Robust multiple-model channel tracking and MMSE-DFE multiuser detection in DS-CDMA fading mobile channels with impulsive noise

Abstract

In this paper, we present a new robust receiver for direct-sequence code division multiple-access (DS-CDMA) communication systems with time-varying non-Gaussian channels. Our receiver is developed based on a robust multiple-model channel tracker together with a robust minimum mean-square error (MMSE) decision feedback equalizer (DFE). The robustness is achieved thanks to the incorporation of nonlinear limiters with properly selected thresholds. We formalize a jump Markov linear-trend framework to cover the overall possible channel dynamics. With this setup, we derive a LT models-based channel tracker. Subsequently, the predicted channel and one-step delayed decisions are utilized to yield a robust MMSE-DFE. Simulations show that the performance of a DS-CDMA system with additive non-Gaussian noise is improved significantly by the proposed receiver