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Visible light communication (VLC) has emerged as 1 a potential wireless connectivity solution for infrastructure-to-2 vehicle networks where street lights can be configured to serve 3 as access points. In this letter, we propose dynamic soft handover 4 algorithm based on coordinated multipoint (CoMP) transmission. 5 The proposed algorithm takes the rate of change in the received 6 power as an input and accordingly revises the handover margin 7 and time-to-trigger value without explicit information of the vehi-8 cle velocity. Our simulation results demonstrate that the proposed 9 algorithm outperforms conventional CoMP and hard handover 10 and maintains a stable signal quality regardless of vehicle velocity.

The increasing adoption of LEDs in exterior automotive lighting makes visible light communication (VLC) a natural solution for vehicular networking. In this paper, we consider a vehicle-to-vehicle link and propose a path loss expression as a function of distance and different weather conditions. We conduct ray tracing simulations and verify the accuracy of proposed expression. We further use this expression to derive the achievable transmission distance for a targeted data rate while satisfying a given value of bit error rate. Numerical results are presented to demonstrate the achievable distances for single and dual photodetector deployment cases.

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Visible light communication (VLC) is based on the idea of modulating the light intensity of LEDs to transmit information and enables the dual use of exterior automotive and road side infrastructure lighting for both illumination and communication purposes. To position VLC as a strong candidate for vehicular connectivity, it is essential to realize multi-directional reception in various deployment scenarios supporting both vehicle-to-vehicle (V2V) and infrastructure-to-vehicle (I2V) links. In this paper, we investigate the performance of a vehicular VLC system in different road types (i.e., multi-lane, curved roads), intersections (i.e., T-shaped, Y-shaped intersections) and traffic scenarios (i.e., cruising in the same or different lanes, lane change etc.). We conduct a channel modeling study based on non-sequential ray tracing to quantify the capability of receiving signals in different cases. Our results reveal that deployment of nine photodetectors with carefully determined locations on the vehicle is enough to create the required quasiomni-directional coverage for both V2V connectivity (in front and back directions) and I2V connectivity. INDEX TERMSVehicular visible light communications; Connected vehicle; Omni-directional coverage; Multi-lane road; Curved road; Intersections; Receiver model.

Visible light communication (VLC) utilizes vehicle headlights as wireless transmitters and has emerged as a strong candidate for vehicle-to-vehicle (V2V) communications. In majority of works on V2V VLC systems, a common underlying assumption is that two vehicles within the same lane follow each other in a perfect alignment. In practical scenarios, a precise alignment is not available between two vehicles even if they are in the same lane. In this paper, we consider a VLC-based V2V system where the destination vehicle is equipped with four photodetectors for an omni-directional coverage. We use ray tracing simulations for channel modelling and calculate the received power for practical cases with imperfect alignment between two vehicles. In addition, we investigate the performance for lane changes. Our simulation results provide insight into which photodetectors are essential for each scenario under consideration.

Visible light communications (VLC) can utilize light-emitting diodes (LEDs) to provide illumination and a safe and low-cost broadcasting network simultaneously. In the past decade, there has been a growing interest in using organic LEDs (OLEDs) for soft lighting and display applications in public places. Organic electronics can be mechanically flexible, thus the potential of curved OLED panels/displays devices. This paper provides unique characteristics of a flexible OLED-based VLC link in a shopping mall. We show that, for curved OLED the radiation pattern displays a symmetry, which is wider than Lambertian. A number of scenarios of VLC system with flexible OLED are analyzed. Numerical models for the delay spread and optical path loss are derived, which followed a 2-term power series model for both empty and furnished rooms. We show that using a full-circular OLED for both empty and furnished rooms offers a uniform distribution of emitted power for the same transmission link spans. The link performance using full and half-circular OLED in an empty room shows that the average optical path losses are lower by 5 and 4 dB, compared with the furnished room.