置信传播(belief propagation,BP)算法的计算复杂度较高，且变量节点和校验节点间信息传递的信息可靠，但是迭代的实现，就最大似然算法来说，验证其提高译码性能的特点。 -Belief propagation (belief propagation, BP) higher computational complexity of the algorithm, and reliable information between variable nodes and check node