Positioning and tracking algorithm using node selection method in wireless sensor networks

For various kinds of applications in sensor network, the position information of each sensor tag is essential. Some conventional linear search algorithms used for time-of-arrival (TOA), however, are easily degraded due to serious multipath fading and non-line-of-sight (NLOS) propagation especially in indoor or urban environments. In this paper, we describe some novel algorithms for accurate indoor positioning of a sensor tag in a network of fixed base station. The proposed technique uses node selection method. The proposed algorithm has two position-fix processes. Firstly, the combination of base station in line-of-sight (LOS) environment is selected by locating the base station from the target sensor tag. Then, positioning result is obtained with only combination of base station in LOS environment. Results using simulated data show usefulness of the proposed algorithm which can achieve more robust and precise estimation compared with conventional methods.