改进的Polar码的最小和译码算法

An Improved Min-Sum Decoding Algorithm for Polar Codes

提出了改进Polar码的最小和译码算法,修正了最小和译码算法中的节点更新公式,即利用分段线性函数来逼近置信度传播译码算法中的函数lncosh(x).相比于最小和译码算法,改进的算法在增加少许复杂度的情况下,增强了译码性能.相比于置信度传播译码算法,该算法在几乎不损失性能的情况下,大大降低了算法的计算复杂度,更易于硬件实现.该算法是基于最小和算法和置信度传播算法提出的,是在复杂度和性能上的一种折中.仿真结果表明,改进的最小和译码算法与置信度传播译码算法的性能几乎相同,比最小和译码算法的性能好.

In order to enhance the performance of the min-sum decoding algorithm for polar codes,an improved min-sum decoding algorithm was proposed. The improved method corrects the node update formulas of the min-sum decoding algorithm which replaces the function lncosh（ x） in the belief propagation（ BP） decoding algorithm with the piecewise linear approximation functions. Compared with the min-sum decoding algorithm,the modified decoding algorithm has better performance in case of increasing a little complexity. Compared with the BP decoding algorithm,the algorithm greatly reduces the computational complexity in case of almost no performance loss,and simplifies hardware implementation. The modified algorithm is based on the min-sum and the BP algorithms,and it is a compromise between the complexity and performance. Simulations show that the performance of the improved min-sum decoding algorithm is almost the same as the BP decoding algorithm,and better than the min-sum decoding algorithm.