Full-Duplex Cooperative NOMA Relaying Systems with I/Q Imbalance and Imperfect SIC

Abstract

The performance of full-duplex (FD) cooperative non-orthogonal multiple access (C-NOMA) relaying systems in the presence of in-phase and quadrature-phase imbalance (IQI) and imperfect successive interference cancellation (ipSIC) is analyzed and evaluated. In particular, by considering two classes of users located far from and near to the information source, closed-form exact and analytical approximate expressions for the outage probability (OP) and ergodic sum rate (ESR), respectively, are derived. The accuracy of the analytical approach is verified by computer simulations which have shown that for both C-NOMA and equivalent OMA systems IQI has a deleterious effect on their OP and ESR performance in moderate and high signal-to-noise ratio (SNR) regions and the OP of C-NOMA is always slightly lower than that of the traditional OMA. Additionally, comparisons with equivalent half-duplex (HD) C-NOMA schemes have revealed that for the far user the FD C-NOMA scheme is less sensitive to ipSIC.