IRS assisted UAV communications for 6G networks: a systematic literature review

6G incorporates Intelligent Reflecting Surfaces (IRS) and Unmanned Aerial Vehicles (UAVs) as effective solutions to overcome the limitations of terrestrial networks in terms of coverage and resource constraints. Compared to communications with conventional UAV networks which face restricted battery longevity, fluctuating channel conditions, and paucity of resources, IRS-assisted UAV communications is seen as an attractive strategy. In this paper, we present an extensive survey on IRS-assisted UAV communications for 6G networks. We highlight various application scenarios and key technologies for integrating IRS and UAVs in 6G architecture. We discuss primary issues along with their solutions and put forward the open research challenges that could serve as a potential area for further investigation in the related discipline. Key findings encompass an in-depth exploration of diverse application scenarios and pivotal technologies crucial for seamless integration of IRS and UAVs within the 6G architecture, providing valuable insights into optimizing communication efficiency and addressing network challenges. This survey serves as a valuable resource for scholars, practitioners, and policymakers in the fields of integrated UAV and IRS communication. It provides insights for making well-informed decisions and driving advancements to meet the constantly evolving demands of our connected world.