English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this paper, we propose an adaptive multiple-input–multiple-output (MIMO) free-space optical (FSO) links using an orbital-angular-momentum (OAM)-multiplexed based on the spatial-mode multiplexing (SMM) through the turbulent channel. We propose to use the SMM and spatial-mode diversity (SMD) combined with an adaptive MIMO technique to mitigate the atmospheric turbulence effects. In this paper, our objective is to design the adaptive MIMO–FSO links based on OAM–MIMO/SMM multiplexed and analyze its performance in the atmospheric turbulence conditions. The simulation results show four OAM modes-based MIMO/SMM and resulting in four OAM-multiplexed channels. Each OAM mode carries a 100-Gbit/s quadrature phase-shift keying signal (aggregate 400 Gbit/s) on a single wavelength channel ( $\lambda \sim 1550$ nm) and is transmitted for a 2-km link. The calculated received power and inter-channel crosstalk of an OAM–MIMO/SMM signal fluctuate by 4.5 −6 dB, respectively. The power penalties can be reduced by 1–4 dB for all channels after OAM–MIMO/SMM equalization at a bit-error rate (BER) of 10−9. The calculating results show that the system using an OAM-based MIMO/SMM and SMD multiplexing achieves superior BER performance using an adaptive MIMO/SMM equalization. The Numerical results show favorable transmission performance of OAM based on MIMO/SMM and the SMD multiplexing compared to the conventional-MIMO (CMIMO) of FSO transmission link. The Simulation models verified the superior BER performance of OAM–SMD-based MIMO/SMM. The SMM/MIMO–SMD technique performed better in the channel capacity and signal-to-noise ratios over other commonly used CMIMO algorithms. To sufficiently discuss the OAM–MIMO/SMM behavior-based SMD multiplexing, the performance of the novel SMM/MIMO–SMD technique is analyzed using simulations based on the Matlab/simulink program in order to verify the accuracy of the models and simulation results. This paper could be useful for the practical implementation of the SMM and the SMD using an adaptive MIMO equalization in the FSO systems.

ieee access

Performance Enhancement of an Orbital-Angular-Momentum-Multiplexed Free-Space Optical Link Under Atmospheric Turbulence Effects Using Spatial-Mode Multiplexing and Hybrid Diversity Based on Adaptive MIMO Equalization