A robust technique for multiuser detection in non Gaussian channels

In many physical channels where multiuser detection techniques are to be applied, the ambient channel noise is known through experimental measurements to be decidedly non-Gaussian, due largely to impulsive phenomenon. This is due to impulsive nature of man-made electromagnetic interference and a great deal of natural noise. This paper presents a robust multiuser detector for combating multiple access interference and impulsive noise in CDMA communication systems. This detector is essentially a robust version of the linear decorrelating multiuser detector. The robustification is based on the Hampel´s M-estimator found in robust statistics. The approach is corroborated with simulation results. Simulation results show that the proposed approach yields significant performance gain over the linear decorrelating multiuser detector with little attendant increase in the computational complexity. Further, it offers better gain over the Huber´s M-estimator.