Reasearch And Application Of LDPC Code Used In DVB-S2 Standard

Low-density parity-check codes come to be one of the best coding technologies because of their low-complicity iterative decoding algorithm and copacity approaching performance ,and they atrack more and more researcher's eyes in recent years.In this thesis, the basis of communication and channel coding theory is introduced briefly. After the definition of LDPC code, the encoding and decoding algorithms, also the performance analysis of decoding algorithms, are studied.Then,it introduces the coding schemes used in DVB-S2and gets the parity check matrix by simulation. It gives some solutions for designing the encoder. Various log-likelihood-ratio-based Belief-Propagation decoding algorithms and their reduced-complexity derivatives for LDPC codesused in DVB-S2 are presented. Finally, it discuss how to get the correction factor and offset factor using in the Normalized BP-Based decoding and Offset BP-Based decoding. Simulation results show that these reduced-complexity decoding algorithms for LDPC codes achieve a performance very close to that of the BP algorithm.