Encoding and decoding method of new type LDPC-based hybrid Turbo structure code

The invention discloses an encoding and decoding method of a new type LDPC-based hybrid Turbo structure code. Compared with the usual LDPC-based Turbo structure code encoding and decoding method, the encoding and decoding method of the invention is characterized in that one of branch information of the new type code is not directly encoded and outputted through LDPC, but is encoded through an outer code LDPC encoder at first, and then pseudo-randomized information is outputted through an inner code LDPC encoder and through an interleaver. According to the invention, the new type code is adopted, so requirements of the Shannon channel encoding theorem on the code length and the randomness can be better satisfied, so the advantage of better encoding performance can be realized. Meanwhile, by adopting the new type code, the output code word minimum code weight is improved so as to eliminate the error floor phenomenon generated by the conventional LDPC-based Turbo structure code in the high signal to noise ratio condition. In same channel environments, the new type code has the advantage of lower bit error rate.