时变强多途干扰影响水声通信系统性能，针对时变强多途干扰问题，提出基于差分编码的水声OFDM通信（Underwater acoustic OFDM communications based on differential coding, DC-OFDM）算法。利用循环前缀技术和OFDM通信技术固有的抗多途特性，有效消除时变多途干扰，避免信道估计环节，直接进行解码判决。南海实测信道仿真（信噪比为8dB时，DQPSK100组仿真试验，2×106个源码，全部正确解码）和水箱试验（信噪比为15dB时，DQPSK100组水箱试验，2×106个源码，在时变强多途干扰下全部正确解码）。结果表明，所提算法能有效解决时变强多途干扰问题，实现时变强多途水声信道下的可靠水声通信。
The performance of underwater acoustic communication system is affected by time-varying strong multi-path interference. Aiming at time-varying strong multi-path interference, an underwater acoustic OFDM communications algorithm based on differential coding is proposed. By using the inherent multi-path resistance of cyclic prefix technology and OFDM communication technology, time-varying multi-path interference can be effectively eliminated, channel estimation can be avoided, and decoding decision can be made directly. The results of south China sea channel simulations (the experiment conditions are: SNR is 8 dB, the number of simulation is 100, the number of the source codes is 2×106, all codes were decoded correctly) and water tank experiments (the experiment conditions are: SNR is 15 dB, the number of experiment is 100, the number of the source codes is 2×106, all codes were decoded correctly under the time-varying strong multi-path interference) are provided to demonstrate that the proposed algorithm can effectively solve the problem of time-varying strong multi-path interference, realize reliable underwater acoustic communication under time-varying strong multi-path channel.
2021,43(4): 159-162 收稿日期：2020-03-16
DOI：10.3404/j.issn.1672-7649.2021.04.032
分类号：TN929.3
基金项目：国家自然科学基金资助项目(61771271)；山东省高等学校科学技术计划项目(J18KA315)；青岛市应用基础研究计划项目青年专项(19-6-2-4-cg)
作者简介：邢延超(1973-),男,博士,副教授,研究方向为数字信号处理,水声通信技术。
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