Research On Detection Algorithm Of Novel Multiple Access For 5G

Due to the explosive growth of Internet of Things and mobile Internet services,5G systems need to meet the requirements of higher spectral efficiency,greater connectivity,greater capacity,and lower latency.However,the traditional orthogonal multiple access technology is not suited to be applied to the demand of future systems,because of the constrained by the conditions of single-user capacity.Novel multiple access technology(NMA)emerges as the times require.NMA realizes the superposition transmission of multiple user signals in the space/time/frequency/code domain,and adopts the advanced detection algorithm to separate user's signal at the receiving side,so as to achieve the increase of the system spectrum efficiency and capacity.This thesis focuses on the detection algorithm of the NMA in the 5G system.The main work is as follows:The deduction of the probability of the system can guide the follow-up study.In this paper,the outage probability and achievable sum data rate of the system are analyzed mathematically for the uplink pattern division multiple access system firstly,and the closed solution equation is established.The numerical simulation results show that,when these users have the same target rate,the achievable sum data rate of the pattern division multiple access system are higher than that of the traditional orthogonal multiple access system.Aiming at the problem of user detection in the NMA system,this thesis presents a detection algorithm based on minimum mean square error and interference cancellation.The algorithm removes some of the interference signals based on the result of the cyclic redundancy check,which improves the detection performance of the system and effectively avoids the error propagation.The simulation results show that the proposed algorithm can decrease the block error ratio compared with the existing interference cancellation algorithms.In order to improve the detection performance of NMA system,this thesis enhances the detection algorithm based on minimum mean square error and interference cancellation,and propose an iterative detection and decoding algorithm based on belief propagation and interference cancellation.This algorithm can improve the detection performance of the system by providing a priori information for the BP detector though channel decoder and eliminating the interference signal based on the result of the cyclic redundancy check.In addition,the algorithm can adaptively adjust the number of iterations of the system,and reduce the computational complexity of the detection algorithm to a certain extent.The simulation results show that the improved algorithm can obtain better block error ratio performance.