Hard decision-directed forward and backward estimation method under symbol insertion and deletion channel

Abstract

The invention belongs to the field of digital communication error control coding, and discloses a hard decision-directed forward and backward estimation method under a symbol insertion and deletion channel. The method is characterized in that a forward and backward algorithm of an internal decoder receives a codeword sequence estimation value output by an external decoder, and combines a watermark sequence and a hard decision codeword into a new reference sequence of the internal decoder for signal point estimation; and a hard decision-directed watermark decoder updates an output probability through an estimated signal point, and calculates a forward metric and a backward metric, so that likelihood information of each symbol output through the forward and backward estimation method is more reliable, the number of residual insertion and deletion errors output by the internal decoder is reduced, and the performance of an overall processing algorithm is further improved. Compared with the traditional processing scheme, the method provided by the invention has the advantages that the estimation accuracy of the forward and backward algorithm is improved, and better overall performance is achieved at the cost of slightly low complexity.

Description

technical field [0001] The invention relates to the field of digital communication error control coding, in particular to a hard-judgment-oriented forward-backward estimation method under symbol insertion and puncture channels for correcting insertion and puncture errors. Background technique [0002] In the process of information transmission or storage, there will be deviations in timing and synchronization, which will cause insertion or deletion of symbols, that is, synchronization errors, including insertion or deletion errors. Insertion and deletion errors are quite different from traditional substitution errors such as those found in binary symmetric channels or binary deletion channels. Due to the memory nature of channels containing insertion / deletion errors, a single uncorrected error can cause a series of burst substitution errors, causing catastrophic error propagation, so it is suitable for traditional error correction coding of memoryless channels and additive n...

AI Technical Summary

Problems solved by technology

[0006] This efficient concatenation scheme can effectively identify block boundaries and maintain synchronization during long-term transmission, but the performance of its symbol-level decoding algorithm still needs to be further improved

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