Researches And Applications On The Structure Of Spatially Coupled LDPC Codes

Channel coding guarantees robust communication transmission, and the research and design of channel coding with good performance plays an impor-tant role in improving the performance of communication system. In recent years, spatially coupled LDPC codes has attracted wide attention because of its capacity approaching performance. Density evolution and threshold satura-tion lay a solid theoretical foundation on the study of spatially coupled LDPC codes. Although there are numerous achievements in theory, the researches on the application of spatially coupled LDPC codes are still lacking. Therefore, it is significantly important to find a low-delay and low-complexity encoding and decoding scheme of spatially coupled LDPC codes.Spatially coupled LDPC codes enable recursive endcoding with linear com-plexity when its structure meets certain conditions. Only when the check node degree is divided by the variable node degree exactly, the universal implemen-tation of spatially coupled LDPC codes allows recursive encoding. In other words, the universal structure can not apply recursive encoding with arbitrary rate.In this thesis, we construct structures which can be used for recursive en-coding by rearranging the edges of the existing ones. In addition, a general guidance for the construction of parity-check matrix for recursive encoding is proposed with given node degrees. A series of structures which can be used for recursive encoding can be constructed by this scheme. Some of the structures achieve better performance than the existing ones.In addition to recursive encoding, spatially coupled LDPC codes allows recursive decoding with linear complexity by windowed decoder. The advan-tages of windowed decoder include low delay and high flexibility. Spatially coupled LDPC codes achieves recursive encoding and decoding with low-delay and low-complexity by using recursive encoder and windowed decoder. There-fore, spatially coupled LDPC codes can be used for the transmission of stream-ing data. In this thesis, we proposed a scheme for the real-time transmission of streaming data by using spatially coupled LDPC codes. And capacity approach-ing performance can be achieved by constructing proper ensembles according to channel conditions.In this thesis, we discuss the encoding and decoding algorithms and appli-cation scenarios of spatially coupled LDPC codes. And a general guidance for the construction of parity-check matrix for recursive encoding is proposed with given node degrees. In addition, by means of recursive encoder and decoder,we propose a real-time streaming data transmission scheme with capacity ap-proaching performance by using the spatially coupled LDPC codes.