Projection-Based Location System via Multiple Discriminant Analysis in Wireless Local Area Networks
ABSTRACT This paper presents a projection-based location system in an indoor wireless local area network (WLAN) environment. Our algorithm projects the received signal strength (RSS) onto a discriminative space such that the information of all access points (APs) is more efficiently utilized. The projection is determined by multiple discriminant analysis (MDA), thereby guaranteeing maximal discriminative information involved in the positioning system. The study conducts a series of experiments on the effects of our approach in a realistic indoor environment. The results show that not only is the positioning accuracy significantly improved, but the system cost, including the computation and data collection, is also greatly reduced at the same time. This is because our approach extracts only useful information for positioning, whereas the redundant noise is discarded to avoid the problem of overfitting and unnecessary calculations. Compared with prior works, this technique can produce a more graceful balance between the positioning accuracy and the computational complexity for the resource-weak clients.
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ABSTRACT: Subspace learning methods have been used to improve indoor positioning accuracy in wireless local area network (WLAN). However, these methods all suffer from the multimodal signal distributions. Furthermore, the variability of RSS over physical locations presents challenge to learning methods. This paper proposes local fisher discriminant analysis (LFDA) for improved WLAN positioning. LFDA adapts multimodality of signal distributions effectively and extracts more separate location features than previous methods. This is because LFDA further considers preserving the within-class local structure of signal space, thereby more freedom is left for maximizing the between-class separability of physical locations. Moreover, we do not perform monolithic LFDA model over the whole region. Instead, clustering analysis is incorporated to take advantages of spatially localized LFDA and reduce complexity. The proposed method is carried and compared with previous methods in a realistic WLAN indoor environment. Experiments show that the proposed method achieves significant accuracy improvement while reducing computation cost.Wireless Communications and Networking Conference (WCNC), 2013 IEEE; 01/2013
Conference Paper: Locating and monitoring tenants in PV based buildings[Show abstract] [Hide abstract]
ABSTRACT: This paper describes a wireless location and occupancy system used to create house and user energetic profile systems. Both procedures will be used to raise consumers' energy awareness in PV efficient building systems. Home energy consumption must be improved in order to evolve towards Net Zero Energy Buildings. Only the combine use of home PV grid-connected power systems with the active and responsible citizen's engagement in addressing the carbon and energy reduction challenge will allow homes and buildings to become Net Zero Energy Buildings. The developed system is composed by two subsystems. The first one (designated as WiLOS) deals with the problem of users' location inside a building, while the second (designated as HUEPS) uses the energy consumption of the building and the location information to create the users' energetic profiles. Both subsystems are described and experimental data is presented in order to show the effectiveness of the proposed methodology.2nd International Conference on Renewable Energy Research and Applications, Madrid, Spain; 10/2013
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ABSTRACT: This study proposes two positioning algorithms, called the focused time delay neural network (FTDNN) and the distributed time delay neural network (DTDNN), to efficiently learn the mobile location from sequential received signal strength (RSS). By embedding the temporal structures of RSS into the spatial structures of networks, the proposed algorithms can extract location information from temporal variation of RSSs rather than removing them. This study applies the proposed algorithms to actual Global System for Mobile communications (GSM) networks, collecting realistic RSS measurements across a campus using commercially available mobile phones. On-site experiments clearly demonstrated that both algorithms provide better positioning accuracy than the traditional Cell-ID method, the Bayesian approach, and the multilayer perceptron with variations, where DTDNN achieves the best performance.IEEE Transactions on Vehicular Technology 02/2012; 61(2):726-736. · 2.64 Impact Factor