Noise Resilient Outdoor Traffic Light Visible Light Communications System Based on Logarithmic Transimpedance Circuit: Experimental Demonstration of a 50 m Reliable Link in Direct Sun Exposure The usage of Visible Light Communications (VLC) technology in automotive applications is very promising. Nevertheless, in outdoor conditions, the performances of existing VLC systems are strongly affected by the sun or other sources of light. In such situations, the strong parasitic light can saturate the photosensitive element and block data communication. To address the issue, this article analyzes the usage of an adaptive logarithmic transimpedance circuit as an alternative to the classical linear transimpedance circuit. The simulation and experimental evaluation demonstrate benefits of the proposed technique, as it significantly expands the communication distance and optical noise functionality range of the VLC systems and reduces the possibility of photoelement saturation. As a result, this approach might enable outdoor VLC sensors to work in strong sun conditions, the experimental results confirming its validity not only in the laboratory but also in outdoor conditions. A reliable 50 m communication distance is reported for outdoor sunny conditions using a standard power traffic light VLC emitter and a PIN photodiode VLC sensor.

Toward a hybrid vehicle communication platform based on VLC and DSRC technologies Wireless communications technologies have the potential to significantly improve the safety and the efficiency of the transportation system. Nevertheless, supporting the requirements imposed by the usage in vehicle safety applications is rather challenging. In such a context, this paper provides an overview of some of the most promising technologies that could be used in communicationbased vehicle safety applications. The paper provides an overview of the DSRC technology as a favorite technology for such applications and of the VLC technology as a very promising emergent alternative. Based on this analysis, a hybrid architecture using DSRC and VLC is proposed. This architecture envisions that neighboring vehicles are interconnected based on VLC, whereas nonline of sight vehicles are connected through the DSRC network. Thus, an application for the connection of these network solutions is proposed and evaluated.