Wireless Multi-Target Vital Sign Detection Using SIMO-FMCW Radar in Multipath Propagation Environments

Frequency-modulation continuous wave (FMCW) radar has been employed to implement a non-contact vital sign monitoring system for future healthcare applications. This paper proposes a multi-target vital sign (heart rate and breath rate) detection scheme with limited channel information for single-input multiple-output (SIMO)-FMCW radar systems in multipath propagation environments. In the proposed method, multipath effect mitigation is first achieved by the decomposition of vital sign signals from self- and mutual-multipath interferences using the multichannel singular spectrum analysis (MSSA) algorithm. Then, the desired vital signs are estimated via the estimation of signal parameters via rotational invariance technique (ESPRIT). Simulation shows that the proposed scheme achieves superior performance in terms of the estimation error in multipath propagation environments.