Active Linear Self Interference Cancellation Method for In-Band Full Duplex Communication

This paper presents a method for linear selfinterference cancellation of an in-band full-duplex communication system, where both transmission and reception are done simultaneously by using the same frequency and antenna resources. A second transmission RF chain is used to regenerate the self-interference signal. Different from the literature, the linear channels are estimated at the same time under the system nonlinearities and impairments; the estimated channels are then applied at the digital baseband signal for both the main and secondary transmission lines. The proposed method significantly reduces the self-interference caused by linear channel effects and synchronization errors. Over 30dB linear self-interference cancellation has been observed on the hardware tests.