Bandwidth efficient modulation for underwater acoustic data-communication

Research in the design of combining coding with bandwidth efficient modulation known as coded modulation has shown that high data rate reliable transmission over a variety of channels is achievable. The application of these coding techniques to the bandlimited underwater vertical channel is examined. A prototype acoustical modem is being developed with emphasis on high data rate, high performance at low power, and low complexity. A statistical model used to simulate the characteristic time and frequency spreading of this vertical underwater channel is presented