Locating in fingerprint space

TLDR

Indoor localization is crucial for pervasive applications, yet radio‑based methods typically require costly site surveys to annotate radio signatures with precise locations. This study explores using built‑in sensors and user motion on modern mobile phones to construct a radio map without a traditional site survey. LiFS, an indoor localization system built on off‑the‑shelf WiFi and mobile phones, crowdsources and automatically calibrates fingerprints, enabling rapid deployment in large office spaces. Experimental results demonstrate that LiFS attains location accuracy comparable to prior approaches while eliminating the need for a site survey.

Abstract

Indoor localization is of great importance for a range of pervasive applications, attracting many research efforts in the past decades. Most radio-based solutions require a process of site survey, in which radio signatures of an interested area are annotated with their real recorded locations. Site survey involves intensive costs on manpower and time, limiting the applicable buildings of wireless localization worldwide. In this study, we investigate novel sensors integrated in modern mobile phones and leverage user motions to construct the radio map of a floor plan, which is previously obtained only by site survey. On this basis, we design LiFS, an indoor localization system based on off-the-shelf WiFi infrastructure and mobile phones. LiFS is deployed in an office building covering over 1600m2, and its deployment is easy and rapid since little human intervention is needed. In LiFS, the calibration of fingerprints is crowdsourced and automatic. Experiment results show that LiFS achieves comparable location accuracy to previous approaches even without site survey.