The Experts below are selected from a list of 6213 Experts worldwide ranked by ideXlab platform
P Bayvel - One of the best experts on this subject based on the ideXlab platform.
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volterra assisted optical phase conjugation a hybrid optical digital scheme for Fiber Nonlinearity compensation
Journal of Lightwave Technology, 2019Co-Authors: Gabriel Saavedra, Gabriele Liga, P BayvelAbstract:Digital Nonlinearity compensation (NLC) schemes such as digital backpropagation and Volterra equalization are well known to be effective techniques in mitigating optical Fiber Nonlinearity, thus offering improved transmission performance. Alternatively, optical NLC, and specifically optical phase conjugation (OPC), has been proposed to relax the digital signal processing complexity. In this paper, a novel hybrid optical-digital NLC scheme combining OPC and a Volterra equalizer is proposed, termed Volterra-Assisted OPC (VAO). It has a twofold advantage: it overcomes the OPC limitation in asymmetric links and substantially enhances the performance of Volterra equalizers. When NLC is operated over the entire transmitted optical bandwidth, the proposed scheme is shown to outperform both OPC and Volterra equalization alone by up to 4.2 dB in a five-channel, 32 GBaud PM-16QAM transmission over a 1000 km EDFA-amplified Fiber link. Moreover, VAO is also demonstrated to be very robust when applied to long-transmission distances, with a 2.5-dB gain over OPC-only systems at 3000 km. VAO combines the advantages of both optical and digital NLC offering a promising tradeoff between performance and complexity for future high-speed optical communication systems.
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volterra assisted optical phase conjugation a hybrid optical digital scheme for Fiber Nonlinearity compensation
arXiv: Signal Processing, 2018Co-Authors: Gabriel Saavedra, Gabriele Liga, P BayvelAbstract:Mitigation of optical Fiber Nonlinearity is an active research field in the area of optical communications, due to the resulting marked improvement in transmission performance. Following the resurgence of optical coherent detection, digital Nonlinearity compensation (NLC) schemes such as digital backpropagation (DBP) and Volterra equalization have received much attention. Alternatively, optical NLC, and specifically optical phase conjugation (OPC), has been proposed to relax the digital signal processing complexity. In this work, a novel hybrid optical-digital NLC scheme combining OPC and a Volterra equalizer is proposed, termed Volterra-Assisted OPC (VAO). It has a twofold advantage: it overcomes the OPC limitation in asymmetric links and substantially enhances the performance of Volterra equalizers. The proposed scheme is shown to outperform both OPC and Volterra equalization alone by up to 4.2 dB in a 1000 km EDFA-amplified Fiber link. Moreover, VAO is also demonstrated to be very robust when applied to long-transmission distances, with a 2.5 dB gain over OPC-only systems at 3000 km. VAO combines the advantages of both optical and digital NLC offering a promising trade-off between performance and complexity for future high-speed optical communication systems.
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optical and digital phase conjugation techniques for Fiber Nonlinearity compensation
Opto-Electronics and Communications Conference, 2015Co-Authors: M E Mccarthy, Sergei K Turitsyn, P Bayvel, Ian Phillips, Domanic Lavery, A D EllisAbstract:We discuss recent progress on the use of optical and digital phase conjugation techniques for Nonlinearity compensation in optical Fiber links. We compare the achievable performance gain of phase conjugated twin wave applied in two polarization states and time segments with mid-link optical phase conjugation and digital back propagation. For multicarrier transmission scheme such as orthogonal frequency division multiplexing, two recently proposed schemes, namely phase-conjugated pilots and phase-conjugated subcarrier coding are reviewed.
A D Ellis - One of the best experts on this subject based on the ideXlab platform.
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combating Fiber Nonlinearity using dual order raman amplification and opc
IEEE Photonics Technology Letters, 2019Co-Authors: Mohammad Alkhateeb, Mingming Tan, Tingting Zhang, A D EllisAbstract:We experimentally demonstrate, for the first time, a significant 34-dB nonlinear product power compensation in a mid-link optical phase conjugation (OPC) system using an optimized dual-order distributed Raman amplification (DRA) technique. The dual-order backward (BW)-pumping scheme shows a record signal power symmetry of 97% over 50.4-km single-mode Fiber (SMF) spans. We also demonstrate that the required accuracy for span-to-span power alignment is within ±1 dB in order to maintain 20-dB nonlinear product compensation. For a 256-Gb/s dual-polarization-16 QAM transmission over 100.8 km ( $2\times50.4$ km) SMF with mid-link OPC, the proposed Raman amplification scheme enables the OPC to improve the nonlinear threshold by ~7 dB and the optimum signal launch power by ~5 dB compared with the system without OPC.
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performance limits in optical communications due to Fiber Nonlinearity
Advances in Optics and Photonics, 2017Co-Authors: A D Ellis, M E Mccarthy, M Al A Z Khateeb, Mariia Sorokina, N J DoranAbstract:In this paper, we review the historical evolution of predictions of the performance of optical communication systems. We will describe how such predictions were made from the outset of research in laser based optical communications and how they have evolved to their present form, accurately predicting the performance of coherently detected communication systems.
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optical and digital phase conjugation techniques for Fiber Nonlinearity compensation
Opto-Electronics and Communications Conference, 2015Co-Authors: M E Mccarthy, Sergei K Turitsyn, P Bayvel, Ian Phillips, Domanic Lavery, A D EllisAbstract:We discuss recent progress on the use of optical and digital phase conjugation techniques for Nonlinearity compensation in optical Fiber links. We compare the achievable performance gain of phase conjugated twin wave applied in two polarization states and time segments with mid-link optical phase conjugation and digital back propagation. For multicarrier transmission scheme such as orthogonal frequency division multiplexing, two recently proposed schemes, namely phase-conjugated pilots and phase-conjugated subcarrier coding are reviewed.
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Fiber Nonlinearity induced penalty reduction in co ofdm by ann based nonlinear equalization
Optics Letters, 2015Co-Authors: Son Thai Le, Ivan Aldaya, Mutsam A. Jarajreh, Mohammad Ghanbarisabagh, M E Mccarthy, Sofien Mhatli, Paul Anthony Haigh, N J Doran, A D EllisAbstract:We experimentally demonstrate ∼2 dB quality (Q)-factor enhancement in terms of Fiber Nonlinearity compensation of 40 Gb/s 16 quadrature amplitude modulation coherent optical orthogonal frequency-division multiplexing at 2000 km, using a nonlinear equalizer (NLE) based on artificial neural networks (ANN). Nonlinearity alleviation depends on escalation of the ANN training overhead and the signal bit rate, reporting ∼4 dB Q-factor enhancement at 70 Gb/s, whereas a reduction of the number of ANN neurons annihilates the NLE performance. An enhanced performance by up to ∼2 dB in Q-factor compared to the inverse Volterra-series transfer function NLE leads to a breakthrough in the efficiency of ANN.
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demonstration of phase conjugated subcarrier coding for Fiber Nonlinearity compensation in co ofdm transmission
Journal of Lightwave Technology, 2015Co-Authors: M E Mccarthy, N J Doran, A D Ellis, Naoise Mac Suibhne, Mohammad Alkhateeb, Elias Giacoumidis, Sergei K TuritsynAbstract:In this paper, we demonstrate through computer simulation and experiment a novel subcarrier coding scheme combined with pre-electrical dispersion compensation (pre-EDC) for Fiber Nonlinearity mitigation in coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. As the frequency spacing in CO-OFDM systems is usually small (tens of MHz), neighbouring subcarriers tend to experience correlated nonlinear distortions after propagation over a Fiber link. As a consequence, Nonlinearity mitigation can be achieved by encoding and processing neighbouring OFDM subcarriers simultaneously. Herein, we propose to adopt the concept of dual phase conjugated twin wave for CO-OFDM transmission. Simulation and experimental results show that this simple technique combined with 50% pre-EDC can effectively offer up to 1.5 and 0.8 dB performance gains in CO-OFDM systems with BPSK and QPSK modulation formats, respectively.
Tadashi Ikeuchi - One of the best experts on this subject based on the ideXlab platform.
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enabling technologies for Fiber Nonlinearity mitigation in high capacity transmission systems
Journal of Lightwave Technology, 2019Co-Authors: Olga Vassilieva, Inwoong Kim, Tadashi IkeuchiAbstract:Fiber Nonlinearity has become a major limiting transmission impairment factor. In this paper, we discuss various Nonlinearity mitigation techniques in electrical and optical domains. In electrical domain, multiple reduced complexity digital back-propagation algorithms were developed, including perturbation back-propagation. One drawback is that they can compensate for intra-channel self-phase modulation (SPM) effects only. The inter-channel Fiber Nonlinearity mitigation can be done in optical domain. For example, digital subcarrier multiplexing (SCM) can effectively mitigate both SPM and cross-phase modulation (XPM) effects. It can become even more beneficial for higher symbol rate systems (e.g., 64 Gbaud and 128 Gbaud) and has a capability to deliver longer reach than single carrier 32 Gbaud DP-16QAM signals and only slightly shorter reach (by up to 7%) compared to 32 Gbaud SCM systems. Another technique, the total intensity directed phase modulation, can provide per-span SPM and XPM compensation. However, this technique is limited to compensation of a few channels only. On the other hand, the proposed enhanced pre-dispersed spectral inversion can effectively compensate for SPM/XPM effects of multiple channels and become more practical by removing limitation to link symmetry even in nonuniform transmission links. Finally, subcarrier power pre-emphasis in optical superchannels can equalize performance of all subcarriers by mitigating intersubcarrier XPM and extend transmission reach by 20%.
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enhanced spectral inversion for Fiber Nonlinearity mitigation
IEEE Photonics Technology Letters, 2018Co-Authors: Inwoong Kim, Olga Vassilieva, Paparao Palacharla, Youichi Akasaka, Tadashi IkeuchiAbstract:We propose a novel technique of balancing dispersion among spans to achieve significantly improved Nonlinearity compensation using spectral inversion, which can effectively extend optical reach up to 80% for a 1 Tb/s DP-16QAM superchannel transmission over non-uniform links in the simulation study.
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Multi-channel Fiber Nonlinearity Mitigation in Coherent DWDM systems
2018 23rd Opto-Electronics and Communications Conference (OECC), 2018Co-Authors: Inwoong Kim, Olga Vassilieva, Paparao Palacharla, Tadashi IkeuchiAbstract:We review recent progresses in optoelectronic and optical domain multi-channel Fiber Nonlinearity compensation techniques in DWDM transmission systems.
Gabriel Saavedra - One of the best experts on this subject based on the ideXlab platform.
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volterra assisted optical phase conjugation a hybrid optical digital scheme for Fiber Nonlinearity compensation
Journal of Lightwave Technology, 2019Co-Authors: Gabriel Saavedra, Gabriele Liga, P BayvelAbstract:Digital Nonlinearity compensation (NLC) schemes such as digital backpropagation and Volterra equalization are well known to be effective techniques in mitigating optical Fiber Nonlinearity, thus offering improved transmission performance. Alternatively, optical NLC, and specifically optical phase conjugation (OPC), has been proposed to relax the digital signal processing complexity. In this paper, a novel hybrid optical-digital NLC scheme combining OPC and a Volterra equalizer is proposed, termed Volterra-Assisted OPC (VAO). It has a twofold advantage: it overcomes the OPC limitation in asymmetric links and substantially enhances the performance of Volterra equalizers. When NLC is operated over the entire transmitted optical bandwidth, the proposed scheme is shown to outperform both OPC and Volterra equalization alone by up to 4.2 dB in a five-channel, 32 GBaud PM-16QAM transmission over a 1000 km EDFA-amplified Fiber link. Moreover, VAO is also demonstrated to be very robust when applied to long-transmission distances, with a 2.5-dB gain over OPC-only systems at 3000 km. VAO combines the advantages of both optical and digital NLC offering a promising tradeoff between performance and complexity for future high-speed optical communication systems.
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volterra assisted optical phase conjugation a hybrid optical digital scheme for Fiber Nonlinearity compensation
arXiv: Signal Processing, 2018Co-Authors: Gabriel Saavedra, Gabriele Liga, P BayvelAbstract:Mitigation of optical Fiber Nonlinearity is an active research field in the area of optical communications, due to the resulting marked improvement in transmission performance. Following the resurgence of optical coherent detection, digital Nonlinearity compensation (NLC) schemes such as digital backpropagation (DBP) and Volterra equalization have received much attention. Alternatively, optical NLC, and specifically optical phase conjugation (OPC), has been proposed to relax the digital signal processing complexity. In this work, a novel hybrid optical-digital NLC scheme combining OPC and a Volterra equalizer is proposed, termed Volterra-Assisted OPC (VAO). It has a twofold advantage: it overcomes the OPC limitation in asymmetric links and substantially enhances the performance of Volterra equalizers. The proposed scheme is shown to outperform both OPC and Volterra equalization alone by up to 4.2 dB in a 1000 km EDFA-amplified Fiber link. Moreover, VAO is also demonstrated to be very robust when applied to long-transmission distances, with a 2.5 dB gain over OPC-only systems at 3000 km. VAO combines the advantages of both optical and digital NLC offering a promising trade-off between performance and complexity for future high-speed optical communication systems.
Abdelkerim Amari - One of the best experts on this subject based on the ideXlab platform.
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A Machine Learning-Based Detection Technique for Optical Fiber Nonlinearity Mitigation
IEEE Photonics Technology Letters, 2019Co-Authors: Abdelkerim Amari, Octavia A. Dobre, Ramachandran Venkatesan, Alex AlvaradoAbstract:We investigate the performance of a machine learning classification technique, called the Parzen window, to mitigate the Fiber Nonlinearity in the context of dispersion managed and dispersion unmanaged systems. The technique is applied for detection at the receiver side and deals with the non-Gaussian nonlinear effects by designing improved decision boundaries. We also propose a two-stage mitigation technique using digital back propagation and Parzen window for dispersion unmanaged systems. In this case, digital back propagation compensates for the deterministic Nonlinearity and the Parzen window deals with the stochastic nonlinear signal-noise interactions, which are not taken into account by digital back propagation. A performance improvement up to 0.4 dB in terms of Q factor is observed.
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a survey on Fiber Nonlinearity compensation for 400 gb s and beyond optical communication systems
IEEE Communications Surveys and Tutorials, 2017Co-Authors: Abdelkerim Amari, Octavia A. Dobre, Ramachandran Venkatesan, O. S. Sunish Kumar, Philippe Ciblat, Yves JaouënAbstract:Optical communication systems represent the backbone of modern communication networks. Since their deployment, different Fiber technologies have been used to deal with optical Fiber impairments such as dispersion-shifted Fibers and dispersion-compensation Fibers. In recent years, thanks to the introduction of coherent detection based systems, Fiber impairments can be mitigated using digital signal processing (DSP) algorithms. Coherent systems are used in the current 100 Gb/s wavelength-division multiplexing (WDM) standard technology. They allow the increase of spectral efficiency by using multilevel modulation formats, and are combined with DSP techniques to combat linear Fiber distortions. In addition to linear impairments, the next generation 400 Gb/s and 1 Tb/s WDM systems are also more affected by the Fiber Nonlinearity due to the Kerr effect. At high input powers, Fiber nonlinear effects become more important and their compensation is required to improve the transmission performance. Several approaches have been proposed to deal with the Fiber Nonlinearity. In this paper, after a brief description of the Kerr-induced nonlinear effects, a survey on Fiber Nonlinearity compensation (NLC) techniques is provided. We focus on the well-known NLC techniques and discuss their performance, as well as their implementation and complexity. An extension of the inter-subcarrier nonlinear interference canceler approach is also proposed. A performance evaluation of the well-known NLC techniques and the proposed approach is provided in the context of Nyquist and super-Nyquist superchannel systems.
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A survey on Fiber Nonlinearity compensation for 400 Gbps and beyond optical communication systems
IEEE Communications Surveys & Tutorials, 2017Co-Authors: Abdelkerim Amari, Octavia A. Dobre, Ramachandran Venkatesan, O. S. Sunish Kumar, Philippe Ciblat, Yves JaouënAbstract:Optical communication systems represent the backbone of modern communication networks. Since their deployment, different Fiber technologies have been used to deal with optical Fiber impairments such as dispersion-shifted Fibers and dispersion-compensation Fibers. In recent years, thanks to the introduction of coherent detection based systems, Fiber impairments can be mitigated using digital signal processing (DSP) algorithms. Coherent systems are used in the current 100 Gbps wavelength-division multiplexing (WDM) standard technology. They allow the increase of spectral efficiency by using multi-level modulation formats, and are combined with DSP techniques to combat the linear Fiber distortions. In addition to linear impairments, the next generation 400 Gbps/1 Tbps WDM systems are also more affected by the Fiber Nonlinearity due to the Kerr effect. At high input power, the Fiber nonlinear effects become more important and their compensation is required to improve the transmission performance. Several approaches have been proposed to deal with the Fiber Nonlinearity. In this paper, after a brief description of the Kerr-induced nonlinear effects, a survey on the Fiber Nonlinearity compensation (NLC) techniques is provided. We focus on the well-known NLC techniques and discuss their performance, as well as their implementation and complexity. An extension of the inter-subcarrier nonlinear interference canceler approach is also proposed. A performance evaluation of the well-known NLC techniques and the proposed approach is provided in the context of Nyquist and super-Nyquist superchannel systems.
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Fifth-order Volterra-based equalizer for Fiber Nonlinearity compensation in Nyquist WDM superchannel system
2017 19th International Conference on Transparent Optical Networks (ICTON), 2017Co-Authors: Abdelkerim Amari, Octavia A. Dobre, Ramachandran VenkatesanAbstract:In the context of long-haul Nyquist wavelength division multiplexed (WDM) superchannel system, a fifth-order Volterra-based nonlinear equalizer (VNLE) is proposed to compensate for the optical Fiber nonlinear effects, which represent the major Fiber impairment in such high data rate systems. A performance comparison of the fifth-order VNLE with the benchmark digital-back propagation (DBP) and the third-order VNLE is provided. We show that the fifth-order VNLE better combats the Fiber Nonlinearity in comparison with the third-order VLNE and exhibits closer performance to the DBP. A significant improvement of the performance in terms of the Q factor, nonlinear threshold, and transmission reach is observed when compared with the third-order VNLE.