Optimal resource allocation for multicarrier MISO-NOMA systems

In this paper, we investigate optimal resource allocation for multicarrier (MC) multiple-input single-output non-orthogonal multiple access (MISO-NOMA) downlink systems. The resource allocation design for the maximization of the weighted system throughput is formulated as a non-convex optimization problem taking into account the quality-of-service requirements of the downlink receivers. We employ monotonic optimization to solve the formulated problem and to obtain the optimal joint precoding and subcarrier allocation policy. The optimal resource allocation policy serves as a performance benchmark due to its high computational complexity. Furthermore, a low-complexity suboptimal resource allocation algorithm is developed and shown to find a locally optimal solution. Our simulation results reveal that the suboptimal algorithm closely approaches the optimal performance. Besides, our results show that MC MISO-NOMA significantly improves the system throughput compared to conventional MC MISO orthogonal multiple access.