HAPS are emerging as key enablers in the evolution of 6G wireless networks, bridging terrestrial and non-terrestrial infrastructures. Operating in the stratosphere, HAPS can provide wide-area coverage, low-latency, energy-efficient broadband communications with flexible deployment options for diverse applications. This survey delivers a comprehensive overview of HAPS use cases, technologies, and integration strategies within the 6G ecosystem. The roles of HAPS in extending connectivity to underserved regions, supporting dynamic backhauling, enabling massive IoT, and delivering reliable low-latency communications for autonomous and immersive services are discussed. The paper reviews state-of-the-art architectures for terrestrial and non-terrestrial network integration, highlights recent field trials. Furthermore, key enabling technologies such as channel modeling, AI-driven resource allocation, interference control, mobility management, and energy-efficient communications are examined. The paper also outlines open research challenges. By addressing existing gaps in the literature, this survey positions HAPS as a foundational component of globally integrated, resilient, and sustainable 6G networks.

翻译：高空平台系统（HAPS）正逐渐成为6G无线网络演进的关键赋能者，架起了地面与非地面基础设施之间的桥梁。在平流层运行的HAPS能够为多样化应用提供广域覆盖、低延迟、高能效的宽带通信，并具备灵活的部署选项。本综述全面概述了6G生态系统中HAPS的用例、技术及融合策略，探讨了HAPS在向服务不足地区延伸覆盖、支持动态回传、赋能海量物联网、以及为自主与沉浸式服务提供可靠低延迟通信等方面的作用。本文回顾了地面与非地面网络融合的最新架构，重点介绍了近期现场试验成果。此外，文中深入分析了信道建模、AI驱动的资源分配、干扰控制、移动性管理和高能效通信等关键使能技术，并指出了开放的研究挑战。通过弥补现有文献中的空白，本综述将HAPS定位为构建全球融合、高韧性与可持续6G网络的基础组成部分。