Asynchronous CDMA decorrelating detector

Multiplex communications – Communication techniques for information carried in plural... – Combining or distributing information via code word channels

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

H04J 1300

Patent

active

059178299

ABSTRACT:
Method and apparatus for optimally decoding messages from CDMA signal sent by a plurality of users and received asynchronously at one receiver, using a minimal number of computations and minimal memory and processing resources. It is based on a novel approach to signal correlation, as well as to subsequent decoding by decorrelation, that requires a correlation period of only one symbol length, by providing for each user a pair of partial signatures sequences, with which the signal is correlated, deccorelating the results with the inverse of the cross-correlation matrix of all partial sequences, and combining the resultant partial symbol estimates--to obtain final estimated symbol values. The partial sequences are formed by separating each original sequence at a point corresponding to the estimated symbol boundary time, relative to an arbitrary correlation window, of one symbol length. The method can be modified to also apply to the case that any of the signals is received over multiple paths, any path possibly undergoing Doppler shift.

REFERENCES:
patent: 4475186 (1984-10-01), Gutleber
patent: 4845726 (1989-07-01), Kurihara et al.
patent: 4908836 (1990-03-01), Rushforth et al.
patent: 5442627 (1995-08-01), Viterbi et al.
patent: 5477195 (1995-12-01), Spilker
patent: 5506861 (1996-04-01), Bottomley
patent: 5533047 (1996-07-01), Mourot et al.
patent: 5544155 (1996-08-01), Lucas et al.
patent: 5553062 (1996-09-01), Schilling et al.
patent: 5615209 (1997-03-01), Bottomley
patent: 5638376 (1997-06-01), Miki et al.
patent: 5671221 (1997-09-01), Yang
patent: 5671248 (1997-09-01), Chau et al.
Verdu, S., "Adaptive Multiuser Detection", Third Int'l. Symposium on Spread Spectrum Techniques and Applications, IEEE ISSSTA, N.Y. 1994, vol. 1, pp. 43-50.
De Gaudenzi et al, "Advances in Satellite CDMA Transmission for Mobile and Personal Communications", Proc. Of IEEE, 84(1): 18-39, 1996.
Moshavi, S., "Multi-User Detection for DS-CDMA Communications", IEEE Communications Magazine, pp. 124-136, Oct. 1996.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Asynchronous CDMA decorrelating detector does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Asynchronous CDMA decorrelating detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Asynchronous CDMA decorrelating detector will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1382668

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.