Comprehensive study on UAV-based FSO links for high-speed train backhauling.

Area of Science:

• Optical wireless communications
• High-speed train communication systems
• Unmanned aerial vehicle (UAV) technology

Background:

• High-speed trains require robust communication systems for data backhauling.
• Free-space optical (FSO) communication presents a high-bandwidth alternative.
• Existing ground-based relays face limitations in deployment and coverage.

Purpose of the Study:

• To introduce and analyze UAV-based FSO systems for high-speed train backhauling.
• To develop a composite channel model accounting for atmospheric turbulence and pointing errors.
• To compare the performance of air-relay versus ground-relay systems.

Main Methods:

• Development of a composite channel model for UAV-based FSO links.
• Derivation of an approximate expression for outage probability.
• Comparative performance analysis considering pointing-acquisition-tracking (PAT) complexity and coverage distance.
• Investigation of system performance under varying weather and fading conditions.

Main Results:

• The proposed air-relay system demonstrates superior performance compared to ground-relay systems.
• Air relays effectively mitigate the impact of fog on communication.
• Longer coverage distances are achievable with UAV-based FSO systems.
• System performance is influenced by beam divergence, displacement deviation, and UAV altitude.

Conclusions:

• UAV-based FSO communication is a viable solution for high-speed train backhauling.
• Air relays offer advantages in coverage, weather resilience, and PAT system design.
• The developed channel model provides a basis for further system optimization.