Hybrid SI cancellation for single-antenna full-duplex radios

A hybrid self-interference (SI) cancellation scheme, composed of a two-tap analogue canceller and a digital multi-path SI canceller, is proposed for single-antenna full-duplex radios. The analogue canceller mitigates the two strongest components of the SI to prevent saturating the receiver. The digital canceller deploys an auxiliary receiver chain to capture the RF-transmitted signal to mitigate the residual multi-path SI signal. As the proposed scheme uses the RF-transmitted signal as reference, the transceiver impairments such as power amplifier non-linearities and phase noise are suppressed along with the SI. Experiments have validated the effectiveness of the proposed scheme on a 20 MHz long-term evolution signal of +20 dBm power.