NSF Award
2421761
Moving into higher frequencies as proposed for 6G-and-beyond wireless networks can support future high-speed connectivity, Internet of Things (IoT), and new radio technologies. However, these advancements come with challenges. Despite massive investments in infrastructures and constant updates to wireless devices, the 5G networks have yet to deliver on their grand promises of ultra-fast speeds and stable connectivity. Unlike lower-generation networks (e.g., 3G and 4G), the performance of higher-frequency wireless networks (5G mm-wave, 6G-and-beyond) degrades significantly when the distance between the base-stations and the users increases or when the environment between the base-stations and the users is cluttered. To overcome these technical challenges, researchers are exploring the use of low-cost artificial surfaces to manipulate the wireless signal propagation environment and circumvent physical channel disruptions. This emerging technology, known as Intelligent Reflecting Surface (IRS), offers an exciting avenue for addressing the challenges posed by higher-frequency wireless networks, and provides a more efficient and economical solution that bolsters wireless connectivity. Despite their significant potentials, IRS technologies face deployment hurdles due to a gap between theoretical designs and practical implementations, primarily because of the disconnection between research conducted in the communications and signal processing (CSP) community and the electromagnetic (EM) community. The project aims to bridge this gap by considering the realistic behaviors of IRS hardware and ensuring adaptation to dynamic wireless signal propagation environments. The research outcome will lead to agile IRS reconfiguration that can optimize wireless network performance under varying and potentially unknown wireless channel conditions. The team will study a holistic design and implementation solution that can ultimately provide a new paradigm for future IRS-assisted wireless networks. The education and outreach plans of this project focus on recruitment, retention, and success of students from underrepresented minority groups in STEM. In addition, an annual industry seminar series will be initiated to share research progress and foster interactions and collaborations with local wireless industry. <br/><br/>This project seeks to develop an end-to-end methodology that optimizes IRS design for wideband wireless operation, precise beam pattern generation, and long-term deployment cost reduction. By adopting a holistic design approach that bridges the gap between CSP and EM research communities, the project aims to make IRS technologies not only theoretically sound but also practical for real-world applications. The project plans to achieve this goal by envisioning a shift from the traditional one-size-fits-all IRS fabrication to a tailored approach. The main innovation of the hardware and fabrication is the IRS meta-atom that has a wideband response and full reconfigurability, achieved by metamaterial transmission lines terminated with the reflection-type amplifiers. This design then undergoes multiple layers of screening, design, and optimization to achieve practical performance as close to the theoretical ideal performance as possible while considering the realistic IRS behavior. Finally, the project integrates the fabricated IRS into a realistic wireless edge network through a revamped design of codebooks and novel machine learning techniques to ensure seamless and efficient operation.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
