Covert communication performance evaluation in UAV-assisted rate-splitting multiple access systems

Area of Science:

• Wireless Communication
• Network Security
• Aerial Networks

Background:

• Unmanned aerial vehicle (UAV) networks face security challenges, particularly covert communication.
• Existing multiple access schemes may not sufficiently address the covertness requirements in UAV-based systems.
• Monitoring by adversaries (e.g., Willie) necessitates robust security measures.

Purpose of the Study:

• To investigate the application of rate-splitting multiple access (RSMA) for covert communication in multi-user UAV downlink networks.
• To analyze the system's covertness and performance under Nakagami-m fading channels.
• To optimize UAV deployment for maximum system covertness.

Main Methods:

• Developed a comprehensive analytical framework for performance evaluation.
• Derived closed-form expressions for key performance metrics: detection error probability (DEP), outage probability (OP), and ergodic rate (ER).
• Employed an alternating optimization algorithm for UAV static positioning and conducted asymptotic analysis in high SNR regions.

Main Results:

• Quantified system covertness using Willie's detection error probability (DEP).
• Analyzed legitimate users' outage probability (OP) and ergodic rate (ER) under Nakagami-m fading.
• Identified optimal UAV positions to maximize covertness.
• RSMA demonstrated significant covertness advantages over non-orthogonal multiple access (NOMA).

Conclusions:

• RSMA is a promising technique for enhancing covert communication in UAV networks.
• The proposed analytical framework and optimization algorithm effectively assess and improve system covertness.
• RSMA outperforms NOMA in achieving superior covertness in monitored UAV environments.