Adaptive minimum dispersion interference suppression for DS/CDMA systems in non-Gaussian impulsive channels

Minimum mean squared error(MMSE) receivers can suppress interference in DS/CDMA systems. The MMSE receivers are near-far resistant in the presence of additive Gaussian noise. But the noise in many communication channels is non-Gaussian and impulsive. Symmetric alpha-stable(SaS) probability density functions can accurately model large classes of impulsive noise. For a SaS process with 0 < alpha < 2, the MMSE performance criterion cannot be used since the noise process has infinite variance. This paper considers the problem of adaptive multiple-access interference(MAI) suppression in SaS non-Gaussian impulsive noise channels to combat the near-far problem. The receiver uses the minimum dispersion(MD) criterion to suppress interference. The receiver is implemented adaptively using least mean p-norm(LMP) algorithm. We investigate the performance of the MD receiver. The simulation results indicate that the proposed receiver is less sensitive to the near-far problem. The adaptive MD receiver shows good near-far resistance in non-Gaussian impulsive noise channels modeled as SaS processes.