Reconfigurable BP Decoder For 5G NR

In order to further increase the data transmission rate,reduce the latency,and increase the system capacity,the fifth-generation mobile communication technology(5G)came into being.As a new generation of cellular mobile communication technology,5G has three application scenarios: enhanced mobile broadband(e MBB),ultra-reliable low-latency communication(URLLC),and large-scale machine communication(m MTC).The release of Release 15,the first standard version of 5G,marks major progress in 5G standardization.The standard stipulates that in the enhanced mobile broadband scenario,polar codes are used for control channel coding and QC-LDPC codes are used for data channel coding.This provides a good simultaneous use scenario for polar codes and QC-LDPC codes.At present,the optimization of a single polar code and QC-LDPC decoder has been widely studied,which can achieve improved throughput and energy efficiency,but the common mode design is rarely mentioned.As the development of Moore's Law slows down,by exploring the similarity in principle between the two decoding algorithms,the realization of common-mode Polar code and QC-LDPC code codecs can improve hardware utilization and meet the high energy efficiency in 5G demand.In this paper,combining the reconfigurable technology and the BP decoding algorithm under the two encoding modes,the following work is carried out under the5 G NR standard:First,through algorithm analysis and operator extraction of BP decoding algorithms for polar codes and QC-LDPC codes,the feasibility of a BP decoder based on a reconfigurable method is proved,and the storage method and reconfigurable computing unit(CU)array are designed to be suitable for this strategy.The proposed design could support the end-to-end BP decoding for polar codes and QC-LDPC codes.Second,when implementing the QC-LDPC code decoder,for its mapping on the reconfigurable CU array,a cyclic shifter based on the reconfigurable Reverse Banyan network and QSN network are designed.The reconfigurable Reverse Banyan network is split into sub-circular networks of different sizes through early termination and combined with QSN networks to support all 51 Z-value cyclic shifts under 5G NR.Compared with pure QSN networks,the number of MUXs is reduced by 55.5%.Third,the designed high-parallel BP decoder supports two modes: intra-frame parallel and inter-frame parallelism.In the case of intra-frame parallelism,the maximum throughput of Polar code decoding is 5.63 Gbps,and the maximum throughput of QC-LDPC code decoding is 668.13Mbps;in the case of inter-frame parallelism,the maximum throughput of polar code decoding is 16.64 Gbps,and the maximum throughput of QC-LDPC code decoding is 4.75Gbps;Compared with a single Polar code decoder and QC-LDPC code decoder,the total area is reduced by 25.7%;And the design is suitable for application scenarios with high energy efficiency and area efficiency requirements in 5G.