LDPC码串行解码算法建模

消息传递机制是影响LDPC码解码性能的重要因素。简要介绍了Gallager提出的LDPC码和基于洪水消息传递机制的和积解码算法。在此基础上引入基于校验节点的串行消息传递机制并提出具体可实现的解码算法模型。该串行解码算法按照校验节点一定的顺序进行消息处理和传递,保证更新的消息能够马上进入迭代过程,从而改善消息传递的收敛特性;同时充分利用消息间相互关联的特点,融合消息传递步骤,可以降低所需的存储容量,简化解码复杂度。分别应用洪水解码算法和串行解码算法在AWGN信道下进行性能仿真。仿真结果表明串行解码算法使解码性能得到明显提高。

Modeling for LDPC serial decoding algorithm

Message-passing mechanism is an important factor affecting the performance of LDPC decoding. In this paper, we introduce briefly LDPC and sum product decoding algorithm based on floodwater message-passing mechanism proposed by Gallager. On this basis, we introduce a serial mechanism based on check nodes and propose a concrete and feasible decoding algorithm modeling. This serial decoding algorithm processes and passes the messages in a definite sequence of check nodes for ensuring that the updated messages can immediately enter the iterative process so as to improve convergence characteristics of the message passing, and use the feature of interdependence between messages to fuse the message passing steps to reduce required memory and decoding complexity. We use respectively the floodwater decoding algorithm and serial decoding algorithm to perform the performance simulation over AWGN channel. The simulation results show that the decoding performance could be improved by serial decoding algorithm.