Optimized Channel Estimation Strategies for RIS-Aided Communication

6th-Generation (6G) networks seek improved coverage and efficiency, with Reconfigurable Intelligent Surfaces (RISs) offering a way to create adaptable radio environments. Achieving optimal performance in RIS-assisted systems, especially with multiple antennas, depends on precise channel estimation. This letter introduces enhanced methods for separate channel estimation that lower pilot overhead and improve efficiency by using deterministic channel models and optimal RIS configurations, addressing challenges in large-scale RIS deployments for next-generation networks.