Construction method for low-density parity-check code

Abstract

The invention provides a construction method for a low-density parity-check code. A check matrix of the low-density parity-check code comprises variable nodes and check nodes. The method is characterized by comprising the following steps of: giving a degree distribution sequence of the variable nodes according to the power-law distribution of a scale-free network, and simultaneously limiting the degree of each check node to be two constant values; controlling the arrangement of the variable nodes from the left to right of the matrix according to an ascending sequence of degrees; constructing the check matrix under the constraint of the step 2 by using a progressive edge growth algorithm; and checking whether the check matrix obtained by the step 3 comprises four rings or not, and if the check matrix obtained by the step 3 comprises the four rings, finding the four rings, deleting a certain number l of rings by using a searing algorithm for the four rings to obtain a matrix without the four rings to obtain a final check matrix. The performance of the low-density parity-check code obtained by the method is not remarkably different from that of the conventional high-quality code, the complexity of the low-density parity-check code is remarkably lowered, and iterative decoding time is shortened.

Description

technical field [0001] The present invention relates to the field of communication, more specifically, to the technical field of channel coding in communication. Background technique [0002] In the field of communication, channel coding technology is usually used to ensure the reliability of communication in noisy channels. For example, in a satellite communication system, due to the influence of geographical and environmental factors, there are a large number of noise sources. These communication channels have their theoretical maximum communication capacity (that is, the well-known Shannon limit), which can be expressed in terms of bit rate (bps) at a specific signal-to-noise ratio (SNR), where a code close to the Shannon limit It is a low-density parity-check (LDPC) code. At present, LDPC codes have been paid attention to and widely studied by many researchers because of their error correction performance approaching the Shannon limit. The research of LDPC codes mainl...

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Problems solved by technology

Therefore, if the message iteration graph model of LDPC codes has a scale-free property, the iterative average path will be shortened, and the message propagation and convergence can be accelerated

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