An Improved EKF Localization Method with RSSI Aid for Mobile Wireless Sensor Networks

A mobile node localization algorithm based on the Extended Kalman Filter (EKF) along with Radio Signal Strength Index (RSSI) information is proposed in this paper for mobile sensor networks. The localization process is two-fold: the initialization phase and subsequent localization phase. If a node receives the information broadcast from three anchor (or beacon) nodes, it will be localized initially and then enter the subsequent phase. Different from the localization methods using EKF with RSSI requiring three anchor nodes or more, the proposed method estimates the position of a localized node whether or not any anchor node is received. The simulation results indicate that the node localization rate of the proposed method outperforms. Also, more anchor nodes received, more accuracy localization results observed.