LDPC Code LLR BP Algorithm Improvement And Hardware

LDPC codes(Low-density Parity-check Codes) is an important innovation after theTurbo code in channel coding field, LDPC code is based on the sparse check matrix of alinear block code, which has the excellent properties of approaching shannon limit andto achieve reliable communication of digital communication system. LDPC codes inis widely used in deep space communications, satellite communications, opticalcommunications, satellite digital video and the upcoming fourth generation mobilecommunication system, etc, it is a hot spot in the field of communication.Firstly the paper introduces some basic knowledge of the channel coding theorem,then drawn LDPC code. It is begin with the definition of LDPC code, making thesystem research and the elaboration for the LDPC code representation methods andconstructing method.Secondly we studied the decoding algorithm of LDPC codes including harddecision and soft decision decoding algorithm decoding algorithms. This paper isstudied the soft decision decoding algorithm of BP algorithm and LLRBP decoding,algorithm, then put forward an improved LLRBP decoding algorithm, and it has beenproved by the simulation decoding performance is superior to the LLR BP decodingalgorithm is proposed.Then in this paper, we carried out the improved LLR-BP decoding algorithmhardware implementation based on the theory of decoding algorithm, using top-downdesign method of LDPC decoder design, compare the structure block diagram is givenin detail and a decoding function module implementation method, using the Quartus IIplatform integrating various modules into a complete decoder, Finally the decoder’sdesign was verified through comprehensive compilation, functional and timing simulation.