Large Scale Indoor VLC Positioning Using Image Sensor with Limited Field of View

Abstract

As global positioning system (GPS) has failed in indoor environments, numerous technologies are proposed to obtain better indoor positioning system performance. One of these technologies is based on visible light communication (VLC), which has become popular due to its benefits. This technique has shown significant advantages, including cost efficiency, long lifetime and good environmental friendliness. In this paper, we use VLC positioning based on the angle difference of arrival (ADOA) to estimate the position of people or devices in a large scale indoor environment using the least square method. Two different placements for light-emitting diodes (LEDs) are considered. Assuming practical limited field of view (FOV) for the user's camera, part of LEDs in the image plane can be observed. Thus, we propose a simple method to find the position of users using the cross-correlation between the reference images and the user image. This approach reduces the search region. Simulation results show that this method can achieve an average error of 32 cm in a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$12\mathrm{m}\times 12\mathrm{m}\times 5.5\mathrm{m}$</tex> space in a 4X-shape LED placement, and in a checkered LED placement the average error is about 38 cm in the same size room.