Design and DSP implementation of signal processing module for underwater acoustic transponder

Abstract Due to the fact that sound waves are the most effective carrier for underwater information transmission, the detection of underwater acoustic signals has become a key link in optimizing the performance of transponders in underwater positioning systems. In this paper, the signal processing module of the hydroacoustic transponder is designed to address the problem of low detection accuracy of the transponder due to the propagation deformation of hydroacoustic signals in hydroacoustic channels. The module uses the TMS320C6748 processor to achieve the transmission, acquisition, and detection of hydroacoustic spread spectrum signals. Among them, the signal detection algorithm in this module integrates an orthogonal demodulation algorithm, carrier synchronization algorithm, and matched filtering algorithm. It has been verified through simulation that it can enhance the anti-interference performance of the module, and the module also adopts a ping-pong caching mechanism to achieve real-time signal processing. Finally, pool testing has shown that this module can effectively assist the responder in completing the response task.