Electromagnetic Interference Mitigation in Automotive Radar by STFT Spectrogram Sliding Cancellation

The massive deployment of frequency modulated continuous wave (FMCW) radars in autonomous vehicles will lead to severe electromagnetic interference issues. Mutual interference mitigation is vital for ensuring the detection performance of automotive FMCW radars. Existing methods struggle to maintain a balance between interference mitigation performance and computational efficiency in complex scenarios with multiple interferences, which restricts the applicability in practical scenarios requiring rapid response. To address the predicament, this article proposes an efficient method for mutual interference mitigation among automotive FMCW radars using the short-time Fourier transform (STFT) spectrogram sliding cancellation. The interferences and target signals exhibit different time–frequency characteristics. After sliding the STFT spectrogram along the time dimension, the intensity of interference bins fluctuates dramatically while that of target bins remains virtually unchanged. Therefore, this intensity variation is employed to detect and cancel interference bins in the STFT domain. The effectiveness of the proposed method is validated through both simulations and experimental results in different interference scenarios. The results show that the proposed method can effectively eliminate the interferences and recover the target signals even if 100% of the samples are contaminated by the interference, and it is computationally efficient.