Optical multipath self-interference cancellation for a wideband in-band full-duplex system using a silicon photonic modulator chip

We propose and experimentally demonstrate a photonic method for wideband multipath self-interference cancellation using a silicon photonic modulator chip.The chip generates phase-inverted reference signals by leveraging the opposite phase between optical sidebands.Effectively managing amplitude and phase imbalances between self-interference and reference signals, the approach rectifies discrepancies through consistent chip manufacturing and packaging processes.Employing photonic multi-dimensional multiplexing, including wavelength and polarization, enables the acquisition of multiple reference signals.Experimental results show multipath cancellation depths of 25.53 dB and 23.81 dB for bandwidths of 500 MHz and 1 GHz, achieved by superimposing 2-path reference signals.