Development of hybrid atmospheric-underwater optical communication system

Underwater optical wireless communications are promising and future-oriented wireless carriers to support underwater activities focused on 5G and beyond (5GB) wireless systems. The main challenges for the deployment of underwater applications are the physicochemical properties and strong turbulence in the transmission channel. Therefore, this paper analyzes the end-to-end performance of a hybrid free space optics (FSO) and underwater wireless visible light communication (UVLC) system under intensity modulation or direct detection (IM/DD) in a method considering a pulse amplitude modulation (PAM) scheme. In this study, a fading model with Gamma-Gamma (GG) distribution is used to deal with channel conditions with moderate and strong turbulence, and the links are designed by combining plane wave modeling in the corresponding links, respectively. The proposed performance methods excel in higher achievable data rates with minimal delay response and improves network connectivity in real-time monitoring scenarios compared to conventional underwater wireless communication techniques. The simulation results provide reliable estimates of system performance metrics such as average bit error rate (ABER) and probability of failure (Pout) in the presence of pointing errors. Finally, this paper uses a Monte Carlo approach for best curve fitting and validate the numerical expression with simulation results.

1. Yahia S., Meraihi Y., Ramdane-Cherif A., Gabis A.B., Acheli D., Guan H. A survey of channel modeling techniques for visible light communications. J. Netw. Comput. Appl. 2021;194:103206.

2. Nguyen T.V., Le H.D., Pham T.V., Pham A.T. Link availability of satellite-based FSO communications in the presence of clouds and turbulence. IEICE Commun. Exp. 2021;10(5):206–211.

3. Miranda F.A. et al. An overview of key optical communications technologies under development at the NASA Glenn Research Center. Proc. Opt. Interconnects XXI. 2021;11692:130–144.

4. Mohsan S.A.H. Amjad H. A comprehensive survey on hybrid wireless networks: Practical considerations, challenges, applications and research directions. Opt. Quantum Electron. 2021;53(9):1–56.

5. Ali M.F., Jayakody D.N.K., Li Y. Recent trends in underwater visible light communication (UVLC) systems. IEEE Access. 2022;10:22169–22225.

6. Hoeher P.A., Sticklus J., Harlakin A. Underwater optical wireless communications in swarm robotics: A tutorial. IEEE Commun. Surveys Tuts. 2021;23(4):2630–2659.

7. Ali M.F., Jayakody D.N.K., Chursin Y.A., Affes S., Sonkin D. Recent advances and future directions on underwater wireless communications. Arch. Comput. Methods Eng. 2020;26(100):1379–1412.

8. Elamassie M. Uysal M. Vertical underwater VLC links over cascaded gamma-gamma turbulence channels with pointing errors. Proc. IEEE Int. Black Sea Conf. Commun. Netw. (BlackSeaCom). 2019:1–5.

9. Aggarwal M., Garg P., Puri P. Analysis of subcarrier intensity modulation-based optical wireless DF relaying over turbulence channels with path loss and pointing error impairments. IET Commun. 2014;8(17):3170–3178.

10. Sokolov A., Chami M., Dmitriev E., Khomenko G. Parameterization of volume scattering function of coastal waters based on the statistical approach. Opt. Exp. 2010;18(5):4615–4636.

11. Elamassie M., Miramirkhani F., Uysal M. Channel modeling and performance characterization of underwater visible light communications. Proc. IEEE Int. Conf. Commun. Workshops (ICC Workshops). 2018:1–5.

12. Gappmair W., Further results on the capacity of free-space optical channels in turbulent atmosphere. IET Commun. 2011;5(9):1262–1267.

13. Varotsos G.K. et al. Probability of fade estimation for FSO links with time dispersion and turbulence modeled with the gamma-gamma or the IK distribution. Optik. 2014;125(24):7191–7197.

14. Varotsos G. K., Nistazakis H. E., Ninos M. P., Tombras G. S., Tsigopoulos A. D., Volos C. K. DF relayed FSO communication systems with time dispersion over gamma gamma turbulence and misalignment. Proc. 6th Int. Conf. Modern Circuits Syst. Technol. (MOCAST). 2017:1–4.

15. Levidala B. K., Ramavath P. N., Krishnan P. Performance enhancement using multiple input multiple output in dual-hop convergent underwater wireless optical communication–free-space optical communication system under strong turbulence with pointing errors. Opt. Eng. 2021;60(10):106106.

16. Farid A.A. Hranilovic S. Outage capacity optimization for freespace optical links with pointing errors. J. Lightw. Technol. 2007;25(7):1702–1710.

17. Ansari I. S., Yilmaz F., Alouini M.-S. Impact of pointing errors on the performance of mixed RF/FSO dual-hop transmission systems. IEEE Wireless Commun. Lett. 2013;2(3): 351–354.

18. Adamchik V., Marichev O. The algorithm for calculating integrals of hypergeometric type functions and its realization in REDUCE system. Proc. Int. Symp. Symbolic Algebr. Comput. 1990:212–224.

19. Generalized G-Meijer Function. URL: functions.wolfram.com/GeneralizedFunctions [дата обращения 29.11.2023].

20. Liao Z., Yang L., Chen J., Yang H.-C., Alouini M.-S. Physical layer security for dual-hop VLC/RF communication systems. IEEE Commun. Lett. 2018;22:12:2603–2606.

21. Ansari I.S., Al-Ahmadi S., Yilmaz F., Alouini M.-S., Yanikomeroglu H. A new formula for the BER of binary modulations with dual-branch selection over generalized-K composite fading channels. IEEE Trans. Commun. 2011;59(10)2654–2658.

22. Odeyemi K.O., Owolawi P.A., Olakanmi O.O. Performance analysis of reconfigurable intelligent surface assisted underwater optical communication system. Progr. Electromagn. Res. 2020;98:101–111.

23. Elamassie M., Sait S.M., Uysal M. Finite-SNR diversity gain analysis of FSO systems over gamma-gamma fading channels with pointing errors. IEEE Commun. Lett. 2021;25(6):1940–1944.