Research And Implementation Of Polar Decoding Algorithm For 5G Systems

Professor Arikan proposed the polar code based on the channel polarization phenomenon.So far,the polar code is the only channel coding scheme that can theoretically prove to reach the Shannon limit.Compared with traditional channel coding schemes,the principle of polar code is simple,and it is applicable to rate matching in different scenarios,thus polar code becomes a channel coding scheme for the control channel in the 5th Generation of Mobile Communication System(5G)of enhanced Mobile Broadband(e MBB)scenario.In order to meet the requirements of high reliability and low latency of 5G communication systems,high-performance polar code decoding algorithms have become a popular research direction.With the support of the “Enhanced Mobile Broadband 5G Terminal Simulator R&D” project,the paper conducts in-depth research on polar code decoding algorithms based on the control channel,and improve existing decoding algorithms to meet project requirements.The main research work and innovations of the paper are as follows:1.By combining the CRC-Aided successive cancellation list decoding algorithm(CA-SCL)and the improved List-sphere decoding(ILSD)algorithm,the joint successive cancellation sphere list(JSCSL)decoding algorithm is proposed.Simulation shows that it is achieved the same decoding performance as the original SC algorithm.When the JSCSL decoding algorithm uses the Pipeline structure,the decoding parallelism is increased,and the decoding complexity is reduced by approximately 27.3%,which is beneficial to the realization of parallelism platform.2.Aiming at the flip index set of successive cancellation list bit-flip decoding algorithm,through the three aspects of the polar code encoding structure,the Loglikelihood ratio of the received sequence and the split state of the CA-SCL candidate path,the flip index set is optimized to include the first error bit index caused by channel noise with greater probability,so the improved successive cancellation list bit-flip decoding algorithm is proposed.Simulation shows that under high signal-to-noise ratio,the ISCLF decoding algorithm has a decoding complexity increase of about 1.5% compared with the CA-SCL decoding algorithm,but the performance is improved by about 2.77 d B,thus meeting the project performance requirements.3.The design and implement of the transmitter and receiver of the physical downlink control channel is completed on the digital signal processor(DSP),and the FSW 200 spectrum analyzer and SMW200 A signal source are used to verify design consistency with the technical specification of 5G NR.In order to balance decoding performance and complexity,the CA-SCL decoding scheme and the ISCLF decoding scheme are adopted respectively under low signal-to-noise ratio and high signal-to-noise ratio.Compared with the previous traditional decoding schemes,the decoding performance is improved by approximately 1.5d B?2.1d B without loss of decoding complexity,which verifies the practical application value of ISCLF decoding algorithm.