Low-complexity joint source-channel encoding and decoding method based on space lattice diagram

Abstract

The invention relates to a low-complexity joint source-channel encoding and decoding method based on a space lattice diagram. In a low-complexity joint source-channel encoding and decoding system based on the space lattice diagram, each symbol in an information source assembly is endowed with a weight (named a symbol weight) in probability correlation with the symbol. At the encoding end, the symbol sequence has three constraint values, namely an accumulated symbol number, an accumulated bit number and an accumulated symbol weight, after being subjected to variable-length encoding. At the decoding end, the three constraint values are utilized to construct the space lattice diagram, the three-dimensional coordinates of the space lattice diagram respectively signify 'symbol number index', 'bit status index' and 'weight status index'. A redundant status transfer path on the space lattice diagram is removed firstly, then status nodes and status transfer branches on the space lattice diagram are projected on a two-dimensional plane to generate a simplified variable-length information source code lattice diagram, and the symbol-level maximum posterior probability decoding algorithm is adopted to realize the low-complexity joint source-channel encoding and decoding method.

Description

Technical field [0001] The present invention relates to a joint source channel coding and decoding method in the field of communication coding and decoding, in particular to a low-complexity joint source channel coding and decoding method based on a spatial grid graph. Background technique [0002] In the current communication system, generally follow Shannon's "Separation Theory" (Separation Theory), that is, the source coding and channel coding are independently optimized and designed to enable the communication system to obtain the best coding performance. However, the premise of the "separation theory" is: Regardless of source coding or channel coding, it is assumed that an infinite time delay can be tolerated (the coding block length is allowed to be unlimited); the statistical characteristics of the transmission channel are mastered in advance. In reality, constraints such as the complexity of coding and decoding, software and hardware resources, and communication delays ma...

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Problems solved by technology

[0005] In order to solve the problem of many state transition branches and high computational complexity in the traditional variable-length signal source code planar grid graph, the present invention proposes a space-based A low-complexity joint source-channel encoding and decoding method for grid graphs. This method designs a construction method for spatial grid graphs and a corresponding encoding and decoding method

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