The research on the sixth-generation (6G) wireless communications for the development of future mobile communication networks has been officially launched around the world. 6G networks face multifarious challenges, such as resource-constrained mobile devices, difficult wireless resource management, high complexity of heterogeneous network architectures, explosive computing and storage requirements, privacy and security threats. To address these challenges, deploying blockchain and artificial intelligence (AI) in 6G networks may realize new breakthroughs in advancing network performances in terms of security, privacy, efficiency, cost, and more. In this paper, we provide a detailed survey of existing works on the application of blockchain and AI to 6G wireless communications. More specifically, we start with a brief overview of blockchain and AI. Then, we mainly review the recent advances in the fusion of blockchain and AI, and highlight the inevitable trend of deploying both blockchain and AI in wireless communications. Furthermore, we extensively explore integrating blockchain and AI for wireless communication systems, involving secure services and Internet of Things (IoT) smart applications. Particularly, some of the most talked-about key services based on blockchain and AI are introduced, such as spectrum management, computation allocation, content caching, and security and privacy. Moreover, we also focus on some important IoT smart applications supported by blockchain and AI, covering smart healthcare, smart transportation, smart grid, and unmanned aerial vehicles (UAVs). We also analyze the open issues and research challenges for the joint deployment of blockchain and AI in 6G wireless communications. Lastly, based on lots of existing meaningful works, this paper aims to provide a comprehensive survey of blockchain and AI in 6G networks.

翻译：第六代（6G）无线通信技术作为未来移动通信网络发展的研究方向，已在全球范围内正式启动。6G网络面临多重挑战，包括资源受限的移动设备、无线资源管理困难、异构网络架构高度复杂、爆发式计算与存储需求，以及隐私与安全威胁。为应对这些挑战，在6G网络中部署区块链与人工智能（AI）有望在安全性、隐私性、效率、成本等方面实现网络性能的新突破。本文对现有关于区块链与AI在6G无线通信中应用的研究工作进行了详细综述。具体而言，我们首先简要概述区块链与AI的基本概念。随后，重点回顾区块链与AI融合的最新进展，并强调在无线通信中同时部署区块链与AI的必然趋势。进一步地，我们深入探究将区块链与AI集成至无线通信系统的方法，涉及安全服务与物联网（IoT）智能应用。特别地，本文介绍了基于区块链与AI的若干核心热点服务，如频谱管理、计算分配、内容缓存以及安全与隐私保护。此外，我们还聚焦于由区块链与AI支撑的重要物联网智能应用，涵盖智慧医疗、智慧交通、智能电网及无人驾驶飞行器（UAVs）。同时，本文分析了在6G无线通信中联合部署区块链与AI所面临的开放性问题与研究挑战。最后，基于大量现有有价值的研究工作，本文旨在为6G网络中区块链与AI的应用提供一份综合性综述。