Impacts on Multi-pulse Pulse Position Modulation Visible Light Communication from Outdoor Daylight Conditions

Abstract

The growing deployment of light-emitting diodes as energy-efficient, cost-effective lighting for vehicles opens opportunities for visible light vehicle-to-vehicle communication. Leveraging existing headlights and taillights on cars for inter-vehicle communication offers an opportunity to save on both hardware costs and the use of the congested radio frequency spectrum. However, most vehicle-to-vehicle visible light communication investigations in the literature have been limited in range. This paper presents an overview of the factors impacting outdoor visible light communications at increasing distances and presents findings from outdoor testing at ranges approaching 200 m. Using software spatial filtering and multi-pulse pulse position modulation, strong throughput is shown at 50 m in daylight conditions, with improving symbol error rates achieved in outdoor daylight conditions at 100 m by increasing intensity modulation.