Human Target Recognition Using MIMO FMCW Radar and Slow-time DC-Value Suppression

Frequency-modulated continuous wave (FMCW) radars provide distinct movement-based features that aid with remote human target identification. A 2D complex-valued range-angle image (RAI) is produced by applying a 2D fast Fourier transform (FFT) to fast-time samples of virtual receiver array generated by the time-division multiplexing (TDM) concept. Unlike the human chest wall, which produces a significant phase shift from one chirp to the next in FMCW radar, stationary clutters exhibit an approximately constant phase during the coherent processing interval (CPI). This paper employs an advanced 77-GHz multiple-input and multiple-output (MIMO) FMCW radar. It applies a DC-value suppression technique along the slow-time axis to develop a stationary-clutter-free RAI for human target identification. The main advantage of this approach is its high precision and low computational complexity for real-time applications. In comparison with analogous research works, a significant reduction of approximately 58% in the average execution time is observed. The conducted experiments and robust graphical representations demonstrate the applicability of the proposed method in a complex, congested environment.