Indoor Positioning Using WLAN Fingerprinting with Post-Processing Scheme
Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Tartu Ülikool
Abstract
Information about a person’s position is a valuable piece of context information on which many
application and location services are based upon. In outdoor environments the Global Positioning
System (GPS) and Assisted GPS (A-GPS) are widely used and they perform reasonably well, but
they underperform when there is no clear access to the sky, i.e. in indoor environments. Most of
the research conducted and solutions developed aim for real-time indoor positioning or personal
tracking, but to the author’s knowledge there are not many studies on the subject of post-
processing. Post-processing has many benefits over real-time solutions, like preserving battery
life of a mobile device, leveraging bigger processing power, using more complex algorithms that
cannot run on mobile devices, and ultimately getting better accuracy on a person’s movements
tracks. In this thesis, an Indoor Positioning System (IPS) using WLAN fingerprinting with post-
processing scheme is proposed. The system uses a large set of fingerprinted Received Signal
Strength (RSS) collections obtained in the offline phase and references them in post-processing
against data collected in the online phase. A series of field experiments have been conducted in
University of Tartu’s Faculty of Mathematics and Computer Science building. The results show
that with a post-processing scheme more computationally extensive algorithms can be used and
better accuracy achieved than in real-time.