QRLoc: User-involved calibration using quick response codes for Wi-Fi based indoor localization

Constructing a radio map is one of essential steps for fingerprint-based localization. A lot of time and efforts are necessary to construct a radio map that covers a large area. Moreover the radio map should be updated when there is a severe change in Wi-Fi environments of a service area. In this paper, we develop a Wi-Fi fingerprint collecting system, QRLoc, to reduce such collection efforts. QRLoc collects Wi-Fi fingerprints with the help from smartphone users and Quick Response (QR) codes (or short-range tag identification technique) attached at fixed walls or pillars across a service area. The key idea of QRLoc is to automatically collect fingerprints when smartphone users scan QR codes attached at known and fixed locations such as signs and posters. QRLoc can address the motiveless problem of users in collecting WiFi fingerprints because the contributions are made in an unobtrusive manner from the user's ordinary activity like capturing QR codes.