Full-duplex cooperative NOMA system under impacts of residual SI and MAI

In this paper, we investigate the performance of a downlink cooperative non-orthogonal multiple access (C-NOMA) system with full-duplex decode-and-forward relaying, where a NOMA user with better channel operates as a full-duplex (FD) relay to assist other NOMA-user to forward its messages to the base station (BS). Specifically, we derive the exact expressions of the system performances in terms of outage probability and ergodic capacity for two users over the Nakagami-fading channels for the case with the direct link from the BS to users. We then analyse the impacts of residual self-interference (SI) due to imperfect self-interference cancellation in the FD mode and multiple access interference (MAI) due to imperfect co-channel interference cancellation (CCIC) on the system performance. Simulation results are provided to verify the theoretical analysis and demonstrate the advantages of the FD-C-NOMA system over the FD non-cooperative NOMA (FD-NC-NOMA) system and the half-duplex C-NOMA (HD-C-NOMA) one.