Vehicular Visible Light Communication With Low Beam Transmitters in the Presence of Vertical Oscillation

The availability of light-emitting diodes (LEDs) in vehicle exteriors makes possible the use of visible light communication (VLC) as a vehicle-to-vehicle (V2V) wireless connectivity solution. While there has been a growing literature on vehicular VLC, the existing works inherently assume the deployment of regular passenger vehicles. In this paper, we consider the use of VLC for vehicular connectivity between heavy vehicles such as trucks. We assume that low beam headlights are used as transmitters. Due to the nature and function of vehicular low beam lighting, the upward distribution of lighting is fundamentally different from its downward distribution. Hence, the vertical displacement (i.e., the height difference between transmitter and receiver) and the vertical oscillation experienced by heavy vehicles might significantly impact the VLC link. Based on experimental measurements, we first propose an accurate path loss model that takes into account the effect of vertical displacement and oscillation. Then, we derive a bit error rate (BER) expression for VLC-based truck-to-truck communication system and investigate the effect of several system and channel parameters on the performance. In an attempt to mitigate the degrading effects of the vertical oscillation, we further investigate the proper selection of photodetector location to minimize the error rate performance.