The course will give to the students the fundamentals of visible light communications (VLC). VLC refers to a data communications medium using visible light between 400 THz (780 nm) and 800 THz (375 nm). Low-cost wireless communication network can be created using VLC, often known as Li-Fi systems. LiFi is a potential solution to the shortage of global wireless radio spectrum. The light can be used as a communication medium for ubiquitous computing, because light-producing devices (such as indoor/outdoor lamps, TVs, traffic signs, commercial displays, car headlights/taillights, etc.) are used everywhere. The course will provide a general background on LiFi technology, discussing the major advantages and existing challenges. Recent key advancements in physical layer techniques, such as localization, ultra-high-speed indoor connection, ultra-low latency outdoor link, will be discussed.
The course includes a demonstrative part where a practical implementation of the standard IEEE 802.15.7 for vehicular communications will be discussed and demonstrated through a dedicated electronic system. In particular, the integration in FPGA of the digital sections of the transmitter and the receiver will be analysed; and the analog electronics necessary to drive and modulate a power LED, and to detect the signal from the photosensor will be reviewed. Finally, live communication over a VLC link will be demonstrated.