Amplify-and-forward virtual full-duplex relaying-based cooperative NOMA

This letter studies the performance of a virtual full-duplex relaying technique in cooperative non-orthogonal multiple access (NOMA)-based systems. In particular, two half-duplex amplify-and-forward relays imitate the operation of full-duplex relaying in cooperative NOMA systems using the successive relaying (SR) technique, in order to recover the loss of spectral efficiency due to the half-duplex constraint at the relays. The closed-form outage probability of the proposed scheme is derived. The simulation results show that the proposed SR-based cooperative NOMA system with an opportunistic power split factor achieves a lower outage probability and a higher ergodic rate than the existing SR-based orthogonal multiple access system and ideal full duplex relaying-based NOMA systems