Rank Optimization for MIMO Channel with RIS: Simulation and Measurement

TL;DR

This paper proposes an efficient method to optimize RIS-assisted MIMO channels, demonstrating through simulations and measurements that it significantly improves the channel rank and achievable data rates.

Contribution

The paper introduces a novel RIS optimization algorithm that enhances MIMO channel rank, validated by both simulations and real-world prototype measurements.

Findings

Significant increase in effective MIMO channel rank with RIS.

Improved achievable data rates demonstrated through experiments.

Validation of the proposed algorithm's effectiveness in real-world setup.

Abstract

Reconfigurable intelligent surface (RIS) is a promising technology that can reshape the electromagnetic environment in wireless networks, offering various possibilities for enhancing wireless channels. Motivated by this, we investigate the channel optimization for multiple-input multiple-output (MIMO) systems assisted by RIS. In this paper, an efficient RIS optimization method is proposed to enhance the effective rank of the MIMO channel for achievable rate improvement. Numerical results are presented to verify the effectiveness of RIS in improving MIMO channels. Additionally, we construct a 2$\times$2 RIS-assisted MIMO prototype to perform experimental measurements and validate the performance of our proposed algorithm. The results reveal a significant increase in effective rank and achievable rate for the RIS-assisted MIMO channel compared to the MIMO channel without RIS.