Parametric Channel Estimation as an Enabler for RIS-Assisted Sensing

While commonly considered for enhancing coverage in blockage scenarios, reconfigurable intelligent surfaces (RISs) may be used as additional anchors in localization contexts to improve position estimation and sensing performance. Additionally, parametric channel estimators are a valuable tool for sensing and communications as they are able to estimate the channel tensor and also extract geometrical properties of the multipath components. We introduce a two-step parametric channel estimation procedure for RIS-enhanced line-of-sight (LOS) channels. The proposed approach accurately estimates angles of arrival and departure, times of flight (with added clock offset), and path magnitudes and phases.