Digital Self-Interference Cancellations Addressing Radio-Frequency Impairments for In-Band Full Duplex

In-band full duplex requires digital self-interference cancellations (SICs). However, digital SICs are significantly challenged due to radio-frequency (RF) impairments. We have proposed several designs and analyses of digital SIC based on parallel Hammerstein models addressing RF impairments. Our proposed designs and analyses use orthogonal frequency division multiplexing in the Hammerstein SICs. Moreover, we have developed a testbed to evaluate the Hammerstein and our proposed SICs. Our experimental results showed that the self-interference cancellation ratio was 48.1 dB for one of the Hammerstein SICs. This paper reveals that our canceler designs and theoretical analyses can improve the Hammerstein SICs.