Optimal Precoder Design and Power Allocation for NOMA-based mmWave Downlink

Millimetre wave communication systems are being developed to meet the capacity demands of the increasing number of mobile devices. A fully digital millimetre wave system architecture is difficult to implement due to critically spaced antennas leading to a prohibitively high transceiver complexity. An alternative that reduces the hardware complexity is the analog beamforming architecture. A major drawback of this analog beamforming architecture is that it cannot transmit information to multiple users at a single instance of time. To overcome this disadvantage, non-orthogonal multiple access (NOMA) is incorporated into the system model. NOMA uses superposition coding at the transmitter and successive interference cancellation (SIC) at the receiver to enable multi-user (MU) transmission. This paper proposes a design of a NOMA-based analog beamformer that transmits information to multiple users in a single resource block such that sum-rate of the network is maximized. In addition, the performance of the proposed design is demonstrated through simulation results.