Title: Improvement in multiple nodes positioning accuracy for wireless sensor networks based on unknown transmitted powers
Authors: Wen-gang Zhou; Ying-chun Qi; Hai-lin Pei
Addresses: Department of Computer Science and Technology, Zhoukou Normal University, Henan, 466001, China ' Department of Computer Science and Technology, Zhoukou Normal University, Henan, 466001, China ' Xi'an Thermal Power Research Institute Co., Ltd., Xi'an, 710026, China
Abstract: In wireless sensor networks, node position is always localised by using received signal strength measurements, which owns the advantage of low cost in engineering implementations. The improvement of multiple nodes localisation accuracy is required when the transmitted powers of anchor nodes are not known. In this paper, we propose a novel localisation refinement method to improve the positioning accuracy for wireless sensor nodes. In the proposed method, we employ linear estimator to estimate the source positions along with the transmitted powers, and then use an addition of source position to improve the nodes positioning accuracy. Furthermore, we obtain the corresponding Cramér-Rao lower bound. It is also shown that, the mean square error decreases as path loss exponent value increases with the proposed method, which is obtained by using perfect knowledge of the path loss exponent.
Keywords: wireless sensor networks; WSNs; positioning accuracy; received signal strength; RSS; Cramér-Rao lower bound; CRLB; path loss exponent; PLE; mean square error; MSE; multiple nodes; node position; localisation.
International Journal of Reasoning-based Intelligent Systems, 2015 Vol.7 No.3/4, pp.214 - 220
Received: 02 Dec 2014
Accepted: 13 Apr 2015
Published online: 09 Nov 2015 *