相干水声通信幅相加权空间分集均衡算法

发布时间：2018-08-17 18:32

【摘要】：水声信道的典型特点为多普勒频移严重、可利用带宽窄以及强多径干扰。空间分集均衡技术是相干水声通信中克服信道多径干扰,消除码间干扰的一种有效手段。为了极大化地输出阵增益,结合无源相位共轭方法和多通道均衡算法,本文设计了组合信噪干比的全新信道评价方法。利用改进的Sigmoid函数对各通道接收信号的幅度进行加权处理;采用二阶锁相环跟踪各通道信号的相位变化,实现各通道信号同相累加。将各通道低通滤波后的信号能量归一化,采用了分数阶-判决反馈分集均衡器,加入各通道权重系数实现了水声通信系统的分集均衡接收。仿真结果和湖试数据处理结果均表明,优化的幅相加权分集均衡接收算法能抵消多径和噪声的干扰,性能优于等增益合并接收算法。湖试数据处理结果误码率降低了1.8%。
[Abstract]:The typical feature of underwater acoustic channel is that the Doppler frequency shift is serious, and the band width and strong multipath interference can be used. Spatial diversity equalization is an effective method to overcome channel multipath interference and inter-symbol interference in coherent underwater acoustic communication. In order to maximize the array gain, combined with the passive phase conjugation method and the multi-channel equalization algorithm, a new channel evaluation method of the combined signal-noise-to-noise ratio is designed in this paper. The amplitude of each channel received signal is weighted by the improved Sigmoid function, and the phase change of each channel signal is tracked by a second-order phase-locked loop to realize the in-phase accumulation of each channel signal. The signal energy of each channel is normalized, the fractional order decision feedback diversity equalizer is adopted, and the diversity equalization of underwater acoustic communication system is realized by adding the weight coefficients of each channel. Simulation results and lake test data processing results show that the optimized amplitude-phase weighted diversity equalization reception algorithm can counteract the multipath and noise interference and the performance is better than the equal-gain combined reception algorithm. The error rate of lake test data was reduced by 1.8%.
【作者单位】：中国科学院大学;中国科学院声学研究研究所;中国科学院声学研究所东海研究站;
【基金】：国家自然科学基金项目(6153000187)资助
【分类号】：TN929.3

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