Experimental Investigation of the Effects of Fog on Optical Camera-based VLC for a Vehicular Environment

The widespread increase in the use of light emitting diodes in vehicle’s head and taillights and also the use of dashboard cameras provides great prospects for the optical camera based visible light communications (VLC) technology in intelligent transport systems. In this paper, we experimentally investigate the impact of fog on the optical camera based VLC technology for vehicle-to-vehicle (V2V) communications. A range of meteorological visibilities between 5–120 m is considered based on realistic inter-vehicle distances in practical vehicular environments and using a real car taillight as the transmitter. We show a reduction in the index of modulation of the signals from 1 to 0.75 and 0.5 to allow for tracking purposes of the light source when sending ‘0’ symbols. The results show that, the link is error-free up to 20 m meteorological visibility for the three modulation index scenarios and degrades considerably below 10 m meteorological visibility.