F-SMART: Target-Protected Slow-Time Reconstruction for Automotive FMCW Radar Interference Mitigation

Non-cooperative frequency-modulated continuous-wave (FMCW) interference degrades automotive radar sensing when an asynchronous interference ridge crosses a target beat-frequency line. Masking, excision, or independent per-chirp recovery can then remove target support or perturb slow-time phase consistency, spreading target energy and increasing false alarms in the range–Doppler map. This paper proposes F-SMART (Fourier-synchrosqueezing slow-time multimodal adaptive reconstruction technique), a detection-oriented pre-detection mitigation method. Target-prioritized evidence constructed by the Fourier synchrosqueezing transform and dynamic programming identifies target support, interference trajectories, and observation reliability. The resulting evidence is mapped to range–slow-time groups, where weighted multimodal modeling estimates supported Doppler modes and selectively rewrites low-reliability observations within accepted target support. F-SMART is evaluated through a 300-case held-out comparison involving nine processing pipelines, controlled representation and structural ablations, operating-boundary and high-load studies, and publicly available measured mutual-interference data. In the held-out comparison, F-SMART achieved a three-family macro-average F1 of 0.9162. F-SMART is therefore best viewed as a detection-oriented range–Doppler cleanup method for non-cooperative FMCW interference, with explicit tradeoffs among detection performance, false-alarm control, and spectral fidelity.