Ergodic Mutual Information and Outage Probability for SIM-Assisted Holographic MIMO Communications

TL;DR

This paper analyzes the ergodic mutual information and outage probability in SIM-assisted MIMO systems using large random matrix theory, providing closed-form expressions and an efficient optimization algorithm.

Contribution

It introduces a novel analytical framework for SIM-assisted MIMO, deriving closed-form outage probability and applying gradient descent for optimization.

Findings

Performance improvements over conventional MIMO systems

Faster optimization algorithm with reduced overhead

Analytical results validated by simulations

Abstract

Stacked intelligent metasurface (SIM) is a promising enabler for next-generation high-capacity networks that exhibit better performance compared to its single-layer counterpart by means of just wave propagation. However, the study of ergodic mutual information (EMI) and outage probability for SIM-assisted multiple-input-multiple-output (MIMO) systems is not available in the literature. To this end, we obtain the distribution of the MI by using large random matrix theory (RMT) tools. Next, we derive a tight closed-form expression for the outage probability based on statistical channel state information (CSI). Moreover, we apply the gradient descent method for the minimization of the outage probability. Simulation results verify the analytical results and provide fundamental insights such as the performance enhancements compared to conventional MIMO systems and the single-layer counterpart. Notably the proposed optimization algorithm is faster than the alternating optimization (AO) benchmark by saving significant overhead.