Research On 5G Oriented LDPC Code And Polar Concatenated Code

The fifth generation mobile communication system(5G)is the current research hotspot,which focuses on solving the problem of data transmission with super high speed,super reliability and low delay.These problems put forward higher requirements for the core module of the physical layer of wireless communication channel coding.With the promotion of 5G standardization,3GPP uses LDPC code and Polar code as the channel coding mode of data transmission and control information transmission in the eMBB scenario respectively,which makes the channel coding usher in a new round of discussion.In the aspect of 5G LDPC coding,this paper focuses on the simplified approximate lower triangular matrix coding algorithm,and designs the preliminary scheme of QC-LDPC encoder based on DSP.This paper makes use of the particularity of H matrix structure and the value of cyclic shift coefficient of submatrix under 5G standard to simplify the calculation of check bit in the approximate lower triangular matrix coding algorithm,and to Elimination matrix inversion.The check bit can be calculated directly by simple linear mathematical operation.The core module of LDPC encoder designed by this algorithm is only the cyclic shift register.Compared with the general approximate lower triangular matrix coding algorithm,it reduces the complexity of coding implementation,improves the coding efficiency,and reduces the consumption of hardware resources.In the practical application process,due to the complexity of LDPC coding mode and many parameter definitions in 5G,in order to make LDPC code verification simple and convenient for the follow-up work,we use matlab to realize the LDPC coding process of long code in 5G,and design a simple user interface.Polar code originates from the phenomenon of channel Polarization,which is the only channel coding method that can reach Shannon limit transmission.It is found that concatenated Polar codes can bring higher performance benefits,and the scheme of concatenated Polar codes has become a research hotspot.Based on the development of 5G,this paper proposes a new scheme based on the concatenation of BCH code and Polar code,in which Polar code is internal code and BCH code is external code,so as to improve the decoding error performance of Polar code under the medium and short code length.The cascade scheme is proved to be effective.