Digital DS-CDMA detection in impulsive noise: base band vs. band-pass nonlinear processing

Abstract

In the context of DS-CDMA detection, a digital base-band model for the received signal after chip-matched filtering, is often adopted. Nonlinear treatment of these samples for robust detection in impulsive environments has been already proposed. In this paper we study the advantages of band-pass nonlinear detection schemes for DS-CDMA receivers, over those in base-band. We consider for both schemes i) an impulsive noise model with independent α-stable distributed sequences and ii) a hard-limiter as memoryless nonlinearity. Probability of error and asymptotic relative efficiency expressions are given, with simulations that validate them. Results shown that band-pass nonlinear detection is preferable.