Multi-Target Vital Signs Detection Based on MIMO-FMCW Radar
To address the problem that multiple-input multiple-output(MIMO)frequency modulated continuous wave(FMCW)radar is difficult to accurately detect multiple people's vital signs in indoor environments,a multi-target vital signs detection method based on MIMO-FMCW radar is proposed in the paper.Firstly,the range fast Fourier trans-form(FFT)and Capon angle estimation are performed on the IF signal to obtain the distance angle map.Accordingly,the distance and angle information of each target is determined by using the two-dimensional constant false alarm detec-tion technique(2D-CFAR)and density-based clustering of applications with noise(DBSCAN)algorithm.Then,the digi-tal beamforming is performed by the linear constraint minimum variation(LCMV)criterion to obtain the slow time sig-nal for each target.In particular,the arctangent demodulation is used to achieve the extraction of phase signal.Finally,the harmonic discrimination criterion is adopted to obtain the respiration rate and heart rate for each target.The experi-mental results show that the proposed method can realize the detection accuracy of respiration rate and heart rate with an average relative error of less than 10%.