An efficient CDMA decoder for correlated information sources

TL;DR

This paper introduces a message-passing based CDMA detection scheme that directly detects correlated sources without source coding, significantly improving bit-error-rate performance under various practical conditions.

Contribution

The paper presents a novel direct detection method for correlated sources in CDMA systems using message passing, eliminating the need for source coding.

Findings

Substantial bit-error-rate improvement over unmodified detectors

Robustness under model mismatches and finite-length codes

Effective detection of correlated sources without source compression

Abstract

We consider the detection of correlated information sources in the ubiquitous Code-Division Multiple-Access (CDMA) scheme. We propose a message-passing based scheme for detecting correlated sources directly, with no need for source coding. The detection is done simultaneously over a block of transmitted binary symbols (word). Simulation results are provided demonstrating a substantial improvement in bit-error-rate in comparison with the unmodified detector and the alternative of source compression. The robustness of the error-performance improvement is shown under practical model settings, including wrong estimation of the generating Markov transition matrix and finite-length spreading codes.