【摘要】 该文设计了一种特殊的高码率准循环低密度校验(QC-LDPC)码,其校验矩阵以单位矩阵的循环移位阵为基本单元,与随机构造的LDPC码相比可节省大量存储单元。利用该码校验矩阵的近似下三角特性,一种高效的递推编码方法被提出,它使得该码编码复杂度与码长成线性关系。另外,该文提出一种分析QC-LDPC码二分图中短长度环分布情况的方法,并且给出了相应的不含长为4环QC-LDPC码的构造方法。计算机仿真结果表明,新码不但编码简单,而且具有高纠错能力、低误码平层。更多还原

【Abstract】 This paper proposes a class of Quasi-Cyclic Low-Density Parity-Check(QC-LDPC)codes with high code rates,which is an efficient encoding algorithm due to the almost lower triangular form and simple structure of their parity-check matrices.Since the parity-check matrix of the QC-LDPC code is composed of blocks of circulant matrices,the required memory for storing it can be significantly reduced,compared with randomly constructed LDPC codes.Based on the quasi-cyclic structure of the parity-check matrix,a new approach is proposed to analyze the distribution of the short length cycles of their bipartite graph,and a corresponding construction method of QC-LDPC codes without cycles of length 4 is presented.Simulation results show that the proposed codes not only have low encoding complexity and low error floor but also perform well with iterative decoding.更多还原