Localization in NLOS Conditions using Large Reconfigurable Intelligent Surfaces

This paper proposes a low-complexity practical algorithm to localize mobile users under NLOS channel conditions using a single base station and a large reconfigurable intelligent surface (RIS). The numerical results show the trade-off between localization accuracy and latency as well as the robustness of the localization algorithm to the presence of synchronization mismatches. An analysis of the soft-coverage capability, i.e., the possibility of maintaining a high level of localization accuracy with RISs that are partially obstructed is also provided.