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| 2. |
- Czegledi, Cristian Bogdan, 1988, et al.
(författare)
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Modified Digital Backpropagation Accounting for Polarization-Mode Dispersion
- 2017
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Ingår i: Optical Fiber Communication Conference. - 9781943580231
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Konferensbidrag (refereegranskat)abstract
- We propose a modified DBP algorithm accounting for PMD. The accumulated PMD at the receiver is factorized into several PMD sections, and inserted into the DBP routine to distributively compensate for PMD, outperforming the conventional approach by 1.1 dB in SNR.
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| 3. |
- Lu, Yang, et al.
(författare)
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Matrix Receiving Scheme Supporting Arbitrary Multiple-Wavelength Reception for Optical Interconnects
- 2017
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Ingår i: European Conference on Optical Communication, ECOC. - : IEEE. - 9781538656242
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Konferensbidrag (refereegranskat)abstract
- An arbitrary multiple-wavelength reception scheme using only a few fixed-wavelength filters is proposed for optical interconnects. Filter matrices design based on error-control coding theory is devised. The feasibility of the proposed scheme is demonstrated in a four-wavelength reception experiment.
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| 4. |
- Agrell, Erik, 1965
(författare)
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Capacity bounds in optical communications
- 2017
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Ingår i: European Conference on Optical Communication, ECOC. ; Volume 2017-September, s. 1-3
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Konferensbidrag (refereegranskat)abstract
- The fundamental concept of channel capacity and related information-theoretic metrics are reviewed and some techniques to quantify them by means of lower and upper bounds are explained. The importance of properly discretizing the channel model is highlighted.
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| 5. |
- Alvarado, Alex, 1982, et al.
(författare)
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High-SNR Asymptotics of Mutual Information for Discrete Constellations
- 2013
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Ingår i: IEEE International Symposium on Information Theory - Proceedings. - 2157-8095. - 9781479904464 ; , s. 2274-2278
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Konferensbidrag (refereegranskat)abstract
- The high-signal-to-noise ratio (SNR) asymptotic behavior of the mutual information (MI) for discrete constellations over the scalar additive white Gaussian noise channel is studied. Exact asymptotic expressions for the MI for arbitrary one-dimensional constellations and input distributions are presented in the limit as the SNR tends to infinity. Using the relationship between the MI and the minimum mean-square error (MMSE), asymptotics of the MMSE are also developed. It is shown that for any input distribution, the MI and the MMSE have an asymptotic behavior proportional to a Gaussian Q-function, whose argument depends only on the minimum Euclidean distance of the constellation and the SNR. Closed-form expressions for the coefficients of these Q-functions are calculated.
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| 6. |
- Li, Shen, 1994, et al.
(författare)
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Antialiased transmitter-side digital backpropagation
- 2020
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 32:18, s. 1211-1214
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Tidskriftsartikel (refereegranskat)abstract
- Digital backpropagation (DBP) is an electronic scheme for compensating nonlinear distortions in fiber transmission systems. Due to the nonlinearity-induced spectral broadening, the data must be oversampled to avoid aliasing, which increases the complexity and power consumption of the scheme. In this work, we show that aliasing can alternatively be prevented by distributed antialiasing filters, at a lower complexity. We proposed a new modified split-step Fourier method (SSFM) with easy-To-implement low-pass filters (LPFs) in the linear steps to avoid aliasing due to spectral broadening. Both the forward fiber propagation and a transmitter-side DBP are simulated using the modified SSFM. High-order modulation formats such as 256-Ary quadrature-Amplitude-modulation (256-QAM) and 1024-QAM transmissions at 28 Gbaud and 64 Gbaud over 1000 km fiber are considered, and our results show that the complexity of the DBP can be reduced by up to 50%. The optimal bandwidth of the LPFs is studied for both forward propagation and the DBP.
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| 7. |
- Li, Shen, 1994, et al.
(författare)
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Power-Efficient Voronoi Constellations for Fiber-Optic Communication Systems
- 2023
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 41:5, s. 1298-1308
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Tidskriftsartikel (refereegranskat)abstract
- Voronoi constellations (VCs) are considered as an effective geometric shaping method due to their high power efficiencies and low complexity. In this paper, the performance of 16- and 32-dimensional VCs with a variety of spectral efficiencies transmitted in the nonlinear fiber channel are investigated. Both single-channel and wavelength-division multiplexing systems are considered for the transmission of the VCs, as well as different signal processing schemes, including chromatic dispersion compensation and digital backpropagation. Multiple performance metrics including the uncoded bit error rate, mutual information (MI), and generalized mutual information (GMI) of VCs are evaluated. Compared with quadrature amplitude modulation (QAM) formats, the VCs provide 1.0--2.4 dB launch power gains, up to 0.50 bits/symbol/dimension-pair MI gains, up to around 30% potential reach increase at the same MI, and up to 0.30 bits/symbol/dimension-pair GMI gains in a limited launch power range. The observed performance gains over QAM are found higher than in the back-to-back case. Moreover, a general GMI estimation method for very large constellations using importance sampling is proposed for the first time.
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| 8. |
- Rabbani, Hami, et al.
(författare)
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Improving the Achievable Rates of Optical Coherent Transmission with Back-Propagation
- 2018
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 30:14, s. 1273-1276
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Tidskriftsartikel (refereegranskat)abstract
- The power allocation in wavelength-division multi- plexed (WDM) fiber-optic links with digital back-propagation (BP) is optimized in order to improve the achievable rates (AR). The power allocation is performed using a convex optimization technique based on a modulation-format-dependent time-domain model capable of including the nonlinear Kerr effects. In a fully loaded WDM link with heterogeneous (uneven) nonlinear interference noise (NLIN) spectrum, the AR gain of nonlinear BP over linear electronic dispersion compensation is 60% larger if per-channel power optimization is allowed than if all transceivers use an equal (flat) optimized power. The heterogeneous NLIN spectrum results from performing BP on a subset of the channels. However, the gain of per-channel power optimization disappears for the homogeneous (nearly flat) NLIN spectrum. Moreover, we show that the improvement obtained by joint channel power allocation is more pronounced for links with a larger number of spans.
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| 9. |
- Secondini, M., et al.
(författare)
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Fiber nonlinearity mitigation in WDM systems: Strategies and achievable rates
- 2017
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Ingår i: European Conference on Optical Communication, ECOC. ; 2017-September, s. 1-3
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Konferensbidrag (refereegranskat)abstract
- After reviewing models and mitigation strategies for interchannel nonlinearity, the synergic effect of symbol-rate optimization and phase-noise compensation is investigated. This effect can be practically exploited for nonlinearity mitigation and for the computation of capacity lower bounds.
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| 10. |
- Yan, Li, 1988, et al.
(författare)
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Regenerator Site Predeployment in Nonlinear Dynamic Flexible-Grid Networks
- 2017
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Ingår i: European Conference on Optical Communication, ECOC.
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Konferensbidrag (refereegranskat)abstract
- A regenerator predeployment algorithm is proposed in dynamic translucent flexible-grid networks based on the GN model. The randomness of traffic bandwidth requests is exploited to allocate regenerators efficiently. Our method accommodates 30% more demands than benchmark methods.
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