摘要： 提出一种基于平衡不完全区组设计(BIBD)和循环置换矩阵的准循环低密度校验码(LDPC)构造方法。根据实际需求，利用BIBD构造相应的模板矩阵，用适合的循环置换矩阵进行扩展。采用该方法构造的LDPC码具有良好的结构和灵活性，该方法在一定范围内可快速方便构造出某一特定码长或码率的准循环LDPC码。仿真结果证明，准循环LDPC码在高斯白噪声信道上采用迭代译码时，具有较优的纠错性能及较低的错误平层。

关键词: 平衡不完全区组设计, 准循环低密度校验码, 循环置换矩阵, 模板矩阵, 有限域

Abstract: A method to construct a flexible length or rate of quasi-cyclic Low Density Parity Check(LDPC) codes based on Balanced Incomplete Block Design(BIBD) and cycle permutation matrix is proposed. Based on actual demand, the corresponding template matrix is constructed by BIBD method. The template matrix is extended by the appropriate cycle permutation matrix. The quasi-cyclic LDPC codes constructed by the proposed method have a good structure and flexibility. This method improves the efficiency of construction good codes which meet the needs of a practical application. Simulations show that quasi-cyclic LDPC codes constructed by the proposed method perform well over AWGN channels with iterative decoding and have a lower error floor.

Key words: Balanced Incomplete Block Design(BIBD), quasi-cyclic Low Density Parity Check(LDPC) code, cycle permutation matrix, template matrix, finite field

中图分类号: 

• TP311