Radio and Optical Communication of Unmanned Aerial Vehicles: A Review of Solutions

This article presents a comprehensive review of contemporary communication methods employed in Unmanned Aerial Vehicles (UAVs) in the context of military applications. It discusses classical radio techniques, spread spectrum systems, and other forms of radio transmission that, while ensuring reliable communication, remain susceptible to detection and interference in electronic warfare environments. Particular attention is given to the emerging optical communication technologies in the infrared domain, including Tethered Fiber Optics (TFO), Spooled Fiber Optics (SFO) and Free-Space Optics (FSO), which offer high throughput, low latency, and strong resistance to electromagnetic interference, although they require precise alignment and are sensitive to atmospheric conditions. In response to the increasing challenges posed by the electronic warfare landscape, the authors propose an innovative concept of emission-free FSO communication, in which the UAV does not emit its own signal but instead reflects and modulates a light beam transmitted from a ground control station using an electro-optical modulator based on a piezoelectric mirror. This solution enables secure, bidirectional data transmission with high resistance to interference, representing a promising alternative to traditional UAV communication methods, especially in special operations and reconnaissance missions requiring stealth and reliability.