We consider a drone-based communication network, where several drones hover above an area and serve as mobile remote radio heads for a large number of mobile users. We assume that the drones employ free space optical (FSO) links for fronthauling of the users’ data to a central unit. The main focus of this paper is to quantify the geometric loss of the FSO channel arising from random fluctuation...

This paper proposes a theoretical study to characterize the transmission of optical code division multiple access (CDMA) systems deploying polarization shift keying (PolSK) over a free space optical (FSO) link under the impact of atmospheric turbulence. In our analysis, a novel transceiver architecture for atmospheric OCDMA FSO systems based on polarization modulation with direct detection is p...

Future non-terrestrial networks aim to achieve a throughput of Terabits/s. Therefore, free-space optical (FSO) communications have been adopted as candidate solution due their ability an extremely high data rate. Nonetheless, FSO are sensitive the adverse effects beam scintillation, beam-wander-induced pointing errors, loss, and weather conditions. Space-air-ground (SAG) transmission hybrid sin...

Free-space optical (FSO) communication has witnessed rapid development recently in response to ever-increasing demands for greater bandwidth. FSO links provide fiberspeed with the flexibility of wireless. Commercially available systems offer transmission speeds up to 2.5 Gbps, 5 Gbps and 10 Gbps, and demonstration systems report data rates as high as 160 Gbps. This is usually not possible with ...

In this paper, we study the communications over the free-space optical (FSO) links in the presence of atmospheric turbulence that induces strong fading on the FSO channel. We consider the three-way systems where a wireless transceiver (or relay) that is present in the neighborhood of the source and destination shares its resources for assisting the source in delivering its message to the destin...

Mobile FSO Communication links have gained significant attention over the last years due to their increasing maturity. They are used in point to point link scenarios where the high gain in power efficiency and datarate is crucial, compared to state-of-the-art RF links. The Optical Communication Group of German Aerospace Center’s Institute of Communication and Navigation is conducting research a...

Existence of line of sight (LOS) and alignment between the communicating antennas is one of the key requirements for free-space-optical (FSO) communication. To ensure uninterrupted data flow, auto-aligning transmitter and receiver modules are necessary. We propose a new FSO node design that uses spherical surfaces covered with transmitter and receiver modules for maintaining optical links even ...

Cell-free massive MIMO (CF-mMIMO) network and its user-centric (UC) version are considered as promising techniques for the next generations of wireless networks. However, fronthaul backhaul assignments challenging issues in these In this paper, energy efficiencies uplink transmission CF- UC-mMIMO networks studied, wherein access points (APs) connected to aggregation nodes (ANs) through radio fr...

Future Internet should be able to support a wide range of services containing large amount of multimedia over different network types at a high speed. The future optical networks will therefore be hybrid, composed of different single-mode fibre (SMF), multi-mode fibre (MMF) and free-space optical (FSO) links. In these networks, novel modulation and coding techniques are needed that are capable ...