Characterization of FSO link performance considering weak to high turbulence conditions
-
Sanmukh Kaur
,
Aanchal Sharma
and
Ajay Sharma
Abstract
Utilizing a line-of-sight link, free space optics (FSO) is a technology that employs a beam of light for the purpose of establishing an optical connection between two distant points, enabling the exchange of information. FSO communication through clear atmosphere suffers from challenges arising due to variations in refractive index of the air caused by random fluctuations in the atmospheric temperature. This results in a reduction of signal-to-noise ratio (SNR) of the received signal, subsequently impacting the overall performance of the link. The present study evaluates the outage probability, average capacity, and bit error rate (BER) performance of FSO communication system under turbulent environment utilizing binary phase shift keying (BPSK) as modulation technique. To evaluate the system’s error performance across varying turbulence levels, the probability density function (PDF) of the received irradiance, post-traversing the atmosphere has been represented through the Gamma–Gamma (G–G) model. Simulation results show that the BER improves from 10−2 to 10−4 with the increase in SNR from 5 dB to 20 dB under moderate turbulence conditions. Higher channel capacity up to 6.8 bits/s/Hz has been achieved, along with significant reduction in outage probability with an increased in the SNR values.
-
Research ethics: Not applicable.
-
Informed consent: Not applicable.
-
Author contributions: The authors have accepted responsibility for the entire content of this manuscript and approved its submission. All authors contributed to the manuscript. Sanmukh Kaur contributed to data analysis and manuscript writing. Aanchal Sharma conceptualized the study, performed the simulations, and helped in writing the manuscript. All authors reviewed and approved the final manuscript.
-
Use of Large Language Models, AI and Machine Learning Tools: None declared.
-
Conflict of interest: The authors state no conflict of interest.
-
Research funding: None declared.
-
Data availability: The raw data can be obtained on request from the corresponding author.
References
1. Chowdhury, MZ, Shahjalal, M, Hasan, MK, Jang, YM. The role of optical wireless communication technologies in 5G/6G and IoT solutions: prospects, directions, and challenges. Appl Sci 2019;9:4367. https://doi.org/10.3390/app9204367.Search in Google Scholar
2. Majumdar, AK. Fundamentals of free-space optical communications systems. In: Optical wireless communications for broadband global internet connectivity. New York: Springer; 2014:1–20 pp.Search in Google Scholar
3. Hamza, AS, Deogun, JS, Alexander, DR. Classification framework for free space optical communication links and systems. IEEE Commun Surv Tutor 2019;21:1346–82. https://doi.org/10.1109/comst.2018.2876805.Search in Google Scholar
4. El-Wakeel, AS, Mohammed, NA, Aly, MH. Free space optical communications system performance under atmospheric scattering and turbulence for 850 and 1550 nm operation. Appl Opt 2016;55:7276–86. https://doi.org/10.1364/ao.55.007276.Search in Google Scholar PubMed
5. Esmail, MA. Experimental performance evaluation of weak turbulence channel models for FSO links. Opt Commun 2021;486:126776. https://doi.org/10.1016/j.optcom.2021.126776.Search in Google Scholar
6. Xu, Z, Xu, G, Zheng, Z. BER and Channel Capacity performance of an FSO communication system over atmospheric turbulence with different types of noise. Sensors 2021;21:3454. https://doi.org/10.3390/s21103454.Search in Google Scholar PubMed PubMed Central
7. Sahu, M, Kiran, KV, Das, SK. FSO link performance analysis with different modulation techniques under atmospheric turbulence. In: 2018 second international conference on electronics, communication and aerospace technology (ICECA). Coimbatore, India: IEEE; 2018:619–23 pp.10.1109/ICECA.2018.8474849Search in Google Scholar
8. Giggenbach, D, Shrestha, A. Atmospheric absorption and scattering impact on optical satellite-ground links. Int J Satell Commun Netw 2022;40:157–76. https://doi.org/10.1002/sat.1426.Search in Google Scholar
9. Kaur, S, Bhardwaj, P. Performance of FSO links for BPSK modulated signal with atmospheric turbulence and pointing error. Int J Comput Appl;975:8887. https://doi.org/10.5120/ijca2018917301.Search in Google Scholar
10. Hanzra, TS, Singh, G. Performance of free space optical communication system with BPSK and QPSK modulation. IOSR J Electron Commun Eng 2012;1:38–43. https://doi.org/10.9790/2834-0133843.Search in Google Scholar
11. Balaji, KA, Prabu, K. Performance evaluation of FSO system using wavelength and time diversity over Malaga turbulence channel with pointing errors. Opt Commun 2018;410:643–51. https://doi.org/10.1016/j.optcom.2017.11.006.Search in Google Scholar
12. Ahmed, MS, Gucluoglu, T. Performance of generalized frequency division multiplexing over gamma-gamma free space optical link. Opt Commun 2020;466:125683. https://doi.org/10.1016/j.optcom.2020.125683.Search in Google Scholar
13. Kappala, VK, Pradhan, J, Sahu, M, Turuk, AK, Das, SK. Performance analysis of FSO for different modulation techniques under atmospheric turbulence with pointing errors. In: 2021 2nd international conference on range technology (ICORT), Chandipur, Balasore, India; 2021:1–5 p.10.1109/ICORT52730.2021.9581438Search in Google Scholar
14. Qin, D, Wang, Y, Zhou, T. Performance analysis of hybrid radio frequency and free space optical communication networks with cooperative spectrum sharing. Photonics 2021;8:108. https://doi.org/10.3390/photonics8040108.Search in Google Scholar
15. Kumar, LJS, Krishnan, P, Shreya, B, Sudhakar, MS. Performance enhancement of FSO communication system using machine learning for 5G/6G and IoT applications. Optik 2022;252:168430. https://doi.org/10.1016/j.ijleo.2021.168430.Search in Google Scholar
16. Amirabadi, MA, Kahaei, MH, Nezamalhosseni, SA. Low complexity deep learning algorithms for compensating atmospheric turbulence in the free space optical communication system. IET Optoelectron 2022;16:93–105. https://doi.org/10.1049/ote2.12060.Search in Google Scholar
17. Geng, C, Yu, S, Lu, G, Wang, Y. On the correlated Gamma–Gamma distribution and coherent detection performance of optical spatial modulation. Optik 2023;276:170622. https://doi.org/10.1016/j.ijleo.2023.170622.Search in Google Scholar
18. Singh, M, Elsayed, EE, Alayedi, M, Aly, MH, Abd El-Mottaleb, SA. Performance analysis in spectral-amplitude-coding-optical-code-division-multiple-access using identity column shift matrix code in free space optical transmission systems. Opt Quant Electron 2024;56:795. https://doi.org/10.1007/s11082-023-05721-9.Search in Google Scholar
19. Elsayed, EE. Performance enhancement of atmospheric turbulence channels in DWDM-FSO PON communication systems using M-ary hybrid DPPM-M-PAPM modulation schemes under pointing errors, ASE noise and interchannel crosstalk. J Opt 2024;1–17. https://doi.org/10.1007/s12596-024-01908-9.Search in Google Scholar
20. Barua, B, Majumder, SP. Free space optical communication with OOK and BPSK modulation under different turbulent conditions. In: 2013 international conference on informatics, electronics and vision (ICIEV). Dhaka, Bangladesh; 2013:1–5 pp.10.1109/ICIEV.2013.6572720Search in Google Scholar
21. Demir, P, Yılmaz, G. The investigation of SNR for free space optical communication under turbulence. Karaelmas Sci Eng J 2018;8:438–45. https://doi.org/10.7212/zkufbd.v8i2.1093.Search in Google Scholar
22. Abd El-Hak, SS, Elfiqi, AE, Morra, AE, Abd El-Samie, FE. Performance analysis of intensity modulation techniques in atmospheric turbulent channels. Menoufia J Electron Eng Res 2020;29:15–21. https://doi.org/10.21608/mjeer.2020.103263.Search in Google Scholar
23. P Jain, J N, L M, A Saxena, A Jain. Outage probability and average capacity analysis over α-µ distribution in free space optical communication system. In 2019 International conference on vision towards emerging trends in communication and networking (ViTECoN). Vellore, India; 2019:1–4 pp.10.1109/ViTECoN.2019.8899462Search in Google Scholar
24. Rani, M, Bhatti, HS, Singh, V. Performance analysis of free space optical communication system using homotopy perturbation method under different weather conditions. J Optoelectron Adv Mater 2018;20:33–7.Search in Google Scholar
25. Lath, S, Goyal, R, Kaler, RS. A review on free space optics with atmospheric and geometrical attenuation. J Opt Commun 2016;37:331–6. https://doi.org/10.1515/joc-2016-0009.Search in Google Scholar
26. Elsayed, EE, Hayal, MR, Nurhidayat, I, Shah, MA, Elfikky, A, Boghdady, AI, et al.. Coding techniques for diversity enhancement of dense wavelength division multiplexing MIMO-FSO fault protection protocols systems over atmospheric turbulence channels. IET Optoelectron 2024;18:11–31. https://doi.org/10.1049/ote2.12111.Search in Google Scholar
27. Li, X, Zhao, X, Zhang, P, Tong, S. BER performance of FSO communication system with differential signaling over correlated atmospheric turbulence fading. China Communications 2020;17:51–65. https://doi.org/10.23919/JCC.2020.04.006.Search in Google Scholar
28. Al-Gailani, SA, Mohd Salleh, MF, Salem, AA, Shaddad, RQ, Sheikh, UU, Algeelani, NA, et al.. A survey of free space optics (FSO) communication systems, links, and networks. IEEE Access 2021;9:7353–73. https://doi.org/10.1109/ACCESS.2020.3048049.Search in Google Scholar
© 2025 Walter de Gruyter GmbH, Berlin/Boston
