物理层网络编码的双向中继系统检测及其性能分析

摘要

In this paper a physical-layer network coded two way relay system applying Low-Density Parity-Check (LDPC)codes for error correction is considered;We first group the existing schemes for physical network coding into two generic schemes, and consider the joint channel-decoding and network-encoding algorithms based on denoise-and-forward (DNF)protocol;In the theory of optimal detection,we fetch out Log-domain decoding algorithm over the Galois field GF (4); Simulation results show that the algorithm outperforms other recently proposed schemes. Finally,the effect of relative carrier phase offset on the system performance over the complex channel is investigated,and the solution is proposed.%主要研究了低密度校验码（LDPC）纠错码技术应用于物理层网络编码（PLNC）下的双向中继通信系统。首先介绍了双向中继系统的各种传输策略，并基于其中的去噪转发协议（DNF）传输策略，详细分析了中继系统各种译码检测算法并提出最佳检测概念。在最佳检测理论下引入了联合信道编码和网络编码GF（4）域下的对数域译码算法（G-LOG），仿真表明该译码迭代算法性能优于最近提出的其他译码算法；另外还系统地分析了信道参数对PLNC下的双向中继系统的影响，并提出了解决方案。