Light-emitting diodes aided indoor localization using visible light communication technology

This paper focuses on designing and analyzing a visible light-based communication and positioning system for indoor wireless communication under light-emitting diodes (LEDs) lighting environments. The indoor positioning system uses trichromatic white LEDs, both for illumination purposes and as transmitters, and an optical processor, based on a-SiC:H technology, as a mobile receiver. An on-off keying modulation scheme is used, proving a good trade-off between system performance and implementation complexity. The relationship between the transmitted data and the received output levels is decoded. LED bulbs work as transmitters, sending information together with different identifiers, IDs, related to their physical locations. Square and diamond topologies for the unit cell are analyzed, and a two-dimensional localization design, demonstrated by a prototype implementation, is presented. Fine-grained indoor localization is tested. The received signal is used in coded multiplexing techniques for supporting communications and navigation concomitantly on the same channel. The location and motion information are found by mapping the position and estimating the location areas.