UAV-Enabled ISAC with Fluid Antennas for Low-Altitude Wireless Networks
This work addresses the problem of optimizing communication and sensing in low-altitude wireless networks for next-generation systems, representing an incremental advancement by integrating fluid antenna technology.
The paper tackles the limitation of fixed-position antennas in UAV-enabled integrated sensing and communication by proposing a framework with fluid antennas, which enhances performance through multi-objective optimization, resulting in significant improvements over benchmark schemes.
Unmanned aerial vehicle (UAV)-enabled integrated sensing and communication (ISAC) is regarded as a key enabler for next-generation wireless systems. However, conventional fixed-position antennas limit the ability of UAVs to fully exploit their inherent potential. To overcome this limitation, we propose a UAV-enabled ISAC framework equipped with fluid antennas (FAs), where the mobility of antenna elements introduces additional spatial degrees of freedom to simultaneously enhance communication and sensing performance. A multi-objective optimization problem is formulated to maximize the communication rates of multiple users while minimizing the Cramér-Rao bound (CRB) for the angle estimation of a single target. Due to excessively frequent updates of FA positions may lead to response delay, a three-timescale optimization framework is developed to jointly optimize transmit beamforming, FA positions, and UAV trajectory based on their characteristics. To solve the non-convexity of the problem, an alternating optimization-based algorithm is developed to obtain a sub-optimal solution. Numerical results show that the proposed scheme significantly outperforms various benchmark schemes, validating the effectiveness of integrating the FA technology into the UAV-enabled ISAC systems.