Interference Suppression Approach for FMCW Radar Based on Complex Iterative Filtering

An interference suppression approach based on complex iterative filtering (CIF) is designed to address the issue of frequency modulation continuous wave (FMCW) radar being susceptible to FM interference which has the same bandwidth with the radar. Based on the fact that the beat signal of target echo is a superposition of multiple single tone signal but the beat signal of interference is an FM signal covering the bandwidth of radar receiver, the CIF algorithm proposed in this paper is used to decompose the beat signal of radar into the intrinsic mode functions (IMFs) domain, and the energy distribution position of interference signal is obtained by the constant false alarm detection of each IMF. Furthermore, a method for eliminating the interference energy and reconstructing the amplitude and phase of target echo is designed. The proposed interference suppression approach is verified by the simulation and measured data. The results show that the proposed approach has a suppression effect of the signals with co-frequency and noncoherent frequency modulation at signal-to-interference-plus-noise-ratio of less than 20 dB. © 2024 China Ordnance Industry Corporation. All rights reserved.