Digital Interference Cancellation in Single Channel, Full Duplex Wireless Communication

This paper describes a single channel, full-duplex wireless communication system that can receive and transmit at the same frequency band in the same time. Recent researches have proved the feasibility of full duplex wireless communication in practice, by canceling the self-interference signal to obtain the desired signal. In this paper, we propose an adaptive digital self-interference cancellation technique, which combines with existing antenna separation and balun based cancellation to achieve the quantity of self-interference cancellation needed for full-duplex system. An adaptive filter based on least mean square (LMS) algorithm is applied to track amplitude and phase variations to produce an expected cancellation signal, after the initial delay and frequency offsets are compensated. Our simulation results display that the adaptive digital interference cancellation scheme has fairly desirable self-interference signal cancellation performance.