Abstract
This research paper investigates free space optic (FSO) system by integrating orbital angular momentum (OAM) and
polarization division multiplexing (PDM) techniques resulting in the data rate enhancement. Simulation of OAM-PDM-FSO
transmission is analyzed by using Optisystem. A successful transmission of 80 Gb/s overall capacity is investigated by
means of individual OAM modes (LG0,0, LG0,13, LG0,40, and LG0,80), enhancing the spectral efficiency of the system under
different climatic conditions. System performance is studied for various modulation schemes including return-to-zero (RZ),
non-return-to zero (NRZ) and offset-quadrature-phase shift keying (OQPSK). The best performance has been shown by
means of OQPSK modulation technique. 8x10 Gb/s transmission under the influence of various external weather conditions
such as rain, fog and dust is reported. A maximum FSO link range of 6 km is realized under clear weather conditions
whereas a maximum FSO range of 0.125 km is achieved under heavy dust conditions. A satisfactory Bit Error rate (BER) <
10-6 and eye diagrams with wider opening heights for all eight channels achieved. The FSO system also achieves
satisfactory BER for various turbulence levels. Performance of proposed hybrid OAM-PDM system is evaluated at different
link lengths in terms of Q-factor, log (BER), received power and eye diagrams.
Keywords
OAM, FSO, OQPSK, MDM, Laguerre Gaussian modes.
Citation
NAGA SUBRAHMANYA VAMSI MOHAN YARRA, SIVANANTHA RAJA A., ESAKKI MUTHU K., 80 Gb/s OAM-PDM-OQPSK FSO system under extensive weather conditions-performance analysis, Optoelectronics and Advanced Materials - Rapid Communications, 17, 9-10, September-October 2023, pp.446-460 (2023).
Submitted at: May 8, 2023
Accepted at: Oct. 9, 2023