Information theoretic aspects of coded random direct-sequence spread-spectrum

Sergio Verdu, Shloma Shamai

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


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 languageAmerican English
Title of host publicationProceedings of the Mediterranean Electrotechnical Conference - MELECON
Editors Anon
Number of pages5
StatePublished - Dec 1 1998
EventProceedings of the 1998 9th Mediterranean Electrotechnical Conference, MELECON. Part 2 (of 2) - Tel-Aviv, Israel
Duration: May 18 1998May 20 1998


OtherProceedings of the 1998 9th Mediterranean Electrotechnical Conference, MELECON. Part 2 (of 2)
CityTel-Aviv, Israel

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this