Affiliation:
1. Computer and Communication Sys. Engineering/Center of Excellence for Wireless and Photonic Network (WiPNET), Faculty of Engineering , University Putra Malaysia , Serdang , Malaysia
2. Electronic and Communication Engineering Department, College of Engineering , University of Baghdad , 47202 Baghdad , Iraq
Abstract
Abstract
This research aims to investigate and improve multi-user free space optic systems (FSO) based on a hybrid subcarrier multiplexing spectral amplitude coding-optical code division multiple access (SCM-SAC-OCDMA) technique using MS code with a direct decoding technique. The performance is observed under different weather conditions including clear, rain, and haze conditions. The investigation includes analyzing the proposed system mathematically using MATLAB and OptiSystem software. The simulation is carried out using a laser diode. Furthermore, the performances of the MS code in terms of angles of bit rate, beam divergence and noise are evaluated based on bit error rate (BER), received power, and transmission distance. The performance of the MS code-based system was subsequently compared with Khazani Syed code (KS), multi-diagonal (MD), and modified quadratic congruence code (MQC) codes under different weather conditions at a bit rate of 1 Gb/s and BER threshold of 10−9. Heavy rain indicates the worst performance in terms of transmission distance of 0.9 km. Nevertheless, the system designed using the MS code outperformed the KS, MD and MQC systems as it is capable of supporting up to 6.3, 0.8, 0.9, and 1.5 km, respectively, under clear weather. In conclusion, this study provides a means of improving FSO communications that suits tropical and Malaysia weather conditions.
Subject
Electrical and Electronic Engineering,Condensed Matter Physics,Atomic and Molecular Physics, and Optics
Reference40 articles.
1. Chacko, N, Davies, S. Free-space optical networking using the spectrum of visible light. Int J Trends Eng Technol 2015;5:217–24.
2. Szweda, R. Lasers for free-space optical communications. III–Vs Rev 2001;14:46–9. https://doi.org/10.1016/s0961-1290(01)80404-x.
3. Ghassemlooy, Z, Zvanovec, S, Khalighi, MA, Popoola, WO, Perez, J. Optical wireless communication systems. Optik 2017;15:1–6. https://doi.org/10.1016/j.ijleo.2017.11.052.
4. Mohammed, HA. 320 Gbps free space optic communication system deploying ultra dense wavelength division multiplexing and polarization mode division multiplexing. J Opt Commun 2022;43:137–45.
5. Husam, AM, Hani, JK, Aqiel, NA. Design and implementation of a network based on wavelength division multiplexing (WDM). J Kerbala Univ 2011;9:55–9.