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United States Patent m
Date of Patent: Jul. 11,1995
 METHOD AND APPARATUS OF JOINT ADAPTIVE CHANNEL ENCODING, ADAPTIVE SYSTEM FILTERING, AND MAXIMUM LIKELIHOOD SEQUENCE ESTIMATION PROCESS BY MEANS OF AN UNKNOWN DATA TRAINING
 Inventor: Yuang Lou, 87 Francis St., Apt. #1, Brookline, Mass. 02146
 Appl. No.: 18,030
 Filed: Feb. 16,1993
 Int. Cl.« H03H 7/30; H04L 27/06;
 U.S. CI 375/324; 375/233;
 Field of Search 375/106, 39, 94, 99,
375/103, 14, 58, 59, 60, 13, 17, 18, 355, 265, 324, 340, 229, 232, 233, 346, 285, 290, 296, 263, 261; 364/724.19, 724.20; 371/43
 References Cited
U.S. PATENT DOCUMENTS
Sato, Y., "A Method of Self-Recovering Equalization for Multilevel Amplitude Modulation Systems," IEEE Transactions on Communications, vol. COM-23, No. 6, Jun. 1975, pp. 679-682.
Godard, D. N., "Self Recovering Equalization and Carrier Tracking in Two Dimensional Data Communication Systems," IEEE Transactions on Communications, vol. COM-28, No. 11, Nov. 1980, pp. 1867-1875. Sethares, W. A., G. A. Rey and C. R. Johnson, Jr., "Approaches to Blind Equalization of Signals with Multiple Modulus," Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing, vol. 2, 1989, pp. 972-975. Chen, Y., C. L. Nikias, and J. G. Proakis, "Blind Equalization with Criterion with Memory Nonlinearity,"
A method and apparatus for detecting, with an unknown data training, high-rate data signals coming through a digital communication system whose characteristics is dynamic and unknown. The method underlying the present invention is based on an error estimation criterion which has embodied the emphasis on system characteristics. By means of this method, an apparatus is able to track the characteristics of a pre-designed partial response signaling system automatically, thereby to effect an adaptive control over the characteristics of the digital communication system described above with an unknown data training. In accordance with the first embodiment of the present invention, an adaptive convolutional channel encoding process is jointly operated with an adaptive system filtering process which tracks the characteristics of the pre-designed partial response signaling system automatically with an unknown data training. In according with the second embodiment of the present invention, an adaptive maximum likelihood sequence search of transmitted data symbols in a Trellis state diagram is jointly optimized with the adaptive convolutional channel encoding and the adaptive system filtering process described in the first embodiment of the present invention. The adaptive receiver with an unknown data training described in the present invention is reliable in the sense that minimized error probability is reached in the sequence search of transmitted data symbols and is flexible in the sense that it has no adverse effects on the operations of a communication network.
12 Claims, 7 Drawing Sheets
Lou, Y., "Channel Estimation Standard and Adaptive Blind Equalization," Proceedings of the IEEE International Symposium on Circuits and Systems, San Diego, Calif., U.S.A., May 1992, vol. 2, pp. 505-508. Lou, Y., "Comparison of Adaptive Blind Equalizers," Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing, San Francisco, Calif., U.S.A., Mar. 1992, vol. IV, pp. 545-548. Ding, Z., R. A. Kennedy, B. D. O. Anderson, and C. R. Johnson, Jr., "Ill Convergence of Godard Blind Equalizers in Data Communication Systems," IEEE Transactions on Communications, vol. COM-39, No. 9, Sep.
1991, pp. 1313-1327.
Ungerboeck, G., "Adaptive Maximum Likelihood Receiver for Carrier-Modulated Data-Transmission Systems," IEEE Transactions on Communications, vol. COM-22, No. 5, May 1974, pp. 624-636.
Forney, G. D., Jr., "Maximum Likelihood Sequence Estimation of Digital Sequences in the Presence of Intersymbol Interference," IEEE Transactions on Information Theory, vol. IT-18, No. 3, May 1972, pp. 363-377.
Forney, G. D., Jr., "The Viterbi Algorithm," Proceedings of the IEEE, vol. 61, No. 3, Mar. 1973, pp. 268-278.