A Subcarrier Selection Method for Wi-Fi-based Respiration Monitoring using IEEE 802.11ac/ax Protocols

This paper proposes a new respiration monitoring system based on IEEE 802.11ac/ax protocols, Fresnel zone model and Wi-Fi channel state information. A new subcarrier selection method based on Signal-Noise-Ratio is proposed and Fast/Slow Breath classified wavelet transform is adopted. The results proved the proposed algorithm is better than the prior work. The overall accuracy for respiration rate estimation is about 90.12% and can be up to 94% in some scenarios.