Under Water Acoustic Modem Design

Abstract

We present a reconfigurable modem for underwater acoustic communication, using BPSK modulation with coherent detection. The modem is capable of throughput up to 16 kbps in the 1- 2 MHz band, while being a flexible platform for deployment in a variety of scenarios, with realtime parameters to optimize communication with respect to channel conditions. In order to maximize the flexibility the system was implemented on an FPGA, so that the implementation can be changed during operation. The transmitter was designed mainly for compactness, using a digital direct synthesizer and IP CORE generator technique to generate the output signal. Phase synchronization technique is adopted for the recovery of transmitted data at the receiver section