Multiple Power Path Loss Fingerprinting for Sensor-Based Indoor Localization

Previous fingerprinting techniques proposed for sensor-based indoor localization assume that the fingerprint database is constructed by the measurement of received signal strength (RSS) at a fixed transmit power of the transmitter sensors. In order to improve the performance of the fingerprinting technique, we consider using the measurement of path loss rather than RSS to better distinguish the signal quality at different locations. In this article, we propose an innovative fingerprint formulation, called multiple power path loss (MPPL) fingerprint, based on distinguished path losses at multiple power levels. By analyzing the signal propagation in an indoor environment, the MPPL fingerprint reveals its subtle advantage of using multiple transmit power. In addition, a location estimation algorithm is deliberately designed to exploit the performance characteristics of the MPPL fingerprint. Extensive experimental results illustrate the usability and superiority of our proposed method.