浅海水声信道中重复累积码性能研究

针对浅海水声信道的强多途、长时延、严重衰落等特点，需采用性能好、能够实现线性编译码便于实时处理的信道纠错码技术以提高水声通信系统可靠性的问题，提出重复累积(Repeat-Accumulate针对浅海水声信道的强多途、长时延、严重衰落等特点，需采用性能好、能够实现线性编译码便于实时处理的信道纠错码技术以提高水声通信系统可靠性的问题，提出重复累积(Repeat-AccumulateRA)码作为浅海水声信道的纠错码方案。建立RA码在浅海水声信道中的仿真模型，比较其在不同浅海水声信道模型下的性能，通过水池数据传输实验研究编译码参数对RA码性能的影响，并以水下图像传输实验进一步验证该编码方案。仿真和实验结果表明：RA码在浅海水声通信系统中具有较强的纠错能力，选择合适的参数会进一步提高编码增益。与Turbo码和LDPC码的编译码复杂度对比，RA码能够实现线性时间编译码，算法复杂度低，硬件实现简单，在水声通信中具有非常好的应用前景。

Performance Analysis of Repeat-Accumulate Codes over Shallow Water Acoustic Channels

Due to a large delay spread caused by multipath propagation and severe attenuation of the channel conditions,the Repeat-Accumulate(RA) code with short length codes,good performance and easy implementation has been proposed to enhance the reliability of the shallow water acoustic(SWA) communication system.A system model including RA coding over the SWA channels was established.As a comparison,the performance of RA codes under different ocean acoustic channel conditions was presented.The experiment in the pool was carried out to show how the encoding and decoding parameters affect the performance of RA codes,which was verified by the image transmission over channels in the pool tank.The simulation and experimental results show that RA codes have a strong error correction capability and the codes with appropriate parameters would further improve the coding gain,while they enjoy encoding and decoding in linear time and have simple hardware implementation,which have a good applied prospect in underwater acoustic communication system.