Optical wireless communications in the visible and infrared spectra have recently received particular attention due to their potential in providing very high-rate data transmission in various indoor and outdoor application scenarios. This presentation provides an overview on the transmission techniques and the challenges in the deployment of these systems. Starting by outdoor applications, we review the most important impairments affecting the performance of free-space optical terrestrial links. In particular, we discuss the effect of atmospheric turbulence and present potential solutions for mitigating the resulting channel fading. For indoor applications, we focus on the emerging field of visible-light communications. In this context, the main limitation on the data transmission rate arises from the limited modulation bandwidth of the commercial LEDs, which are supposed to replace the traditional luminaries in the near future. To address this, we review several spectrally efficient transmission schemes including optical-OFDM. Finally, we briefly introduce the recent research works on underwater optical communications in Institut Fresnel, Marseille, and the remaining challenges for implementing such links.
Dr. Ali Khalighi received his PhD degree in Telecommunications from the Institut National Polytechnique de Grenoble, France, in 2002. From 2002 to 2005, he was with GIPSA-lab, Télécom Paris-Tech, and IETR-lab, as a post-doctoral research fellow. He joined École Centrale Marseille and Institut Fresnel in 2005, where he currently holds an Associate Professor position. He also received his HDR (Accreditation for Research Supervision) degree from Aix-Marseille University in 2014. His main research areas of interest include signal processing for wireless communication systems with an emphasis on the physical layer aspects of free-space, underwater, and indoor visible-light optical communications. He has served as the Technical Program Committee of more than 20 international conferences and workshops in the communications area. Also, he was the Vice Chair of Working Group 2 of the FP7 IC1101 COST Action on optical wireless communications. Dr. Khalighi is the recipient of the Scientific Excellence Award from the French Ministry of Research and Higher Education for the period 2009–2017.
Coffe and sweets will be served!