Distributed TDoA estimation for wireless sensor networks

A novel distributed TDoA (Time-Difference-of-Arrival) estimation method for wireless sensor networks (WSN) is proposed in this letter. Linear frequency modulation (LFM) waves are emitted from two anchors simultaneously to create an interference field. Through the frequency measurement of local RSSI (Received Signal Strength Indication) signal, the TDoA is estimated independently at each sensor to detect range difference from the sensor to the two anchors. Furthermore, an extended method applied to mobile sensors is also presented. The proposed method only relies on radio transceivers and requires no time synchronization for sensors. Simulations results demonstrate the effectiveness of our method.