On CSI and Passive Wi-Fi Radar for Opportunistic Physical Activity Recognition

The use of Wi-Fi signals for human sensing has gained significant interest over the past decade. Such techniques provide affordable and reliable solutions healthcare-focused events such as vital sign detection, prevention falls long-term monitoring chronic diseases, among others. Currently, there are two major approaches sensing: (1) passive radar (PWR) which uses well established from bistatic radar, channel state information (CSI) based wireless (SENS) exploits human-induced variations in communication between a pair transmitter receiver. However, not been comprehensive study to understand compare differences terms effectiveness limitations real-world deployment. In this paper, we present fundamentals systems with associated methodologies signal processing. A thorough measurement campaign was carried out evaluate activity detection performance both systems. Experimental results show that SENS system provides better line-of-sight (LoS) condition, whereas PWR performs non-LoS (NLoS) setting. Furthermore, on our findings, recommend future applications should leverage advantages