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Throughput optimization of optical communication systems is a key challenge for current optical networks. The use of gain-flattening filters (GFFs) simplifies the problem at the cost of insertion loss, higher power consumption and potentially poorer performance. In this work, we propose a component wise model of a multi-span transmission system for signal-to-noise ratio (SNR) optimization. A machine-learning based model is trained for the gain and noise figure spectral profile of a C-band amplifier without a GFF. The model is combined with the Gaussian noise model for nonlinearities in optical fibers including stimulated Raman scattering and the implementation penalty spectral profile measured in back-to-back in order to predict the SNR in each channel of a multi-span wavelength division multiplexed system. All basic components in the system model are differentiable and allow for the gradient descent-based optimization of a system of arbitrary configuration in terms of number of spans and length per span. When the input power profile is optimized for flat and maximized received SNR per channel, the minimum performance in an arbitrary 3-span experimental system is improved by up to 8 dB w.r.t. a system with flat input power profile. An SNR flatness down to 1.2 dB is simultaneously achieved. The model and optimization methods are used to optimize the performance of an example core network, and 0.2 dB of gain is shown w.r.t. solutions that do not take into account fiber nonlinearities. The method is also shown to be beneficial for systems with ideal gain flattening, achieving up to 0.3 dB of gain w.r.t. a flat input power profile.
Metodi Plamenov Yankov; Pawel Marcin Kaminski; Henrik Enggaard Hansen; Francesco Da Ros. SNR optimization of multi-span fiber optic communication systems employing EDFAs with non-flat gain and noise figure. Journal of Lightwave Technology 2021, PP, 1 -1.
AMA StyleMetodi Plamenov Yankov, Pawel Marcin Kaminski, Henrik Enggaard Hansen, Francesco Da Ros. SNR optimization of multi-span fiber optic communication systems employing EDFAs with non-flat gain and noise figure. Journal of Lightwave Technology. 2021; PP (99):1-1.
Chicago/Turabian StyleMetodi Plamenov Yankov; Pawel Marcin Kaminski; Henrik Enggaard Hansen; Francesco Da Ros. 2021. "SNR optimization of multi-span fiber optic communication systems employing EDFAs with non-flat gain and noise figure." Journal of Lightwave Technology PP, no. 99: 1-1.
Training of autoencoders using the back-propagation algorithm is challenging for non-differential channel models or in an experimental environment where gradients cannot be computed. In this paper, we study a gradient-free training method based on the cubature Kalman filter. To numerically validate the method, the autoencoder is employed to perform geometric constellation shaping on differentiable communication channels, showing the same performance as the back-propagation algorithm. Further investigation is done on a non-differentiable communication channel that includes: laser phase noise, additive white Gaussian noise and blind phase search-based phase noise compensation. Our results indicate that the autoencoder can be successfully optimized using the proposed training method to achieve better robustness to residual phase noise with respect to standard constellation schemes such as Quadrature Amplitude Modulation and Iterative Polar Modulation for the considered conditions.
Ognjen Jovanovic; Metodi Plamenov Yankov; Francesco Da Ros; Darko Zibar. Gradient-free training of autoencoders for non-differentiable communication channels. Journal of Lightwave Technology 2021, PP, 1 -1.
AMA StyleOgnjen Jovanovic, Metodi Plamenov Yankov, Francesco Da Ros, Darko Zibar. Gradient-free training of autoencoders for non-differentiable communication channels. Journal of Lightwave Technology. 2021; PP (99):1-1.
Chicago/Turabian StyleOgnjen Jovanovic; Metodi Plamenov Yankov; Francesco Da Ros; Darko Zibar. 2021. "Gradient-free training of autoencoders for non-differentiable communication channels." Journal of Lightwave Technology PP, no. 99: 1-1.
The perturbation-based nonlinearity compensation (NLC) method is considered in conjunction with a forward error correction (FEC) code that is capable of detecting block errors. The FEC decoding is performed prior to the NLC, and NLC is then performed only for blocks, that could not be decoded correctly. The total NLC complexity is thus dramatically reduced to down to 1% in some cases w.r.t. the standard, hard decision-directed NLC performed prior to the FEC decoding. Negligible FEC decoding complexity increase is required for the subsequent decoding of the nonlinearty-compensated blocks. The proposed method achieves and sometimes outperforms the standard perturbation based NLC at a fraction of the overall complexity. Polar codes are used to exemplify the method.
Metodi P. Yankov; Tayyab Mehmood; Shajeel Iqbal; Soren Forchhammer; Edson Porto da Silva. Block Error Detection Driven Nonlinearity Compensation for Optical Fiber Communications. IEEE Photonics Technology Letters 2021, 33, 461 -464.
AMA StyleMetodi P. Yankov, Tayyab Mehmood, Shajeel Iqbal, Soren Forchhammer, Edson Porto da Silva. Block Error Detection Driven Nonlinearity Compensation for Optical Fiber Communications. IEEE Photonics Technology Letters. 2021; 33 (9):461-464.
Chicago/Turabian StyleMetodi P. Yankov; Tayyab Mehmood; Shajeel Iqbal; Soren Forchhammer; Edson Porto da Silva. 2021. "Block Error Detection Driven Nonlinearity Compensation for Optical Fiber Communications." IEEE Photonics Technology Letters 33, no. 9: 461-464.
In this paper, machine learning is used to create a differentiable model for the input-output power spectral profile relations of C-band erbium-doped fiber amplifiers (EDFAs). The EDFA model is demonstrated to generalize to multiple physical devices of the same make while only trained on experimental data from a single unit. The model is combined with a differentiable model for simulating stimulated Raman scattering (SRS) effects during propagation through the the optical fiber to create a differentiable model for a multi-span system with an arbitrary configuration of number of spans, length per span and launch power per span. The cascade system model is used to predict and optimize the power profile output of several such experimental configurations of up to three spans with an arbitrary target power profile. A flat target profile is exemplified experimentally, achieving $<$ 3 dB of power excursions for EDFAs exhibiting $>$ 10 dB of excursion per device in the cascade. The experimental data used to create the EDFA model is made public and available online.
Metodi Plamenov Yankov; Uiara Celine de Moura; Francesco Da Ros. Power Evolution Modeling and Optimization of Fiber Optic Communication Systems With EDFA Repeaters. Journal of Lightwave Technology 2021, 39, 3154 -3161.
AMA StyleMetodi Plamenov Yankov, Uiara Celine de Moura, Francesco Da Ros. Power Evolution Modeling and Optimization of Fiber Optic Communication Systems With EDFA Repeaters. Journal of Lightwave Technology. 2021; 39 (10):3154-3161.
Chicago/Turabian StyleMetodi Plamenov Yankov; Uiara Celine de Moura; Francesco Da Ros. 2021. "Power Evolution Modeling and Optimization of Fiber Optic Communication Systems With EDFA Repeaters." Journal of Lightwave Technology 39, no. 10: 3154-3161.
In this work, we present a novel strategy to satisfying the nonlinearity compensation criteria by optical phase-conjugation (OPC). Contrary to the most common approach, which relies on tailoring power profiles using distributed Raman-amplification, we achieve the required OPC propagation symmetry through optimized dispersion management across the link. The method is applied to transmission systems with periodic lumped amplification, and the symmetry enhancement is directly translated into a substantial increase in the OPC compensation gains. This study is based on a numerical analysis combined with experimental validation of the findings. The numerical part provides a comprehensive overview of different dispersion management techniques, and compares them against the symmetric schemes we propose. It is consistently shown that the symmetry-optimized systems provide the best performance when OPC is included, with the signal-to-noise ratio (SNR) gains reaching up to 6.6 dB and 5.2 dB for transmission of a single and seven wavelength channels, respectively. These results are verified in an experimental investigation, where we implemented and compared a standard dispersion mapping scheme to the optimized design. For all distances considered, the optimized link is demonstrated superior once OPC is included, leading up to 1.9 dB improvement in SNR for seven-channel transmission.
Pawel Marcin Kaminski; Francesco Da Ros; Metodi Plamenov Yankov; Anders Thomas Clausen; Soeren Forchhammer; L.K. Oxenlowe; Michael Galili. Symmetry Enhancement Through Advanced Dispersion Mapping in OPC-Aided Transmission. Journal of Lightwave Technology 2021, 39, 2820 -2829.
AMA StylePawel Marcin Kaminski, Francesco Da Ros, Metodi Plamenov Yankov, Anders Thomas Clausen, Soeren Forchhammer, L.K. Oxenlowe, Michael Galili. Symmetry Enhancement Through Advanced Dispersion Mapping in OPC-Aided Transmission. Journal of Lightwave Technology. 2021; 39 (9):2820-2829.
Chicago/Turabian StylePawel Marcin Kaminski; Francesco Da Ros; Metodi Plamenov Yankov; Anders Thomas Clausen; Soeren Forchhammer; L.K. Oxenlowe; Michael Galili. 2021. "Symmetry Enhancement Through Advanced Dispersion Mapping in OPC-Aided Transmission." Journal of Lightwave Technology 39, no. 9: 2820-2829.
Probabilistic shaping for intensity modulation and direct detection (IM/DD) links is discussed and a peak power constraint determined by the limited modulation extinction ratio (ER) of optical modulators is introduced. The input distribution of 4-ary unipolar pulse amplitude modulation (PAM) symbols is optimized for short-reach transmission links without optical amplification nor in-line dispersion compensation. The resulting distribution is symmetric around its mean allowing to use probabilistic amplitude shaping (PAS) to generate symbols that are protected by forward error correction (FEC) and that have the optimal input distribution. The numerical analysis is confirmed experimentally for both an additive white Gaussian noise (AWGN) channel and a fiber channel, showing gains in transmission reach and transmission rate, as well as rate adaptability.
Thomas Wiegart; Francesco Da Ros; Metodi Plamenov Yankov; Fabian Steiner; Simone Gaiarin; Richard D. Wesel. Probabilistically Shaped 4-PAM for Short-Reach IM/DD Links With a Peak Power Constraint. Journal of Lightwave Technology 2020, 39, 400 -405.
AMA StyleThomas Wiegart, Francesco Da Ros, Metodi Plamenov Yankov, Fabian Steiner, Simone Gaiarin, Richard D. Wesel. Probabilistically Shaped 4-PAM for Short-Reach IM/DD Links With a Peak Power Constraint. Journal of Lightwave Technology. 2020; 39 (2):400-405.
Chicago/Turabian StyleThomas Wiegart; Francesco Da Ros; Metodi Plamenov Yankov; Fabian Steiner; Simone Gaiarin; Richard D. Wesel. 2020. "Probabilistically Shaped 4-PAM for Short-Reach IM/DD Links With a Peak Power Constraint." Journal of Lightwave Technology 39, no. 2: 400-405.
Probabilistic constellation shaping is studied and developed for optical phase conjugation (OPC)-based nonlinearity compensation of Kerr nonlinearities in optical fiber links. The mid-link OPC scenario is considered for dispersion compensated systems. It is demonstrated in simulations and experimentally that transmission strategies optimal for classical additive white Gaussian noise (AWGN) channels can be sub-optimal for these systems without nonlinearity compensation. On the contrary, when nonlinearity compensation is applied with mid-link OPC, the channel noise is demonstrated to be Gaussian and AWGN-like transmission strategies thus remain effective. A channel-agnostic probability mass function (PMF) optimization algorithm is proposed for the input constellation in order to further improve the shaping gains in both scenarios. Operating arbitrary PMFs on arbitrary channels is enabled by a channel-agnostic digital signal processing (DSP) chain. After 2000 km of transmission, mid-link OPC is demonstrated to provide 1 dB of gain in effective SNR, which translates to 0.4 bits/QAM symbol of gain in achievable information rate. The gain is then increased by an extra 0.2 bits/QAM symbol by applying probabilistic shaping.
Metodi Plamenov Yankov; Henrik Enggaard Hansen; Francesco Da Ros; Pawel Marcin Kaminski; Edson Porto da Silva; Michael Galili; Leif Katsuo Oxenloewe; Soeren Forchhammer. Probabilistic Shaping for the Optical Phase Conjugation Channel. IEEE Journal of Selected Topics in Quantum Electronics 2020, 27, 1 -16.
AMA StyleMetodi Plamenov Yankov, Henrik Enggaard Hansen, Francesco Da Ros, Pawel Marcin Kaminski, Edson Porto da Silva, Michael Galili, Leif Katsuo Oxenloewe, Soeren Forchhammer. Probabilistic Shaping for the Optical Phase Conjugation Channel. IEEE Journal of Selected Topics in Quantum Electronics. 2020; 27 (2):1-16.
Chicago/Turabian StyleMetodi Plamenov Yankov; Henrik Enggaard Hansen; Francesco Da Ros; Pawel Marcin Kaminski; Edson Porto da Silva; Michael Galili; Leif Katsuo Oxenloewe; Soeren Forchhammer. 2020. "Probabilistic Shaping for the Optical Phase Conjugation Channel." IEEE Journal of Selected Topics in Quantum Electronics 27, no. 2: 1-16.
Probabilistic constellation shaping is investigated in the context of nonlinear fiber optic communication channels. Based on a general framework, different link types are considered—1. dispersion-managed channels, 2. unrepeatered transmission channels and 3. ideal distributed Raman amplified channels. These channels exhibit nonlinear effects to a degree that conventional probabilistic constellation shaping strategies for the additive white Gaussian (AWGN) noise channel are suboptimal. A channel-agnostic optimization strategy is used to optimize the constellation probability mass functions (PMFs) for the channels in use. Optimized PMFs are obtained, which balance the effects of additive amplified spontaneous emission noise and nonlinear interference. The obtained PMFs cannot be modeled by the conventional Maxwell-Boltzmann PMFs and outperform optimal choices of these in all the investigated channels. Suboptimal choices of constellation shapes are associated with increased nonlinear effects in the form of non-Gaussian noise. For dispersion-managed channels, a reach gain in 2 spans is seen and across the three channel types, gains of >0.1 bits/symbol over unshaped quadrature-amplitude modulation (QAM) are seen using channel-optimized probablistic shaping.
Henrik Enggaard Hansen; Metodi P. Yankov; Leif Katsuo Oxenløwe; Søren Forchhammer. Optimization of Probabilistic Shaping for Nonlinear Fiber Channels with Non-Gaussian Noise. Entropy 2020, 22, 872 .
AMA StyleHenrik Enggaard Hansen, Metodi P. Yankov, Leif Katsuo Oxenløwe, Søren Forchhammer. Optimization of Probabilistic Shaping for Nonlinear Fiber Channels with Non-Gaussian Noise. Entropy. 2020; 22 (8):872.
Chicago/Turabian StyleHenrik Enggaard Hansen; Metodi P. Yankov; Leif Katsuo Oxenløwe; Søren Forchhammer. 2020. "Optimization of Probabilistic Shaping for Nonlinear Fiber Channels with Non-Gaussian Noise." Entropy 22, no. 8: 872.
In this paper, a rate-adaptive coded modulation (CM) system combining polar codes and many-to-one probabilistic shaping is constructed and experimentally demonstrated. We propose to control the polar codes using a fraction of bits referred to as pre-set bits. This not only allows to offset the puncturing loss of rate-adaptive polar codes but also provides shaping gains compared to the non-punctured polar codes. Pre-set bits and many-to-one shaping are combined to form a rate-adaptive bit-interleaved CM system. We experimentally evaluate the system performance for 10x8-GBd dual polarization 256 quadrature amplitude modulation (QAM) wavelength division multiplexed (WDM) system with various input data rates ranging from 61 Gbps to 91 Gbps per carrier. The experimental results demonstrate a 200 km reach increase over a wide range of distances compared to the non-punctured polar codes and punctured polar codes.
Shajeel Iqbal; Pawel Marcin Kaminski; Frederik Klejs; Metodi Plamenov Yankov; Edson Porto Da Silva; Francesco Da Ros; Leif Katsuo Oxenløwe; Soeren Forchhammer. Probabilistically Shaped Rate-Adaptive Polar-Coded 256-QAM WDM Optical Transmission System. Journal of Lightwave Technology 2019, 38, 1800 -1808.
AMA StyleShajeel Iqbal, Pawel Marcin Kaminski, Frederik Klejs, Metodi Plamenov Yankov, Edson Porto Da Silva, Francesco Da Ros, Leif Katsuo Oxenløwe, Soeren Forchhammer. Probabilistically Shaped Rate-Adaptive Polar-Coded 256-QAM WDM Optical Transmission System. Journal of Lightwave Technology. 2019; 38 (7):1800-1808.
Chicago/Turabian StyleShajeel Iqbal; Pawel Marcin Kaminski; Frederik Klejs; Metodi Plamenov Yankov; Edson Porto Da Silva; Francesco Da Ros; Leif Katsuo Oxenløwe; Soeren Forchhammer. 2019. "Probabilistically Shaped Rate-Adaptive Polar-Coded 256-QAM WDM Optical Transmission System." Journal of Lightwave Technology 38, no. 7: 1800-1808.
In this work, we present a comprehensive experimental and numerical investigation of the impact of system parameters on wavelength converters based on four-wave-mixing, with focus on practical system implementations in addition to the interaction within the nonlinear medium. The input signal power optimization is emphasized according to the trade-off between the linear and the nonlinear impairments, and the origin of the limitations at the optimum is studied. The impact of the input signal quality on the converted idler is discussed, and depending on the dominant noise contribution a varying conversion penalty is demonstrated. The penalty is also shown to scale with increasing number of WDM channels due to additional nonlinear cross-talk between them. Finally, by means of numerical simulations we extend the experimental characterization to high pump powers, showing the impact of parametric noise amplification, and different pump laser linewidths, which lead to increased phase-noise transfer. The experimental characterization employs an integrated AlGaAs-on-insulator waveguide, and the numerical simulations accompany the results to make the analysis general for $\chi^{(3)}$ materials that satisfy the assumptions of the split-step Fourier method.
Pawel Marcin Kaminski; Leif Katsuo Oxenløwe; Michael Galili; Francesco Da Ros; Edson Porto Da Silva; Minhao Pu; Metodi Plamenov Yankov; Elizaveta Semenova; Kresten Yvind; Anders Clausen; Soeren Forchhammer. Characterization and Optimization of Four-Wave-Mixing Wavelength Conversion System. Journal of Lightwave Technology 2019, 37, 5628 -5636.
AMA StylePawel Marcin Kaminski, Leif Katsuo Oxenløwe, Michael Galili, Francesco Da Ros, Edson Porto Da Silva, Minhao Pu, Metodi Plamenov Yankov, Elizaveta Semenova, Kresten Yvind, Anders Clausen, Soeren Forchhammer. Characterization and Optimization of Four-Wave-Mixing Wavelength Conversion System. Journal of Lightwave Technology. 2019; 37 (21):5628-5636.
Chicago/Turabian StylePawel Marcin Kaminski; Leif Katsuo Oxenløwe; Michael Galili; Francesco Da Ros; Edson Porto Da Silva; Minhao Pu; Metodi Plamenov Yankov; Elizaveta Semenova; Kresten Yvind; Anders Clausen; Soeren Forchhammer. 2019. "Characterization and Optimization of Four-Wave-Mixing Wavelength Conversion System." Journal of Lightwave Technology 37, no. 21: 5628-5636.
A family of texture-based generative models for fingerprint images is proposed. The generative models are used to estimate upper bounds on the image entropy for systems with small sensor acquisition. The identification capacity of such systems is then estimated using the mutual information between different samples from the same finger. Similar to the generative model for entropy estimation, pixel-level model families are proposed for estimating similarity between fingerprint images with a given global affine transformation. These models are used for mutual information estimation, and are also adopted to compensate for local deformations between samples. Finally, it is shown that sensor sizes as small as 52x52 pixels are potentially sufficient to discriminate populations as large as the entire world population that ever lived, given that a complexity-unconstrained recognition algorithm is available which operates on the lowest possible pixel level.
Metodi P. Yankov; Martin A. Olsen; Mikkel B. Stegmann; Soren Sk. Christensen; Soren Forchhammer. Fingerprint Entropy and Identification Capacity Estimation Based on Pixel-Level Generative Modelling. IEEE Transactions on Information Forensics and Security 2019, 15, 56 -65.
AMA StyleMetodi P. Yankov, Martin A. Olsen, Mikkel B. Stegmann, Soren Sk. Christensen, Soren Forchhammer. Fingerprint Entropy and Identification Capacity Estimation Based on Pixel-Level Generative Modelling. IEEE Transactions on Information Forensics and Security. 2019; 15 (99):56-65.
Chicago/Turabian StyleMetodi P. Yankov; Martin A. Olsen; Mikkel B. Stegmann; Soren Sk. Christensen; Soren Forchhammer. 2019. "Fingerprint Entropy and Identification Capacity Estimation Based on Pixel-Level Generative Modelling." IEEE Transactions on Information Forensics and Security 15, no. 99: 56-65.
A perturbation-based nonlinear compensation scheme assisted by a feedback from the forward error correction (FEC) decoder is numerically and experimentally investigated. It is shown by numerical simulations and transmission experiments that a feedback from the FEC decoder enables improved compensation performance, allowing the receiver to operate very close to the full data-aided performance bounds. The experimental analysis considers the dispersion uncompensated transmission of a 532 GBd WDM system with DP-16QAM and DP-64QAM after 4200 km and 1120 km, respectively. The experimental results show that the proposed scheme outperforms single-channel digital backpropagation.
Edson Porto Da Silva; Metodi Plamenov Yankov; Francesco Da Ros; Toshio Morioka; Leif Katsuo Oxenløwe. Perturbation-Based FEC-Assisted Iterative Nonlinearity Compensation for WDM Systems. Journal of Lightwave Technology 2018, 37, 875 -881.
AMA StyleEdson Porto Da Silva, Metodi Plamenov Yankov, Francesco Da Ros, Toshio Morioka, Leif Katsuo Oxenløwe. Perturbation-Based FEC-Assisted Iterative Nonlinearity Compensation for WDM Systems. Journal of Lightwave Technology. 2018; 37 (3):875-881.
Chicago/Turabian StyleEdson Porto Da Silva; Metodi Plamenov Yankov; Francesco Da Ros; Toshio Morioka; Leif Katsuo Oxenløwe. 2018. "Perturbation-Based FEC-Assisted Iterative Nonlinearity Compensation for WDM Systems." Journal of Lightwave Technology 37, no. 3: 875-881.
The nonlinear Fourier transform is a new approach of addressing the capacity limiting Kerr nonlinearities in optical communication systems. It exploits the property of integrability of the lossless nonlinear Schrödinger equation and thus incorporates nonlinearities as an element of the transmission. However, practical links employing erbium-doped fiber amplifiers include losses/gains and introduce noise which breaks the integrability of the nonlinear Schrödinger equation. Although the lossless path average approximation proposes an integrable model, its imprecision still leads to unintended distortions and thus performance degradation. We propose an alternative receiver for nonlinear frequency division multiplexing optical communication systems using techniques from machine learning. It is highly adaptive as it learns from previously transmitted pulses and thus holds no assumptions on the system and noise distribution. The detection method presented is fully applied in time-domain and omits the nonlinear Fourier transform. The numerical results provide a benchmark for nonlinear Fourier transform based detection of high order solitons for fiber links with losses and noise present.
Rasmus T. Jones; Simone Gaiarin; Metodi P. Yankov; Darko Zibar. Time-Domain Neural Network Receiver for Nonlinear Frequency Division Multiplexed Systems. IEEE Photonics Technology Letters 2018, 30, 1079 -1082.
AMA StyleRasmus T. Jones, Simone Gaiarin, Metodi P. Yankov, Darko Zibar. Time-Domain Neural Network Receiver for Nonlinear Frequency Division Multiplexed Systems. IEEE Photonics Technology Letters. 2018; 30 (12):1079-1082.
Chicago/Turabian StyleRasmus T. Jones; Simone Gaiarin; Metodi P. Yankov; Darko Zibar. 2018. "Time-Domain Neural Network Receiver for Nonlinear Frequency Division Multiplexed Systems." IEEE Photonics Technology Letters 30, no. 12: 1079-1082.
We demonstrate wavelength-division-multiplexed (WDM) and space-division-multiplexed (SDM) transmission of probabilistically shaped polarization-division-multiplexed (PDM) 1024-state quadrature amplitude modulation (QAM) channels over a 9.7-km single-mode 30-core fiber, achieving aggregated spectral efficiency of 297.82 bit/s/Hz on a 12.5-GHz grid and 7.01-Tbit/s spatial-super-channel on a 25-GHz grid without multiple-input multiple-output (MIMO) processing. Actual soft-decision forward error correction (SD-FEC) decoding was employed to obtain error-free performance, and adaptive rates and spectral efficiencies for individual WDM/SDM channels have been applied according to their channel conditions, by adjusting the SD-FEC overhead without changing the modulation format. Probabilistically shaped PDM-1024-QAM has been used to further increase the aggregated achievable rate due to the added performance improvement through shaping gain.
Hao Hu; Leif Katsuo Oxenløwe; Toshio Morioka; Metodi Plamenov Yankov; Francesco Da Ros; Yoshimichi Amma; Yusuke Sasaki; Takayuki Mizuno; Yutaka Miyamoto; Michael Galili; Søren Forchhammer. Ultrahigh-Spectral-Efficiency WDM/SDM Transmission Using PDM-1024-QAM Probabilistic Shaping With Adaptive Rate. Journal of Lightwave Technology 2017, 36, 1304 -1308.
AMA StyleHao Hu, Leif Katsuo Oxenløwe, Toshio Morioka, Metodi Plamenov Yankov, Francesco Da Ros, Yoshimichi Amma, Yusuke Sasaki, Takayuki Mizuno, Yutaka Miyamoto, Michael Galili, Søren Forchhammer. Ultrahigh-Spectral-Efficiency WDM/SDM Transmission Using PDM-1024-QAM Probabilistic Shaping With Adaptive Rate. Journal of Lightwave Technology. 2017; 36 (6):1304-1308.
Chicago/Turabian StyleHao Hu; Leif Katsuo Oxenløwe; Toshio Morioka; Metodi Plamenov Yankov; Francesco Da Ros; Yoshimichi Amma; Yusuke Sasaki; Takayuki Mizuno; Yutaka Miyamoto; Michael Galili; Søren Forchhammer. 2017. "Ultrahigh-Spectral-Efficiency WDM/SDM Transmission Using PDM-1024-QAM Probabilistic Shaping With Adaptive Rate." Journal of Lightwave Technology 36, no. 6: 1304-1308.
In this paper, finite state machine sources (FSMSs) are used to shape quadrature amplitude modulation (QAM) for nonlinear transmission in optical fiber communication systems. The previous optimization algorithm for FSMSs is extended to cover an average power constraint, thus enabling temporal optimization with multi-amplitude constellations output, such as QAM. The optimized source results in increased received SNR and thereby increased achievable information rates (AIR)s under memoryless assumption. The AIR is increased even further when taking the channel and transmitter memory into account via trellis processing at the receiver. Significant gains are reported in the highly nonlinear region of transmission for an FSMS of up to second order and 16QAM and particularly for unrepeated transmission. At the optimal launch power of WDM transmission, the FSMS order needs to be increased further in order to notably outperform previous probabilistic shaping schemes.
Metodi Plamenov Yankov; Knud J. Larsen; Søren Forchhammer. Temporal Probabilistic Shaping for Mitigation of Nonlinearities in Optical Fiber Systems. Journal of Lightwave Technology 2017, 35, 1803 -1810.
AMA StyleMetodi Plamenov Yankov, Knud J. Larsen, Søren Forchhammer. Temporal Probabilistic Shaping for Mitigation of Nonlinearities in Optical Fiber Systems. Journal of Lightwave Technology. 2017; 35 (10):1803-1810.
Chicago/Turabian StyleMetodi Plamenov Yankov; Knud J. Larsen; Søren Forchhammer. 2017. "Temporal Probabilistic Shaping for Mitigation of Nonlinearities in Optical Fiber Systems." Journal of Lightwave Technology 35, no. 10: 1803-1810.