Photonic-assisted RF Transceiver with Simultaneous Image Rejection and Self-interference Cancellation

A photonics-assisted RF transceiver with simultaneous image rejection and self-interference cancellation for full-duplex communication is proposed and experimentally demonstrated. The image rejection is realized in receiver by carrier-suppressed double-sideband modulation with tunable phase and sideband filtering. The intermediate frequency (IF) signal to be transmitted is utilized as the reference signal to cancel the self-interference caused by the high-power transmitted signal. Compared to the self-interference cancellation in the RF domain, the proposed scheme realizes the self-interference cancellation in the IF domain, thereby reducing the requirement for precise delay regulation. A proof-of-concept experiment is carried out with the results showing that an image rejection ratio of 27.1 dB and self-interference cancellation depth of 20.4 dB with 1 GHz bandwidth. The weak signal of interest (SOI) with 16-QAM modulation is successfully recovered by the scheme with the cancellation of image interference and self-interference. The maximum interference to SOI power ratio is measured with 20.5 dB for image interference and 18.7 dB for self-interference.