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

Abstract

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.

Description

(1) Technical field [0001] The invention belongs to the field of channel coding, and in particular relates to a novel coding and decoding method of a hybrid Turbo structure code based on LDPC. (2) Background technology [0002] Shannon's theorem is the basic theory of channel coding. Although Shannon's theorem is an existence theorem and does not provide a specific coding implementation method, it points out the direction for the research of communication information. The following are the three basic conditions needed in a theorem proof: [0003] (1) Adopt random edge and decoding methods; [0004] (2) The encoding length is long enough; [0005] (3) The decoding is the best maximum likelihood decoding method. [0006] Therefore, finding a good code that satisfies Shannon's condition has become the direction of people's efforts. So far, in the field of channel coding, Turbo codes and low-density parity-check (LDPC) codes are the best two codes, both of which have perfor...

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Problems solved by technology

However, this method also has disadvantages. Because the randomness in the channel coding conditions is not fully satisfied, the error curve of this code tends to be flat under the condition of high signal-to-noise ratio, which is the so-called error floor effect.

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