Mutual information of a 3x3 RGB MIMO VLC scheme based on Amplitude Shift Keying

Visible Light Communications (VLC) are a new key in the Internet access as well as, a possible enabler of Internet of Things. This kind of systems can allow, in principle, high data rate by stressing the bandwidth and also the spatial dimension. We deal in this work with a 3×3 VLC system characterized by red, green and blue LEDs at the transmitter and three photodiodes at the receiver. Each photodiode is tuned on a different color. In this paper we analyze the mutual information expression when thermal noise is present and we distinguish two different approaches. The first one considers the effect of interference of colors, while the second one aims at equalizing, from a spatial/color point of view, the channel. More, we show the numerically evaluated mutual information and the effect of some system parameters.