"Characterization of RSSI based Proximity Detection"

Abstract: Real Time Locating System (RTLS) is a widely used monitoring application that assists in tracking and identifying persons or any objects using Anchors(nodes), RF tags and WSN. This is simplified by using the Chirp Spread Spectrum (CSS) technology . The combination of RTLS and CSS gives a better location accuracy ,it is therefore important to develop a effective localization algorithm. This research is mainly focused on implementing localization algorithm RSSI (Received Signal Strength Indicator) by measuring at 2.4GHz in an indoor environment. The substantial amount of information on location is collected by Anchors(Nodes) and RF tags which gives an overview of the measured data in an indoor environment.The measured data is based on TDOA (Time Difference of Arrival).The common approach of RTLS system is using Log-normal shadowing propagation with TDOA model for an indoor environment but as a changer Log-Normal shadowing with RSSI model is implemented.This measured data is further used in extracting the RSSI values and using an appropriate propagation model to determine .The simulation was done on Matlab. Finally, the measurement results were compared with simulated results thus obtaining an improved location methodology.