ADAPTIVE CODING USING TIME-VARYING PERIODIC LDPC CONVOLUTIONAL CODES BASED ON QUASI-CYCLIC LDPC BLOCK CODES

摘要

The present invention discloses a coding and decoding method, apparatus, and system for forward error correction, and pertains to the field of communications. The method includes: determining check matrix parameters of time-varying periodic LDPC convolutional code according to performance a transmission system, complexity of the transmission system, and a synchronization manner for code word alignment, constructing a QC-LDPC check matrix according to the determined check matrix parameters, and obtaining a check matrix H c of the time-varying periodic LDPC convolutional code according to the QC-LDPC check matrix; de-blocking, according to requirements of the H c , data to be coded, and coding data of each sub-block according to the H c , so as to obtain multiple code words of the LDPC convolutional code; and adding the multiple code words of the LDPC convolutional code in a data frame and sending the data frame. In the present invention, forward error correction is performed by using time-varying periodic LDPC convolutional code with a QC-LDPC structure. The check characteristics of the QC-LDPC may decrease the complexity of the check; furthermore, the performance of LDPC convolutional code is better than that of LDPC block codes, and the performance of time-varying LDPC convolutional code is better than that of time-invariant LDPC convolutional code. Therefore, the present invention may be applicable to the high-speed optical transmission system and meet the requirements of high-gain performance and high throughput.