The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Weisheng Hu - One of the best experts on this subject based on the ideXlab platform.
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machine learning for 100 gb s λ passive optical network
Journal of Lightwave Technology, 2019Co-Authors: Lilin Yi, Tao Liao, Luyao Huang, Peixuan Li, Weisheng HuAbstract:Responding to the growing bandwidth demand by emerging applications, such as fixed-mobile convergence for fifth generation (5G) and beyond 5G, 100 Gb/s/ λ access network becomes the next research focus of passive optical network (PON) roadmap. Intensity modulation and direct detection (IMDD) technology is still considered as a promising candidate for 100 Gb/s/ λ PON attributed to its low cost, low Power consumption, and small footprint. In this paper, we achieve 100 Gb/s/ λ IMDD PON by using 20G-class optical and electrical devices due to its commercial availability. To mitigate the system linear and nonlinear distortions, neural network (NN) based equalizer is used and the performance is compared with feedforward equalizer (FFE) and Volterra nonlinear equalizer (VNE). We introduce the rules to train and test the data while using NN-based equalizer to guarantee a fair comparison with FFE and VNE. Random data have to be used for training, but for test, both random data and pseudorandom bit sequence are applicable. We found that the NN-based equalizer has the same performance with FFE and VNE in the case of linear distortion, but outperforms them in a strong nonlinearity case. In the experiment, to improve the loss budget, we increase the Launch Power to 18 dBm, achieving a 30-dB loss budget for 33 GBd/s PAM8 signal at the system frequency response of 16.2 GHz, attributed to the strong nonlinear equalization capability of NN.
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symmetric 40 gb s twdm pon with 51 db loss budget by using a single soa as preamplifier booster and format converter in onu
Optics Express, 2014Co-Authors: Zhengxuan Li, Lilin Yi, Weisheng HuAbstract:In this paper, we propose to use a semiconductor optical amplifier (SOA) in the optical network unit (ONU) to improve the loss budget in time and wavelength division multiplexed-passive optical network (TWDM-PON) systems. The SOA boosts the upstream signal to increase the output Power of the electro-absorption modulated laser (EML) and simultaneously pre-amplifies the downstream signal for sensitivity improvement. The penalty caused by cross gain modulation (XGM) effect is negligible due to the low extinction ratio (ER) of upstream signal and the large wavelength difference between upstream and downstream links. In order to achieve a higher output Power, the SOA is driven into its saturation region, where the self-phase modulation (SPM) effect converts the intensity into phase information and realizes on-off-keying (OOK) to phase-shifted-keying (PSK) format conversion. In this way, the pattern effect is eliminated, which releases the requirement of gain-clamping on SOA. To further improve the loss budget of upstream link, an Erbium doped fiber amplifier (EDFA) is used in the optical line terminal (OLT) to pre-amplify the received signal. For the downstream direction, directly modulated laser (DML) is used as the laser source. Taking advantage of its carrier-less characteristic, directly modulated signal shows high tolerance to fiber nonlinearity, which could support a downstream Launch Power as high as + 16 dBm per channel. In addition, the signal is pre-amplified by the SOA in ONU before being detected, so the sensitivity limitation for downstream link is also removed. As a result, a truly passive symmetric 40-Gb/s TWDM-PON was demonstrated, achieving a link loss budget of 51 dB.
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symmetric 40 gb s 100 km passive reach twdm pon with 53 db loss budget
Journal of Lightwave Technology, 2014Co-Authors: Zhengxuan Li, Hao He, Meihua Bi, Shilin Xiao, Lilin Yi, Weisheng HuAbstract:A truly passive long-reach, symmetric 40-Gb/s time and wavelength division multiplexed passive optical network (TWDM-PON) with a high loss budget is demonstrated, using direct modulation and direct detection in both upstream and downstream directions. Thermally tuned directly modulated lasers (DMLs) are employed to serve as both upstream and downstream transmitters, not only owing to their low cost, but also, as a carrier-less modulation method, where the signal generated by direct modulation is demonstrated to be more robust to high Launch Power induced fiber nonlinearities compared with external intensity modulation formats with strong carrier Power. Therefore, DML is suitable for applying in TWDM-PON to achieve a high loss budget. Moreover, the frequency chirp induced dispersion of directly-modulated signal is managed thanks to the combination of optical spectral reshaping and dispersion supported transmission effects, which makes it possible for the directly-modulated signal to reach a distance of 100 km and still with a good quality. As a result, a system loss budget of 53 dB is achieved, supporting more than 1000 users with 100-km purely passive reach, which is the first demonstration of high loss budget, long reach TWDM-PONs to our best knowledge.
Polina Bayvel - One of the best experts on this subject based on the ideXlab platform.
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A Modulation Format Correction Formula for the Gaussian Noise Model in the Presence of Inter-Channel Stimulated Raman Scattering
Journal of Lightwave Technology, 2019Co-Authors: Daniel Semrau, Robert I. Killey, Eric Sillekens, Polina BayvelAbstract:A closed-form formula is derived, which corrects for the modulation format dependence of the Gaussian noise (GN) model in the presence of inter-channel stimulated Raman scattering (ISRS). The analytical result enables a rapid estimate of the nonlinear interference (NLI) for arbitrary modulation formats and avoids the need for complex integral evaluations and split-step simulations. It is shown that the modulation format dependent NLI can be approximated by two contributions, one originating from a single span and one asymptotic contribution for a large number of spans. The asymptotic contribution is solved in closed-form for arbitrary links consisting of identical spans, making the result applicable for fiber systems using lumped, distributed, or hybrid amplification schemes. The methodology is applied to the ISRS GN model and a modulation format correction formula in closed-form is derived, which accounts for an arbitrary number of spans, ISRS, arbitrary Launch Power distributions and wavelength dependent dispersion and attenuation. The proposed formula is validated by numerical simulations over the entire C+L band for multiple fiber types.
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a closed form approximation of the gaussian noise model in the presence of inter channel stimulated raman scattering
Journal of Lightwave Technology, 2019Co-Authors: Daniel Semrau, Robert I. Killey, Polina BayvelAbstract:An accurate, closed-form expression evaluating the nonlinear interference (NLI) Power in coherent optical transmission systems in the presence of inter-channel stimulated Raman scattering (ISRS) is derived. The analytical result enables a rapid estimate of the signal-to-noise ratio and avoids the need for integral evaluations and split-step simulations. The formula also provides a new insight into the underlying parameter dependence of ISRS on the NLI. Additionally, it accounts for the dispersion slope and arbitrary Launch Power distributions including variably loaded fiber spans. The latter enables real-time modeling of optical mesh networks. The results is applicable for lumped amplified, dispersion unmanaged, and ultra-wideband transmission systems. The accuracy of the closed-form expression is compared to numerical integration of the ISRS Gaussian noise model and split-step simulations in a point-to-point transmission, as well as in a mesh optical network scenario.
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the gaussian noise model in the presence of inter channel stimulated raman scattering
Journal of Lightwave Technology, 2018Co-Authors: Daniel Semrau, Robert I. Killey, Polina BayvelAbstract:A Gaussian noise (GN) model, precisely accounting for an arbitrary frequency dependent signal Power profile along the link, is presented. This allows accurate evaluation of the impact of inter-channel stimulated Raman scattering (ISRS) on the optical Kerr nonlinearity. Additionally, the frequency dependent fiber attenuation can be taken into account and transmission systems that use hybrid amplification schemes can be modeled, where distributed Raman amplification is partly applied over the optical spectrum. For the latter two cases, a set of coupled ordinary differential equations must be numerically solved to obtain the signal Power profile yielding a semianalytical model. However for lumped amplification and negligible variation in fiber attenuation, a less complex and fully analytical model is presented denoted as the analytical ISRS GN model. The derived model is exact to first-order for Gaussian modulated signals and extensively validated by numerical split-step simulations. A maximum deviation of only 0.1 dB in nonlinear interference Power between simulations and the ISRS GN model is reported. The model is applied to a transmission system that occupies the entire C + L band (10 THz optical bandwidth). At optimum Launch Power, changes of up to 2 dB in nonlinear interference Power due to ISRS are reported. The ISRS GN model is quantitatively compared with other models published in the literature and found to be significantly more accurate.
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Routing, modulation, spectrum and Launch Power assignment to maximize the traffic throughput of a nonlinear optical mesh network
Photonic Network Communications, 2015Co-Authors: David J Ives, Polina Bayvel, Seb J SavoryAbstract:We investigate the optimization of routing, modulation format adaptation, spectral and Launch Power assignment as a means of improving the utilization of limited network resources and increasing the network throughput. We consider a transparent optical network operating in the nonlinear transmission regime and using the latest software adapted coherent optical techniques. We separate the problem into one of routing, modulation adaption and channel assignment, followed by channel spectral assignment, and Launch Power allocation. It is shown, for three test networks, that the Launch Power allocation and channel spectral assignment can improve the transmission SNR margin over the fixed modulation, fixed Power, fully loaded link worst case by approximately 3–4 dB. This increase in SNR margin can be utilized through modulation format adaption to increase the overall network throughput. This paper highlights that increased gains in network throughput can be achieved in nonlinear impaired networks when individual transmitter spectral assignment and Launch Power are optimized to minimize the nonlinear interference.
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adapting transmitter Power and modulation format to improve optical network performance utilizing the gaussian noise model of nonlinear impairments
Journal of Lightwave Technology, 2014Co-Authors: David J Ives, Polina Bayvel, Seb J SavoryAbstract:This paper serves to highlight the gains in SNR margin and/or data capacity that can be achieved through a proper optimization of the transceiver parameters, for example, Launch Power, modulation format, and channel allocation. A simple quality of transmission estimator is described that allows a rapid estimation of the signal quality based on ASE noise and nonlinear interference utilizing the Gaussian noise model. The quality of transmission estimator was used to optimize the SNR and maximise the data throughput of transmission signals in a point-to-point link by adjusting the Launch Power and modulation format. In a three-node network, the Launch Power and channel allocation were adjusted to minimise the overall effect of nonlinear interference. This paper goes on to show that by optimizing the transceiver modulation format as part of the channel allocation and routing problem gains in network data throughput can be achieved for the 14-node NSF mesh network.
Daniel Semrau - One of the best experts on this subject based on the ideXlab platform.
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effect of channel Launch Power on fill margin in c l band elastic optical networks
Journal of Lightwave Technology, 2020Co-Authors: Abhijit Mitra, Daniel Semrau, Nishant Gahlawat, Anand Srivastava, P Bayvel, Andrew LordAbstract:Increasing traffic in the optical backbone network has made it incumbent upon operators to extend the use of optical spectrum beyond the C-band. In this work we estimate network performance over the C+L band using a physical layer model for estimating the optical signal to noise ratio (OSNR) for lightpaths operating over the C+L band optical spectrum. The model considers nonlinear interference (NLI) due to inter-channel stimulated Raman scattering (ISRS) and the impact of ISRS gain on amplified spontaneous emission (ASE) noise generated by in-line amplifiers while estimating the OSNR. This model is used to account for the capacity benefits associated with OSNR estimation while considering current state of spectral occupancy to account for NLI as compared to the fully-filled, worst-case NLI assumption. OSNR estimation based on current state of spectral occupancy provide higher capacity benefits for smaller networks like the BT-UK while for larger networks like the USA NSFNET the capacity benefit is significantly reduced. Further network capacity benefits of operating over C+L band as compared to C band have been reported. For BT-UK the capacity benefit is more than 100% while for larger networks like USA NSFNET the maximum capacity benefit is 73% with 37.5 GHz of bandwidth until 10% of demands are blocked.
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A Modulation Format Correction Formula for the Gaussian Noise Model in the Presence of Inter-Channel Stimulated Raman Scattering
Journal of Lightwave Technology, 2019Co-Authors: Daniel Semrau, Robert I. Killey, Eric Sillekens, Polina BayvelAbstract:A closed-form formula is derived, which corrects for the modulation format dependence of the Gaussian noise (GN) model in the presence of inter-channel stimulated Raman scattering (ISRS). The analytical result enables a rapid estimate of the nonlinear interference (NLI) for arbitrary modulation formats and avoids the need for complex integral evaluations and split-step simulations. It is shown that the modulation format dependent NLI can be approximated by two contributions, one originating from a single span and one asymptotic contribution for a large number of spans. The asymptotic contribution is solved in closed-form for arbitrary links consisting of identical spans, making the result applicable for fiber systems using lumped, distributed, or hybrid amplification schemes. The methodology is applied to the ISRS GN model and a modulation format correction formula in closed-form is derived, which accounts for an arbitrary number of spans, ISRS, arbitrary Launch Power distributions and wavelength dependent dispersion and attenuation. The proposed formula is validated by numerical simulations over the entire C+L band for multiple fiber types.
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effect of reduced link margins on c l band elastic optical networks
IEEE\ OSA Journal of Optical Communications and Networking, 2019Co-Authors: Abhijit Mitra, Daniel Semrau, Nishant Gahlawat, Anand Srivastava, P Bayvel, Andrew LordAbstract:Network traffic is growing exponentially, which has increased the onus on network operators to expand their network spectral resources beyond the C band. This work explores the effect of operating at a reduced link margin (LM) over the combined C and L bands. For this purpose, we utilize a lightpath optical signal-to-noise ratio (OSNR) estimation model that considers nonlinear interference due to inter-channel stimulated Raman scattering and amplified spontaneous emission noise generated by in-line amplifiers while predicting the OSNR. This model is utilized to account for the benefits of operating at reduced LM in the BT-UK, Pan Europe, and USA-NSFNET networks. Our results indicate that significant gains in capacity can be achieved by operating at low margins across all the networks. Furthermore, it is concluded that the Launch Power of network lightpaths should be optimized based upon the network size and operating LM.
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a closed form approximation of the gaussian noise model in the presence of inter channel stimulated raman scattering
Journal of Lightwave Technology, 2019Co-Authors: Daniel Semrau, Robert I. Killey, Polina BayvelAbstract:An accurate, closed-form expression evaluating the nonlinear interference (NLI) Power in coherent optical transmission systems in the presence of inter-channel stimulated Raman scattering (ISRS) is derived. The analytical result enables a rapid estimate of the signal-to-noise ratio and avoids the need for integral evaluations and split-step simulations. The formula also provides a new insight into the underlying parameter dependence of ISRS on the NLI. Additionally, it accounts for the dispersion slope and arbitrary Launch Power distributions including variably loaded fiber spans. The latter enables real-time modeling of optical mesh networks. The results is applicable for lumped amplified, dispersion unmanaged, and ultra-wideband transmission systems. The accuracy of the closed-form expression is compared to numerical integration of the ISRS Gaussian noise model and split-step simulations in a point-to-point transmission, as well as in a mesh optical network scenario.
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the gaussian noise model in the presence of inter channel stimulated raman scattering
Journal of Lightwave Technology, 2018Co-Authors: Daniel Semrau, Robert I. Killey, Polina BayvelAbstract:A Gaussian noise (GN) model, precisely accounting for an arbitrary frequency dependent signal Power profile along the link, is presented. This allows accurate evaluation of the impact of inter-channel stimulated Raman scattering (ISRS) on the optical Kerr nonlinearity. Additionally, the frequency dependent fiber attenuation can be taken into account and transmission systems that use hybrid amplification schemes can be modeled, where distributed Raman amplification is partly applied over the optical spectrum. For the latter two cases, a set of coupled ordinary differential equations must be numerically solved to obtain the signal Power profile yielding a semianalytical model. However for lumped amplification and negligible variation in fiber attenuation, a less complex and fully analytical model is presented denoted as the analytical ISRS GN model. The derived model is exact to first-order for Gaussian modulated signals and extensively validated by numerical split-step simulations. A maximum deviation of only 0.1 dB in nonlinear interference Power between simulations and the ISRS GN model is reported. The model is applied to a transmission system that occupies the entire C + L band (10 THz optical bandwidth). At optimum Launch Power, changes of up to 2 dB in nonlinear interference Power due to ISRS are reported. The ISRS GN model is quantitatively compared with other models published in the literature and found to be significantly more accurate.
Seb J Savory - One of the best experts on this subject based on the ideXlab platform.
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design considerations for low margin elastic optical networks in the nonlinear regime invited
IEEE\ OSA Journal of Optical Communications and Networking, 2019Co-Authors: Seb J Savory, Robert J Vincent, David J IvesAbstract:We demonstrate from a system design perspective that nonlinearity can be exploited to minimize the impact of system margins on system performance for both point-to-point links and elastic optical networks. A nonlinear interaction causes a 2 dB reduction in Launch Power to be reduced to $ \lt\!{0.25}\,\,{\rm{dB}}$ signal-to-noise ratio (SNR) penalty, and likewise, a 2 dB peak–peak (pk-pk) perturbation to the output Power of an optical amplifier is reduced to $ \lt\!{0.25}\,\,{\rm{dB}}$ SNR penalty (for 5, 10, and 20 spans). Extending this to a gain ripple of 1 dB pk-pk with an internode spacing of ${5} \times {80}\,\,{\rm{km}}$, ${10} \times {80}\,\,{\rm{km}}$, and ${20} \times {80}\,\,{\rm{km}}$, the penalty is 0.4 dB, 1.5 dB, and 5.1 dB, respectively, with pre-emphasis reducing this to 0.01 dB, 0.3 dB, and 1.2 dB, respectively. In elastic optical networks, we consider the nonlinear relationship among SNR, margin, and the fraction of capacity available. We consider scaling internode distances of a 9-node German scale network (DT9), such that the initial network diameter increases from 1120 km to 6720 km (six-fold scaling). We generate 1000 different topologies based on the scaled DT9 node locations to quantify the impact of margin. For the unscaled DT9 network, a 3 dB margin results in, on average, a 21% reduction in network throughput; however, when the internode spacing is increased six-fold to a continental scale network, the network throughput is reduced by 40%, on average, for the same 3 dB margin.
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Routing, modulation, spectrum and Launch Power assignment to maximize the traffic throughput of a nonlinear optical mesh network
Photonic Network Communications, 2015Co-Authors: David J Ives, Polina Bayvel, Seb J SavoryAbstract:We investigate the optimization of routing, modulation format adaptation, spectral and Launch Power assignment as a means of improving the utilization of limited network resources and increasing the network throughput. We consider a transparent optical network operating in the nonlinear transmission regime and using the latest software adapted coherent optical techniques. We separate the problem into one of routing, modulation adaption and channel assignment, followed by channel spectral assignment, and Launch Power allocation. It is shown, for three test networks, that the Launch Power allocation and channel spectral assignment can improve the transmission SNR margin over the fixed modulation, fixed Power, fully loaded link worst case by approximately 3–4 dB. This increase in SNR margin can be utilized through modulation format adaption to increase the overall network throughput. This paper highlights that increased gains in network throughput can be achieved in nonlinear impaired networks when individual transmitter spectral assignment and Launch Power are optimized to minimize the nonlinear interference.
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adapting transmitter Power and modulation format to improve optical network performance utilizing the gaussian noise model of nonlinear impairments
Journal of Lightwave Technology, 2014Co-Authors: David J Ives, Polina Bayvel, Seb J SavoryAbstract:This paper serves to highlight the gains in SNR margin and/or data capacity that can be achieved through a proper optimization of the transceiver parameters, for example, Launch Power, modulation format, and channel allocation. A simple quality of transmission estimator is described that allows a rapid estimation of the signal quality based on ASE noise and nonlinear interference utilizing the Gaussian noise model. The quality of transmission estimator was used to optimize the SNR and maximise the data throughput of transmission signals in a point-to-point link by adjusting the Launch Power and modulation format. In a three-node network, the Launch Power and channel allocation were adjusted to minimise the overall effect of nonlinear interference. This paper goes on to show that by optimizing the transceiver modulation format as part of the channel allocation and routing problem gains in network data throughput can be achieved for the 14-node NSF mesh network.
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physical layer transmitter and routing optimization to maximize the traffic throughput of a nonlinear optical mesh network
Optical Network Design and Modelling, 2014Co-Authors: David J Ives, Polina Bayvel, Seb J SavoryAbstract:This paper investigates the physical layer optimization as a means of improving the utilization of limited network resources. A transparent optical network operating in the nonlinear transmission regime using coherent optical technology is considered. A physical layer model is described that allows the transmission signal quality to be included in the optimization process. Initially a fixed Power, route-adapted modulation format approach is taken using integer linear programming to solve the static route allocation problem. It is shown that for the 14-node, 21-link NSF mesh network adaptation of the modulation formats leads to increases in data throughput of 17%. Optimization of the individual transmitter Launch Powers and spectral channel allocation results in a SNR margin of 2.3 dB, which is used to further increase the overall network traffic throughput exceeding the fixed PM-QPSK modulation format by as much as 50%. Compared to other work this paper highlights that increased gains in network throughput can be achieved if nonlinear interference is included in the routing and spectral assignment algorithm and individual transmitter spectral assignment and Launch Power is optimized to minimize nonlinear interference.
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characterization of long haul 112gbit s pdm qam 16 transmission with and without digital nonlinearity compensation
Optics Express, 2010Co-Authors: Sergejs Makovejs, Robert I. Killey, Seb J Savory, David S Millar, Domanic Lavery, Carsten Behrens, P BayvelAbstract:In this paper long-haul, single channel, polarization multiplexed 16-state quadrature amplitude modulation (PDM-QAM-16) transmission at 112 Gbit/s is investigated. Novel digital signal processing techniques are used to perform carrier phase estimation and symbol estimation, in combination with nonlinear digital backpropagation. The results obtained demonstrate that the use of digital nonlinear backpropagation increases the optimum Launch Power from -4 dBm to -1 dBm with a consequent increase in maximum reach from 1440 km to 2400 km, which is a record transmission distance for QAM-16 reported to date for an SMF link with EDFAs only. Furthermore, experimental measurements are supported by simulations, based on the link used in the experiment.
P Bayvel - One of the best experts on this subject based on the ideXlab platform.
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effect of channel Launch Power on fill margin in c l band elastic optical networks
Journal of Lightwave Technology, 2020Co-Authors: Abhijit Mitra, Daniel Semrau, Nishant Gahlawat, Anand Srivastava, P Bayvel, Andrew LordAbstract:Increasing traffic in the optical backbone network has made it incumbent upon operators to extend the use of optical spectrum beyond the C-band. In this work we estimate network performance over the C+L band using a physical layer model for estimating the optical signal to noise ratio (OSNR) for lightpaths operating over the C+L band optical spectrum. The model considers nonlinear interference (NLI) due to inter-channel stimulated Raman scattering (ISRS) and the impact of ISRS gain on amplified spontaneous emission (ASE) noise generated by in-line amplifiers while estimating the OSNR. This model is used to account for the capacity benefits associated with OSNR estimation while considering current state of spectral occupancy to account for NLI as compared to the fully-filled, worst-case NLI assumption. OSNR estimation based on current state of spectral occupancy provide higher capacity benefits for smaller networks like the BT-UK while for larger networks like the USA NSFNET the capacity benefit is significantly reduced. Further network capacity benefits of operating over C+L band as compared to C band have been reported. For BT-UK the capacity benefit is more than 100% while for larger networks like USA NSFNET the maximum capacity benefit is 73% with 37.5 GHz of bandwidth until 10% of demands are blocked.
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effect of reduced link margins on c l band elastic optical networks
IEEE\ OSA Journal of Optical Communications and Networking, 2019Co-Authors: Abhijit Mitra, Daniel Semrau, Nishant Gahlawat, Anand Srivastava, P Bayvel, Andrew LordAbstract:Network traffic is growing exponentially, which has increased the onus on network operators to expand their network spectral resources beyond the C band. This work explores the effect of operating at a reduced link margin (LM) over the combined C and L bands. For this purpose, we utilize a lightpath optical signal-to-noise ratio (OSNR) estimation model that considers nonlinear interference due to inter-channel stimulated Raman scattering and amplified spontaneous emission noise generated by in-line amplifiers while predicting the OSNR. This model is utilized to account for the benefits of operating at reduced LM in the BT-UK, Pan Europe, and USA-NSFNET networks. Our results indicate that significant gains in capacity can be achieved by operating at low margins across all the networks. Furthermore, it is concluded that the Launch Power of network lightpaths should be optimized based upon the network size and operating LM.
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characterization of long haul 112gbit s pdm qam 16 transmission with and without digital nonlinearity compensation
Optics Express, 2010Co-Authors: Sergejs Makovejs, Robert I. Killey, Seb J Savory, David S Millar, Domanic Lavery, Carsten Behrens, P BayvelAbstract:In this paper long-haul, single channel, polarization multiplexed 16-state quadrature amplitude modulation (PDM-QAM-16) transmission at 112 Gbit/s is investigated. Novel digital signal processing techniques are used to perform carrier phase estimation and symbol estimation, in combination with nonlinear digital backpropagation. The results obtained demonstrate that the use of digital nonlinear backpropagation increases the optimum Launch Power from -4 dBm to -1 dBm with a consequent increase in maximum reach from 1440 km to 2400 km, which is a record transmission distance for QAM-16 reported to date for an SMF link with EDFAs only. Furthermore, experimental measurements are supported by simulations, based on the link used in the experiment.
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10 7 gb s electronic predistortion transmitter using commercial fpgas and d a converters implementing real time dsp for chromatic dispersion and spm compensation
Optics Express, 2009Co-Authors: R Waegemans, P Bayvel, S Herbst, Ludwig Holbein, P M Watts, Cornelius Furst, Robert I. KilleyAbstract:We present an experimental demonstration of simultaneous chromatic dispersion and self-phase modulation compensation at 10.7 Gb/s using real-time electronic digital signal processing. This was achieved using a pre-distorting transmitter based on commercially available field programmable gate arrays and 21.4 GS/s, 6-bit resolution digital-to-analog converters. The digital signal processing employed look-up tables stored in RAM. This resulted in the achievement of a BER of 10(-6) at an OSNR of 16 dB after transmission over a 450 km link of uncompensated standard single mode fiber with + 4 dBm Launch Power.
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investigation of fibre Launch Power margin in 40 gb s transmission with all optical regeneration
European Conference on Optical Communication, 2005Co-Authors: G Gavioli, Benn C Thomsen, V Mikhailov, P BayvelAbstract:An experimental investigation of 40 Gb/s transmission with all-optical regeneration using an SOA-assisted fibre interferometer is reported. A dynamically-reconfigurable optical fibre loop is used to investigate the regenerator dynamic range. (2 pages)