Cancellation of dolphin sonar click in communication signal

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In long-range underwater communication, the conventional passive Time Reversal Processing (TRP) is widely used to mitigate the distortion due to the multipaths and temporal spreading. However, the signals produced by marine animals were present in the data acquired during the experiment, contaminating the communication signal and acted as an unwanted signal. In particular, because the impulsive signal such as a dolphin sonar click has a wide bandwidth and a short pulse duration, it is difficult to separate the communication signal from the impulsive signal. This overlapping problem affects critically the communication performance. In this study, we propose a method to successfully cancel click sound. The method involves combining the adaptive TRP and the estimation of Green’s function of click sound. The adaptive TRP was successfully used in canceling crosstalk between interferers in a multiuser environment. Also, the estimation of Green’s function utilized the characteristics of the impulsive signal with clear distinction between paths. The effect of spatially nulling click sounds without distorting the phase of the communication signal showed a remarkable improvement in communication performance in the seagoing experimental data of BLAC18.