一种简化的LDPC码BP译码算法的研究

Study of Simple LDPC Codes BP Algorithm

低密度奇偶校验码(LDPC码)是一种逼近香农限的线性分组码,译码的复杂度较低;在LDPC码译码算法中性能较好的是置信传播译码(BP)算法,他能够在迭代译码过程中确定码字是否已译出,但是复杂度高,运算量大。采用一种改进的BP译码算法,在迭代译码过程中对校验节点的更新信息进行曲线拟合,以减小译码运算量,有利于硬件的并行实现,减少译码延时。仿真结果表明,改进的BP算法译码性能和原来的BP算法接近,而且复杂度较低。

Low Density Parity Check Codes （LDPC） is a kind of linear group codes which can be near the Shannon limit, the complexity of decoding is low. The BP decoding algorithm has a good performance among the decoding algorithms,it can make certain that if the codes are decoded in the iterative decoding process,but it is complicated and needs large operations. In this paper,a better algorithm is proposed to reduce the amount of operations by curve fitting when updating the computation of check codes, it is useful for the realizing of hardware and can reduce decoding delay. The results of computer simulation have shown that the proposed algorithm has similar performance with the traditional BP algorithm,and it is less complicated.