Research And Realization Of Underwater Communication Key Technologies Based On Band-pass Sampling

Because of the shortage of land resources,more and more people have turned their attention and focus to the oceans that include rich resources.However,marine resources exploitation,marine hydrological information collection,marine communication network deployment and other activities need basic technical support.Therefore,underwater communication as the bridge of the marine exploration activities is even more important.Due to the greater complexity of underwater acoustic channels over radio channels,many communication technologies in the land can not be directly applied to underwater communication.In this background,this paper try to study underwater communication key technologies and design the software radio transceiver system,specifically to do the following work:Firstly,this paper based on software and radio technology designs the overall structure of underwater acoustic transceiver,and briefly explains its working principle and hardware composition according to software radio concept.In this process,this paper has researched the characteristics of close underwater acoustic channel and the key technologies of transceiver deeply,such as the modulation and demodulation,channel coding,carrier synchronization,timing synchronization and so on.And the principle and implementation method of the key technologies algorithm of transceiver are also described.Secondly,aiming at the problem that the initial phase of the phase-locked loop in the band-pass sampling environment will cause a large amount of symbol cost,this paper propose a band-pass sampling fast-acquisition carrier tracking ring algorithm,improvements have been made to traditional phase-locked loop,the loop is based on the sample rate processing module and the phase is tracked at a higher data rate.Experiments according to the new algorithm theory show that the new algorithm can reduce the symbol overhead in the initial acquisition phase.Then,according to the overall design way of underwater acoustic transceiver under software radio architecture,the algorithms are integrated and simulated in the Matlab environment,and the performance and applicability of the algorithm are verified and analyzed by simulation results.The complete design of the transceiver system has a useful reference.Finally,relying on the existing experimental conditions,the hardware experiment platform is built,and the software of the simulation is transplanted into the hardware platform with DSP as the core and the transceiver is tested and verified on the experimental platform to complete the principle communication experiment.The experimental results show that the parameters of the system are set up reasonably,the applicability of the key algorithm is good,the transceiver operation is stable and normal and it can achieve the expected function.