Pulse or digital communications – Receivers – Particular pulse demodulator or detector
Patent
1997-07-28
2000-10-24
Le, Amanda T.
Pulse or digital communications
Receivers
Particular pulse demodulator or detector
375349, H04L 2508
Patent
active
061378437
ABSTRACT:
A multi-signal cancelling demodulator in which signals of interest are demodulated using information obtained during demodulation of adjacent signals. By utilizing detected information in an across-channel fashion, exemplary cancelling demodulators provide superior adjacent channel interference rejection. The cancelling demodulation is conducted in either serial or parallel fashion. In exemplary parallel demodulation embodiments, two channels are demodulated simultaneously in iterative fashion. Detected information obtained at each step in the iterative process is used as a priori information for demodulation in a following step. In exemplary serial demodulation embodiments, the stronger of two received signals is demodulated, and the resulting detected information is used as a priori information for demodulation of the weaker of the two received signals. For both the serial and parallel demodulation embodiments, novel techniques are disclosed for transforming symbols detected in one frequency band to corresponding symbols in adjacent frequency bands. Such inter-channel transformations are also applied in the context of channel estimation. In an exemplary channel estimator, multiple channel parameter estimates for a particular frequency channel are provided based on a received baseband signal corresponding to that frequency channel. Since inter-channel information is used in providing the channel parameter estimates, the exemplary channel estimator provides superior adjacent channel interference rejection.
REFERENCES:
patent: 5202903 (1993-04-01), Okanoue
patent: 5390215 (1995-02-01), Antia et al.
patent: 5566209 (1996-10-01), Forssen et al.
patent: 5615409 (1997-03-01), Forssen et al.
patent: 5896424 (1999-04-01), Uchida et al.
patent: 5937015 (1999-08-01), Dent et al.
Internatrional Search Report completed Oct. 7, 1998.
S.S.H. Wijayasuriya et al., "A Near-Far Resistant Sliding Window Decorrelating Algorithm for Multi-User Detectors in DS-CDMA Systems," IEEE 1992, pp. 1331-1338.
S.S.H. Wijayasuriya et al., "Rake Decorrelating Receiver for DS-CDMA Mobile Radio Networks," pertinent pages.
S.S.H. Wijayasuriya et al., Rake Decorrelation as an Alternative to Rapid Power Control in DS-CDMA Mobile Radio, IEEE, 1993, pp. 368-370.
A. Xie et al., "A Family of Suboptimum Detectors for Coherent Multiuser Communications," IEEE Journal on Selected Areas in Communications, vol. 8, No. 4, May 1990, pp. 683-690.
J. Thielecke et al., "Interference Reduction Applied to Channel Estimation in CDMA Systems, " IEEE, 1994, pp. 752-756.
R.S. Mowbray et al., "New Antimultipath Technique for Spread Spectrum Receivers," Electronic Letters, vol. 28, No. 5, Mar. 4, 1993, pp. 456-458.
G. Ungerboeck, "Adaptive Maximum-Likelihood Receiver for Carrier-Modulated Data-Transmission Systems," IEEE Transactions on Communications, vol. COM-22, No. 5, May 1974, pp. 624-636.
Z. Zvonar et al., "Coherent and Differentially Coherent Multiuser Detectors for Asynchronous CDMA Frequency-Selective Channels," IEEE, 1992, pp. 442-446.
S. Verdu, "Minimum Probability of Error for Asynchronous Gaussian Multiple-Access Channels," IEEE Transactions on Information Theory vol. IT-32, No. 1, Jan. 1986, pp. 85-96.
R. Lupas, "Linear Multiuser Detectors for Synchronous Code-Division Multiple-Access Channels," IEE Transactions on Information Theory, vol. 1, No. 1, Jan. 1986, pp. 123-136.
R. Lupas et al., "Near-Far Resistance of Multiuser Detectors in Asychronous Channels," IEEE Transactions on Communications, vol. 38, No.4, Apr. 1990, pp. 496-508.
Z. Zvonar et al., "Suboptimum Multiuser Detector for Synchronous CDMA Frequency-Selective Rayleigh Fading Channels," CTMC, 1992, pertinent pages.
Z. Zvonar et al., "Optimum Detection in Asynchronous Multiple-Access Multipath Rayleigh Fading Channels," 26th Annual Conference on Info-Sciences Systems, 1992, pertinent pages.
Z. Xie et al., "Joint Signal Detection and Parameter Estimation in Multiuser Communications," IEEE Transactions on Communications, vol. 41, No. 7, Aug. 1993, pp. 1208-1216.
Y.C. Moon et al., "A Spread-Spectrum Multiaccess System with Cochannel Interference Cancellation for Multipath Fading Channels," IEEE Journal on Selected Areas in Communications, vol. 11, No. 7, Sep. 1993, pp. 1067-1075.
Y.C. Moon et al., "A Spread-Spectrum Multiaccess System with Cochannel Interference Cancellation for Multipath Fading Channels," IEEE Journal on Selected Areas in Communications, vol. 11, No. 7, Sep. 1993, pp. 1067-1075.
A. Kajiwara, "On Synchronous CDMA For Mobile Communications," IEEE, 1992, pp. 858-862.
Z. Zvonar et al., "Adaptive Multiuser Receiver for Fading CDMA Channels with Severe ISI," Proceedings of Conference on Information Sciences and Systems, Mar. 1993, pertinent pages.
Z. Zvonar et al., "A Comparison of Differentially Coherent and Coherent Multiuser Detection with Imperfect Phase Estimates in a Rayleigh Fading Channel," p. 48.
Z. Zvonar et al., "On Multiuser Detection in Asynchronous CDMA Flat Rayleigh Fading Channels," PIMRC, 1992, pertinent pages.
Z. Zvonar et al., "Optimum Multiuser Detection in Single-Path Rayleigh Fading Channels," 29.sup.th Allerton Conference on Communication, Control and Computing, Oct. 1991, pertinent pages.
S. Sampei et al., "Rejection Method of Adjacent Channel Interference for Digital Land Mobile Communications," The Transactions of the IECE of Japan, vol. E69, No. 5, May 1986, pp. 578-580.
P. Dent, et al., CDMA-IC: A Novel Code Division Multiple Access Scheme Based on Interference Cancellation, PIMRC, Boston, pertinent pages, 1992.
P. Patel et al., "Anaylsis of a Simple Successive Interference Cancellation Scheme in a DS/CDMA System," IEEE Journal on Selected Areas in Communications, vol. 12, No. 5, pp. 796-807, Jun. 1994.
R. Kohno et al., "An Adaptive Canceller of Cochannel Interference for Spread-Spectrum Multiple-Access Communication Networks in a Power Line," IEEE Journal on Selected Areas in Communications, vol. 8, No. 4, pp. 691-699, May 1990.
R. Kohno et al., "Combination of an Adative Array Antenna and a Canceller of Interference for Direct-Sequence Spread-Spectrum Multiple-Access System," IEEE Journal on Selected Areas in Communications, vol. 8, No. 4, pp. 675-682, May 1990.
A.J. Viterbi, "Very Low Rate Convolutional Codes for Maximum Theoretical Performance of Spread-Sprectrum Multiple Access Channels", IEEE Journal on Selected Areas in Communications, vol. 8, No. 4, pp. 641-649, May 1990.
K. Giridhar et al., "Joint Estimation Algorithms for CoChannel Signal Demodulation", Proceedings of the International Conference on Communications (ICC), Geneva, May 23-26, 1993, vol. 3 of 3, IEEE, pp. 1497-1501.
B. R. Petersen et al., "Suppression of Adjacent-Channel, CoChannel, and Intersymbol Interference by Equalizers and Linear Combiners", IEEE Transactions on Communications, vol. 42, No. 12, Dec. 1994, pp. 3109-3118.
Bottomley Gregory E.
Chennakeshu Sandeep
Dent Paul W.
Ramesh Rajaram
Ericsson Inc.
Le Amanda T.
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