Performance analysis of the RoFSO system over a log-normal turbulent link

Abstract This study provides a comprehensive analysis of the design and performance evaluation of a radio over free space transmission link using Optisystem v.20 software. The research focuses on the integration of four transmission channels through the use of a multiplexer to achieve a transfer rate of 40 Gbps over a distance of 2 km, with each channel carrying 10 Gbps of data. This is achieved by modulating data on 20 GHz radio frequency signals, which are subsequently transmitted via laser waves at different frequencies. The performance of the proposed communication is assessed by evaluating its behavior in the presence of different levels of atmospheric turbulence, classified as light, medium, and strong. This analysis involves calculating based on metrics such as the Q-factor, bit error rate (BER), and log values (BER). The results showed that the Q factor decreased by (4.7) under the influence of a strong disturbance, while in contrast, it decreased by (0.2) under the influence of a weak disturbance. The results also indicated a minimum log BER (at −7.96) for the wavelength (193.3 THz) at 1.5 km. Besides, the best frequency for data transfer was (193.1 THz), followed by (193.4 THz).