The Design Of LDPC Decoder Based On NGB-W System

LDPC code is a kind of excellent error correction of coding in performance. Withcharacteristics such as decoding with high eiffciency，parallel operation, easy toimplement.etc. It can still achieve good decoding performance in the low SNRenvironment, so the LDPC code has a broad application prospect in the ifeld of highreliability requirements of communication information transmission. And it has becameone of the most visible highlights in scientiifc research about the channel encoding-decoding.Broadcasting Network is the most convenient and most popular information carrierfor people. With the rapid development of science and technology, constructing thetri-networks integration, the same as Next Generation Broadcasting (NGB)，which issuitable for China’s national conditions, based on the networks of China MobileMultimedia Broadcasting (CMMB) and combine the wired and wireless network, hasbecome an inevitable trend.Combined the program involved when I was an intern in theNewmedia wireless technology research center of Shanghai advanced research institute,Chinese academy science,the research title was Next-Generation Broadcast NetworkWireless Systems. By combining of theoretical analysis, computer simulation andhardware platform, several key problems for LDPC code decoder’s design andsimulation-implementation based on NGB-W system were studied in this topic. SinceLDPC codes are a class of linear block codes，so the linear block code and LDPC codesare ifrstly introduced briefly;Then the compiled code principle of LDPC codes isintroduced, and NGB-W LDPC codes in the performance of system simulation underthe Min-sum algorithm and BP algorithm is carried out. This thesis determines theoptimal decoding algorithm of the hardware implementation, conifrm the ifxed-pointsolutions of LDPC code decoder in NGB-W system through simulation, and provides areliable reference basis for the development of LDPC code decoder design，introducesthe development of LDPC code decoder design scheme in detail, points out the LDPCcode decoder in NGW-W system deifciencies for further study, and simulation ofimplementation scheme of LDPC code decoder has been carried on.By combining the C language and matlab, the lfoating point simulationimplementation of LDPC code decoder in NGB-W system was realized, compared the simulation results, determine the designated bit-wide of the LDPC code decoder; Basedon the characteristic calibration matrix of LDPC code in the NGB-W system, optimizethe use of memory design，greatly reduces the use of memory resources, which has acertain practical value. Through a combination of Quartus and Modelsim，part of theLDPC code decoder module simulation function of NGB-W system has been realized.