Researchers from the Institute of Informatics and Telecommunications at the National Centre for Scientific Research “Demokritos” in Greece have been exploring the potential of Reconfigurable Intelligent Surfaces (RISs) to create Smart Wireless Environments (SWEs) that could significantly impact the energy sector. The team, comprising George C. Alexandropoulos, Kostantinos D. Katsanos, George Stamatelis, and Ioannis Gavras, has published their findings in a chapter titled “RIS-Enabled Smart Wireless Environments: Fundamentals and Distributed Optimization.”
The researchers introduce the concept of SWEs, driven by the emerging technology of RISs, which are programmable metasurfaces that can control and manipulate electromagnetic waves. These surfaces can be integrated into various environments to enhance wireless communication systems’ performance, a feature that could be particularly beneficial for the energy sector, where efficient and reliable communication is crucial for operations and maintenance.
The team discusses several key performance objectives and use cases of RIS-enabled SWEs, including spectral and energy efficiency, physical-layer security, integrated sensing and communications, and over-the-air computing. These aspects are particularly relevant to the energy industry, where secure, efficient, and reliable data transmission is essential for monitoring and controlling energy infrastructure, such as smart grids and renewable energy systems.
Focusing on the recent trend of Beyond-Diagonal (BD) RISs, the researchers present two distributed designs of SWEs. The first design involves a multi-user Multiple-Input Single-Output (MISO) system operating within the area of influence of a SWE comprising multiple BD-RISs. The team proposes a hybrid distributed and fusion machine learning framework based on multi-branch attention-based convolutional Neural Networks (NNs), NN parameter sharing, and neuroevolutionary training. This framework enables online mapping of channel realizations to the BD-RIS configurations and the multi-user transmit precoder, achieving near-optimal sum-rate performance with low online computational complexity. This could translate to more efficient and reliable data transmission in energy systems, reducing energy consumption and improving overall performance.
The second design focuses on the wideband interference MISO broadcast channel, where each base station exclusively controls one BD-RIS to serve its assigned group of users. The researchers present a cooperative optimization framework that jointly designs the base station transmit precoders and the tunable capacitances and switch matrices of all metasurfaces. Numerical results demonstrate the superior sum-rate performance of the designed RIS-enabled SWE for multi-cell MISO networks over benchmark schemes, considering non-cooperative configuration and conventional diagonal metasurfaces. This could lead to improved communication and control in energy systems, enhancing their efficiency and reliability.
The research was published in the book “Reconfigurable Intelligent Surfaces for Wireless Communications: Fundamentals and Applications,” edited by H. Sadat and C. Yuen, and published by Cambridge University Press. The findings highlight the potential of RIS-enabled SWEs to revolutionize wireless communication systems, with significant implications for the energy sector. By enhancing spectral and energy efficiency, physical-layer security, and integrated sensing and communications, these technologies could contribute to the development of more sustainable and resilient energy systems.
This article is based on research available at arXiv.