Research On Encoding And Decoding Algorithm Of Non-binary LDPC Codes

With the technology evolution, promoting the transmission system is the most direct andeffective way to improve the transmission performance of fourth-generation mobilecommunications (4G) and the reliability of digital communication system. In the modifiedtechnology system, channel coding and modem/demodem technology occupy a key positionand also need to be developmented, especially channel coding is more urgent.As a starting point, the most outstanding performance of the error correcting code--LDPC codes are researched and discussed deeply in the thesis, and the emerging Non-binaryLDPC codes are also as a subject body. In contrast to binary LDPC codes, unique advantagesof Non-binary LDPC codes are better error correction and burst error resistance capability,suitable for combination with higher-order modulation technology to increase datatransmission rate and bandwidth utilization. As a guide, this thesis focuses on the constructionof parity-check matrix, encoding, decoding and application aspects for Non-binary LDPCcodes.First, several construction algorithms for check matrix of Non-binary LDPC codes aredescribed, encoding process is analyzed, and the advantages and disadvantages of eachalgorithm are compared with. The decoding algorithms are emphatically introduced andgreatly improved based on the original method to reduce complexity.Then, in the white Gaussian noise channel with BPSK modulation, the simulation resultsare given involving various parameters such as different construction methods, decodingalgorithms, code lengths and code rates of Non-binary LDPC codes in different Galois fields.And after that the appropriate parameter values are determined.At last, the basic principles of modulation and demodulation for the continuous phasemodulation (CPM) are introduced. What’s more, Non-binary LDPC codes are combined withthe high-order modulation CPM, and the system model is built up to design demodulation anddecoding iteration receiving mechanism and demonstrate the selected parameters for thefollow-up study of the hardware research.