A Review of UV Communications for UAVs

As an important branch of free-space optical (FSO) communication technology, ultraviolet (UV) communication is mainly applied to mobile communication platforms represented by unmanned aerial vehicle (UAV). With the development of LEDs and UV detector devices, UAV UV communication technology has shown great potential in related fields. But at the same time, it also faces some challenges. As the communication distance increases, the path loss of the UV communication system can reach 0.12dB/m, and the variation in bit error rate (BER) can rapidly deteriorate from the order of $10^{-8}$ to $10^{-1}$ . Additionally, the UV communication system mounted on a UAV platform can emit radiation into the environment, which may have negative effects on human health when the radiation intensity exceeds $0.5{\mu }$ W/cm2. These issues can be summarized as the availability, stability, and effectiveness of UAV-based UV communication technology. This paper aims to comprehensively address both UAVs and UV communication, providing a detailed introduction to the challenges and solutions facing UAV-based UV communication technology. Focusing on the specific aspects of these three issues, the paper first introduces the research background, value, and challenges of UAV-based UV communication technology, and investigates the current research status of UV communication channel models and positioning techniques. In order to solve the problem of UV environmental radiation, the article goes on to introduce beamforming and power control in UV optical communication technology. To solve the problem of reducing signal attenuation and increasing the communication range, the article introduces diversity technology and networking technology. In order to balance the communication quality and communication rate during UAV movement, the article introduces adaptive modulation and adaptive coding technology. Finally, the future development direction of UAV UV communication technology is summarised.