Joint Beamforming and Power Allocation Design in Non-Orthogonal Multiple Access Systems

Nonorthogonal multiple access (NOMA) transmission is a popular candidate technology for the next generation broadband mobile communication systems because of high spectrum efficiency. In this paper, we proposed two beamforming scheme, namely, matched-to-the-stronger-channel (MSC) beamforming and optimal beamforming schemes for a two-user downlink NOMA system. Moreover, we also develop optimal power allocation for both schemes. It shows through simulation results that the optimal scheme is capable to combat the near-far effect and provides high achievable sum rate especially when the geographical angle between two users is small.