A Novel mmWave MIMO-NOMA Scheme Based on Beam Aggregation

Millimeter wave (mmWave) multiple-input and multiple-output (MIMO) technology is one of the key technologies of the fifth generation (5G) wireless communication system. The application of non-orthogonal multiple access (NOMA) to mmWave MIMO system can further improve the throughput and spectrum efficiency. The existing researches on mmWave MIMO-NOMA normally assume that multiple UEs are served by one beam and thus suffers from beam misalignment. In this paper, we propose a novel beam aggregation-based mmWave MIMO-NOMA scheme where multiple UEs are served by a group of beams in a non-orthogonal fashion. Numerical simulation results reveal that our proposed NOMA scheme has significant advantages with respect to the achievable sum-rate and fairness compared with power-domain NOMA.