Study Of Channel Coding Technique For 5G Communication System

As the fourth-generation mobile communication system is reaching maturity and has been large-scale commercialized,future-oriented fifth-generation mobile communication system(5G)has become a research focus.In the joint efforts of global industry and academic communities,5G vision and key requirements have become concrete,and the international standardization of 5G is in progress.Channel coding technology is being investigated as one of key wireless techniques in 5G.In order to achieve the significant improvements of5 G key performance parameters,the channel coding technology for 5G should own several characteristics,which include large coding gains,low coding and decoding complexity,low coding and decoding delay,high data throughput,broad and flexible code parameters.A single channel coding scheme is difficult to fully meet all the 5G requirements.The future 5G will choose different channel coding schemes to meet the corresponding technical requirements of different scenarios and applications.This dissertation investigates the channel coding technology for 5G.Specifically,the research includes the construction,decoding and application of rate-compatible LDPC(RC-LDPC)codes,rate-variable non-binary LDPC(NB-LDPC)codes,multiplicative repetition based superposition transmission(MRST)codes and cross-layer codes.The main contributions are summarized as follows:Researched on the construction of efficient channel coding scheme for the data channel of5 G e MBB scenario.Firstly,a new method for constructing RC-LDPC codes is proposed,which is based on combining algebraic-based and graph-based construction methods of LDPC codes.The proposed RC-LDPC codes have advantages in hardware implementations of the encoder and decoder,and can achieve good performance in the waterfall region within a wide range of code rates.Secondly,a new method for constructing LDPC codes whose information length and rate are both compatible(IC-RC-LDPC)is proposed with the assistance of algebraic methods.The proposed IC-RC-LDPC codes own low construction and storage complexity.Simulation results show that the resulting codes are able to achieve good performance in terms of water-fall region and decoding convergence,and are suitable for the data transmission of 5G e MBB scenario.Researched on the construction of efficient channel coding scheme for the burst short packet service of 5G u RLLC scenario.Two kinds of rate-variable NB-LDPC codes are constructed.The first kind is the multi-rate NB-LDPC(MR-NB-LDPC)codes,which are constructed based on expurgating method.The second kind is the rate-compatible NB-LDPC(RC-NB-LDPC)codes,which are constructed based on incremental redundancy method.The resulting codes possess desirable structure for hardware implementations of the encoder and decoder.Simulation results show that the codes can achieve good performance within a wide range of code rates both in the waterfall and error-floor regions,and are suitable for the burst short packet transmission of 5G u RLLC scenario.Researched on the construction of efficient channel coding scheme for the continuous large packet service of 5G u RLLC scenario.A new kind of big convolutional codes,which is called MRST codes,is constructed based on multiplicative repetition and superposition.In order to realize the flexibility of code rate,an improved coding scheme,which is referred to as P-MRST codes,is also proposed based on the puncture method.Simulation results show that both MRST and P-MRST codes with sliding-window decoding algorithm can achieve good performance with short basic code and less memory order.The proposed codes own lower decoding complexity and decoding delay,and are suitable for the continuous large packet transmission of 5G u RLLC scenario.Researched on the application of efficient channel coding scheme for the 5G high mobility scenario.Firstly,the application of cross-layer coding scheme over the high mobility channels is studied.Then,a new mobility adaptive coding transmission strategy based on cross-layer coding schemes is proposed.Simulation results show that the cross-layer coding scheme can effectively guarantee the reliable transmission under the high mobility scenario,and the proposed mobility adaptive coding transmission strategy can improve the system throughput under the condition of reliable transmission.