Density evolution based polarization code constructing method and polarization code coding and decoding system

Abstract

The invention discloses a density evolution based polarization code constructing method and polarization code coding and decoding system. According to the invention, the code length N and the information bit length K of an information code to be processed are obtained, an expectation value set of a log-likelihood ratio probability density function of N bit channels, K bit channels are selected as the information bit channels according to the expectation value set and information bit information index vector quantity is generated; an information bit sequence and a fixed bit sequence are mixed and the mixed bit vector quantity is multiplied by a polarization code for generating a matrix so as to output an encoding sequence; the encoding sequence is modulated and input into a transmission channel and the sequence output by the transmission channel is subjected to decoding operation by adopting a polarization code decoding algorithm, bit error probability and frame error rate of the decoded code are calculated and a design signal to noise ratio is changed, the above operation is repeated until the bit error probability and frame error rate become the minimum. The method and system provided by the invention are suitable for general binary system memoryless channels, the bit error probability and frame error rate are low, the calculation complexity is low and the communication performance of a communication system is improved.

Description

technical field [0001] The present invention relates to the technical field of channel coding, in particular to a density evolution-based polar code construction method and a polar code encoding and decoding system. Background technique [0002] In existing communication systems, channel polar codes are usually used for coding. In the existing communication, since Shannon's limit theory was proposed, the channel coding schemes Turbo code and LDPC code widely used in WiFi and LTE technology make the development of channel coding in the field of wireless communication reach its peak. Although the channel capacity of the two channel coding methods is close to the Shannon limit, these two coding methods cannot reach the Shannon limit in theory, and have relatively high computational complexity. Arikan proposed a new coding method polar code in 2007, which can reach the Shannon limit in binary memoryless channels and has low computational complexity. Therefore, polar codes are ...

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Problems solved by technology

[0034] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a polar code construction method based on density evolution and a polar code encoding and decoding system, aiming to solve the problem of high computational complexity and bit errors in the polar code construction method in the prior art. High rate and frame error rate, low communication quality defects

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