Lossless Data Compression Method, Error Repair Method, Encoder and Decoder Based on lz77

Abstract

The invention relates to a lossless data compression method based on LZ77, a bit error repair method, an encoder and a decoder. The compression method includes: reading a character string to be compressed, obtaining an encoded symbol sequence and an encoded character string; according to the sliding window The parsing sequence searches and records the longest matching prefix of the current character string to be encoded in turn; determines the embedded bit information according to the matching multiplicity of the longest matching prefix of the current character string to be encoded; combines the embedded bit information with the current Each longest matching prefix of the string to be encoded is mapped one by one; according to the preset embedded value, the corresponding longest matching prefix is ​​selected as the codeword of the current string to be encoded and output until the string to be encoded has a codeword Output, complete data compression. The invention can protect the extra redundant data by channel coder without losing any compression ability, so as to correct a limited number of errors, and has strong compatibility and practicability.

Description

technical field [0001] The invention belongs to the technical field of data compression, and in particular relates to a lossless data compression method based on LZ77, a code error repair method, an encoder and a decoder. Background technique [0002] Under the guidance of the source-channel separation theory, in the current communication system, source coding realizes the problem of communication validity, and channel coding realizes the problem of communication reliability. Due to the limitations of the separation theorem, the design idea of ​​cascade coding makes the anti-interference ability of the coded sequence of the source very weak. In fact, the lack of repair ability of adaptive data compression is a prominent shortcoming in many applications. From the analysis of the source coding mechanism, it can be seen that the data obtained by source coding is almost without redundancy. After the data is transmitted through the channel, there are often bit errors due to the ...

AI Technical Summary

Problems solved by technology

In the practical application of encoding, some additional information will need to be carried according to the requirements, but according to the LZ77 encoding idea, if the additional information is directly added to the string to be encoded, it will be easily obtained during the transmission process, and the practicability and security will be compromised. discount, so there is an urgent need for an encoding compression method that can carry additional hidden information to improve the security and reliability of network compressed data transmission

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