物理层网络编码与LDPC码联合系统设计及性能优化

Joint design and performance optimization of physical-layer network coding and LDPC code

在双向中继通信系统中,针对物理层网络编码与LDPC码联合方案编译码算法复杂度较高、译码运算时间较长等问题,提出了一种新的系统性能优化方案.首先设计了基于QPSK调制的物理层网络编码与LDPC码联合通信系统模型,给出中继映射方案和系统各节点译码算法;然后分析了联合通信系统中LDPC码的码率、码长、最大迭代次数等因素对系统误比特率性能的影响,对系统性能进行改进优化;最后对系统译码迭代方案进行优化.实验仿真表明,该通信系统优化方案能够保证良好的译码性能、缩减译码运算时间、提升信息交换效率.

In the two-way relay communication system,a new system performance optimization scheme is proposed.It is to solve the problem that the joint scheme of Physical-layer Network Coding and LDPC code coding algorithm with higher complexity and longer decoding operation time.Firstly,the joint communication system of Physical-layer Network Coding and LDPC code based on QPSK modulation is designed,the relay mapping scheme and the decoding algorithm of the system are given in this paper.Then,the factors such as code rate,code length and maximum iteration number of LDPC code are analyzed,those factors can influence Bit Error Rate of the joint communication system.Finally,the system decoding iteration scheme is optimized.The experimental simulation shows that the optimization scheme can ensure the system has good decoding performance,reduce decoding operation time and improve information exchange efficiency.