Performance Analysis and Power Allocation of Full Duplex Cooperative NOMA System with Imperfect SIC

With the development of non-orthogonal multiple access (NOMA) technology, cooperative non-orthogonal multiple access (CNOMA) has received extensive attention. This paper investigates a full-duplex (FD) cooperative NOMA (FD-CNOMA) system, including one base station (BS), one near user, and one far user, where the near user acts as one FD relay to transmit the signal of the far user. Considering whether there is a direct link between the BS and the far user, and the residual interference caused by imperfect successive interference cancellation (SIC), the task of user power allocation under this model is also addressed in this paper. Finally, based on this model, we derive the closed-form expression of the outage probability and the average rate of the relay user and the far user. Theoretical analysis and simulation results show that the FD-CNOMA system performs better than the half-duplex (HD) cooperative NOMA (HD-CNOMA) and NOMA systems, even in the presence of imperfect SIC and self-interference. At the same time, both imperfect SIC and relay user self-interference have negative effects on user performance, and the effect of imperfect SIC on the ergodic rate of the HD mechanism is more notable than that of the FD mechanism. Finally, compared with random and fixed power allocation, the proposed power allocation method achieves 13% and 10% system sum-rate improvement respectively. © 2024 Chinese Institute of Electronics. All rights reserved.