Analog Domain Self-Interference Cancellation Method Based on Digital Aided Processing

The demand for spectrum is becoming more and more intense, Co-time and Co-frequency Full Duplex (CCFD) can effectively improve the efficiency of spectrum utilization, but due to the influence of self-interference in the same frequency band, self-interference cancellation is required. This paper presents a self-interference cancellation method based on digital aided processing in the analog domain, which has strong expansibility, portability and low complexity. Through simulation, the analog domain self-interference cancellation method is adopted to cancel BPSK signal with bandwidth of 2.592 MHz, and the cancellation can be 36.425 dB under ITAP, which is better than the traditional method by 8.3 dB; under 3TAP, it can cancel by 47. 143dB, which is better than the traditional method by 1.891dB. The experimental results show that the proposed method can suppress BPSK modulated signal up to 45.320 dB and single tone signal up to 50.858 dB. The method presented in this paper is conducive to the better application of Co-time and Co-frequency Full Duplex in practical engineering fields and has a wide range of application scenarios.