中文摘要：

构造了一种新的基于有限域的QC-LDPC码作为分量码，与分组码和截短分组码相比，有效改善了目标QC-LDPC码的性能．首先简要描述了QC-LDPC码的基本定义，接着回顾了已有的基于中国余定理（Chinese Remainder Theory，CRT）QC-LDPC码设计方法，进一步阐述了采用有限域（finitefield）方法设计构造QC-LDPC码的过程，在此基础上给出了改进的基于中国余定理QC-LDPC码设计方法，仿真结果表明，基于有限域方法设计的QC-LDPC码性能优良，其作为分量码应用于中国余定理的QC-LDPC码设计，可以很大程度上改善构造的目标QC-LDPC码的性能．

英文摘要：

This paper proposes a novel component code, QC-LDPC code constructed by finite field method. It can improve the performance of objective QC-LDPC code effectively, when compared with the array code or shortened array code. In this paper, the background of QC-LDPC code is depicted firstly. Then, the QC-LDPC code design method based on CRT （Chinese Remainder Theory） is reviewed. Furthermore, the procedure of QC-LDPC code construction algorithm based on finite field method is given. Finally, the improved QC-LDPC code construction method based on CRT is described. Simulation results show that the finite field based QC-LDPC code can improve the performance effectively of the objective QC-LDPC code when adopted as the component code of the CRT method.