In this article, we present a tutorial on recent optical camera communication (OCC) technologies that deploy light-emitting diodes (LEDs) and image sensors. The article contains a discussion on the amendment of the IEEE 802.15.7-2018 standard, termed the IEEE 802.15.7a (TG7a) Higher Rate, Longer Range OCC Task Group, which has a significant influence on the advancement of OCC technology. In addition, the tutorial article presents the enabling technical issues in TG7a and a comparison with the existing standard. The current status, new challenges, and future directions of research and development are also discussed.
IntroductIonCommunication systems based on radio frequencies (RFs) have experienced substantial growth over the last decade. Qualcomm, the telecommunication company, predicts that upcoming wireless communication technologies will need to increase their capacity by a factor of a thousand [1]. However, conventional RF systems may not be able to adequately match the expected network traffic growth in the future. Hence, there is a need to explore innovative solutions that can operate within spectra that require no license (e.g., light waves). Light waves are situated at the higher end of the electromagnetic spectrum, do not contain any electromagnetic radiation, and have a bandwidth that extends considerably beyond the entire RF spectrum. Moreover, light waveforms support remarkable line of sight (LoS) separation features and can provide economical augmented-reality user experiences. Because of the increasing demands placed on wireless communication systems (such as speed, reliability, and security), the developers of wireless communication technologies are focusing on light wave communication due to the benefits of light waveforms. Accordingly, optical wireless communication (OWC) is expected to become a crucial wireless technology in the near future.In 1880, visible light communication (VLC) systems were proposed by Alexander Graham Bell in Washington, D.C., where speech was transmitted with sunlight over hundreds of meters [2]. However, the first demonstration of a VLC system was conducted in Japan ( 2004) with a high-speed communication system that used photodiodes.