Visible Light Communication System in Presence of Indirect Lighting and Illumination Constraints

Visible Light Communication (VLC) systems are designed to provide illumination and data services simultaneously. To achieve this goal, LED lamps are usually deployed on the ceiling of the rooms, in order to maximize the chances of having Line-of-Sight (LoS) connectivity between the VLC transmitter and the random locations that the VLC receiver can take. In an early stage of adoption, where the cost of LED lighting fixtures incorporating VLC technology will be high to enable ultra-dense deployments, it is expected that only one VLC transmitter is placed per room. In this situation, the use of direct illumination may have serious problems to satisfy the illumination constraints and provide a homogeneous data rate coverage. Moreover, the use of a single powerful LED lamp per room may create discomfort glare effect to users and over-exposure problems in areas of the room at which the light beam is directed. In order to address these problems, this paper studies the data rate that VLC technology can achieve with indirect illumination. That is, when the LED lamp is pointing upwards, and the VLC user receives the optical signal that is reflected back from the ceiling. Obtained simulation results show that indirect illumination provides a more homogeneous data rate coverage when compared to the direct case, while simultaneously verifying the illumination constraints in most of the places that the VLC receiver may take in the room.