Performance investigation of 2 × 20 Gb/s MDM-RoFSO link incorporating spiral-phased Hermite–Gaussian modes under strong weather conditions

This research paper presents a novel high bit rate and spectral efficient 20 Gb/s mode division multiplexed (MDM) radio over free space optical communication (MDM-RoFSO) system. 10 MZM/QAM-16-modulated data streams, each from two distinct channels, are transported spiral-phased Hermite–Gaussian (HG) laser modes, HG00 HG01, respectively. These HG channels using MDM at GHz RF signal, amplified transmitted the atmospheric link an wavelength of 1550 nm. The proposed MDM-RoFSO system is simulated for MZM modulation modes in clear sky, dense haze, fog, strong rain weather conditions. performance evaluated metrics such as BER, eye diagram, Q factor, transmission range. simulation results show that more robust extended range achieved (7 to 24.4) km (24.4 2.98) factor sky further by (2.9 1.7) when QAM-16 incorporated composite (HG00 + HG01) then similar conditions acceptable BER < 10–5. Finally, confirm modulated able mitigate travel longer distance compared individual transmission.