Capacity of CDMA with random spreading and multiuser detection

Sergio Verdu, Shlomo Shamai

Research output: Contribution to conferencePaperpeer-review

2 Scopus citations

Abstract

Information theoretic aspects of Code Division Multiple Access (CDMA) random direct-sequence spread-spectrum (DSSS) are investigated. The CDMA-DSSS channel with randomly and independently chosen spreading sequences accurately models the situation where pseudo-noise sequences span many symbol periods. Its information theoretic analysis provides a comparison baseline for CDMA channels with carefully designed signature waveforms that span one bit period on one hand and optimal multiple-user coded systems on the other. We analyze the spectral efficiency (total capacity per chip) as a function of the number of users, spreading gain and signal-to-noise ratio, and we quantify the loss in efficiency relative to an optimally chosen set of signature sequences and to an optimal multiaccess system without spreading. White Gaussian background noise and equal-power synchronous users are assumed. The analysis comprises the following receivers: a) optimal joint processing, b) single-user matched filtering; c) decorrelation and d) minimum mean square error linear processing. Some implications due to fading are also addressed.

Original languageEnglish (US)
Pages155-159
Number of pages5
StatePublished - Jan 1 1998
EventProceedings of the 1998 IEEE 5th International Symposium on Spread Spectrum Techniques & Applications, IEEE ISSSTA. Part 3 (of 3) - Sun City, S Afr
Duration: Sep 2 1998Sep 4 1998

Other

OtherProceedings of the 1998 IEEE 5th International Symposium on Spread Spectrum Techniques & Applications, IEEE ISSSTA. Part 3 (of 3)
CitySun City, S Afr
Period9/2/989/4/98

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Fingerprint Dive into the research topics of 'Capacity of CDMA with random spreading and multiuser detection'. Together they form a unique fingerprint.

Cite this