Visible - Light Communication Demonstrator : System modeling and analogue distribution network design by Amita Shrestha

Visible-light communications (VLC) is a technology for wireless communication using light that can be perceived by the naked eye. VLC uses frequencies other than radio, and they are unrestricted and licence free. In recent years, optical wireless communication (OWC) for short ranges (up to 10’s of meters) has experienced increasing interest amongst researchers. Currently, Siemens Corporate Technology (CT) is participating in Home Gigabit Access (OMEGA), an EU integrated platform within the seventh Frame Programme. The technology to be demonstrated is visible-light communication using white LEDs with a target data rate of 100 Mbits/s. To date, visible light communication using one LED has been successfully implemented. However, in order to illuminate the VLC area of OMEGA demonstration showroom, arrays of LEDs have to be placed on the ceiling. Modeling of the placement of these LEDs needs to be designed such that the VLC area is homogenously illuminated and leakage outside the area is minimized. In addition, analogue signal distribution network has to be designed in order to distribute the signal to all the LEDs. This thesis addresses these issues. The lighting levels within the VLC area was simulated for different configurations of LED placement. Furthermore, various network topologies like linear-bus, star, and tree were experimented. It was observed that star network uniformly distributes the signal to all the LEDs and offers higher signal to interference ratio. Following the results of this thesis, star distribution network for the chosen LED placement scenario will be implemented in the OMEGA demonstration showroom.