基于预失真的异步物理层网络编码相位纠正算法  

A phase offset equalization algorithm based on pre-distortion for asynchronous physical-layer network coding

作　　者：成聿伦[1] 杨龙祥[2] 

机构地区：[1]南京邮电大学江苏省无线通信重点实验室,南京210003 [2]南京邮电大学教育部宽带无线通信与传感网技术重点实验室,南京210003

出　　处：《高技术通讯》2015年第8期766-774,共9页Chinese High Technology Letters

基　　金：973计划(2013CB329104);国家自然科学基金(61372124;61171093;61427801);江苏省高校自然基金重大项目(11KJA510001);江苏省973计划(BK2011027);南京邮电大学引进人才科研启动基金(NY214138)资助项目

摘　　要：研究了异步物理层网络编码(PLNC)系统中的载波相位偏移问题,提出一种基于预编码的相位纠正算法。该算法首先在用户符号中引入预先设定的相位失真矢量,然后在中继侧利用该参数对接收的PLNC信号进行相位均衡,同时修改迭代译码过程中的置信传播(BP)公式,以达到缩小相位偏移的目的。建立了相位均衡收益模型,利用该模型证明了上述算法相位纠正性能的上界,并且对相位失真矢量以及算法的健壮性进行了优化。对该算法进行了验证试验,试验结果表明,该算法能有效减小相位偏移对BP译码过程的影响,改善系统的误比特性能。进行的建模与优化,为星座图不规则下的BP译码提供了一种简单有效的性能分析方法。The problem of phase offset equalization in asynchronous physical-layer network coding （ PLNC ） systems was sudied, and an equalization algorithm based on pre-distortion was proposed. The algorithm embeds the desired phase distortion vector into the symbols of users in advance, and then, utilizes this parameter by the relay to equal- ize the phase of received PLNC signals. Meanwhile, it modifies the belief propagation （BP） equations in the deco- ding process accordingly to reduce the phase offset. A phase equalization profit model was established, and on the basis of that, the upper bound of the algorithm＇ s equalization performance was theoretically proved, and the phase distortion vector and the algorithm＇ s robustness were also optimized. The simulations were performed and the re-suits verified that the proposed algorithm could effectively reduce the influence of the phase offset in the ding vide tion. process, and improve the bit error performance. The modeling and optimization carried out in this study provide a simple and effective method for the performance analysis of BP decoding process under irregular constellation.

关 键 词：物理层网络编码(PLNC) 异步 相位偏移 置信传播(BP) 预失真 

分 类 号：TN92[电子电信—通信与信息系统]