apartment 23D, Clarkston, Ga.
30021
[21] Appl. No.: 519,268
[22] Filed: Aug. 1, 1983
[51] Int. Q.4 H04J3/00
[52] U.S. CI 370/109; 371/43
[58] Field of Search 370/109, 104;,375/122;
371/43, 44, 45
[56] References Cited
U.S. PATENT DOCUMENTS
4,208,739 6/1980 Lu et al 371/43
4,211,996 7/1980 Nakamura 371/43
OTHER PUBLICATIONS
IEEE Transactions on Communication Technology; vol. COM-19, No. 5, "A High-Speed Sequential Decoder: Prototype Design and Test"; Forney, Jr. et al., Oct. 1971, pp. 821-835.
IBM Journal of Research and Development; "Error Correcting Cones for Satellite Communication Channels"; Chen et al; Mar. 1976; pp. 168-175.
A. L. McBride, "Scientific-Atlanta's 3-Meter Digital
Audio Terminal", (7 pages).
Satellite Communications Division, Scientific-Atlanta,
Inc., "Proposal For Digital Audio Satellite Distribution
for Network Radio 55TP022A".
Scientific-Atlanta, Inc., "Satellite Distributed, Digital
Audio for Network Radio".
Brochure—"Digital Audio 3-Meter Earth Station", (2 pages).
Primary Examiner—Douglas W. Olms
Assistant Examiner—Frank M. Scutch, III
Attorney, Agent, or Firm—Kilpatrick & Cody
[57] ABSTRACT
A digital audio satellite transmission system involving analog-to-digital conversion of audio signals, processing of such signals and transmission to and reception from a satellite transponder link. The digitized audio signal is digitally compressed to reduce the data rate. Several such signals are then time division multiplexed together. Differential encoding, bit interleaving and forward error correction coding is utilized to maintain high signal quality, together with binary phase shift key carrier modulation. Matched filter reception of the BPSK signal transmitted over a conventional satellite transponder link is provided together with BPSK demodulation, TDM demultiplexing, differential decoding, bit deinterleaving and threshold FEC decoding. The compressed digital signal is then expanded and converted to an analog audio signal.
15 Claims, 14 Drawing Figures
