A Multi-Stage Self-Interference Canceller for Full-Duplex Wireless Communications

As full-duplex being considered as one of the most promising techniques for 5G, self- interference (SI) cancellation has drawn significant research attention. In this work, we present the design of a multi-stage SI canceller for full-duplex wireless communication. The SI canceller consists of a two-stage passive reconstruction based analog cancellation which can suppress not only the strongest SI component but also multi-path SI components received within tens of nanoseconds, and a final stage of digital cancellation for suppressing the remaining SI components, in which distortion of SI signal caused by transceiver in-phase/quadrature-phase imbalance is taken into account. We show by indoor experiments that the proposed SI canceller can provide 122dB of SI suppression over 20MHz bandwidth.