Development Of Underwater Acoustic Communication Signal Processing System

With the development of human society,people demand more and more resources,land resources have not been enough for these kinds of demand.In this case,people realize that the oceans which account for more areas of the Earth may be new fields of resources.People should solve the problem of long-range underwater wireless communication as soon as possible.In recent years,people has found that only acoustic communication technology can work well in long-range underwater wireless communication.Underwater acoustic communication technology has developed a lot and been a hotspot during decades.The speed of the development of underwater acoustic communication is slower than that of electromagnetic wave communication.One of the main reasons is that underwater acoustic channel environment is more complex,it is more susceptible due to multipath interference.Modern underwater acoustic communication systems mainly consist of digital communication systems.More advanced coding methods,better channel estimation algorithms and equalization means greatly improve the reliability of underwater acoustic communication and increase its transmission distance.Common digital signal processing platform is unavailable for the performance requirements of digital coding,so it is necessary to develop underwater acoustic communication signal processing system with high-speed signal processing capability.In this paper,high-performance low-power digital signal processor OMAPL138 and EP3C120 are the main processors,they are used to design a high-speed underwater acoustic communication signal processing platform.The technical requirements of this design are introduced during this paper,meanwhile all the design procedure of hardware functional module and the selection of instruments are discussed in detail.The main functional modules of this platform include power supply module,digital signal processing module,6-channel high-precision A/D sampling module,CAN bus,micro-controller module,serial port network communication module and real-time clock module.This paper demenstrates the hardware circuit design process and method of each module in detail and summarizes the problems encountered during the design process and solutions.In order to verify the feasibility of the design,this paper introduces the signal integrity simulation of the key signal after PCB layout and wiring and the power integrity simulation to the whole board,these simulations proves that the design has reached technical requirements.The followed work are debug of various functional modules: DDR2 memory test,AD chip sampling test,SD card read and write test,NAND FALSH storage test,serial communication test and network communication test.After that,the research made in lake and sea shows that the signal processing platform can meet the design requirements and can be applied to the complex environment of underwater acoustic communication.Finally,the paper summarizes the main achievements and the shortcomings of this research,and make the following scheme in future.