Title: An empirical investigation of RSSI-based distance estimation for wireless indoor positioning system

Authors: Nazrul M. Ahmad; Anang Hudaya Muhamad Amin; Mohd Faizal Abdollah; Robiah Yusof

Addresses: Thundercloud Research Laboratory, Faculty of Information Science & Technology (FIST), Multimedia University (MMU), Jalan Ayer Keroh Lama, 75450 Melaka, Malaysia ' Thundercloud Research Laboratory, Faculty of Information Science & Technology (FIST), Multimedia University (MMU), Jalan Ayer Keroh Lama, 75450 Melaka, Malaysia ' Faculty of Information and Communication Technology (FTMK), University Teknikal Malaysia Melaka (UTeM), 76100 Durian Tunggal, Melaka, Malaysia ' Faculty of Information and Communication Technology (FTMK), University Teknikal Malaysia Melaka (UTeM), 76100 Durian Tunggal, Melaka, Malaysia

Abstract: RSSI-based distance estimation techniques for wireless indoor positioning system require extensive offline calibration to construct propagation model in order to describe the relationship between received signal strength and distance. This paper investigates the accuracy of the well-known propagation models against the measured data at indoor building. From the results, the dual slope model exhibits the best propagation model and it is chosen as the reference for further investigation. The accuracy of dual slope model in distance estimation suffers from the degradation due to the presence of Non Line of Sight (NLOS) condition between mobile station and access point. Therefore, to further improve the accuracy, this paper studies the effect of breakpoint distance and evaluates two simple techniques, running variance and kurtosis index, to identify the NLOS condition. Once the NLOS condition is identified, the best dual slope model can be selected for accurate distance estimation.

Keywords: indoor positioning; distance estimation; dual slope propagation model; NLOS identification; non line of sight; wireless networks; RSSI; received signal strength indicator; running variance; kurtosis index.

DOI: 10.1504/IJWMC.2015.068626

International Journal of Wireless and Mobile Computing, 2015 Vol.8 No.2, pp.206 - 212

Received: 20 Nov 2013
Accepted: 14 Aug 2014
Published online: 07 Apr 2015 *

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