Improved Robust Multiuser Detection in Non-Gaussian Channels Using a New M-Estimator and Spatiotemporal Chaotic Spreading Sequences

Abstract

Robust multiuser detection is known in the literature for suppression of multi access interference (MAI) and impulse noise in CDMA communications. However, the performance of the robust multiuser detector depends on the selection of M-estimator and the spreading sequence. Thus, the detector proposed in (Wang and Poor, 1999) with Huber estimator and PN sequence such as gold sequence spreading may not yield optimal performance for highly impulsive noise. This paper proposes a new M-estimator based robust multiuser detector using spatiotemporal chaotic spreading sequences. It is shown that the autocorrelation of the spatiotemporal chaotic sequence results in performance improvement with respect to gold sequences and the improvement is an extremely good approximation of optimum performance achievable. Simulation results demonstrate that the detector using spatiotemporal chaotic spreading offers significant performance gain as compared to detectors with gold sequences as spreading sequences