Age of Information Minimization in UAV-Enabled Integrated Sensing and Communication Systems

TL;DR

This paper introduces an AoI-focused UAV-ISAC system that jointly optimizes trajectory and beamforming using deep reinforcement learning to enhance information freshness in sensing and communication tasks.

Contribution

It proposes a novel AoI-centric framework with a DRL-based algorithm for real-time UAV trajectory and beamforming optimization in integrated sensing and communication systems.

Findings

Achieves lower average AoI compared to baseline methods.

Effectively balances sensing accuracy and communication quality.

Demonstrates real-time decision-making capabilities with DRL.

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.