A Survey on STAR-RIS: Use Cases, Recent Advances, and Future Research Challenges

作者：Manzoor Ahmed, Abdul Wahid, Sayed Shariq Laique, Wali Ullah Khan, Asim Ihsan, Fang Xu, Symeon Chatzinotas, Zhu Han · 发表于：IEEE Internet of Things Journal · 年份：2023 · DOI：10.1109/jiot.2023.3279357 · 被引用次数：241 · 研究领域：Advanced Wireless Communication Technologies、Advanced Antenna and Metasurface Technologies、Satellite Communication Systems

The recent development of metasurfaces, which may enable several use cases by modifying the propagation environment, is anticipated to substantially affect the performance of sixth-generation (6G) wireless communications. Metasurface elements can produce passive subwavelength scattering to enable a smart radio environment. Simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS), which refers to reconfigurable intelligent surfaces (RISs) that can transmit and reflect concurrently (STAR), is gaining popularity. In contrast to the widely studied RIS, which can only reflect the wireless signal and serve users on the same side as the transmitter, the STAR-RIS can reflect and refract (transmit), enabling 360° wireless coverage, thus serving users on both sides of the transmitter. This article presents a comprehensive review of the STAR-RIS, focusing on the most recent schemes for diverse use cases in 6G networks, resource allocation, and performance evaluation. We begin by laying the foundation for RIS (passive, active, and STAR-RIS), and then discuss the STAR-RIS protocols, advantages, and applications. In addition, we categorize the approaches within the domain of use scenarios, which include increasing coverage, enhancing physical-layer security (PLS), maximizing sum rate, improving energy efficiency (EE), and reducing interference. Next, we will discuss the various strategies for resource allocation and measures for performance evaluation. We ai...