Beamforming, Antenna Selection, and Power Allocation Factor Design for Downlink Two-User MISO-NOMA Systems

In this paper, we consider the joint antenna selection (AS), beamforming (BF), and power allocation factor (PAF) design problem for a two-user downlink power-domain nonorthogonal multiple access (PD-NOMA) systems. Different from conventional sum-rate-oriented problems, the proposed problem is concerned about the fairness between users, which is improved by maximizing the achievable rate of the weaker user with hardware constraints such as the total power constraint (TPC), per-antenna power constraint (PAPC), and the number of activated antennas, to prevent the extremely low communication quality. To solve the problem, we divide it into two stages due to its complexity. Simulation results demonstrate that with such procedures, the proposed approach achieves better fairness performance than most sum-rate-oriented counterparts and it can be bettered if we perform the two-stage design.