BP decoding method and device for polarization code

Abstract

The invention discloses a BP decoding method and device for a polarization code, and belongs to the technical field of channel coding. A BP decoding algorithm based on an early termination iteration strategy is used for decoding the polarization code, and a judgment condition of early termination of the BP decoding algorithm based on the early termination iteration strategy is that a symbol of the log-likelihood ratio of the leftmost end of a factor graph does not change in continuous two iteration processes. The invention also discloses a BP decoding device for the polarization code. Through the convergence characteristic of the symbol of the log-likelihood ratio, the method and device carry out the judgment of iteration termination of BP coding, can remarkably reduce the number of iteration times under the condition of causing no loss of decoding performance, and are more remarkable in effects under the conditions of medium and high signal-to-noise ratios. The method is simple and easy, is low in calculating complexity, and is simple in hardware implementation.

Description

technical field [0001] The present invention relates to a polar code decoding method, in particular to a polar code BP decoding method and device, and belongs to the technical field of channel coding. Background technique [0002] The polar code (polarcode) was proposed by Erdal Arikan in the article "ChannelPolarization: AMethod for Constructing Capacity-Achieving Codes for Symmetric Binary-Input Memoryless Channels". He proved from the theoretical level that through the combination and separation of channels, when the number of channels tends to infinity, some channels tend to be perfect, while some channels tend to be pure noise channels, which is called channel polarization phenomenon. Based on this channel polarization phenomenon, we select a better channel in the combined channel to construct a polar code. ErdalArikan proved that when the number of channels tends to infinity, polar codes can theoretically approach the Shannon limit. [0003] The main decoding methods...

AI Technical Summary

Problems solved by technology

However, this method needs to use the likelihood ratio numerical information of three consecutive iterations for calculation, the calculation complexity is high, the hardware (register) is expensive, and it has been verified by experiments that the effect of reducing the number of iterations is limited

Since the final step of BP decoding is to judge and decode the information bit by the likelihood ratio of the information bit and the sign of the left information instead of the value, and the patent uses the value change less than a preset threshold as the iteration early termination condition, which is obviously not optimal

And the preset threshold is a fixed value, which is not suitable for complex and changeable channel conditions in real communication scenarios, and is not self-adaptive

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