Design And Implementation Of OFDM Underwater Acoustic Communication Module Based On DSP

The demand of underwater acoustic communication is increasing gradually both inmilitary and civilian areas. But, due to the particularity of underwater acoustic channel, thedevelopment of it is still at the primary stage. Looking for a kind of communication systemthat adapts to the characteristics of underwater acoustic channel has still been the hotspotproblem in research of underwater acoustic communication. Orthogonal frequency divisionmultiplexing technology (OFDM) has the advantages of high transmission rate, highfrequency spectrum utilization efficiency, resistance to multiplicity of extended andconvenient implementation using DSP. And, it is widely concerned in the application ofunderwater acoustic communication.An OFDM underwater acoustic communication module based on DSP is designed inthe paper after learning professional knowledge of OFDM communication technology andthe underwater acoustic channel. The hardware platform of the communication module ismade up of digital signal processing chip, audio signal processing chip, logic control chip,and peripheral circuit including power circuit, clock circuit, reset circuit, JTAG interface andexternal storage circuit. The paper introduces each part of the hardware circuit and softwareprogramming in details. The software of the communication module includes three parts oftransmitting module program, receiving module program and logic control program.Transmitting module is used for speech acquisition, compression, modulation, and sendingmodulated signal. Receiving module is used for signal detection, demodulation, speechdecompression and restoring the original speech. Finally, it is verified that the communicationmodule can realize stable and reliable communication though the joint debugging experiment.