Remote Measurement of Human Breathing and Heartbeat in Large Scene Based on TX-RX Joint Beamfoming

Radar sensors have been widely used in non-contact vital signs detection, especially for breathing and heartbeat monitoring. However, most of the achievements in the field are verified in small scenes. In this article, a unique TX-RX joint beamforming mechanism for multi-people breathing and heartbeat measurement is proposed, where a mm-wave FMCW radar with 9 TX channels and 16 RX channels is used. The transmitting beam pointing to the desired subject is formed by phase-shifting, which contributes to a longer detection range than the state-of-art system. Digital beamforming is designed to obtain optimal spatial filtering at the receiving end, which enhances the capability in multi-people measuring. Experimental results showed that, at a large scene with the detection range from 1.8 m to 12 m, the proposed mechanism can distinguish the breathing and heartbeat signal from different people accurately.