The Research And Implementation Of The Underwater Acoustic MQAM Technology

Because of the development and utilization of the marine resources, the demand of the high speed underwater communication technology is needed. In recent years the underwater sounder carrier communication is developing towards the direction of the high rate. Under this background this article mainly aims at the close of underwater acoustic communication system, we carry on the thorough research of the multi-band orthogonal amplitude modulation technology. The following work:First of all, in this paper, according to the characteristics of the close underwa ter acoustic channel, we analyzed the key technical problem of MQAM of the underwater acoustic communication system.The second, we simulate the underwater acoustic communication system based on the 4-QAM and 16-QAM modulation in the MATLAB environment. According to the common underwater acoustic channel model, we simulate the implements of the modulation signal, the transmission of underwater acoustic channel, time synchronization, the load-balancing algorithm. And this shows that the underwater acoustic communication system can use the MQAM modulation technology.Once again, we studied the hardware and software platform of the MQAM modulation of the underwater acoustic communication. According to the requirements of high speed underwater acoustic communication, we choose the TMS320VC5509 A digital processing chip of TI company as the core of hardware platform. The software development platform is an integrated development environment CCS3.3. Then we do the overall experiment of the underwater acoustic communication system in the DSP environment. And we also do the underwater experiment in the laboratory based on. the 4-QAM and 16-QAM modulation. This prove the feasibility of the system.At last, In underwater acoustic communication system based on 64-QAM modulation, we also simulate the constellation of 64-QAM, the underwater channel, the maximum average power timing synchronization algorithm, the balancing algorithm in the MATLAB environment.