Stepwise refinement algorithms for prediction of user location using receive signal strength indication in infrastructure WLANs

This paper examines several algorithms for improving the estimation of user location using received strength signal indication (RSSI) values in a standard infrastructure wireless local area network (WLAN). The basic method of estimating a mobile user´s position is the variation of RSSl with transmitter/receiver separation. Unfortunately, due to both external interference and the inherent uncertainty present in RSSI measurements, this approach leads to unacceptable errors in the position estimates. In order to improve the overall accuracy of the system, several refinement algorithms have been examined and simulated to investigate their effect on the system accuracy, with the results presented herein.