Underwater acoustic noise with generalized Gaussian statistics: Effects on error performance

Abstract

Noise in an underwater acoustic (UWA) channel does not necessarily follow Gaussian statistics, especially in a shallow water environment which is dominated by impulsive noise sources. However most of the receivers are designed with the assumption that the channel noise is additive white Gaussian (AWGN). Such receivers may not be the optimum ones to deal with the non-Gaussian UWA noise. Several non-Gaussian statistics have been proposed in previous literature to model UWA noise among which the Generalized Gaussian (GG) model has been very popular due to its flexible parametric form. However, to the best of our knowledge, no analytical error analysis with the assumption of channel noise being generalized Gaussian has yet been reported. In this paper, we derive the analytical expression for probability of error considering the presence of GG noise in the UWA channel. We also try to study the performance of an AWGN receiver in the presence of non-Gaussian noise. We consider three different communication systems using BPSK, QPSK and M-ary PAM constellations, and observe, for all three of them, that if noise kurtosis is greater than the Gaussian kurtosis, the system performance degrades. Thus here is an initial phase of designing UWA system with GG noise assumptions instead of the traditional Gaussian receiver. It is still a matter of argument, due to all possible redesign complexities, whether it is worth taking all the redesign complexities or the performance degradation can be tolerated as per the requirements of system application.