Non-contact Human Respiratory Monitoring Using FMCW Radar

This paper presents a comprehensive signal processing framework for non-contact respiration rate estimation using Frequency Modulated Continuous Wave (FMCW) radar. The aim is to explore the inherent harmonic characteristics of the respiratory signal and to monitor the respiratory rate over an extended period. Firstly, the radar echo data undergoes preprocessing. The phase corresponding to the selected distance target is extracted using the phase unwrapping method. Subsequently, the Nonlinear Least Squares (NLS) algorithm-based respiration estimation framework is proposed to identify the inherent harmonic structure of the respiration signal. Finally, the experimental results show that the proposed method enhances the performance of non-contact respiratory rate estimation and exhibits robustness in human respiratory monitoring.