Study of de-noising techniques for SNR improvement for underwater acoustic communication

Abstract

A wide variety of underwater applications, such as warning systems and deep water positioning systems used to track autonomous underwater vehicles etc, warrant underwater wireless communication in both shallow and deep water. These systems do, in the main, use underwater wireless acoustic communication modems and hence they play a vital role in underwater networking systems. However, the acoustic signals, particularly in shallow water suffer severe disturbances due to ambient noise from the sea. The ambient noise underwater is very unique, location specific and deterministic. This paper aims at developing a de-noising algorithm to improve the Signal to Noise Ratio (SNR) using the Gabor Wavelet and compares this with another important Shannon wavelet by way of study. The simulation was carried out using the MATLAB Simulink tool. The ambient noise used for the validation is sea truth data collected in the Bay of Bengal using broad band hydrophones. The results obtained were very encouraging as, in the range of input SNR-15 dB to 0 dB, the improved output SNR was in the order of 8 dB. This shows the efficiency of the algorithm simulated.