Link Optimization and Performance Analysis of a 40 Gbps DQPSK Modulated Ultra DWDM System with 32 Orthogonally Polarized channels (original) (raw)
Related papers
2016
Abstract: The paper presents a comprehensive analysis of a 40 Gbps Dense Wavelength Division Multiplexing system with 32 channels, spaced at 50 GHz. The design has been optimized for a long haul optical link for Modified Duobinary Return-to-Zero modulation format to establish its superiority over the conventional Duobinary Return-to-Zero format using OptiSystem simulator. The proposed system is designed and tested under perfect dispersion compensation for dispersion management and also with some residual dispersion in the link to mitigate the existing non-linearities. This paper also outlines the superiority of duobinary coding over the conventional non-return to zero modulation with the integration of unequal channel spacing to minimize the Four-Wave Mixing effect. The proposed system has been optimized for a maximum propagation length using different dispersion compensation methods by evaluating the link performance using Q value.
Cogent Engineering
The paper presents a comprehensive analysis of a 40 Gbps Dense Wavelength Division Multiplexing system with 32 channels, spaced at 50 GHz. The design has been optimized for a long haul optical link for Modified Duobinary Return-to-Zero modulation format to establish its superiority over the conventional Duobinary Return-to-Zero format using OptiSystem simulator. The proposed system is designed and tested under perfect dispersion compensation for dispersion management and also with some residual dispersion in the link to mitigate the existing non-linearities. This paper also outlines the superiority of duobinary coding over the conventional non-return to zero modulation with the integration of unequal channel spacing to minimize the Four-Wave Mixing effect. The proposed system has been optimized for a maximum propagation length using different dispersion compensation methods by evaluating the link performance using Q value.
Growing demands of the internet users is one of the reasons that lead using dense wavelength division multiplexing (WDM) networks to transmit optical data. This modulation technique has the capability of transmitting several wavelengths through a single optical fiber. In this study, we have simulated a 160 Gb/s DWDM network with transmission power of 0 dBm, using NRZ encoding technique through a 32-chanels optical transmitter over a distance of 1000 km. To this aim, we have assumed a link of 10 spans with a length of 100 km fiber for each span. An EDFA and a DCF have been used for amplifying signals and compensating pulse dispersion, respectively. All simulations have been run by using Optisystem software. The quality of the network was estimated by using the eye-diagrams of the received signals. The maximum quality factor of 20.7 and minimum bit error rate of 7.6×10-95 are obtained at wavelength of 1552.5 nm. The eye-diagrams showed an ideal quality for the received signals. More research works are needed to evaluate the parameters that affect on the quality of the DWDM optical systems.
The use of new types of fibre with high density and high capacity dense wavelength division multiplexing (DWDM) systems leads to the investigation of system performance with these fibres. This paper compares the performance of a high-density (0.8bits/s/Hz) DWDM transmission system with 25 channels and 40Gb/s per channel with a channel spacing of 50GHz, using conventional single-mode fibre or non-zero dispersion shifted fibre (NZDSF). For this, semi-analytical simulation of the DWDM system is performed using rigorous models for optical multiplexer and external modulator. Nonlinear transmission phenomena in the fibre are also included in the simulation. The results show that NZDSF allows significant extension of reachable distances with dispersion compensation and in-line amplification.
Modeling and minimization of FWM effects in DWDM-based long-haul optical communication systems
Photonic Network Communications, 2020
Optical communication systems (OCSs) mainly represent the backbone of modern long-haul communication networks because of low loss transmission over long distances and ultra-high capacity. However high data-rate transmission through optical fiber suffers from deterioration due to nonlinear impairments, such as four-wave mixing (FWM) in particular. At high launch power levels, which are required for the long-haul transmission over hundreds of km, these nonlinear effects become more severe which imposes a challenge to achieve satisfactory transmission performance. In this paper, a theoretical model for the FWM effects and its mitigation is presented and validated through simulation results. Moreover, two other nonlinear effects, polarization mode dispersion and nonlinear dispersion variations are also investigated for various values of launch power level. The transmission performance of the proposed OCS model is evaluated on the basis of bit error rate, optical signal-to-noise ratio and quality factor using different transmission channel parameters such as effective area, nonlinear refractive index, nonlinear dispersion, and linear dispersion. Keywords Four-wave mixing (FWM) • Nonlinear dispersion management • Bit error rate (BER) • Optical signal-to-noise ratio (OSNR) • Dense wavelength division multiplexing (DWDM)
Physical limits of the applicability of 10 and 40 Gbps speed DWDM systems
2006
Due to the growing transmission demands and the technical evolution, the use of DWDM systems that have more and more channels for the transmission of bundles of higher and higher speeds is spreading. In case of the application of 10 Gbps, but especially 40 Gbps systems, the dispersion characteristics of the optical fibres come to the focus of attention. Due to the high optical levels that can be provided with optical amplifiers, non-linear phenomena in the optical fibres can be observed. The imperfection of the passive optical devices used for the multiplexing/de-multiplexing of the wavelengths causes channel cross-talks. The aforementioned phenomena are in close relation with the high-speed transmission and they have to be taken into account when designing, installing and operating such systems. In general, the problems of the physical layer appear much more in case of high speed multiplex wavelength transmissions than as it used to be in case of known lower speed systems.
Optimization Techniques for 160 GBPS WDM Optical Links to Minimize Nonlinear Effects
Computer Engineering & Information Technology, 2017
Increased channel capacity of optical transmission system is obtained by either increasing the bit rate of transmission or by using the technique of Wavelength Division Multiplexing (WDM). In long distance communication, higher launched power is required to achieve the required signal-to-noise ratio (SNR) but with increased launched optical powers, rates and the number of wavelength channels, nonlinear optical effects have been increased. DWDM (Dense Wavelength Division Multiplexing) Systems facilitate the maximum channelization of the huge bandwidth offered by Optical Systems. The paper recognizes Cross Phase Modulation (XPM) and Four Wave Mixing (FWM) as major performance limitations for DWDM Systems. We have optimized the 160 GBPS, 16 channel optical link and have observed the optimization by variation of parameters like Dispersion, Channel Spacing and Pulse Width alongside NZDSF (Non-Zero Dispersion Shifted Fiber) and DCF (Dispersion Compensated Fiber) have been employed to further optimize the system performance. System parameters have been proposed for optimum performance yielding a Q-factor value of 34.89 dB and BER (Bit Error Rate) value of the order of 10-268 .
IEEE Photonics Technology Letters, 2000
In the perspective of smooth capacity upgrades of legacy systems, we experimentally investigate the performance of one 100-Gb/s coherent polarization-division-multiplexed quaternary-phase-shift-keying (PDM-QPSK) channel inserted in a 10-Gb/s ultra-long-haul (ULH) wavelength-division-multiplexing system relying on nonzero dispersion-shifted fibers. The impact of copropagating 10-Gb/s nonreturn-to-zero (NRZ) channels operating ULH distances onto the operational power range of the inserted 100-Gb/s coherent PDM-QPSK channel is analyzed. Moreover, the performance penalties brought by copropagating 10-Gb/s NRZ channels onto 100-Gb/s PDM-QPSK data are also analyzed depending on the number of channels in the multiplex and on the introduction of guardbands between both type of channels.
Optics Express, 2010
This paper, for the first time, investigates the nonlinear degradation of 40 Gbaud single-and dual polarization RZ-DQPSK/D8PSK signals caused by SPM and XPM-induced crosstalk from neighboring 10 Gbit/s NRZ-OOK channels in an WDM upgrade scenario. The investigations were numerically and experimentally conducted over a 320 km transmission link with three different wavelength configurations to address the impact of the walk-off length. The paper also presents the first numerical analysis of the XPM dependence on the relative state of polarization of the D8PSK with respect to the neighbors.
Study and Analysis of Spectrally Efficient Modulation Formats in High Speed DWDM Optical Systems
2017
The exponentially increasing demand for the channel capacity in long haul high speed transmission systems has pushed the fiber-optic communication technology to adopt dense wavelength division multiplexing (DWDM) system as a viable solution. To maximize the performance of such optical networks, suitable system design strategies to optimize the parameters related to data transmission within the channel characteristics becomes a critical area of research. Usually the optical channel capacity is influenced by signal shape, dispersive and non-linear characteristics of the guiding medium and the interference from various sources. These impairments appear to be much detrimental in a multichannel optical guiding medium especially at a higher data rate in the presence of fiber nonlinearit ies. Thus, in order to exploit the best system transmission capacity with the least performance degradation, a thorough understanding, modeling and characterization of optical channel behavior under variou...