Enabling Real-Time Indoor Tracking of IoT Devices through Visible Light Retroreflection
Document Type
Article
Publication Date
4-1-2020
Abstract
Visible light communication (VLC)-based indoor localization approaches enjoy many advantages, such as utilizing ubiquitous lighting infrastructure, high location accuracy, and no interruption to RF-based devices. However, existing VLC-based localization methods lack a real-time backward channel from the device to landmarks and necessitate computation at the device, which make them unsuitable for real-time tracking of small IoT devices. In this paper, we propose and prototype RETRO, that establishes an almost zero-delay backward channel by retroreflection. RETRO localizes passive IoT devices without requiring computation and heavy sensing (e.g., camera) at the devices. Multiple photodiodes (i.e., landmarks) are mounted on any single unmodified light source to sense the retroreflected optical signal (i.e., location signature). We derive a closed-form expression, which is validated by experiments and ray tracing simulations, for the reflected optical power relative to the location and the orientation of the retroreflector. The expression is applied to a received signal strength indicator and trilateration based localization algorithm. Extensive experiments demonstrate centimeter-level location accuracy and single-digit angular error. For practicality concern, to mitigate the thickness problem of a single retroreflector, the capabilities of different retroreflector arrays are studied. The range of the localization system is theoretically evaluated for different light emission patterns.
Identifier
85081645581 (Scopus)
Publication Title
IEEE Transactions on Mobile Computing
External Full Text Location
https://doi.org/10.1109/TMC.2019.2901665
e-ISSN
15580660
ISSN
15361233
First Page
836
Last Page
851
Issue
4
Volume
19
Grant
CNS-1617924
Fund Ref
National Science Foundation
Recommended Citation
Shao, Sihua; Khreishah, Abdallah; and Khalil, Issa, "Enabling Real-Time Indoor Tracking of IoT Devices through Visible Light Retroreflection" (2020). Faculty Publications. 5369.
https://digitalcommons.njit.edu/fac_pubs/5369