Ergodic Capacity of Triple-Hop All-Optical Amplify-and-Forward Relaying over Free-Space Optical Channels

TL;DR

This paper analyzes the ergodic capacity of triple-hop all-optical amplify-and-forward relaying systems over free-space optical channels, considering various noise sources and optical degrees of freedom.

Contribution

It derives exact and approximate expressions for noise variance and evaluates system capacity, advancing understanding of optical relaying performance.

Findings

Exact noise variance expressions derived for full CSI relaying

Approximate models validated for analytical simplicity

System capacity evaluated considering multiple noise sources

Abstract

In this paper, we propose a comprehensive research over triple hop all-optical relaying free-space optical (FSO) systems in the presence of all main noise sources including background, thermal and amplified spontaneous emission (ASE) noise and by considering the effect of the optical degree-of- freedom (DoF). Using full CSI relaying, we derive the exact expressions for the noise variance at the destination. Then, in order to simplify the analytical expressions of full CSI relaying, we also propose and investigate the validity of different approximations over noise variance at the destination. Finally, we evaluate the the performance of considered triple-hop all-optical relaying FSO system in term of ergodic capacity.