Performance analysis of the single input multiple output acoustic system for high frequency shallow water communications

Abstract

A Single Input Multiple Output (SIMO) acoustic communication system has been developed to improve high data rate communications at short range in the shallow water acoustic channel. The proposed communication system operates at very high frequency and combines an adaptive spatial diversity and parallel Decision Feedback Equalizer (DFE). Experimental results using selective combining with three, four and five receivers demonstrate ability to improve the quality of the acoustic channel in terms of Bit Error Rate (BER) and Signal-to-Noise-and-Interference Ratio (SNIR). The work presented in this article focuses on statistical evaluation of the proposed SIMO system using simulated data. For that purpose, a simulation channel model is developed based on experimental channel model and Rician fading channel. Adaptive multilevel combining is performed on simulated messages with high individual BER before SIMO processing. The simulation results achieved with selective diversity and SIMO system with three, four and five receivers show that the BER and SNIR of the combined message improve dramatically, compared to the BER and SNIR of the individual message and demonstrate that the proposed SIMO system can significantly improve the reliability of the shallow water acoustic channel.