Detecting Locations and Vital Signs of Multiple Humans With MIMO FMCW Radar

This paper presents methods to detect locations and vital signs of multiple humans with a multiple-input and multiple-output (MIMO) frequency-modulated continuous wave (FMCW) radar. Digital beamforming of virtual receiver arrays generated by the MIMO FMCW radar allows to find ranges and angles of multiple targets. Human targets are distinguished from stationary clutters by the proposed method, which estimates the lengths of their I/Q trajectories. These are proportional to the amount of phase variations. Vital signs of detected human targets can be also extracted through a phasetracking method using multiple frequencies of a FMCW signal. Experimental results show that ranges, angles, and vital signs of three human targets are simultaneously monitored with the proposed MIMO FMCW radar.