Bionic Underwater Acoustic Communication by Mimicking Dolphin Whistle Based on Frequency Shift Keying

Abstract

To meet the demand of covert Underwater Acoustic Communication (UAC), a bionic UAC method by mimicking dolphin whistle based on Frequency Shift Keying (FSK) is proposed. The information modulated baseband signal is added to the selected spectrum contour of the dolphin whistle with a certain weight to obtain the synthetic contour. Then generate the synthetic whistle to transmit the information. The receiver extracts the received synthetic whistle, and coherently multiples it with the local whistle, whose contour has a fix frequency difference from the selected whistle contour. A low-pass filtering is adopted to obtain the FSK signal, which is used for demodulation. The bionic effect is analyzed through Time-Frequency Correlation Coefficient (TFCC) and Mel frequency cepstrum Distance (MelD). Simulation and sea trial verified its feasibility. A reliable communication can be achieved at 2km when the symbol width is 0.1s and the TFCC is over 0.99. The low complexity makes the proposed bionic UAC method more suitable for implement, which provides technical support for the practical application of bionic UAC.