Robust multiuser detection in frequency-selective non-Gaussian channels

This paper addresses the problem of multiuser detection in multipath fading code division multiple-access channels with non-Gaussian noise. A robust multipath decorrelator with equal-gain combining for differential coherent detection of differential phase-shift keying signals is proposed to mitigate multiple-access interference and multipath interference, and to ameliorate non-Gaussian ambient noise. The asymptotic (i.e., large processing gain) performance of the proposed multiuser detector is derived and compared with that of the linear multipath decorrelator for differential coherent detection. Computer simulations are carried out to corroborate the asymptotic results. These results show that, in highly impulsive noise and under slow fading conditions, the robust multipath decorrelator assures substantial performance improvement over the linear multipath decorrelator for a wide range of values of signal-to-noise ratio, with little attendant increase in the algorithmic complexity.