Design And Implementation Of NR LDPC Encoding And Decoding System Based On Software Defined Radio

As the cornerstone of reliable communication in mobile communi-cation systems,channel coding is particularly important in the Fifth Generation Wireless System(5G).Due to the strengths such as the performance close to the Shannon limit,low-complexity encoding and decoding algorithms,the Low Density Parity Check(LDPC)code is identified as the coding scheme of the data channel in the 5G enhanced Mobile Broadband(eMBB)scenario.Up to now,the relevant standards for 5G eMBB scenario have been completed,but there is still no low-cost air interface platform that can be used for 5G protocol and algorithm research in the academic community,especially the performance of New Radio(NR)LDPC code in the actual air interface environment.Therefore,according to 5G related standards,this thesis designs and implements a NR LDPC encoding and decoding system based on Software Defined Radio(SDR)platform.In order to improve the development efficiency and verify the feasibility of NR LDPC encoding and decoding in mobile communication systems,the thesis designs and implements the NR PDSCH channel encoding and decoding process based on OpenAirInterface(OAI)DLSIM platform.Certainly,in order to fully reflect the performance of NR LDPC code,the thesis designs and implements the determination of NR MCS,the calculation of TBS and the support of 256QAM in DLSIM.By testing the performance of LTE Turbo and NR LDPC,it is verified that NR LDPC code has good performance on DLSIM platform.Based on NR LDPC DLSIM platform,the influence of relevant decoding parameters on system performance is tested,which lays a foundation for the construction of air interface SDR platform.Considering the real-time performance of the NR LDPC encoding and decoding system based on the OAI air interface platfonn,the thesis proposes two methods to accelerate the LDPC encoding and decoding based on the NR LDPC DLSIM simulation platform.The AVX-256 extended instruction set is used to accelerate the LDPC encoding and decoding for every data block.Moreover,multi-thread is used to realize parallel decoding for multiple code blocks.In order to compare and analyze the performance of NR LDPC SDR system,the thesis builds OAI LTE-Advacned platform based on OAI LTE platform,which completes the comparison of throughput test of multiple systems in real air interface environment.The experimental results show that the NR LDPC platform can obtain higher throughput than other reference systems under the same experimental conditions.