Localization in Presence of Multipath Effect in Wireless Sensor Networks

摘要

Localization in an urban area is a challenging problem due to the blocking of Line-of-Sight (LOS) signal by various obstacles and also the multipath effect arising out of reflections and scattering of signals. Assuming that there are a few anchor nodes which know their positions accurately and which transmit ultrasonic signals, we propose here a technique to find the position of other sensor nodes based on receiving these ultrasonic signals reflected by some reflectors. Our proposed technique can calculate the position of a node correctly by receiving two reflected signals (Non-Line-of-Sight (NLOS)) from an anchor. We, however, assume that a signal is reflected at most once before reaching a node and the two reflecting surfaces are non-parallel to each other.