Authors: Jiaqing Wu; Robert E. Williams; Lance C. Pérez
Addresses: Department of Technical Management and R&D, Greenland Group, Shanghai, China ' Mechanical and Materials Engineering Department, University of Nebraska, Lincoln, NE, USA ' Electrical Engineering Department, University of Nebraska, Lincoln, NE, USA
Abstract: Radio Frequency Identification (RFID) is an information exchange technology based on radio wave communication. It is also a possible solution to indoor localisation. Owing to multipath propagation and anisotropic interference in the indoor environment, theoretical propagation models are generally not sufficient for RFID-based localisation. In fact, the received radio frequency signal distribution may not even be monotonic and this makes range-based localisation algorithms less accurate. On the other hand, range-free localisation algorithms, such as k Nearest-Neighbour (kNN), require reference tags to be spread throughout the whole three-dimensional (3D) space which is frequently not practical. In this work, a hybrid real-time localisation algorithm that combines reference tags with Received Signal Strength Indicator (RSSI) ranging is introduced to improve RFID-based 3D localisation in indoor environments. The localisation algorithm is implemented in MATLAB and is synchronised with radio signal data in real-time. Results show that the proposed hybrid algorithm achieves an average 3D localisation error of 1.08 m which represents a significant improvement over algorithms that use only kNN or RSSI.
Keywords: RFID tags; radio frequency identification; 3D indoor localisation; error prediction; RSSI; received signal strength; RSS indicator.
International Journal of Radio Frequency Identification Technology and Applications, 2015 Vol.4 No.4, pp.309 - 324
Received: 11 Mar 2014
Accepted: 13 Oct 2014
Published online: 10 Jul 2015 *