A Modified Belief Propagation Algorithm Based on Attenuation of the Extrinsic LLR
Low-Density Parity-Check (LDPC) codes was first proposed by R. Gallager in 1963 and rediscovered by MacKay in the late 1990s. It is proved to be a family of capacity-achieving codes and has been a hot research spot over the years. In addition to insight theoretical studies, LDPC codes are applied in many error sensitive communication systems, such as long haul optical channels, data storage and deep-space communication systems, and also adopted by many communication standards, such as IEEE 802.16e/n WMAN standard, ETSI DVB T2 and DVB S2 standard. Besides the common features of conventional block codes, LDPC codes have two major features, i.e., the low-density parity-check matrix and the Belief Propagation (BP) decoding algorithm.