Key Technologies for Low-Altitude Sensing in 5G-A Integrated Communication and Sensing Networks

‍ ‍With the expanding low-altitude economy， effective regulation of low-altitude drones has emerged as a critical prerequisite for industrial sustainability. This paper systematically investigates the technical challenges of radar-based drone detection in urban environments. Two primary challenges are identified： the miniaturization and high maneuverability of consumer-grade drones impose significant constraints on radar target detection performance and dynamic and static clutter in dense urban areas contribute to low detection rates and high false alarm rates. Single-station radar systems are shown to be ineffective under these conditions， necessitating advanced networking solutions. Radar networking technology enhances detection capabilities through improved detection rates and reduced false alarms， positioning it as a transformative trend in modern radar development. However， large-scale implementation encounters significant technical and engineering hurdles. Innovatively， 5G-A communication-sensing integrated base stations were proposed to address these issues by leveraging existing 5G-A infrastructure. This architecture resolves critical technical barriers in large-scale radar networking， particularly time-frequency-space synchronization. A hierarchical master-slave networking framework was developed to support multi-station joint signal detection using coherent/non-coherent mechanisms and advanced target tracking/recognition through data fusion. Theoretical analysis and field validation confirmed the efficacy of these technologies. In urban deployments， track association success rates and equipment cost reductions were demonstrated compared with conventional radar systems. By dynamically multiplexing communication resources， implementing intelligent interference suppression， and enabling collaborative multi-station processing， 5G-A communication-sensing integration establishes a scalable solution for urban low-altitude sensing systems. This breakthrough satisfies the stringent requirements of low-altitude detection and provides a technological foundation for smart city infrastructure development.