Visible Light Communication for Vehicular Networks: A Tutorial

TL;DR

This paper surveys visible light communication (VLC) for vehicular networks within 5G and ITS contexts, detailing system architecture, channel models, standardization efforts, and network topologies. It analyzes practical implementation issues, including interference from ambient light, flicker, dimming, uplink viability, mobility, and security, and discusses mitigation strategies such as filters, coding schemes, RLL, MIMO, WDM, and hybrid RF/VLC solutions. Throughput enhancement techniques like pre-distortion, equalization, laser diodes, MIMO, and polarization multiplexing are reviewed, with demonstrations reaching multi-Gb/s rates on short indoor links. The paper highlights open challenges and outlines future research directions to advance toward commercial VLC-enabled vehicular systems, including mobility-aware channels and integration with RF technologies.

Abstract

The advent of the fifth-generation technology promises to bring about more vertical applications and emerging services that include vehicular networks and intelligent transportation systems (ITSs). To achieve their vision of real-time and safetyapplications, vehicular networks rely on short-range to medium-range communications. One emerging technology that aims to provide reliability and high-data rate in short-range communications is the visible light communications (VLC). Due to its remarkable advantages, some studies have recently investigated the integration of VLC in vehicular networks and ITSs. Despite their attractive features, such networks also face several implementation issues. This paper provides an extended tutorial on the implementation of VLC-based vehicular networks. To begin with, we present the implementation characteristics of these systems and discuss some related issues. The underlying system considers a general structure with transmitters, channels, and receivers based on photodetectors and cameras, as well as standardization efforts and types of topologies. In addition, we discuss the impact of the sun and artificial light sources, flickering, dimming, throughput enhancement, uplink security, and mobility on practical implementation. Finally, we highlight some key challenges and potential solutions and provide some directions for future research investigations that could constitute an advancement toward the development of commercial VLC-based vehicular systems.

Figures (3)

• Figure 1: Visible light communication system block diagram.
• Figure 2: MAC topologies, adapted from 8697198.
• Figure 3: Spectral density distribution of incandescent and fluorescent lamps, and the emissions of the solar radiation as a function wavelength.