Improvement of vlc technology and deployment in the context of smart city

Abstract

The demand for wireless communication systems has increased dramatically due to their ability to enable the exchange of information between various devices, o?ering the potential to enhance safety, manage tra?c and improve convenience. Extensive research and standardization e?orts in wireless communications have focused on radio frequency (RF) technologies. Nevertheless, RF technologies are susceptible to high levels of interference and channel congestion in heavily populated areas, which can adversely a?ect the performance of delay-sensitive applications. To mitigate such problems, researchers from academia and industry started to explore and develop new communication technologies. Visible light communication (VLC) is considered one of the promising technologies. VLC uses the visible part of the electromagnetic spectrum and o?ers an alternative solution to the limitations posed by RF communications. The data transmission through VLC technology depends on the ability to modulate the intensity of the Light-Emitting-Diode (LED), enabling the dual use of LED for illumination and communication purposes. This results in a highly e?cient, low-power, and low-latency communication solution, that is immune to interference from other communication technologies. VLC deploys the existing lighting infrastructures, which o?ers an innovative way to transmit data in widespread areas and for various applications such as indoor communication, vehicular communications, and smart cities. VLC is still new in some applications and requires extensive e?orts to cope with several challenges in di?erent aspects, including system and channel modeling, transceiver modeling and design, optimization of various system parameters, and performance analysis. This thesis provides a comprehensive study of di?erent research topics in VLC technology. The objective is to shed light on the new applications of VLC systems, illustrating the challenges that limit the system performance and introducing novel solutions to improve such performance. In the ?rst part of this dissertation, we provide a comprehensive review of VLC technology, illustrating the existing research e?orts on di?erent prospects. That starts from the system and channel modeling and reaches the performance analysis and system implemen- III ABSTRACT tation. Since channel modeling is critical for system design and performance estimation, we then focus on that and present a comprehensive study of the traditional and advanced channel modeling approaches for VLC systems. We illustrate the advantages and the capabilities of utilizing the advanced non-sequential ray tracing channel modeling approach. These include the ability to incorporate and model practical and commercial light sources with their di?erent radiation patterns and the consideration of many re?ections to provide more accurate results. Therefore, we adopt this channel modeling approach, which forms the foundation of our research, to model and evaluates the performance of di?erent VLC applications and scenarios in the other parts of the thesis. Our work focuses primarily on improving the performance and e?ciency of VLC systems in indoor and outdoor applications. In the second part of this thesis, we consider the outdoor scenarios aiming to improve the system performance through novel receiver designs, including imaging and non-imaging receivers. Utilizing the proposed structure, we investigate the performance of both vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) VLC applications. The third part of this thesis focuses on indoor applications where a novel resource allocation scheme is proposed to enhance the performance of Massive Optical internetof-things (IoT) systems. The proposed technique depends on an improved version of the Aquila Optimization (AO) algorithm, which integrates chaotic maps, Quasi-OppositionBased Learning (QOBL) concept, Fitness-distance balance (FDB) selection methods, and cosine functions into the original AO algorithm to enhance its performance. Extensive simulations and analyses are conducted to compare the system performance using the proposed designs, algorithms, and schemes with the existing literature work. The results demonstrate the e?ectiveness of our proposed work in improving the performance and e?ciency of the VLC system in indoor and outdoor scenarios. To conclude, this dissertation provides a comprehensive study of VLC technology, o?ering new insights into system and channel modeling, receiver design, transmission schemes, and system optimization, paving the way for future research extensions in this area