可快速编码的大围长QC-LDPC码构造  

Construction of quasi-cyclic LDPC codes with fast encoding and large girth

作　　者：刘原华 何华 LIU Yuanhua;HE Hua(School of Communication and Information Engineering,Xi’an University of Posts and Telecommunications,Xi’an 710121,China)

机构地区：[1]西安邮电大学通信与信息工程学院,陕西西安710121

出　　处：《现代电子技术》2018年第11期1-4,共4页Modern Electronics Technique

基　　金：陕西省自然科学基金资助项目(2016JQ6033);国家自然科学基金资助项目(61201194);国家自然科学基金资助项目(61601362)~~

摘　　要：为保证LDPC码在低编码复杂度的同时,减少短环对其迭代译码性能的影响,提出一种可快速编码的大围长准循环LDPC码构造方法。该方法将校验矩阵分成两部分,其中右半部分具有准双对角线结构,使其可利用校验矩阵直接进行快速编码,有效降低了LDPC码的编码复杂度;左半部分通过逐个设置其循环置换子矩阵以确保当前矩阵中的短环数最少,有效避免了短环的出现,保证了大围长的特性。仿真结果表明,与IEEE 802.16e中的LDPC码相比,新方法构造的LDPC码具有更大的围长和更少的短环,在低编码复杂度的基础上获得了更优的纠错性能。A construction method of quasi-cyclic（QC）LDPC codes with fast encoding and large girth is proposed to reduce the effect of short cycles on the performance of iterative decoding while maintaining the low encoding complexity of LDPC codes.The check matrix is divided into two parts. The right part of the matrix has the quasi-dual-diagonal structure,which can perform the fast encoding directly,and reduce the encoding complexity of LDPC codes effectively. The circulant permutation sub-matrices are set one by one in the left part of the matrix to ensure the minimum number of short cycles,avoid the occurrence of short cycles,and guarantee the characteristic of large girth. The simulation results show that,in comparison with LDPC codes in IEEE 802.16e,the codes constructed with the new method have larger girth and less short cycles,and better error correction performance while maintaining the low encoding complexity.

关 键 词：LDPC码 准循环 循环置换矩阵 快速编码 校验矩阵 编码复杂度 

分 类 号：TN911.22[电子电信—通信与信息系统]