DEVELOPMENT OF UNIVERSAL SOFTWARE RADIO PERIPHERAL AMPLIFIER FOR UNDERWATER ACOUSTIC PLATFORM USING SOFTWARE DEFINED RADIO Improved acoustic platform would allow more efficient transmission of information between Underwater Acoustic (UWA) equipment such as autonomous vehicles, piloted vehicles, and underwater profilers. A flexible and configurable UWA modem is required for easy modification in order to be employed for different UWA equipment. In this paper, we proposed an underwater acoustic platform using software defined radio (SDR) platform called GNU radio and universal software defined radio peripheral (USRP). The UWA modem design includes an amplifier that is designed for the USRP. The experiments shown that using the USRP amplifier the bit rate of the transmission is improved and a significant increment of the number of packet received.