Free-Space Optical Communication With Reconfigurable Intelligent Surfaces

TL;DR

This paper investigates the use of reconfigurable intelligent surfaces to enhance free-space optical communication performance under atmospheric turbulence and pointing errors, providing analytical expressions and simulations to validate improvements.

Contribution

It introduces analytical models for FSO systems with RIS considering turbulence and pointing errors, demonstrating the benefits of large RIS arrays through derived formulas and simulations.

Findings

Analytical expressions for outage probability, BER, and capacity are derived.

Accuracy of the models improves with more reflecting elements at the RIS.

Simulations confirm the analytical results and performance gains.

Abstract

Despite the promising gains, free-space optical (FSO) communication is severely influenced by atmospheric turbulence and pointing error issues, which make its practical design a bit challenging. In this paper, with the aim to increase the communication coverage and improve the system performance, reconfigurable intelligent surfaces (RISs) are considered in an FSO communication setup, in which both atmospheric turbulence and pointing errors are considered. Closed-form expressions for the outage probability, average bit error rate, and channel capacity are derived assuming large number of reflecting elements at the RIS. Specifically, according to central limit theorem (CLT), while assuming multiple reflecting elements approximate expressions are proposed. It is shown that the respective accuracies increase as the number of elements at the RIS increases. Illustrative numerical examples are shown along with insightful discussions. Finally, Monte Carlo simulations are presented to verify the correctness of the analytical results.