Deployment and Beamforming Design for RIS-Assisted Indoor Wireless Communication in Smart Home

Reconfigurable intelligent surfaces (RISs) assisted indoor wireless communication for smart home is investigated to improve the communication coverage efficiency and spectral efficiency by designing deployment and beamforming. A two-stage communication scheme is proposed. In the first stage, RIS deployment is designed with the location information of long-term stationary obstacles to maximize the normalized effective coverage efficiency (NE-CE). Three RIS deployment algorithms are proposed, which are the Heuristic Deployment (H-D) algorithm, the Simulated Annealing Angle Optimization-based Deployment (SAAO-D) algorithm, and the Simulated Annealing-based Deployment (SA-D) algorithm. In the second stage, partial channel state information (CSI)-based beamforming is designed to ensure spectral efficiency while reducing the complexity of channel estimation. In this stage, terminal association and passive beamforming are designed based on the deployed RISs and terminal location information. Additionally, closed-form active beamforming is derived based on partial CSI. Simulation results demonstrate that the NE-CE of the proposed algorithm is 1.45 times higher than that of the existing scheme when deploying 2 RISs with 64 elements each. The spectral efficiency of the partial CSI-based beamforming scheme reaches 96.5% that of the perfect-CSI-based scheme with 3 obstacles and 3 RISs.