Investigation of WDM VLC Using Standard 5 mm RGB LEDs

摘要

This paper investigates wavelength division multiplexing (WDM) uisng standard off-the shelf commercial 5 mm red, green, blue chip light-emitting diodes for visible light communications (VLC). From the initial observations of the illuminance footprint, it is found that the illumination overlap from each of the three colours is difficult to achieve a white light due to the physical layout of the emitting elements. We experimentally demonstrate that WDM is only achievable with a horizontal misalignment of +/? 0.5 cm or +/? 2 cm of the origin at a transmission span of 10 and 40 cm. Furthermore, with respect to the angular misalignment, WDM is achievable within a cone area of +5° of the origin at 10 cm distance and only along the origin at a distance of 40 cm.