Reconfigurable Intelligent Surface (RIS) is a planar array of programmable electromagnetic elements that can dynamically manipulate the phase, amplitude, and direction of incident radio signals to reshape wireless propagation environments on demand. In the context of WiFi CSI sensing, RIS matters because it enables controlled and enhanced signal coverage, suppresses interference, and creates richer multipath environments that improve sensing accuracy and energy efficiency without requiring additional active transmitters. Key variants include passive RIS, which reflects signals without amplification, active RIS, which incorporates signal amplification at each element, and hybrid or semi-passive configurations that balance hardware complexity with performance gains.
Source Papers
- A Survey on Green Wireless Sensing: Energy-Efficient Sensing via WiFi CSI and Lightweight Learning ↗ — A Survey on Green Wireless Sensing: Energy-Efficient Sensing
- Radio Radiance Field: The New Frontier of Spatial Wireless Channel Representation ↗ — Radio Radiance Field: The New Frontier of Spatial Wireless C