Investigation of Reconfigurable Intelligent Surface for Millimeter-Wave Coverage Enhancement

Reconfigurable intelligent surfaces (RISs) for coverage enhancement in millimeter-wave bands are investigated through system-level simulations. A large-scale RIS model is developed to approximate the forwarding beam pattern in both far-field and near-field conditions, and a pragmatic low-complexity RIS assignment procedure is considered. The impacts of RIS in regular cellular scenarios and those with blind-spot areas are compared. This study identifies that a substantial portion of users benefit from RIS deployment; RIS-induced interference is generally negligible, except in rare cases; and strategically deploying small- to medium-sized RISs effectively addresses blind-spot coverage.