面向非对称水声信道的物理层网络编码优化方案

Ocean underwater acoustic communication systems are typical systems with limited information transmission capability and this is extremely asymmetric with humanity’s increasing underwater communication needs. This fact is the bottleneck which redistricts the development of underwater acoustic communications. Traditional technological schemes can not solve the above problem radically, but physical-layer network coding provides a good idea for breaking through this bottleneck. Under this background, this project takes designing suitable physical-layer network coding scheme for underwater acoustic communications as its final target. Firstly, asymmetric two-way relaying underwater acoustic communication systems are modeled through the feature analysis of underwater acoustic channels; then, after analyzing and simulating the performance of physical-layer network coding in asymmetric underwater acoustic channels, the related conclusions are obtained and the main reasons for affecting the performance of physical-layer network coding in underwater communications are found; finally, improved and optimization physical-layer network coding schemes are designed. Through the research of these key technologies, this project solves problems for the application of physical-layer network coding in ocean underwater acoustic communications and promotes the development of China’s ocean information technologies.

海洋水声通信系统是典型的信息传输能力受限的系统，这与人类对水下通信与日俱增的需求呈现严重的非对称性，是制约水声通信发展的瓶颈。传统技术方案难以根本解决这一难题，而物理层网络编码技术为突破这一瓶颈提供了新的思路。在这种背景下，本项目以设计适合水声通信的物理层网络编码方案为目标，首先通过分析水声信道特点来建立非对称双向中继水声通信系统模型，然后对物理层网络编码在非对称水声信道中的性能进行分析与仿真，得到相关结论并找到在水声通信中影响物理层网络编码性能的主要原因，最后设计物理网络编码的改进优化方案。通过对这些关键技术的研究，为物理层网络编码在海洋水声通信中的应用解决技术难题，推动我国海洋信息技术的发展。

为了解决海洋水声通信系统传输能力受限的问题，采用了物理层网络编码技术。本项目以设计符合非对称双向中继水声通信的物理层网络编码方案为目标，首先为了充分描述非对称双向中继水声信道模型，定义了非对称系数，利用非对称系数把非对称双向中继水声通信系统分成五种非对称情形，建立了非对称模型，并提出了一种适用于水声通信的自适应均衡算法；在无线电信道中，分析并仿真了非对称信道条件下物理层网络编码的抗噪声性能，对数据长度非对称物理层网络编码性能进行了研究并提出了一种改进方案，提升了性能；在各种非对称情形下，对水声信道中物理层网络编码进行了理论分析与仿真实验，得到了相关结论；最后提出了一种非对称水声信道中物理层网络编码的改进优化方案，适合用于非对称双向中继水声信道，较大提升了系统的抗噪声性能。