On the coexistence of non-orthogonal multiple access and millimeter-wave communications

In this paper, the application of non-orthogonal multiple access (NOMA) to millimeter-wave (mmWave) communications is considered, where random beamforming is used in order to reduce the system overhead. Stochastic geometry is used to characterize the performance of the proposed mmWave-NOMA transmission scheme, by using the key features of mmWave systems, e.g., mmWave transmission is highly directional and potential blockages will thin the user distribution. The provided analytical and numerical results demonstrate that the combination of NOMA and mmWave yields significant gains in terms of sum rates and outage probabilities, compared to conventional orthogonal multiple access based mmWave systems.