中文摘要：

介绍了低密度校验码（LDPC码）的Tanner图表示和洪水译码算法后，引入基于校验节点的串行译码算法及半串行译码算法，通过密度进化和树的深度两方面束讨论串行译码的消息收敛特性，证明其消息收敛速度比洪水译码算法约快2倍，并且降低了译码复杂度。分别应用洪水译码算法和串行译码算法在AWGN信道下进行计算机仿真。理论分析与仿真结果均表明，串行译码算法明显改善了译码性能。

英文摘要：

Tanner graph of LDPC and flooding decoding algorithm are briefly introduced. On this condition, present serial decoding algorithm and semi-serial decoding algorithm which based on check nodes. By analysing DE（Density Evolution） and tree depth of message convergence, it＇s proved that the message convergence speed grows about twice as fast in the serial decoding algorithm compared to the flooding decoding algorithm, and reduce the decoding complexity. Respectively apply flooding decoding algorithm and serial decoding algorithm to simulate over AWGN channel. Theory and results of simulation show that the decoding performance could be improved by serial decoding algorithm.