协作通信下联合IRA码和网络编码的译码算法  

Joint Decoding Algorithm for IRA Code Combined with Network Coding in Cooperative Communications

作　　者：戴翠琴[1] 冉海霞[1] 

机构地区：[1]重庆邮电大学移动通信技术重点实验室,重庆400065

出　　处：《应用科学学报》2015年第2期105-116,共12页Journal of Applied Sciences

基　　金：国家自然科学基金(No.61201205);重庆市自然科学基金(No.cstc2012jj A40042);重庆市科委重点实验室专项经费;长江学者和创新团队发展计划基金(No.IRT1299)资助

摘　　要：针对协作中继网络中目的端接收来自不同源节点发送的多个信息副本的合并方式,提出了联合非规则重复累积码与网络编码的改进译码算法.首先对各链路的调制信息进行软解调处理,并根据中继处网络编码的异或信息和直达链路中原信息的函数对应关系,提取出协作节点发送到目的端的信息副本;然后更新非规则重复累积码在译码过程中直达链路与协作链路下的两个信息副本的软解调信息,构造出新的译码判决方法,进而推导了16QAM软解调对数似然比值的简化方法;最后分析了系统的中断概率及频谱效率.仿真结果表明,该译码算法在QPSK、16QAM两种调制方式下均能获得较低的误比特率,且采用对数似然比值的简化方法,能在0.3 d B性能损失代价下降低系统的译码难度.By combining multiple information copies from different source nodes at the destination node in a cooperative relay network, we propose a joint irregular repeat accu- mulate （IRA） code and network coding modified decoding （JI-NMD） algorithm. We first demodulate the modulation information with soft demodulation information of each link, and extract the information copies from the relay node at the destination. This is done according to the functional relationships between the network coding at relay node and the original information in the direct link. We then update the soft demodulation information of the two copies from the direct and cooperative links in the IRA decoder, and construct a new decoding decision method. We further obtain a simplified log-likelihood ratio （LLR） method. Finally, we analyze the outage results show that the JI-NMD algorithm probability and spectral efficiency. Simulation has lower bit error rate for QPSK and 16QAM,and the LLR simplified method of 16QAM has low decoding complexity at the cost of performance loss of 0.3 dB.

关 键 词：协作通信 非规则重复累积码 网络编码 对数似然比 正交振幅调制 

分 类 号：TN929.5[电子电信—通信与信息系统]