Many solutions have been proposed for positioning, going from satellite-based techniques (i.e. GPS…), video tracking or radio-electrical waves combining…. However, these techniques reach their limit when very high accuracy is required (lower than 10 cm), especially in indoor environment.
In such a stringent requirement, Ultra Wide Band (UWB) based techniques have emerged as accurate solutions. UWB are radios having relative bandwidths larger than 20% or absolute bandwidths of more than 500 MHz. Such radios combine low to medium rate communications with positioning capabilities using ranging techniques [1].
If UWB offers outstanding accuracy, the performance degrades significantly in severe environments, i.e. in presence of multipath due to crowded rooms or when machines generate impulsive noise in factories. Moreover, to propose energy efficient solutions, a complete cross layer approach has to be envisaged, including hybrid algorithms combining Two Way Ranging (TWR) and Angle of Arrival (AoA) methods [2], as well as dedicated MAC protocols.
The first phase of this work will be dedicated to the bibliography study on UWB communications and localization techniques [3]. It exists many localization techniques among which we can cite the trilateration but some others have already been developed in the GRANIT team, either opportunistically selecting best anchors for trilateration [6] or using embedded Inertial Motion Unit that gives direction information [7].
A recent version of Decawave UWB transceiver embeds two antennas, offering the possibility to perform AoA estimation. On the one hand, this technique simplifies the MAC protocol and increase the scalability because exhaustive TWR are no more required, but on the other hand this method does not support low angles. The candidate should then be able to improve these techniques considering application-specific aspects (number of persons/sensors, accuracy required, orientation, noise, speed of the persons…) and even propose a hybrid, adaptive localization scheme that takes profit of the complementarity of TWR, AoA or direction-based approaches.
Then, these techniques will be implemented in a new version of the Zyggie [8] platform developed in the team, which embeds decaWave UWB transceivers.
[1] IEEE802.15.4a/D7, Wireless MAC and PHY Specifications for Low-Rate Wireless Personal Area Networks
[2] I. Dotlic, A. Connell, H. Ma, J. Clancy, and M. McLaughlin, Angle of arrival estimation using decawave dw1000 integrated circuits, 14th Workshop on Positioning, Navigation and Communications, 2017
(WPNC), pages 1–6. IEEE, 2017.
[3] G.M. Hoang, M. Gautier, A. Courtay, Cooperative-cum-Constrained Maximum Likelihood Algorithm for UWB-based Localization in Wireless BANs, IEEE International Conference on Communications (ICC), 2015
[4] S. Monica and G. Ferrari, UWB-based localization in large indoor scenarios: optimized placement of anchor nodes, in IEEE Transactions on Aerospace and Electronic Systems, vol.51, no.2, pp.987-999, April 2015
[5] GRANIT Team: https://www-granit.irisa.fr/
[6] A. Courtay, M. Le Gentil, O. Berder, P. Scalart, S. Fontaine, A. Carer, Anchor Selection Algorithm for Mobile Indoor Positioning using WSN with UWB Radio, IEEE Sensors Applications Symposium (SAS), 2019
[7] M.L. Diallo, A. Courtay, M. Le Gentil, O. Berder, Direction-Aided Indoor Positioning Leveraging Ultra-Wideband Radio, IEEE International Conference on Vehicular Technology (VTC), 2019
[8] A. Courtay, M. Le Gentil, O. Berder, A. Carer, P. Scalart, O. Sentieys, Zyggie: A Wireless Body Area Network platform for indoor positioning and motion tracking, IEEE International Symposium on Circuits and Systems (ISCAS), 2018
[9] T. Ertan, B. M. Ledvina, R. W. Brumley, A. S. Meyer, P. C. Tsoi, Electronic Devices with Motion Sensing and Angle of Arrival Detection Circuitry, U.S. Patent Application 2019/0317177, issued October 17, 2019