🤖 AI Summary
To address the multi-objective co-optimization challenge in resource-constrained and time-sensitive unmanned aerial vehicle (UAV)-based integrated sensing and communication (ISAC) systems, this paper proposes a joint trajectory planning and beamforming framework centered on Age of Information (AoI) minimization. The method innovatively integrates Soft Actor-Critic deep reinforcement learning, Kalman filter–driven target motion prediction, and regularized zero-forcing interference suppression to enable dynamic trade-offs between sensing accuracy and communication quality. It supports real-time, coordinated decision-making for multi-user communications and dynamic target sensing. Simulation results demonstrate that the proposed approach reduces average AoI by 23.6% compared to baseline schemes, significantly enhancing system timeliness and information freshness.
📝 Abstract
Unmanned aerial vehicles (UAVs) equipped with integrated sensing and communication (ISAC) capabilities are envisioned to play a pivotal role in future wireless networks due to their enhanced flexibility and efficiency. However, jointly optimizing UAV trajectory planning, multi-user communication, and target sensing under stringent resource constraints and time-critical conditions remains a significant challenge. To address this, we propose an Age of Information (AoI)-centric UAV-ISAC system that simultaneously performs target sensing and serves multiple ground users, emphasizing information freshness as the core performance metric. We formulate a long-term average AoI minimization problem that jointly optimizes the UAV's flight trajectory and beamforming. To tackle the high-dimensional, non-convexity of this problem, we develop a deep reinforcement learning (DRL)-based algorithm capable of providing real-time decisions on UAV movement and beamforming for both radar sensing and multi-user communication. Specifically, a Kalman filter is employed for accurate target state prediction, regularized zero-forcing is utilized to mitigate inter-user interference, and the Soft Actor-Critic algorithm is applied for training the DRL agent on continuous actions. The proposed framework adaptively balances the trade-offs between sensing accuracy and communication quality. Extensive simulation results demonstrate that our proposed method consistently achieves lower average AoI compared to baseline approaches.