Performance analysis of coded OFDM systems using a novel class of LDPC codes  

利用一种新LDPC码的编码OFDM系统性能分析(英文)

作　　者：何善宝[1] 张立[1] 赵春明[1] 

机构地区：[1]东南大学移动通信国家重点实验室,南京210096

出　　处：《Journal of Southeast University(English Edition)》2004年第4期401-404,共4页东南大学学报（英文版）

基　　金：KeyProjectoftheNationalNaturalScienceFoundationofChina(No.60496311).

摘　　要：A new method of constructing regular low-density parity-check (LDPC) codes was proposed. And the novel class of LDPC codes was applied in a coded orthogonal frequency division multiplexing (OFDM) system. This method extended the class of LDPC codes which could be constructed from shifted identity matrices. The method could avoid short cycles in Tanner graphs with simple inequation in the construction of shifting identity matrices, which made the girth of Tanner graphs 8. Because of the quasicyclic structure and the inherent block configuration of parity-check matrices, the encoders and the decoders were practically feasible. They were linear-time encodable and decodable. The LDPC codes proposed had various code rates, ranging from low to high. They performed excellently with iterative decoding and demonstrate better performance than other regular LDPC codes in OFDM systems.提出了一种新的构造LDPC码的方法,并把用该方法产生的LDPC码应用到编码正交频分复用(OFDM)系统中进行了研究.该方法拓展了单位阵移位构造的LDPC码,它利用简单的不等式可确保在置换单位阵构造中不会产生Tanner图中的短圈,使得产生的LDPC码的Tanner图最小圈长为8.由于该类码是准循环码以及其校验矩阵所固有的分层结构,编码器和解码器都易于实现,它们分别是线性可编和线性可译的.所提出的LDPC码码率范围较大,可以灵活选取.利用迭代解码进行计算机仿真,发现新的LDPC码比其他的规则LDPC码在编码OFDM系统中具有更好的性能.

关 键 词：Computer simulation Iterative methods Mobile telecommunication systems QUASICRYSTALS Turbo codes 

分 类 号：TN929.533[电子电信—通信与信息系统]