Geolocation and Wayfinding Services Using Visible Light Communication

Abstract

This paper investigates the applicability of an intuitive wayfinding system in complex buildings using Visible Light Communication (VLC). Typical scenarios include finding places. Data from the sender is encoded, modulated and converted into light signals emitted by the transmitters. Tetra-chromatic white sources are used providing a different data channel for each chip. At the receiver, the modulated light signal, containing the ID and the 3D geographical position of the transmitter and wayfinding information, is received by SiC photodetector with light filtering and demultiplexing properties. Each luminaire for downlink transmission become a single cell, in which the optical access point (AP) is located in the ceiling and the mobile users are scattered within the overlap discs of each cells underneath. The light signals emitted by the LEDs are interpreted directly by the receivers of the users underneath. The effect of the location of the APs is evaluated and a model for the cellular networks is analyzed using orthogonal topologies. A 3D localization design, demonstrated by a prototype implementation, is presented. Uplink transmission is also implemented and the 3D best route to navigate calculated. The results showed that the system allows to determine the position of a mobile target inside the network, to infer the travel direction along the time and to interact with information received optimizing the route towards the destination.

Keywords

• visible light communication
• indoor navigation
• bidirectional communication
• wayfinding
• optical sensors
• transmitter/receiver
• multiplexing/demultiplexing techniques