Adaptive Spread-Spectrum based RAKE Receiver for Shallow-Water Acoustic Channels

The focus of this paper is concentrated on the design of an adaptive RAKE receiver design for spread-spectrum based communications in shallow water acoustic channels. The objective is to exploit the multipath profile and to combine, rather than cancel, the energy arriving at the receiver via bottom and surface reflections. The optimisation of the receiver parameters such as filter weights and phase is achieved by employing the minimum mean-square error (MMSE) criterion. Results indicate that the suggested receiver algorithm can dramatically reduce the number of receive elements required without any significant performance degradation compared to multichannel combining methods.