Performance analysis of VLC systems with multi-color light sources beyond RGB LEDs

Visible light communication (VLC) is being considered as a solution to reinforce the indoor wireless communication services provided so far almost exclusively over radio frequency bands. Multi-color light-emitting diodes (LEDs) are convenient light sources in this context, which can multiply the number of data streams with the aid of wavelength division multiplexing while providing an aggregate white light that is suitable for illumination. Although Red-Green-Blue (RGB) is the most popular combination considered in the literature for tricolor LEDs, other less explored options can also be considered to reach different illumination and communication key performance indicators in VLC systems. To carry out this analysis, an exact closed-form procedure is derived in this paper for the allocation of power per individual LED chip for any tri-color combination, which is beyond the state-of-art of the approximated methods used so far. The most convenient tri-color LED combination is also identified for providing communication and illumination services at different correlated color temperatures (CCTs). While RedOrange-Green-Blue is the most energy-efficient tri-color LED combination for illumination (in lm/W), RedOrange-Cyan-Blue is the most convenient tri-color combination to maximize the spectral efficiency for communication (in bps/Hz/W).