## 1 Introduction
Addressing these issues requires intensive efforts to develop robust noise-mitigation techniques, adaptive architectures, and eventually, efficient error-correction mechanisms. By following this path, we can unlock the full potential of VLC as a transformative technology for next-generation intelligent transportation systems. In this context, this article proposes a new field of view (FoV) adaptive VLC receiver aimed for vehicular-communication-based safety applications. Differently from previous works, where the VLC receiver had a static FoV, the proposed concept in this work uses an automatic system, which constantly adjusts the receiver's FoV in accordance with the intensity and location of the optical noise source relative to the photodetector. This concept aims to maintain an FoV as wide as possible, reducing it only when the intensity of the optical noise source rises to a value that endangers the reliability of the link. In order to evaluate the proposed concept, a new VLC receiver prototype was implemented and experimentally tested in outdoor sun-exposure conditions. To better emphasize the benefits of the proposed concept, the demonstrative prototype was evaluated in parallel with a similar architecture, but without the adaptive FoV option. The experimental results confirmed the benefits of the proposed concept, enabling the I2V VLC prototype to maintain a 50 m communication range for the entire day and allowing it to cope with a sunlight irradiance that rose up to 67,000 \(\upmu\)W/cm\({}^{2}\), including when the sunlight was directly incident on the VLC receiver's lens. For comparison, the proposed concept significantly extended the connectivity compared to the situation in which the adaptive FoV was disabled. It should be mentioned that the authors of [27; 28; 29; 30] have previously used the dynamic FoV concept in indoor applications, with the purpose of better coping with dense optical networks. Nevertheless, as far as we know, this is the first work that experimentally demonstrates the benefits of an adaptive FoV VLC receiver designed for vehicular VLC applications. Different from [27; 28; 29; 30], this prototype adjusts its FoV in accordance with the location of the optical noise source relative to the VLC receiver, and also relative to its intensity. Thus, the main contributions of this work can be summarized as follows:  
1. Proposing and implementing a new adaptive FoV VLC receiver concept designed for vehicular applications;
2. Experimentally demonstrating an improved reliability for the adaptive FoV VLC receiver concept in real outdoor conditions;
3. Paving the way for the better mitigation of interference due to multiple vehicular VLC sources;
4. Opening the possibility of further improving the VLC receiver with more sensitive photodiodes in order to increase the communication distances;
5. Marking an important step forward in the direction of context-adaptive VLC systems. The rest of this article is structured as follows. Section 2 provides a brief analysis, which points out some of the challenges generated by an outdoor VLC channel and presents some of the existing solutions to address these challenges. Section 3 presents the adaptive FoV VLC receiver concept developed this work. Section 4 describes the comprehensive experimental setup that was designed in order to demonstrate the viability and the benefits of the proposed concept, together with the experimental results, a discussion on the experimental results, and the future perspectives of this work. At the end, Section 5 delivers the conclusions of this article. Enhancing the Optical Noise Resilience and Compatibility with the Mobile Conditions in Vehicular Visible Light Communication  
As described in the previous section, vehicular VLC applications are very challenging, whereas noise resilience and enhancing the compatibility with the mobile conditions are probably the most stringent issues associated with the use of VLC technology in vehicular applications [12].