Robust Joint Doppler Disambiguation and Phase-Compensated DOA Estimation for FMCW-TDM MIMO Radar

Abstract

This study addresses the combined challenges of reduced maximum unambiguous Doppler velocity and DOA estimation blurring inherent in time-division multiplexing (TDM) multi-input–multi-output (MIMO) frequency-modulated continuous wave (FMCW) radar. We propose a novel joint de-aliasing framework that integrates peak searching via matched filtering with a compensated direction-of-arrival (DOA) processing scheme. A key advantage of the proposed method is its versatility: it can work with general MIMO configurations without the requirement of overlapped virtual elements, whereas existing state-of-the-art methods typically necessitate specific virtual array configurations. The framework efficacy is validated through numerical simulations to establish theoretical performance, experimental data from a radar target simulator (RTS) utilizing an irregular MIMO topology based on Texas instruments (TIs) cascaded radar boards, and real-world driving scenarios to demonstrate practical robustness. Results indicate that the proposed method achieves an estimation error comparable to state-of-the-art benchmarks—within a 1% margin in RTS experiments—while providing reliable target localization in complex dynamic environments.