Low-Complexity Suppression of Adjacent Channel Interference in FDD Transceiver

Abstract

The transmitter-induced adjacent channel interference (ACI) due to power amplifier nonlinearity poses severe desensitization to the receiver in frequency-division duplexing transceivers. To tackle this issue, this paper proposed a digital suppression method with a low-complexity circuit structure to eliminate the interference. The transmitter baseband signal and leakage were employed to estimate the system nonlinear parameters in the digital baseband domain, and the interference was regenerated and then subtracted from the received signal. The proposed method can simplify the circuit structure and facilitate engineering implementation in practice. The simulation and experimental results show that the proposed method can suppress about 25 dB ACI, which can effectively improve the signal-to-interference-plus-noise ratio of the desired signal.