Interference Suppression Approach for FMCW Radar Based on Complex Iterative Filtering

doi:10.12382/bgxb.2023.0996

Abstract

Abstract:

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 20dB.

Key words: frequency modulation continuous wave, co-frequency interference, interference suppression, complex iterative filtering, intrinsic mode function

CLC Number:

TN957.51

CHEN Qile, YANG Jin, QAO Caixia, ZHANG Ruiheng. Interference Suppression Approach for FMCW Radar Based on Complex Iterative Filtering[J]. Acta Armamentarii, 2024, 45(12): 4589-4596.

Figures/Tables 14

Fig.1 Beat signal under interference

Fig.2 Scheme of interference suppression method

Fig.3 Pseudocode ofinterference suppression and signal reconstruction method

Table 1 Simulation parameters

参数	数值
载波频率/GHz	10
调制周期/μs	30
调制带宽/MHz	100
带通滤波器频带/MHz	1~45
雷达探测范围/m	10~2000
ADC速率/MHz	90

Fig.4 Time domain and frequency domain of beat signal under interference

Fig.5 IMFs and the Hilbert spectrum of beat signal

Fig.6 Simulated results of interference suppression

Fig.7 Beat signal after interference suppression

Fig.8 Ranging results with different interference suppression methods for SINR=-23dB

Fig.9 Interferencesuppression effects of the proposed method under different SINRs

Table 2 Computational time s

方法	数值
本文方法	0.0194
ANC方法	0.0030
自适应滤波方法	0.3848
EMD是方法	0.6241

Fig.10 Measured scene

Fig.11 Time domain diagram ofbeat signal under swept frequency jamming

Fig.12 Comparison of ranging results

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