Design And Implementation Of An Underwater Acoustic Communication Experiment Platform

With the improvement of utilizing and developing of the resource of the sea,people's demand for underwater communication is growing.Underwater acoustic has been developed rapidly in recent years for its technical characteristics and unique advantages.However,the underwater acoustic channel is a so complex application environment with serious degeneration and frequency selective fading that many mature communication technologies in the land cannot apply very well in the underwater environment.Nowadays most of the underwater acoustic communication systems adopt digital communication,combined with the efficient modem technologies,complex channel estimation and equalization advanced coding and so on to realize a high-speed,stable and reliable underwater acoustic digital communication system.The OFDM/OQAM technique is applied to underwater acoustic communication system for its characteristics,such as high spectrum and power efficiency,resistance of intersymbol interference together with intercarrier interference,very low out-of-band radiation,and simple implementation of its system and so on.In order to speed up the development progress of underwater acoustic communication system based on OFDM/OQAM and apply it in the actual underwater acoustic environment as soon as possible,this dissertation designs an experimental platform of underwater acoustic communication combined with OFDM/OQAM technique.The experiment platform has the following characteristics:First,it adopts Field Programmable Gate Array(FPGA)as the main control unit,which has the ability to control peripheral circuits flexibly and process data highly and parallel;Second,considering underwater acoustic communication system will be toward the direction of mass quantity data in the future,so it uses Universal Serial Bus(USB)as data transmission channel;Third,it completes data processing and controlling combined with application on the PC,so it makes the experimental platform has flexible control capability and good man-machine interactive.This dissertation firstly introduces the principle of OFDM/OQAM technique and fast implementation methods,and analyzes the advantages of OFDM/OQAM technique to be applied to underwater acoustic environment.Secondly,we design and implement underwater acoustic communication experiment platform based on FPGA and application through the analysis of system requirements,introduce the design method of each module of the experimental platform and give the circuit principle diagram,which includes master control module,digital-to-analog conversion module,analog-to-digital conversion module,low pass filter module,memory module,communication interface module,power supply module.Thirdly,we complete the software design including the design of the FPGA control logic,the USB firmware program and the application according to the system parameter.Finally,we test the design of the system hardware and software,including the functional testing of firmware program,application and each module of experimental platform,and the results are given and analyzed.