Overview of the NLOS Ultraviolet Communication Technology

In recent years, thanks to the rapid progress of the technology for creating invisible ultraviolet LEDs and the technology for detecting ultraviolet rays, ultraviolet communication has gradually become an urgent object of research due to its inherent advantages: low solar background noise, the possibility of organizing communication in the absence of direct visibility (NLOS) and good stealthiness. The strong scattering characteristics of the ultraviolet signal in atmospheric render ultraviolet waveband the ideal choice for achieving NLOS optical communication. This article reviews the research history and status of ultraviolet communication both in Russia and abroad, and especially introduces three main issues of ultraviolet communication: channel model, system analysis and design, light sources and detectors. For each aspect, current open issues and prospective research directions are analyzed.