A New Color Space Based Constellation Diagram and Modulation Scheme for Color Independent VLC

In this paper, generation of a constellation diagram, data to light intensity mapping, and light intensity to data demapping are introduced for the visible light communication (VLC) systems. We propose a new constellation diagram and modulation scheme named generalized color modulation (GCM) based on light color space which can be uniquely applied to modulate the light signals used to deliver data information regardless of target colors of VLC signals. At first, we describe the generation of a constellation in a light color space considering the target color of VLC signals. Then we represent the data symbols as constellation points, resulting in every data symbol having a specific position and corresponding color in the light color space. After that, we determine the position of received signal points in the light color space at the receiver by manipulating the intensities of received signals from the photo detectors. Finally, we convert these received points to data symbols by matching them to the constellation points generated by the receiver. We consider both single color and multiple colors scenarios and investigate two cases to obtain the color information at the receiver. Simulation results show that our proposed scheme can be applied to the development of a more efficient VLC system.