Blind adaptive interference suppression in DS-CDMA communications with impulsive noise

In many wireless systems where multiuser detection techniques may be applied, the ambient channel noise is known through experimental measurements to be decidedly non-Gaussian, due largely to impulsive phenomena. The performance of many multiuser detectors can degrade substantially in the presence of such impulsive ambient noise. In this paper, a blind adaptive robust multiuser detection technique is developed for combating both multiple-access interference and impulsive noise in CDMA communication systems. This technique is nonlinear in nature and it is based on the signal subspace tracking method and the M-estimation method for robust regression. It is seen that the proposed technique offers significant performance gain over linear adaptive multiuser detectors in impulsive noise, with little attendant increase in computational complexity.