Optimal multi-channel equalizer design for underwater acoustic communications

Adaptive equalization is a widely used method of mitigating the effects of multipath propagation and Doppler spreading in underwater acoustic communication channels. This paper examines some specifics associated with the design of a multi-channel equalizer for time-varying underwater acoustic channels. More specifically, we study how the number of sensors and separation between them impact the equalization performance of a sparse time-varying channel. We develop a theoretical model and, to illustrate the ideas, find the optimal equalizer for a particular arrival model. Finally, we show how the BER performance depends on sensor separation via processing experimental data.