User scheduling for full‐duplex non‐orthogonal multiple access systems with reconfiguration antennas

Abstract

As the promising technologies for providing higher network throughput, full-duplex (FD) communications and non-orthogonal multiple access (NOMA) have attracted wide attention in recent years. In this study, the authors propose a user scheduling algorithm for the full-duplex non-orthogonal multiple access system (FD-NOMA) where an FD base station equipped with a pair of reconfigurable antennas serves multiple half-duplex downlink (DL) and uplink (UL) users simultaneously. Firstly, they formulate a user scheduling problem to maximise the sum rate of the FD-NOMA system. Then, they eliminate the inter-user interference from caused by the UL users to the DL users through the blind interference alignment based on reconfigurable antennas and decouple the user scheduling problem into a DL user scheduling problem and a UL user scheduling problem. Next, for the DL and UL user scheduling subproblems, they pair the users aligned with the same directions based on the channel correlation metric. Finally, they employ the exhausting search and iterative power allocation algorithm to solve the subproblems. Simulation results show that the proposed FD-NOMA system can achieve up to 233 of gain in the average sum rate compared with the existing baseline schemes.