Spatial diversity and combination technology using amplitude and phase weighting method for phase-coherent underwater acoustic communications

作     者：LI Jilong HUANG Minyan CHENG Shuping TAN Qianlin FENG Haihong 

作者机构：University of Chinese Academy of Sciences Beijing 100049 Institute of Acoustics Chinese Academy of Sciences Beijing 100190 ShangHai Acoustics Laboratory Chinese Academy of Sciences Shanghai 200032 

出 版 物：《Chinese Journal of Acoustics》 (声学学报（英文版）)

年 卷 期：2018年第37卷第1期

页      面：45-59页

核心收录：

学科分类：07[理学] 

基　　金：supported by National Natural Science Foundation of China(61531018) 

主　　题：SNR BER Spatial diversity and combination technology using amplitude and phase weighting method for phase-coherent underwater acoustic communications SDE 

摘      要：The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propagation, spatial diversity equalization is the main technical means. The paper combines the passive phase conjugation and spatial processing to maximize the output array gain. It uses signal-to-noise-plus-interference to evaluate the quality of signals received at different channels. The amplitude of signal is weighted using Sigmoid function. Second order PLL can trace the phase variation caused by channel, so the signal can be accumulated in the same phase. The signals received at different channels need to be normal- ized. It adopts fractional-decision feedback diversity equalizer （FDFDE） and achieves diversity equalization by using different channel weighted coefficients. The simulation and lake trial data processing results show that, the optimized diversity receiving equalization algorithm can im- prove communication system＇s ability in tracking the change of underwater acoustic channel, offset the impact of multipath and noise and improve the performance of communication system. The performance of the communication receiving system is better than that of the equal gain combination. At the same time, the bit error rate （BER） reduces 1.8%.