UAV-Relay Assisted RSMA Fluid Antenna System: Outage Probability Analysis

2025-03-20

AI Summary

This work investigates the performance gains of fluid antenna systems (FAS) in an unmanned aerial vehicle (UAV)-assisted multi-user rate-splitting multiple access (RSMA) network. We consider a system comprising a fixed-location antenna base station, a half-duplex decode-and-forward (DF) UAV relay, and multiple FAS-enabled users. To the best of our knowledge, this is the first study to integrate FAS into a UAV-relayed RSMA architecture. A novel channel modeling framework based on the multivariate t-distribution is established, and compact closed-form expressions for the outage probability (OP) are derived, along with high-SNR asymptotic analytical solutions. Theoretical analysis and simulations demonstrate that FAS users achieve significantly lower OP compared to conventional fixed-antenna users. Moreover, under limited antenna elements, FAS enhances channel diversity gain and spectral efficiency, thereby improving the reliability and robustness of UAV-relay networks.

Technology Category

• Multiagent Systems: Multiagent Systems under Uncertainty
• Intelligent Robots: Multi-Robot Systems
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• User Modeling, Personalization and Recommendation: Fairness-aware retrieval and ranking
• Social Networks and Social Media: Fairness and bias in social network and social media analysis
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization

Abstract

This letter studies the impact of fluid antenna system (FAS) technology on the performance of unmanned aerial vehicle (UAV)-assisted multiuser communication networks. Specifically, we consider a scenario where a fixed-position antenna (FPA) base station (BS) serves K FAS-equipped users with the assistance of a UAV acting as an aerial relay. The BS employs rate-splitting multiple access (RSMA), while the UAV operates in half-duplex (HD) mode using the decode-and-forward (DF) strategy. For this system, we derive a compact analytical expression for the outage probability (OP) and its asymptotic behavior in the high signal-to-noise ratio (SNR) regime, leveraging the multivariate t-distribution. Our results show how deploying FAS at ground users (GUs) in UAV-aided communications improves overall system performance compared to using FPA GUs.

Problem

• Analyzes outage probability in UAV-relay assisted RSMA networks
• Compares FAS vs FPA performance in multiuser UAV communications
• Derives asymptotic outage behavior in high SNR regimes

Innovation

• UAV relay with fluid antenna system
• RSMA for multiuser communication networks
• Outage probability analysis using t-distribution