Portable Doppler/FSK/FMCW Radar Systems for Life Activity Sensing and Human Localization

This paper presents recent progress on portable Doppler, frequency-shift keying (FSK) and frequency-modulated continuous-wave (FMCW) radar systems for life activity sensing and human localization. It starts from a software-based calibration technology that significantly improves the accuracy and reliability of millimeter-wave interferometry radar front-end for physiological motion and vocal vibration detection. Then, the operation principle and unique features of FSK and FMCW radar, such as RF/digital beamforming, for human-aware sensing and localization will be presented. To reject clutter noise, which is a common challenge for practical deployment of short-range radar system, intermodulation radar technique will be discussed. Then, machine learning will be presented as an efficient approach to make the radar system smart for automatic classification and decision making. Finally, challenges for biomedical radar systems and future development directions will be discussed.