Using Antenna Array in Multipath Environment for Wireless Sensor Positioning.

The rapid growth in demand for location based service has encouraged research into the performance improvement for wireless sensor positioning systems. Most of proposed localization techniques for wireless sensor networks rely on multilateration or cooperative localization. In this paper, we propose a novel approach in the context of multiple-input multiple-output (MIMO) communication technique to determine the position of sensor nodes. MIMO communication systems use antenna array in both source and receive nodes to exploit the spatial properties of the multipath channel, thereby offering more information for sensor positioning. Based on estimated multipath signal parameters such as angle-of-arrival, angle-of-departure and delay-of-arrival through adaptive array signal processing techniques, the proposed approach try to minimize the errors occurring from the estimation of multipath signal parameters and gives an optimal estimation of the position of the neighbor sensor node by simultaneously resolving a set of nonlinear location equations. Computer simulations show that the position of sensor node can be determined using only one other sensor node. The mean-square errors are measured and compared with the Cramer-Rao Lower Bound to demonstrate the performance of the proposed method.