In-band full duplex (in-band FD) communication is a breakthrough technology enabling simultaneous uplink and downlink transmission over the same spectrum, which not only virtually doubles the spectrum but also shortens the latency of bi-directional communications. One of the key challenges to bring full duplex into reality is practically implementable self-interference cancellation (SIC). This paper explored a practical joint-design of SIC capable of >120dB SIC gain to make in-band FD commercially viable, consisted of novel integrated SIC antenna, multi-tap tunable RF SIC and non-linear digital SIC. Further, a self-developed prototype implemented with commercial level hardware components, as a representative implementation for 5G NR system using in-band FD, not only verified in-band FD is practically implementable with the proposed joint SIC, but also achieved world-best SIC result, i.e. 122.5dB SIC capability with 32dBm transmit power. This result confirmed the appealing potential of in-band FD and conclusively the developed in-band FD communication with an effective SIC turns out to be a promising enabler for future business thriving.

https://ieeexplore.ieee.org/abstract/document/9838784