Uncrewed aerial vehicles (UAVs) are increasingly considered as aerial platforms capable of providing both sensing and communication services, representing a promising paradigm for intelligent transportation systems. This paper investigates the optimal time allocation for a UAV-enabled integrated sensing and communication (ISaC) system operating in the X-band for vehicular networks. We analyze the trade-off between sensing accuracy and communication performance under practical UAV constraints and fading effects, considering both single-shadowing and double-shadowing channel models. An optimization framework is developed to allocate time between sensing and communication while guaranteeing minimum communication rates and sufficient sensing reliability. Simulation results demonstrate adaptive time allocation strategies, highlighting how UAV-to-ground channel conditions and target distances influence the balance between sensing and communication in smart mobility scenarios.

翻译：无人机（UAV）日益被视为能够同时提供感知与通信服务的空中平台，这代表了智能交通系统中一种极具潜力的范式。本文研究了面向车辆网络、工作在X波段的无人机赋能通感一体化（ISaC）系统中的最优时间分配问题。我们在实际无人机约束与衰落效应下，分析了感知精度与通信性能之间的权衡，并考虑单阴影与双阴影信道模型。我们建立了一个优化框架，用于在保障最低通信速率与充足感知可靠性的前提下，在感知与通信之间分配时间。仿真结果展示了自适应的时间分配策略，揭示了在智能出行场景中，无人机到地面信道条件及目标距离如何影响感知与通信之间的平衡。