Research On Decoding Technology Of Polar Codes Based On Simplified Successive-Cancellation Decoding

The polar code is a channel coding that can achieve the channel capacity.Due to the low complexity of the coding and decoding,and the reachability of the channel capacity,many scholars have drawn attention from it.However,the serial output characteristics of conventional successive-cancellation decoding algorithms result in large delays.Although the simplified successive-cancellation decoding algorithm proposed later achieves the parallel decoding output of the partial constituent code,the delay caused by the serial decoding of a large part of the constituent code has not been solved.To solve this problem,this paper proposed predecoding based maximum likelihood simplified successive-cancellation(PDM-SSC)decoding algorithm.Pre-decoding the information bits of the left child node of the decoding node by hard decision,XOR operation and bit mapping on the input channel likelihood ratio vector of the decoding node;and then combining the maximum likelihood decoding estimates the remaining information bits of the decoding node,thereby obtaining the final decoded output,which effectively solves the problem of some serial decoding of the node.The experimental results show that compared with the existing algorithms,the proposed algorithm can effectively reduce the decoding delay and does not affect the error performance.Firstly,this paper introduced the origin and development of channel coding technology,and introduced the research status of polarization codes in detail.From these research,the main research directions of polarization codes in recent years are analyzed.The relevant theoretical basis of the polarization code is also introduced,including channel polarization,polar coding and conventional successive-cancellation decoding algorithms.The theory of channel combination,channel diffusion and channel polarization characteristics in channel polarization is elaborated in detail.Then,the simplified successive-cancellation(SSC)decoding algorithm and its enhancement algorithms are mainly studied.By analyzing the decoding principle and decoding performance,the limiting factors affecting the decoding rate are obtained,and that is the decoding of the rate-R node.In the simulation,the structure of the rate-R node is statistically analyzed,and the L-REP and L-Bi REP nodes are determined as the research nodes of this topic.For the L-REP and L-Bi REP nodes,the concept of precoding is introduced,and the estimate bits of the information bits on the left child node are obtained in advance according to the input information vector.Then,based on the pre-decoding scheme,combined with the idea of maximum likelihood decoding,the complete L-REP and L-Bi REP decoders are designed to further reduce the number of serial decoding nodes in the rate-R node.Finally,PDM-SSC decoding algorithm proposed in this paper is verified by simulation.On the Visual Studio platform,use C++ to build a polar code simulation platform,and change the parameters of the code rate,code length and computing resources of the polar code to compare.The experimental results show that the proposed algorithm can effectively reduce the decoding delay without affecting the error performance.