Pulse or digital communications – Receivers – Particular pulse demodulator or detector
Reexamination Certificate
2006-11-21
2006-11-21
Phu, Phuong (Department: 2611)
Pulse or digital communications
Receivers
Particular pulse demodulator or detector
C375S229000
Reexamination Certificate
active
07139337
ABSTRACT:
A reduced state maximum likelihood sequence estimator allows the use of improved equalization techniques that provides greatly improved performance for channels with severe attenuation and spectral nulls. The reduced state maximum likelihood sequence estimator retains knstates of a total number of K states, kn<K, with each retained state having an associated state metric. (J)(kn) new states are determined based on knprevious states and a most recently received sample, using J transitions, J being a less than L, where L is a size of a symbol alphabet. (J)(kn) new state metrics are determined which are respectively associated with each new state. The new state metrics are compared to a threshold and those states whose metric does not exceed the threshold are retained. The reduced complexity of the MLSE allows for the use of partial response equalizers, e.g., a partial response class V (PRV) equalizer. The number of retained states knvaries according to an adaptive threshold which limits the number of retained states between a lower bound and an upper bound. The threshold may be determined according to the metric of the most likely state of the retained states and a selected one of a plurality of transition metrics associated with the most likely state metric.
REFERENCES:
patent: 5031195 (1991-07-01), Chevillat et al.
patent: 5245611 (1993-09-01), Ling et al.
patent: 5331666 (1994-07-01), Dent
patent: 5408503 (1995-04-01), Kahlman
patent: 5588028 (1996-12-01), Parizhsky
patent: 5684811 (1997-11-01), Doran
patent: 5784415 (1998-07-01), Chevillat et al.
patent: 5859861 (1999-01-01), Oh
patent: 5905742 (1999-05-01), Chennakeshu et al.
patent: 6198711 (2001-03-01), Fujita et al.
patent: 98/29995 (1998-07-01), None
Foschini, Gerard J., “A Reduced State Variant of Maximum Likelihood Sequence Detection Attaining Optimum Performance for High Signal-to-Noise Ratios”, IEEE Transactions on Information Theory, vol. IT-23, No. 5, Sep. 1977, pp. 605-609.
Ungerboeck, Gottfried, “Cannel Coding with Multilevel/Phase Signals”, IEEE Transactions on Information Theory, vol. IT-28, No. 1, Jan. 1982, pp. 55-63.
Vermeulen, Franklin L. and Hellman, Martin E., “Reduced State Viterbi Decoders for Channels with Intersymbol Interference”, Proceedings of the International Conference on Communications, Minneapolis, MN, Jun. 1974, pp. 37B-1 thru 37B-4.
Gitlin, Richard D. et al., “Data Communications Principles”, Plenum Press, New York, 1992, pp. 233-517.
Bergmans, Jan W.M., “Digital Baseband Transmission and Recording”, Kluwer Academic Publishers, Netherlands, 1996, pp. 264-373.
Vermeulen, Franklin Louis, “Low Complexity Decoders for Channels with Intersymbol Interference”, A Dissertation Submitted to the Department of Electrical Engineering and the Committee on Graduate Studies of Stanford University . . . , Aug. 1975, pp. 1-120.
International Telecommunication Union, “Series V: Data Communication Over the Telephone Network”, V.90, Sep. 1998, pp. 1-50.
K. J. Knudson et al., “Dynamic Threshold Implementation of the Maximum-Likelihood Detector for the EPR4 Channel,” Proceedings of theIEEE Telecommunications Conference Global '91, Phoenix, AZ, Dec. 2, 1991, (GLOBECOM), IEEE, vol. 3, pp. 2135-2139, XP000313770, ISBN: 0-87942-697-7.
W-T. Lee et al, “A Single-Chip Viterbi Decoder for a Binary Convolutional Code Using an Adaptive Algorithm,”IEEE Transactions on Consumer Electronics, N.Y., vol. 41, No. 1, Feb. 1, 1995, pp. 150-159, XP000529220, ISSN: 0098-3063.
M. Nasiri-Kenari and C. K. Rushforth, “A Reduced-Complexity Sequence Detector with Soft Outputs for Partial-Response Channels,” Proceedings of theIEEE Global Telecommunications Conference(GLOBECOM), N.Y., Nov. 29, 1993, pp. 1955-1959, XP000436148.
Broadcom Corporation
Phu Phuong
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