Research on Beamforming and Power Allocation in IRS-BASED NOMA System

A beamforming and power allocation method for IRs-based NOMA systems is proposed in this paper. The method designs beamforming vectors under three different strategies, and optimizes the power distribution factor based on maximizing the sum transmission rate, and alternates between beamforming vector and power distribution factor, finally the optimal beamforming vector and the power distribution factor are obtained. At the same time, the sum transmission rate, the number of iterations are taken as the performance indexes of the proposed algorithm. The simulation results show that when designing the beamforming vector based on the principle of maximizing the useful signal energy, compared with the forced zero design and the traditional fixed-beamforming vector and fixed-power distribution factor strategy, it can significantly improve the sum transmission rate.