Insertion, deletion and substitution error oriented hard decision guide forward-backward estimation method

Abstract

The invention, which belongs to the field of digital communication error control coding, discloses an insertion, deletion and substitution error oriented hard decision guide forward-backward estimation method. The invention aims at a cascade watermark and error correcting code scheme and is used for introducing the hard decision result exported by an external decoder into the insertion and deletion error estimation forward-backward algorithm, then enables the reference sequence of an internal decoder to be superposition of a watermark sequence and a sparse hard decision codeword sequence; a hard decision guide watermark decoder is introduced, the reference sequence and an updated valid substitution error probability are utilized to recalculate an output probability, and a forward metric value and a backward metric value are further calculated, thereby enhancing the likelihood information reliability of each symbol exported from the forward-backward estimation method to the external decoder. The invention, compared with the traditional processing schemes, enhances the accuracy of the forward-backward estimation method and obtains more performance gain with less extra complexity.

Description

technical field [0001] The invention relates to the field of digital communication error control coding, in particular to a hard decision-oriented forward and backward estimation method for insertion, deletion and substitution errors. Background technique [0002] In the process of information transmission or storage, due to timing and synchronization deviations and other reasons, the insertion or deletion of symbols is called synchronization error, including insertion or deletion errors. Insertion or deletion errors are quite different from traditional substitution errors such as those found in binary symmetric channels or binary deletion channels. Because the channel disturbed by insertion and deletion errors has memory, a single uncorrected synchronization error will trigger a series of sudden substitution errors, resulting in disastrous error propagation, which is suitable for traditional correction of memoryless channels and additive noise. Few of the error coding tech...

AI Technical Summary

Problems solved by technology

[0005] The concatenated scheme of watermark code and general error correction code can effectively identify block boundaries and correct insertion and deletion errors, but there is still a lot of room for improvement in the performance of its bit-level decoding algorithm.

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