Ray Antenna Array Enhanced Low-Altitude ISAC: Performance Analysis and Beamforming Design

2026-06-17

AI Summary

This study addresses the limitations of conventional antenna arrays in low-altitude economies—namely high cost, poor scalability, and coverage blind spots directly above base stations—by introducing, for the first time, ray antenna arrays (RAAs) into integrated sensing and communication (ISAC) scenarios. The authors propose a low-cost, phase-shifter-free architecture that enables flexible beamforming through dynamic ray selection. By integrating a joint optimization algorithm with an alternating optimization approach, the design simultaneously enhances sensing coverage uniformity and communication performance. Theoretical analysis and simulations demonstrate that the proposed scheme significantly improves sensing signal-to-noise ratio, eliminates coverage blind zones, and achieves high angular resolution, thereby offering a cost-effective and high-performance solution for low-altitude ISAC applications.

Abstract

The low-altitude economy (LAE) heavily relies on aerial vehicles, yet these platforms remain vulnerable to environmental and security risks, necessitating robust airspace monitoring. Integrated sensing and communication (ISAC) as one of the key technologies of 6G provides potential solutions for safe LAE. However, conventional antenna arrays face limitations in cost, scalability, and coverage, especially directly above the base station, due to hardware complexity and degraded angular resolution. By exploiting the recently proposed ray antenna array (RAA), this paper considers a RAA-enhanced low-altitude ISAC system. RAA architecture employs multiple ray-arranged arrays directly connected without phase shifters, significantly reducing hardware costs while supporting flexible beamforming via dynamic ray selection. Moreover, RAA can provide uniform angular resolution and eliminates coverage holes, making it particularly suitable for low-altitude ISAC. In this paper, we formulate an optimization problem for joint ray selection and beamforming to enhance sensing coverage under communication constraints. An efficient alternating optimization algorithm is proposed to solve this problem. Analytical and simulation results demonstrate that RAA achieves higher sensing signal-to-noise ratio compared to traditional arrays, offering a cost-effective and high-performance solution for achieving low-altitude ISAC.

Problem

• low-altitude ISAC
• antenna array
• coverage hole
• angular resolution
• hardware cost

Innovation

• Ray Antenna Array
• Integrated Sensing and Communication (ISAC)
• Low-Altitude Economy
• Beamforming Design
• Coverage Hole Elimination