Browsing by Author "Zitouni, Abdelkader(Supervisor)"

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Comparative study of different modulation schemes in optical fiber communication system
(Université M’Hamed BOUGARA de Boumerdes : Institut de génie electrique et electronique (IGEE), 2018) Bella, Douniazed; Tamalt, Meriem; Zitouni, Abdelkader(Supervisor)
In this project, we investigate and comprehensively compare Non-return-to-zero (NRZ) with the advanced modulation schemes: carrier- suppressed return-to-zero (CSRZ) and Duo-Binary (DB) modulations using three approaches to compensate the dispersion: pre-compensation, post-compensation, and symmetric compensation at operating wavelength 1550 nm and 90km fiber length through computer simulations. The influence of the LASER input power has been studied at three bit rates: 5 Gbps, 25 Gbps, and 40 Gbps.The performance characteristics like bit error rate, Q-factor, and eye diagram are compared and discussed by simulating different cases using tables and graphs in order to compare the different results.
Effect of Polarization Mode Dispersion on Pulse Propagation in Optical Fiber Links
(Université M’Hamed bougara : Institute de Ginie électric et électronic, 2023) Hamraoui, Yanis; Hamiche, Youcef; Zitouni, Abdelkader(Supervisor)
Polarization mode dispersion (PMD) remains one of the main sources for signal distortion in fiber optics to this day. This project focuses on studying the effects of PMD on optical signals using the Optisystem software.To investigate the impact of the different orders of PMD, we isolated the first and second order effects by manipulating specific parameters in the PMD emulator. We tried different methods to mitigate the dispersion effects associated with first order PMD. Additionally, we explored the impact of second order PMD in the presence of PCD. Lastly, we evaluated the effects of PMD in a real-world fiber environment while employing compensation techniques for both chromatic dispersion and PMD. The simulation results were analyzed using BER analyzers, oscilloscope visualizers and eye-diagrams. We have tested the PMD effects at three transmission bit rates (2.5 Gbps, 10 Gbps and 40 Gbps), while also varying different PMD emulator parameters (DGD, polarization rate, length, dispersion and attenuation). We have found that the first order PMD can cause detrimental pulse splitting of the signal, but it can be almost completely negated by either the PST or optical delay compensation method. As for second order effects, it can cause serious degradation of the signal at high bit rates, especially when paired with PCD. Finally, we have seen how CD and attenuation cause serious degradation to the signal. Using the FBG method alongside the PST method to compensate for PMD, CD and PCD gave satisfying outcomes resulting in a low BER signal and a high Quality factor .These obtained results were presented as tables, figures and graphs.
Effect of Polarization Mode Dispersion on Pulse Propagation in Optical Fiber Links
(Université M’Hamed bougara : Institute de Ginie électric et électronic, 2023) hamraoui, Yanis; Hamiche, Youcef; Zitouni, Abdelkader(Supervisor)
Polarization mode dispersion (PMD) remains one of the main sources for signal distortion in fiber optics to this day. This project focuses on studying the effects of PMD on optical signals using the Optisystem software.To investigate the impact of the different orders of PMD, we isolated the first and second order effects by manipulating specific parameters in the PMD emulator. We tried different methods to mitigate the dispersion effects associated with first order PMD. Additionally, we explored the impact of second order PMD in the presence of PCD. Lastly, we evaluated the effects of PMD in a real-world fiber environment while employing compensation techniques for both chromatic dispersion and PMD. The simulation results were analyzed using BER analyzers, oscilloscope visualizers and eye-diagrams. We have tested the PMD effects at three transmission bit rates (2.5 Gbps, 10 Gbps and 40 Gbps), while also varying different PMD emulator parameters (DGD, polarization rate, length, dispersion and attenuation). We have found that the first order PMD can cause detrimental pulse splitting of the signal, but it can be almost completely negated by either the PST or optical delay compensation method. As for second order effects, it can cause serious degradation of the signal at high bit rates, especially when paired with PCD. Finally, we have seen how CD and attenuation cause serious degradation to the signal. Using the FBG method alongside the PST method to compensate for PMD, CD and PCD gave satisfying outcomes resulting in a low BER signal and a high Quality factor .These obtained results were presented as tables, figures and graphs.
Study and simulation of different amplification techniques in optical fiber communication link
(2020) Benabdallah, Okba; Mokeddem, Walid; Zitouni, Abdelkader(Supervisor)
The aim of this work is to do a comparative study between a two popular optical amplifiers performances: the RAMAN amplifier and the EDFA (erbium doped fiber amplifier) in dense wavelength division multiplexing (DWDM) system. by using two modulation formats non-return to zero (NRZ) and return to zero (RZ). We have studied the effect of the bit rate, length of fiber and input power on the performance of the concerned amplifiers in a point to point 8 channel DWDM topology, operating at wavelength 1550 nm. For getting better results a hybrid configuration has been done by cascading EDFA and RAMAN. OptiSystem 17 software is used to simulate the overall system. The performance characteristics in terms of Q-factor, eye diagram ,bit error rate, gain and noise are compared and discussed by simulating different cases using tables and graphs in order to compare the different results.
Study and simulation of DWDM star topology network
(2018) Bouchafa, Safia; Khodja, Khalida; Zitouni, Abdelkader(Supervisor)
Nowadays, optical networks employing Dense Wavelength Division Multiplexing (DWDM) are the adopted technique used in modern communication networks that can meet the everincreasing demand for bandwidth of the end users. The development of nodal elements, such as Optical Cross-Connects (OXC) for DWDM networks, has led to huge possible network architectures for the optical layer. In this project, we study the effect of the input power, transmission speed, pre- and postcompensation techniques on the performance of an eight channel DWDM star topology operating at wavelength 1550 nm and consisting of a central node to which 64 other nodes are connected. OptiSystem 7.0 is used for building the overall system and carrying out simulations. The performance analysis is based on eye diagrams, Q Factor and simulated Bit Error Rate (BER).