Interference Mitigation for FMCW Radar Systems with Modulo Sampling Framework

Abstract

The problem of interference in frequency modulated continuous wave (FMCW) radars is considered. The application of modulo analog-to-digital converters (ADCs) to sample interfered intermediate-frequency (IF) signals is proposed to preserve both target returns and interference signals with high-amplitude resolution without signal saturation. Both the high dynamic range (HDR) self-interference (SI) and the desired IF signal segments are recovered from modulo samples with low quantization. To integrate modulo sampling with interference mitigation, a new interference detection method leveraging the spectral spread property of the modulo nonlinearity is proposed. The different recovered segments of the IF signals are then aligned in the temporal domain. The identified mutual interference (MI) can be interpolated from the recovered IF signal segments. The effectiveness of the proposed method in handling MI and preserving high-resolution HDR samples of both targets and SI is demonstrated in numerical experiments for different automotive radar scenarios.