Multi-tap analog self-interference cancellation for full-duplex communications

Abstract

A single antenna multi-tap (MT) canceller is considered for full-duplex (FD) communications, where the tap coefficients are obtained from the estimated self-interference (SI) channel state information (CSI). The estimated SI channel suffers from the radio frequency (RF) impairment imperfections of the transmit and receive RF chains, which should be calibrated to obtain more accurate CSI. Then, the residual SI power with RF impairment imperfections calibrated and uncalibrated after the MT cancellation are calculated respectively. Considering the dynamic range of the analog-to-digital converter and the linearity of the receiver chain, the achievable capacity of FD transceivers is derived as a function of the residual SI power after MT cancellation. Furthermore, the simulation results demonstrate that the RF impairment coefficients and the tap delay alignment error, i.e., the error between the corresponding tap delay of the canceller and that of the SI channel, reduce the cancellation ability and bring rate gain loss over half-duplex transceivers.