DMT analysis of multi-hop coherent FSO communication over atmospheric channels

In this paper, we investigate the diversity-multiplexing tradeoff (DMT) of a multi-hop coherent free-space optical (FSO) system over atmospheric channels. We consider a relay-assisted FSO system with decode-and-forward relay nodes and multiple heterodyne receivers with modal compensation. Based on a recently introduced statistical characterization for the combined effects of turbulence-induced amplitude fluctuations and phase aberrations, we quantify the potential performance improvements through the derivation of DMT. Our results demonstrate significant performance gains that can be achieved by multi-hop transmission in coherent FSO systems.