Optimizing High Data Rate Up to 2.5 Tbps Transmission using 64-Channel DWDM System with DCF and NRZ Modulation

Chromatic Dispersion Compensation (CDC) using Fiber Bragg Grating (FBG) techniques in Dense Wavelength Division Multiplexing (DWDM) system is presented in this article. Pulse broadening effects on the transmitted signal can be limited by Dispersion Compensation (DC) mechanisms. To overcome this problem and improve the system performance, a suggested system for 10 Gbps using Chirped Fiber Bragg Grating (CFBG) as a dispersion compensator, Non-Return-to-Zero (NRZ) modulation format and an Erbium Doped fiber Amplifier (EDFA) on a Single Mode Fiber (SMF) is designed. The result shows that, with using CFBG grating length of 90 mm, SMF length of 30 Km, input power of 15 dBm and attenuation coefficient 0.1 dB/Km, the Quality-Factor (QF) is 39.9373 dB. However, increasing SMF length to 100 Km, the QF is 12.173 dB. Thus, Results show that this model is more efficient in terms of QF, Bit Error Rate (BER) and eye diagrams related to other published papers which can be useful in many applications in telecommunication system like Sensor Networks, Remote Radar Networks, Tele-spectroscopic process control network, and many more networks.

Design and comparative performance evaluation of chirped FBG dispersion compensation with DCF technique for DWDM optical transmission systems

The ever increasing demand for higher data rates and minimum latency has resulted in a widespread growth of optical fiber communication over the last decade. Dense Wavelength Division Multiplexing (DWDM) technique is one of the most important techniques used to establish a long-distance link with higher data rate transmission. However, when the requirement is to transmit the data inside a metropolitan (shorter range) city, DWDM has certain limitations like wideband change, more power consumption, and high-cost factor for lower channels. CWDM (Coarse Wavelength Division Multiplexing) can easily overcome these disadvantages. In this paper, the performance of 8 channel optical transmission link for Coarse Wavelength Division Multiplexing based optical network has been analyzed and compared. Here we’ve compared the performances in terms of Q-factor (Quality factor), BER (Bit Error Rate), and eye height in the eye diagram. For experimental setup and simulation, Optisystem-18 software is used.KeywordsCWDMBitrateAPD photodetectorLow pass filterQ-factor

The main limitation factor of high capacity multichannel DWDM (Dense Wavelength Division Multiplexing) systems are fiber nonlinear effects. The optical signal is severely degraded due to fiber nonlinear effects also known as Kerr fiber nonlinearity. Nonlinear effects under investigation are self-phase modulation (SPM) and cross-phase modulation (XPM). There are several methods to compensate these nonlinear distorts, some less or more effective. Nonlinear distort due to SPM and XPM can be effectively mitigated through implementation of optical DQPSK modulation over commonly used intensity modulation known as OOK (On-Off Keying). This paper presents a numerical simulation model of 1.28 Tbps DWDM system with optical DQPSK modulation. We present several scenarios and methods to mitigate fiber nonlinear effects including Fractional Fourier Transform (FrFT). Linear and nonlinear effects are considered together, so we implement the inline FrFT module in the optical domain which causes a time-frequency plane rotation to mitigate combined linear and nonlinear effects. The performance of proposed 1.28 Tbps DQPSK modulated DWDM system is evaluated in term of bit error rate (BER) and Q factor value.

The positioning of Erbium-Doped Fiber Amplifiers (EDFAs) plays a crucial role in optimizing the performance of Dense Wavelength Division Multiplexing (DWDM) systems, particularly in addressing signal attenuation challenges in long-distance optical transmission. This study investigates the impact of EDFA placement configurations (booster, in-line, and pre-amplifier) on signal quality using OptiSystem software simulations. The research examines systems with 4 to 16 DWDM channels, operating at 10 Gbit/s per channel with 50 GHz spacing, varying total input power between -10 dBm to 5 dBm. Results demonstrate that the booster amplifier configuration performs best, while the pre-amplifier setup exhibits more pronounced degradation. The in-line amplifier configuration shows a balanced performance, effectively restoring signal strength while requiring less pump power than the booster configuration, making it a viable option for optimizing energy efficiency in DWDM systems. A critical performance threshold was identified between 10-12 channels, where all configurations experience significant changes in error performance.

Bandwidth and quality of service requirements in transport networks are constantly growing. One of the probable solution to this problem is optical transmission systems usage based on Dense Wavelength Division Multiplexing (DWDM) technology. However, due to increasing number of optical channels and channel rates in the system, a number of limitations occurs caused by harmonic distortion. Primarily, these constraints affect the allowable power of the optical signal in fiber. The work is devoted to the method of power calculation, which is redistributed between the optical channels of DWDM systems due to the impact of the stimulated Raman scattering effect (SRS). In case of energy redistribution channels degradation with higher frequencies take place, thereby the number of bit error rate (BER) increase. It is shown that SRS could affect system performance in case of inefficient frequency diversity and high input signal power. Therefore, the Raman scattering effect calculation is required in high load multi-channel DWDM systems deployment. The proposed calculation method allows to determine: SRS appearance threshold power, the amount of the main signal power loss for each channel, the remaining total energy in the target channel, the amount of energy that passes from the short wavelengths channels to longer wavelengths channels. The 8-channel DWDM system calculation example has been shown.

Based on comprehensive computer modeling and numerical simulation of dense wavelength-division multiplexing (DWDM) systems, it is demonstrated that by judicious use of erbium-doped fiber amplifiers (EDFAs) and distributed Raman amplifiers (DRAs), theQ factor and op- tical signal-to-noise ratio (OSNR) are improved compared with EDFA alone. This hybrid combination yields a 13.5-dB improvement in OSNR and a peak Q factor of 12.1 for the hybrid versus a peak of 8.1 when

This paper compares the efficiency of on-off Keying (OOK) modulation formats non-return-to-zero (NRZ) and return-to-zero (RZ) in both electrical and optical chromatic dispersion compensation. While In electrical compensator feed forward-decision feedback equalizer (FFE-DFE) method was applied, Dispersion Compensation Fiber (DCF) was chosen to evaluate the effect of modulation format on them. Transmission distance, subsequently are varied in both systems with mentioned compensation systems to evaluate the Bit Error Rate (BER) regarding to mentioned modulation techniques.

Tunable optical filters are important components for controlling light in dense wavelength division multiplex (DWDM) systems. They can be used in many optical components, and their tunability can be realized using mechanical equipment, or/and changing the refractive index in transmission media. In DWDM systems several types of tunable filters are used. They are produced with different technologies, and they have different technical parameters, but the most important one is still their price

Chirped fibre Bragg gratings (CFBGs) are required to be concatenated to compensate the fibre dispersion in the dense wavelength-division multiplexing (DWDM) systems. When the channel spacing is small, the performance of CFBGs is degraded, which restricts the usage of fibre gratings. The origin of the interactions between the gratings is analysed and methods of suppressing the interactions are also proposed.

The Optical OFDM system is considered to be the essential backbone of the next generation of ultra-high-speed networks. A Dispersion effect is considered one of the common limitations in optical OFDMA system especially at very high date rate. When the pulse width reaches less than a few pico-seconds, not only the second-order but even higher-order dispersion must be taken into account. High order dispersion such as a third-order and higher-order dispersion effects are not fully compensated using the traditional dispersion compensating devices such as Dispersion compensating fiber (DCF). Thus the received signals at the receiver end would be distorted dramatically, even if only a small outside effect affects the transmission link. The tunable adaptive equalizer (TAE) system is proposed in this work at the receiver end to recover higher-order dispersion which would not be compensated by DCF fiber. Therefore, the overall system performance based TAE system is improved in terms of (Bit error rate and eyes diagram) which is considered the solution for optical OFDMA next generation optical networks.

The present paper proposes the optimal transmission parameters for non-return-to-zero (NRZ), return-to-zero differential phase shift keying (RZ-DPSK), carrier-suppressed RZ-DPSK (CSRZ-DPSK) and duobinary (DB) modulation formats in 16-channel 10 Gbit/s wavelength division multiplexed passive optical network (WDM-PON) transmission system. The paper investigates influence of laser output power, length of dispersion compensating fiber (DCF) and application of erbium-doped fiber amplifiers (EDFA), as well as impact of optical components configuration on received signal quality. It compares demand of these modulation formats for amplification and dispersion compensation with the increase of transmission distance, determining the optimal conditions for achieving maximal network reach for each of them. It is shown, that DB is the most resistant to chromatic dispersion (CD) and is able to achieve the longest transmission distance (100 km) without dispersion compensation. Whereas RZ-DPSK and CSRZ-DPSK modulation formats demonstrated maximal achievable reach (180 km) using DCF and EDFA.

Design and Performance Study of Soliton based WDM systems for long distance optical communication

This paper proposes an ultra-high capacity free space optical communication (FSO) system, employing optical dual polarization quadrature phase shift keying (DP-QPSK) modulation format. It is a 16-channel dense wavelength division multiplexing (DWDM) system with 120 Gbps/channel bit rate. The FSO system is analyzed with three optical advanced modulation schemes; such as 4-quadrature amplitude modulation (4-QAM), quadrature phase shift keying (QPSK) and DP-QPSK. The main focus of the projected system is to improve the FSO setup performance in terms of eye diagram, bit error rate (BER), high received power and Q-factor. The center channel wavelength used for the proposed system is 1550 nm. In the present wireless communication world, the proposed system will be highly helpful as an ultrahigh capacity wireless system.

Zero Cross-Correlation (ZCC) code stands out amongst the most helpful codes in Spectral Amplitude Coding-Optical Code Division Multiple Access (SAC-OCDMA) system because of its features like zero cross-correlation and high auto-correlation. However, for long-range communication, as the number of user’s increases, the performance of the system is degraded. In this paper, we made an effort to enhance the performance of SAC-OCDMA system using Dense Wavelength Division Multiplexing (DWDM). SAC-OCDMA is an inseparable part of the global optical communication systems. It provides high speed, high bit-rate, security and high bandwidth for advanced services in different networks. Therefore, the hybrid DWDM and SAC-OCDMA system makes it believable to create other codes like multi diagonal (MD) and random diagonal (RD). Our results show that the number of users increases ten times by using a combination of 20-channel DWDM and SAC-OCDMA ZCC code system at a bit-rate of 10 Gbps for 60 Kms.