Research On Polar Codes Decoding Algorithm Based On SCL

With the rapid development of mobile communication technology in recent years,excellent channel coding technology has been able to greatly increase the channel gain which close to or even reaches the code rate to the channel capacity.As a channel coding method based on channel polarization theory,Polar Codes can reach Shannon's channel capacity and have low coding and decoding complexity.However,in terms of Polar Codes decoding algorithm we are still faced with the problem that high decoding performance and low decoding complexity can not have both.To solve this problem,this paper proposes a SCL decoding algorithm based path-reused.In the multiple SCL decoding process,the path-reused idea is used to effectively solve the problem of path computation redundancy in the decoding process.Simulation results show that the algorithm proposed can achieve about 50% lower than the CA-SCL decoding algorithm for decoding latency with the premise of maintaining the same decoding performance.First,this paper systematically introduces the historical development process of communication systems and channel coding and the research background of polar codes,and describes the theory of channel polarization of Polar Codes.The related theory of channel merging,channel diffusion,and channel polarization in the polarization phenomenon is introduced.Related construction methods and decoding processes of Polar Codes are explained.Secondly,this paper mainly studies the method of Polar Codes decoding.Through the research and analysis of the decoding performance of the polar code decoding algorithms such as SC,SCL and CRC-SCL under different decoding widths,code rates and code lengths,etc.,we summarize the structural characteristics and decoding performance in the decoding process.In the above analysis process,it is found that there is a duplicate path phenomenon in the decoding process.Based on the analysis of this redundant phenomenon,the concepts ofcommon subpath and dominant factor are proposed,and two SCL decoding algorithms based on path-reused are proposed.In the multi-SCL decoding process,the path-reused mechanism is introduced to achieve the goal of greatly reducing the decoding complexity of the polar code without losing the bit rate.Finally,this thesis uses C++ language to simulate the proposed decoding algorithm on the Visual Studio platform.The comparison experiment was conducted by controlling the code rate,code length,decoding search width and other relevant factors.The experimental results show that both path-reused decoding schemes can obtain lower decoding delay,and PPR-SCL decoding can be achieved with CA-SCL completely consistent decoding performance,while PR-SCL has less loss in decoding performance but can obtain lower average decoding complexity.