Lossless data compression method based on LZ77, error code repair method, encoder and decoder

Abstract

The invention relates to a lossless data compression method based on LZ77, an error code repair method, an encoder and a decoder. The compression method comprises the steps of: reading to-be-compressed character strings, and acquiring an encoded symbol sequence and to-be-encoded character strings; according to a sliding window parsing sequence, sequentially searching and recording longest matchingprefixes of a current to-be-encoded character string from the encoded symbol sequence; according to the matching multiplicity of the longest matching prefixes of the current to-be-encoded character string, determining embedded bit information; carrying out mapping on the embedded bit information and each longest matching prefix of the current to-be-encoded character string one by one; and according to a preset embedding value, selecting the corresponding longest matching prefix as a code word of the current to-be-encoded character string, outputting the code word, and until the code words ofall the to-be-encoded character strings are output, completing data compression. According to the invention, in a case of not losing any compression capability, additional redundant data can be protected by utilizing a channel encoder so as to correct a limited number of errors; and the lossless data compression method, the error code repair method, the encoder and the decoder have high compatibility and practicality.

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 have been 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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