Improving RFID-based indoor positioning accuracy using Gaussian processes

The received signal strength (RSS) of radiofrequency signals emitted from beacons placed at known locations in an environment, can be used by a local positioning system (LPS) to estimate the location of a person or a mobile object. In indoor environments, interference, multipath propagation of RF signals, and the presence of obstacles and people, lead to a complex spatial distribution of the RSS, which is inaccurately described by simple parametric models. In this work, we present a Bayesian method for an indoor RFID location system which uses an observation model based in Gaussian processes (GPs) nonparametric regression to represent the environment-specific RSS distributions for the individual RFID tags. The experimental results in an indoor environment demonstrate the effectiveness of GPs in order to increase positioning accuracy.