A Smart User-Centric Visible Light Communication System

This paper presents a smart user-centric visible light communication (VLC) system for indoor communication application. In the proposed system, the VLC transmitter is incorporated with a barrier detection circuit which automatically detects the barrier between the the VLC transmitter and receiver and dynamically changes its spatial location in two dimensions (2D) in order to get good signal-to-noise-ratio (SNR) performance at the receiver. The experimental set-up of the proposed smart VLC transmitter with a barrier detection circuit consists of a micro-controller, ultrasonic sensor and low-resolution camera. Analytical expression to calculate the SNR at the receiver with blockage due to the barrier has been derived. It has been shown that high SNR could be maintained uniformly in the presence of blockage with fewer light-emitting-diodes (LEDs), by using simple hardware circuitry, irrespective of the location of the user.