Indoor Localization of a Multi-story Residential Household using Multiple WiFi Signals

Tracking individuals, equipment, store locations, and floor level in a multi-story building becomes accessible through the implementation of an indoor positioning system. In this experimental study, we implement a multi-story indoor localization scheme by utilizing multiple WiFi Received Signal Strength Indicator (RSSI) signals installed in various locations of a three-floor residential household. Initially, our work focuses on static target locations spaced one meter apart and captures RSSI readings from four WiFi routers coming from different floors. These RSSI readings are stored in a database of fingerprints. To localize an indoor target, the cross-correlation between the offline and online (captured by a smartphone with a developed RSSI-capturing application) RSSI readings is calculated. Our empirical results have shown a 90% rate of correctly localizing a static indoor location when using only the average of a three-minute time series of RSSI values. We captured the WiFi RSSI values every 200 ms and present the localization utilizing the Time Reversal Resonating Strength (TRRS) concept.