Experimental analysis of RSSI-based indoor localization with IEEE 802.15.4

Abstract

This paper presents a comparison between some of the most used ranging localization methods based on the Received Signal Strength Indicator (RSSI) in low-power IEEE 802.15.4 wireless sensor networks. In particular, the Trilateration, the Min-Max and the Maximum-Likelihood algorithms have been compared using only a limited number of reference nodes. In order to perform an exhaustive comparison we carried out tests in an indoor environment: dozens of RSSI values for every estimation have been gathered and cleaned from outliers values. Our results show that it is possible to some extent to obtain positioning information from nodes equipped with IEEE 802.15.4 radio modules, given the position and the number of reference nodes.

Low-Complexity Localization and Tracking in Hybrid Wireless Sensor Networks

“…However, increasing the number of anchors does not continuously improve the accuracy. On the contrary, adding noisy values may degrade the output [6,8]. Hence, our system uses only the 6 smallest range data and discards the other values at each step.…”

“…However, in real-world deployment the ideal distribution is not always applicable: the radio signal is affected by a lot of degrading effects, such as multipath and shadowing. All these phenomena deeply impact the accuracy of RSSI measurements, often resulting in inaccuracies in the estimated distance [8].…”

“…The intersection of three circles is sufficient to determine the position of the target node. However, the intersections can be zero or more than one if range measurements are affected by errors, and some geometrical rules must be used to cope with this issue [8,16].…”

“…A way to improve ranging accuracy consists of using ancillary radio hardware, such as multiple and/or directional antennas [8], and equipping them with an absorbing plate in order to bound reflections and multipaths. The results obtained in [9,10] have demonstrated that hardware upgrades can lead to satisfactory results.…”

“…We chose two simple geometric techniques: Multilateration and MinMax. Their selection was driven by their wide use in literature because of their low complexity and good performances [3,8].…”