Configuring reconfigurable intelligent surfaces using a practical codebook approach

Area of Science:

• Electromagnetic wave manipulation
• Wireless communication systems
• Metamaterials and intelligent surfaces

Background:

• Reconfigurable intelligent surfaces (RISs) offer dynamic control over electromagnetic signal propagation.
• Optimizing RIS phase configurations is crucial for maximizing wireless system performance.
• Existing methods like semidefinite relaxation (SDR) face challenges in computational complexity.

Purpose of the Study:

• To investigate the achievable data rate in a single-input-single-output (SISO) wideband system using optimized RIS.
• To develop a novel beamforming codebook and power allocation algorithm for RIS phase optimization.
• To compare the proposed method's efficiency and performance against the SDR scheme.

Main Methods:

• Development of a new beamforming codebook for selecting the maximum signal-to-noise ratio (SNR) configuration.
• Utilization of channel state information (CSI) and the selected SNR configuration for RIS optimization.
• Implementation of a fair power allocation algorithm across subcarriers for wideband systems.

Main Results:

• The proposed method demonstrates significantly lower computational complexity compared to the SDR scheme.
• An optimized RIS configuration resulted in a 2.5-fold increase in achievable data rate.
• The developed algorithm effectively optimizes RIS phase configurations for improved system performance.

Conclusions:

• The novel RIS optimization technique offers a computationally efficient and high-performance solution for wireless systems.
• Optimized RIS surfaces can substantially enhance achievable data rates in wideband communication.
• This approach presents a promising direction for future wireless network advancements.