Connecting Vehicles with Light

Connected autonomous vehicles boost a high demand on communication bandwidth in order to timely share what are perceived by in-car sensors (e.g., LiDAR). While visible light communication (VLC) presents itself as a possible solution and has shown its potential to offer Gigabit-level throughput for indoor applications, the throughput drops to only a few Mbps when it is moved outdoor. In this talk, I will present our solutions to address the problem. In the first part, I will present an interference-free outdoor mobile VLC system called RayTrack. The key idea is to build a receiver with a small but real-time adjustable FOV tracking the transmitter, which can effectively repel interference from the environment and from other transmitters and boost the system throughput. This realizes virtual point-to-point links, and eliminates the need of link access control. Real-world driving experiments demonstrate that our prototype is capable of tracking the transmitter with over 90% detection accuracy with 70 - 100 km/hr driving speed. In the second part, I will present demonstrate our preliminary work of a VLC transmitter prototype with steerable light beam called RayGen. The narrow light beam produced by RayGen carries digital data, tracks the movement of a moving receiver, and does not produce any interference to neighboring vehicles. Experimental results show that RayGen can achieve a throughput of 50 Mbps at 20 m under relative lateral velocity of up to 1.7 m/s, and more than 150 Mbps at 20 m in static scenarios.