A new M-estimator based robust multiuser detection in flat fading synchronous non-Gaussian channels

In many realistic wireless channels the ambient noise is known through experimental measurements to be decidedly non-Gaussian, due largely to impulsive phenomenon. Frequently, code-division multiple-access (CDMA) transmissions are made over fading channels. This paper deals with the problem of multiuser detection in direct-sequence CDMA fading channels with impulsive noise. A new M-estimator-based structure for noncoherent demodulation of differentially phase-shift keyed (DPSK) signals transmitted simultaneously via a synchronous CDMA flat-fading channel and embedded in impulsive noise, is proposed and analyzed. Simulation results show that, in highly impulsive noise, the performance gain afforded by the proposed multiuser detector can be substantial when compared to the linear decorrelating detector for DPSK, with little attendant increase in computational complexity.