Research On Multi-antenna NOMA Uplink Based On GSIC

With the commercialization of the 5th generation(5G)mobile network worldwide,countries are exploring the 6th generation(6G)mobile network.Facing the application scenarios of massive device access and massive machine-type communications,multiple access technology that can effectively improve spectrum efficiency has been a hot spot in today’s mobile communication research.This paper focuses on non-orthogonal multiple access(NOMA),one of the candidates of multiple access technologies for 5G,and investigates a group-based successive interference cancellation(GSIC)user grouping scheme for uplink multi-antenna NOMA systems.In this grouping scheme,the base station detects users in groups according to their locations,and inter-group interference is cancelled by SIC,while the intra-group interference is removed by spatial parallel interference.This paper focuses on a single-cell uplink multi-antenna NOMA system with the following research work.Firstly,the system model with single antenna at user equipments and the user grouping scheme with group-based successive interference cancellation are investigated.The joint optimisation problem of power control and receiver detection algorithm is also investigated to maximise the system sum rate,and the original problem is transformed into a power control problem by using a zero-forcing receiver detection algorithm.The simulation results indicate that the new grouping scheme investigated in this paper allows for a further increase in the sum rate of the NOMA system compared to the traditional OMA scheme and the NOMA scheme based on SIC among users in the same cluster.Secondly,the joint optimisation problem of power control and equaliser with error propagation is investigated to minimize the total transmit power and satisfy the service requirements of each user.Through the relationship between the equaliser and the transmit power coefficient,the original problem is transformed into a power control problem using a minimum mean square error receiver detection algorithm,and an iterative power control algorithm is used to further solve the problem.Simulation results show that,in terms of total power consumption,the new grouping scheme investigated in this paper outperforms both the conventional OMA scheme and the NOMA scheme based on SIC among users in the same cluster.