一种基于极化码的OFDM水声通信系统  

An OFDM underwater acoustic communication system based on Polar code

作　　者：邢莉娟 李卓[1] 陈远鹏 侯悦 XING Lijuan;LI Zhuo;CHEN Yuanpeng;HOU Yue(School of Telecommunications Engineering,Xidian University,Xi’an 710071,China)

机构地区：[1]西安电子科技大学通信工程学院,陕西西安710071

出　　处：《西安邮电大学学报》2024年第4期13-20,共8页Journal of Xi’an University of Posts and Telecommunications

基　　金：国家自然科学基金项目(61372072);111工程基金项目(B08038)。

摘　　要：为了降低水声信道强多径效应、大多普勒频移等特性对水声通信系统的影响,提出一种基于极化码的正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)的水声通信系统。选择极化(Polar)码作为信道编码方案,通过量化信道输出直接统计信道转移概率,替代通过信道估计得到的信道冲激响应,再计算转移概率,以降低通信系统的复杂度。在特性随时不变、时变、快时变的3种类型水声信道模型下,分别基于蒙特卡罗算法构造Polar码。仿真结果表明,Polar码在3种信道上的编码增益优于同码长同码率的低密度奇偶校验(Low Density Parity Check,LDPC)码和Turbo码,且信道条件越复杂,取得的编码增益越大,所提系统能够明显降低信道多径效应、多普勒频移对水声通信系统的扰乱,提高系统的可靠性。In order to reduce the influence of the strong multipath effect of underwater acoustic channel and the large Doppler frequency shift on the underwater acoustic communication system,an underwater acoustic communication system based on the Polar code orthogonal frequency division multiplexing is established.The Polar code is selected as the channel coding scheme,and the channel transition probability is directly counted by quantifying the channel output,which replaces the step of calculating the transfer probability after obtaining the channel impulse response through channel estimation,so as to reduce the complexity of the communication system.Under three underwater acoustic channel models,namely the time-invariant model,the time-varying model and the fast-time-varying model,the Monte Carlo algorithm is used to construct the Polar code.Simulation results show that the Polar code has better coding gain compared with the low density parity check(LDPC)code and Turbo code over the three channels,and the more complex the channel conditions are,the greater coding gain could be achieved.The proposed system can obviously decrease the multipath effect,the disturbance brought by the Doppler frequency shift,and can improve the reliability of the system.

关 键 词：水声通信 正交频分复用 极化码 信道转移概率 蒙特卡罗构造 

分 类 号：TN911[电子电信—通信与信息系统]