White Light Constrained Multi-Primary Modulation For Visible Light Communication

The application of visible light communication (VLC) systems is to transmit data while maintaining efficient and good quality illumination service. In order to meet standard lighting requirements when multi-colored modulation techniques are used, such as color shift keying (CSK), the color fluctuation becomes a relevant issue. This paper presents a multi-primary (multi-color) modulation technique which provides reliable data transmission while keeping a strong constraint on the light color illuminated by every symbol of the modulation alphabet. The number of possible primary color combinations that ensure white light are calculated for a given set of multi-color light sources. The system performance in terms of bit error rate for different constellation is evaluated and compared against other multi-color VLC schemes in the literature, considering a range of channel impairments due to the optical front-end components.