In-band full-duplex technology: self-interference cancellation

As an effective means to solve the problem of spectrum resource shortage, in-band full-duplex (IBFD) communication system can theoretically double the spectrum utilization rate and provide a new solution to the problems of hiding terminals, channel congestion and end-to-end delay. The self interference (SI) of IBFD directly affects the communication quality level. Due to the uncertainty in signal propagation process, SIC with complex process is the bottleneck of IBFD development. Therefore, how to eliminate self interference (SI) and apply it to engineering practice is a hot issue in future research. In this paper, SIC technologies are classified and studied. According to three SIC methods: Antenna-Domain SIC, Analog-Domain SIC and Digital-Domain SIC, the existing SIC technologies are compared and their advantages and disadvantages and shortcomings in practical application are discussed. Finally, the key research directions and application prospects of SIC are put forward.