Reconfigurable Intelligent Surface-Empowered 6G

1 Introductions and Basics1.1 Background and Requirements1.2 Overview of RISs1.2.1 History of Meta-materials1.2.2 Working Principles1.2.3 Applications of RISs1.3 Fundamentals of RIS-aided Wireless Communications1.3.1 Response Model1.3.2 Channel Model1.3.3 Comparisons with Existing TechniquesReferences2 RIS Aided MIMO Communications2.1 Limited Phase Shifts: How Many Phase Shifts Are Enough?2.1.1 Motivations2.1.2 System Model2.1.3 Achievable Data Rate Analysis2.1.4 Analysis on the Number of Phase Shifts2.1.5 Simulation Results2.1.6 Summary2.1.7 Appendix2.2 Size Effect: How Many Reflective Elements Do We Need?2.2.1 Motivation2.2.2 System Model2.2.3 Analysis on Asymptotic Capacity2.2.4 Analysis on the Number of Reflective Elements2.2.5 Simulation Results2.2.6 Summary2.3 Coverage Extension: RIS Orientation and Location Optimization2.3.1 Motivations2.3.2 System Model2.3.3 Cell Coverage Analysis2.3.4 RIS Placement Optimization2.3.5 Simulation Results2.3.6 Summary2.4 Hybrid Beamforming Design2.4.1 Motivations2.4.2 System Model2.4.3 RIS-based Hybrid Beamforming and Problem Formulation for Multi-user Communications 2.4.4 Sum Rate Maximization Algorithm Design2.4.5 Performance Analysis of RIS-based Multi-userCommunications2.4.6 Simulation Results2.4.7 Summary2.5 Full-dimensional Coverage Extension2.5.1 Motivations2.5.2 Intelligent Omni-Surface2.5.3 System model2.5.4 Problem Formulation and Decomposition2.5.5 Sum-rate Maximization: Algorithm Design2.5.6 Performance Analysis of the IOS-Assisted Communication System2.5.7 Simulation Results2.5.8 SummaryReferences3 Convergences of RISs with Existing Wireless Technologies3.1 RIS Aided Device-to-Device Communications3.1.1 Motivations 3.1.2 System Model3.1.3 Problem Formulation3.1.4 Sum Rate Maximization Algorithm3.1.5 Performance Evaluation3.1.6 Summary3.2 RIS Aided Cell-free MIMO3.2.1 Motivations3.2.2 System Model3.2.3 Hybrid Beamforming and Problem Formulation3.2.4 Energy Efficiency Maximization Algorithm Design3.2.5 Theoretical Analysis of RIS Aided Cell-free System3.2.6 Simulation Results3.2.7 Summary 3.2.8 Appendix 3.3 RIS Aided Spatial Equalization3.3.1 Motivations3.3.2 System Model3.3.3 Problem Formulation3.3.4 Algorithm Design3.3.5 Simulation Results3.3.6 Summary3.3.7 AppendixReferences4 RIS Aided RF Sensing and Localization4.1 2D Sensing4.1.1 Motivations4.1.2 System Design4.1.3 Problem Formulation of RIS-based Posture Recognition4.1.4 Algorithms for Configuration Matrix and Decision Function Optimizations4.1.5 Performance Analysis 4.1.6 System Implementation4.1.7 Simulation and Experimental Results4.1.8 Summary4.1.9 Appendix 4.2 3D Sensing4.2.1 Motivations4.2.2 System Model4.2.3 Problem Formulation4.2.4 Algorithm Design4.2.5 Algorithm Analysis4.2.6 Simulation and Evaluation4.2.7 Summary4.3 Indoor Localization4.3.1 Motivations4.3.2 Related Work4.3.3 System Overview4.3.4 Radio Map Preparation Phase4.3.5 Fine-grained Localization Phase4.3.6 Implementation4.3.7 Evaluation4.3.8 Discussion4.3.9 SummaryReferences