A New Construction Of IRA-QC-LDPC Codes Based On Finite Field

Low-density parity-check (LDPC) codes have attracted considerable attention,because they can achieve near capacity performance with iterative message-passingdecoding, IEEE and DVB standard both use it as codes in channel coding. This papersupported by National Natural Science Foundation of China “The Research of KeyTechnology in Noncoherent MIMO Communication System” studies the construction ofalgebraic structured LDPC codes, we obtain some research achievement, mainlysummarized as follows:1. Proposed a construction method of IRA-QC-LDPC codes of algebraic structure,analyzed the girth of proposed LDPC codes, degree distributions and constructionlimitations, the constructed IRA-QC-LDPC codes have a new base matrixarrangement, Permutation matrix structure, the cyclic shift values, Simulationsshow that the constructed QC-LDPC codes BER performance is better with theIEEE802.16e standard and DVB-S2standards;2. Analyzed the IRA-QC-LDPC codes iterative decoding performance using theEXIT curve analysis and compare with the IEEE802.16e standard, thecomparison results also showed that the constructed QC-LDPC codes iterativedecoding performance is better;3. Study the history of the development of the channel coding, and summarizes theresearch focus of modern LDPC codes. Explains the basic principle of the LDPCcodss, introduce the matrix representations and Tanner graph representations ofLDPC codes, the concept of degree distribution, regular LDPC codes andirregular LDPC codes, the structural characteristics of QC-LDPC code, analyzethe girth problem of LDPC codes and summarize some typical encoding anddecoding schemes;4. Study the LDPC module of IEEE802.16e standard, analyze six rates of QC-LDPCcodes of the strandard, introduced an algebraic method to construct LDPC codesand a geometric method to construct LDPC codes.