编码协作MARC上全分集LDPC码的实现与性能分析

本文研究了多接入中继信道(MARC)上全分集LDPC码的实现与性能。首先,分析了MARC模型及其固有分集,然后构造了在MARC上能取得全分集的LDPC码,新构造的码字采用根校验节点把源节点传输与中继节点传输联系起来,从而获得全分集。接着,研究了所构造码字的密度演化过程,在密度演化的基础上,进一步分析了全分集LDPC码校验矩阵的结构,给出了通过提高全分集校验比特的比例,改善全分集LDPC码在MARC上编码增益的方法。仿真结果表明,本文所提算法在MARC信道上不仅能实现全分集,而且能取得较高的编码增益。

Full diversity LDPC codes realization and performance analysis for coded cooperation MARC channels

Cooperative communication is a well known technique to yield transmit diversity in multi-user environment.Multiple Access Relay Channel(MARC) is the most common method to acquire cooperative communication,where two source users share a common relay node in their transmission to the destination.In order to improve the performance of communication system with MARC,a kind of full diversity LDPC on MARC is proposed in this paper.The new proposed LDPC codes connect the source node transmissions with the relay transmissions by root-connection to get extern diversity gain.In addition,the relationship between the structure of full diversity LDPC codes and the coding gain is given,and an algorithm to improve coding gain is brought forward by increasing the proportion of full diversity parity bits in this paper.Simulation results show that the proposed algorithm can not only achieve full diversity,but also get better performance than constructed LDPC codes for MARC at present.