Hierarchical approach to enhancing topology-based WiFi indoor localization in large environments

Hernández, Noelia; Alonso, José María; Ocaña, Manuel

Year: 2016

Type of Publication: Article

Journal: Journal of Multiple-Valued Logic and Soft Computing

Volume: 3

Number: 5

Pages: 221-241

Month: March

ISSN: 1542-3980

Abstract:

Traditionally, WiFi has been used for indoors localization purposes due to its important advantages. There are WiFi access points in most buildings and measuring WiFi signal is free of charge even for private WiFi networks. Unfortunately, it also has some disadvantages: when extending WiFi-based localization systems to large environments their accuracy decreases. This has been previously solved by manually dividing the environment into zones. In this paper, an automatic partition of the environment is proposed to increase the localization accuracy in large environments. To do so, a hierarchical partition of the environment is performed using K-Means and the Cali´nski-Harabasz Index. Then, different classification techniques have been compared to achieve high localization rates. The new approach is tested in a real environment with more than 200 access points and 133 topological positions, obtaining an overall increase in the accuracy of approximately 10% and reducing the error to the real position to 2.45 metres.