针对水声通信系统信道多径干扰带来的码间串扰问题，本文从均衡技术的原理出发，以单载波水声扩频通信系统为载体，分析通过选取恰当的均衡器抑制单载波水声信道的频率选择性衰落，从而提升通信接收质量。运用Matlab仿真比较频域均衡中BPSK，QPSK两种方式下的调制信号，并对线性均衡的ZF均衡（迫零均衡）与MMSE均衡（最小均方误差均衡）星座图进行了比较。结果表明：2种调制方式下，ZF与MMSE均衡都能降低系统输出信噪比，但MMSE均衡较ZF均衡的效果更好。最后，通过水池实验验证算法的可行性。得出结论：系统的通信速率与通信带宽正相关，但通信的正确率会因信道多径干扰而降低；合适的均衡技术可以产生与信道相反的特性来修正误差、消除码间串扰，最终获取正确的判决结果。
Aiming at the problem of inter-symbol crosstalk caused by multi-path interference in the underwater acoustic communication system, this paper starts from the theoretical basis of equalization technology, takes the single-carrier underwater acoustic spread spectrum communication system as the carrier, and analyzes how to suppress the frequency selective fading of the underwater acoustic channel and improve the communication reception quality by selecting an appropriate equalizer. The research uses Matlab simulation to compare the modulated signals of BPSK and QPSK in the frequency domain equalization, and compares the constellation diagrams of ZF equalization and MMSE equalization. The results show that both ZF and MMSE equalization can reduce the system output signal-to-noise ratio under the two modulation methods, but MMSE equalization is better than ZF equalization. Finally, the feasibility of the algorithm is verified by the pool experiment, and it is concluded that the communication rate of the system is positively related to the communication bandwidth, but the correct rate of communication will be reduced due to channel multipath interference; appropriate equalization technology can produce the opposite characteristics of the channel. To correct errors, eliminate inter-symbol crosstalk, and finally obtain correct judgment results.
2022,44(21): 124-128 收稿日期：2022-08-15
DOI：10.3404/j.issn.1672-7649.2022.21.025
分类号：TN929
作者简介：吴亮(1980-),男,工程师,从事舰船监造和电子设备检验验收工作
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