Ldpc Code Design And Implementation,

Low-desity parity-check(LDPC)code was invented by Dr. Gallager in the year of 1962, but its importance was not realized until the end of the last century. It can achieve information rate very close to Shannon limit, with a decoder which is of linear time complexity versus block length and can support the throughput tens times of turbo code decoder. With the success, in the fields of space communication, fiber communication and storage industry, LDPC is becoming a powerful competitor.In this thesis, At first, the basis of communication and channel coding theory is introduced briefly. After the definition of LDPC code, several methods of encoding algorithms and their performances are studied. After the analysis of these methods, the algorithm of Q_matrix encoding is selected to implement the encoder with FPGA technique. Then we present the soft-decision decoding algorithms emphatically, and using matlab to analyze several main factors which affecting the decoding performance. At last, we choose Log_BP algorithm to implement the parallel decoder with FPGA technique.