The low power DSP platform design of underwater acoustic communication system

The underwater acoustic communication system has a number of restrictions to DSP core because of the bad underwater environment. In view of this situation, we have designed a DSP platform with high performance, small scale, low power consumption and high reliability. This platform has only one processer, and a high speed and volume, low power SDRAM is integrated to improve the computation ability. Due to the powerful MCBSP interface and the Ping-Pong buffer transfer of EDMA3, the DSP platform can handle a large amount of high-speed serial data stream without frequently occupying CPU. This guarantees the CPU to focus on data processing. There are two modulation types available in this platform, i.e., MFSK and QPSK modulation. The two modulation types are selectable based on the status of underwater acoustic channel and can work on a half-duplex mode. The software upgrade of the platform is very convenient, since the UART is both used to communicate with the user or other device and update the program file in the SD card. A series of experiments indoor and in the sink have been conducted to test the key performance indictor of this platform. The MFSK data rate is 300bps and the QPSK data rate is 4.2kbps. The maximum total power consumption of the platform is only 775mW and the platform size is only 50 60mm.