The probability density distribution of the a posteriori symbols and probabilistic shaping capacity analysis in underwater acoustic communication

• 作者: WU Xisheng WU Yanbo ZHU Min LI Dong FANG Xiaofang
• 来源期刊: 声学学报（英文版）
• 年，卷（期）: 2021,（3）
• 页码范围: 362-377
• 页数: 16页
• 语种: 英文

摘要

Considering the effects of underwater acoustic channels on underwater acoustic communications,the system capacity of the underwater acoustic(UWA)communication sys-tem is analyzed,and an underwater acoustic channel capacity assessment algorithm is studied.A piecewise symbol-variance transfer function mode based on the a posteriori Gaussian distri-bution is proposed via the statistical analysis of the a posteriori symbols which are the outputs of the equalizers under different conditions.Probabilistic shaping is introduced to analyze and assess the capacity of the practical underwater acoustic communication system,and the Maxwell-Boltzmann distributions are used to perform probabilistic shaping on the output sym-bol of the equalizer.Finally,the capacities with different modulation modes are obtained by analyzing the multipath channel data of pool and lake experiments.The results show that the maximum improvement of the channel capacity by using probabilistic shaping over the conven-tional equiprobability mapping is 0.5 bits/symbol,in the specific signal-to-noise ratio(SNR)region.