Nonlinear iterative multiuser detection and equalization for CDMA receivers in the presence of interchip interference

Abstract

This paper addresses the problem of (nonlinear) iterative multiuser detection (MUD) for synchronous CDMA. In the literature, there are several related methods for solving this problem. These methods involve a linear estimator combined with nonlinear detection of the transmitted symbols but generally do not apply per-symbol iteration. However, the convergence analysis of iterative schemes has not been addressed yet (to our knowledge). In this paper, we present a new algorithm for MUD and provide a convergence analysis for an approximation to it. We believe this approach yields an understanding not only of the behavior of our proposed scheme but also of other possible iterative algorithms for MUD.