Photonic-enabled RF self-interference cancellation technology for in-band full-duplex communications

The in-band full-duplex (IBFD) communication technology transmitting and receiving signals simultaneously on the same frequency, can double the spectrum utilization efficiency and data transmission rate, and has a great potential application in beyond fifth generation (B5G), sixth generation (6G) communications and satellite communications. However, the high-power signal sent from the transmitting antenna will interfere the low-power signal of interest (SOI) that received by the receiving antenna, or even submerge it completely, which is called radio frequency (RF) self-interference. The RF self-interference is a key issue for the application of IBFD. Compared with the electronic technology, the photonic technology for RF self-interference cancellation (SIC) has the advantages of wide bandwidth and high tuning precision, exhibiting the great potential to realize high interference cancellation depth over broad band. In this paper, the operation principle of photonic RF SIC for IBFD communications is introduced and the recent work in our group is presented, including the photonic RF SIC system composed of separate optoelectronic devices and the silicon photonic integrated RF SIC system.