Implementation and Evaluation of VLC-Based Indoor Positioning Systems for Smart Supermarkets

This paper presents an experimental implementation and performance evaluation of an indoor positioning system based on visible light communications (VLC). The system hardware, including a VLC transmitter and a receiver, is designed taking into account the illumination flicker, brightness, signal synchronization, noise and path loss issues. In addition, we propose a simple protocol design for location identification (ID), including the location ID format, the ID frame structure and its error control. The experiments are performed to optimize the design of the receiver so that the pulse-error rate (PER) is minimized. Furthermore, we also confirm the location ID detectability in case of with and without Golay error correction code. Experimental results confirm that it is possible to achieve the PER bellow 10-3 at 9 m or shorter distance. In addition, the location ID detectability is higher than 95% when the receiving time of 0.7 seconds, which is equivalent to the walking speed of 1.4 m/sec, under the LED coverage cell of 2 m.