Effects of Atmospheric Turbulence on OAM-POL-FDM Hybrid Multiplexing Communication System

Abstract

This paper proposes a 32-channel-hybrid-multiplexing system on atmospheric turbulence. With the utilization of the hybrid multiplexing of orbital angular momentum (OAM), polarization, and frequency, the communication speed of the system can be significantly improved, and this system can be well combined with the existing frequency division multiplexing (FDM) optical communication network. Within this communication system, we discuss the effects of different turbulence intensities on the phase, OAM crosstalk, spectrum, and bit error rate (BER) in turbulent channels. Under strong turbulence, 46.8% of the energy leaks to the neighbor OAM and become noise when multiple topological charge states are transmitted. The research reflects the impact of various parameters of the OAM hybrid multiplexing system under turbulence, which is closer to a practical application scenario and is significant for implementing OAM communication in the turbulence channel.

Post-Flood UAV-Based Free Space Optics Recovery Communications with Spatial Mode Diversity

“…This leads to aberration of the beam wavefront from random power and phase perturbations [65]. This results in the signal initially launched in a particular mode to spread to other modes [66]. The amount of spreading is influenced by the strength of the atmospheric turbulence.…”

Performance Evaluation of a 4 × 20-Gbps OFDM-Based FSO Link Incorporating Hybrid W-MDM Techniques

“…The application of OAM modes to realize high-speed FSO links has also been reported by different research groups [35][36][37][38][39]. The designing and evaluation of a low-density parity check coded FSO link incorporating high-capacity transmission under strong turbulence conditions using OAM multiplexing has been discussed by Z Qu.…”

“…L. Li et al reported an OAM-multiplexed FSO communication system, where 80-Gbps information is transmitted between two ground terminals separated at 100 m via an unmanned aerial vehicle (UAV) using two independent 40-Gbps QPSK-modulated OAM beams [38]. Z. Zhao et al reported an ultrahigh capacity FSO communication system over strong atmospheric turbulence conditions by incorporating hybridization of OAM multiplexing, polarization multiplexing, and frequency multiplexing [39]. The research works in references [40][41][42][43][44] report the simulative analysis of MDM-based high-capacity radio over fiber (RoF) links.…”

Design and Performance Analysis of Probabilistically Shaped QAM Signals for Coherent FSO Systems with Gamma-Gamma Turbulence Channels

“…There are several technologies that can significantly improve the channel capacity in an FSO system, for instance, high-level modulation formats [4], wavelength division multiplexing [5], space division multiplexing [6], and angular momentum multiplexing [7]. However, the gap between the capacity of an FSO system and Shannon limit still exists.…”