机构地区: 华南理工大学电子与信息学院
出 处: 《电讯技术》 2007年第4期166-168,共3页
摘 要: LDPC码译码采用的是BP算法,但由于回路的存在,使译码重复迭代,特别是短长度的回路使LDPC码的性能下降。为此,用树图法分析了LDPC码的回路及其特性,给出了求解回路长度和所经过节点的方法,非常适合于计算机进行求解。同时也用树图的方法来构造LDPC码,可以在树生成的过程中了解其中的回路数目及长度。 Belief- Propagation(BP) algorithm is used in LDPC code's decoding, but small loops degrade the code's performance. This paper analyzes the LDPC code's Loops by tree graph and also presents a method to obtain the loop lenghth and the nodes passing by. This nethod is easy to be realized by computer. At the same time, LDPC code can also be constructed with tree graph and the number of loop and the lenghth can be known during the generation of tree.