Residual Self-Interference Analysis for Full-Duplex OFDM Transceivers Under Phase Noise and I/Q Imbalance

In this letter, we investigate the detrimental effects of phase noise (PN) and in-phase/quadrature (I/Q) imbalance (IQI) on full-duplex OFDM transceivers. In particular, we derive a closed-form expression for the average residual self-interference (SI) power and show its functional dependence on the parameters of the radio-frequency impairments and channel taps' power. Moreover, for perfect digital-domain cancellation, we show that the effects of PN and IQI can be approximately decoupled for small PN and IQI levels and the average residual SI is linearly proportional to the I/Q image rejection ratio and PN 3-dB bandwidth. Our numerical simulations validate the accuracy of the derived closed-form expressions and our findings.