Large System Analysis of Reflecting Intelligent Surface Aided MIMO systems with Imperfect Channel State Information

Abstract

This paper considers both uplink and downlink reconfigurable intelligent surface (RIS)-aided massive multiple-input multiple-output (MIMO) system with imperfect channel state information (CSI). The RIS is deployed to assist the traditional massive MIMO system serving the users in the dead zone blocked by an obstacle. We derive closed form expression for the sum rate considering the Rician channel model, linear minimum mean squared error (LMMSE) is considered for uplink channel estimation, while maximum ratio transmission (MRT) is considered for the downlink.