Object Tracking in an Indoor Scenario: Potential for Centimeter Accuracy with LiFi

Localization in indoor scenarios is difficult based on radio technologies, due to fading and the dominant multipath propagation. Optical wireless technology also denoted as LiFi, propagates mostly via the line-of-sight. Therefore, it has the potential to provide the required centimeter accuracy for indoor Internet-of-Things applications. In this paper, we consider positioning as an extra service offered by the LiFi communication system. Our vision is to detect the required location of automatic guided vehicles, intelligent transport systems, and mobile assembly units in an industrial environment, by using the same hardware also used for wireless communication. Our proposal is based on time-of-flight measurements. We reuse the physical layer from the ITU-T recommendation G.9991 for LiFi for ranging and subsequent trilateration. In this paper, we have further developed this approach towards continuous object tracking and evaluated the accuracy of the 3D position detection in an indoor environment. We observe that the results depend critically on the layout of the LiFi cell. Moreover, we demonstrate that the time-of-flight technique allows object tracking at a speed of 1 measurement / second with an average accuracy of 3 cm in each dimension. The proposed scheme is promising for future real-time implementation and has a high potential for future Internet-of-Things applications.