Impact of dispersion map management on the performance of back-propagation for nonlinear WDM transmissions
ABSTRACT We investigate the dependence of digital back-propagation on dispersion map and the number of back-propagated channels for a 112Gb/s/channel PM-mQAM (m=4,16) WDM link. With the optimum dispersion map, single-channel back-propagation approaches the maximum spectral efficiency.
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ABSTRACT: We experimentally demonstrate performance enhancements enabled by weighted digital back propagation method for 28 Gbaud PM-16QAM transmission systems, over a 250 km ultra-large area fibre, using only one back-propagation step for the entire link, enabling up to 3 dB improvement in power tolerance with respect to linear compensation only. We observe that this is roughly the same improvement that can be obtained with the conventional, computationally heavy, non-weighted digital back propagation compensation with one step per span. As a further benchmark, we analyze performance improvement as a function of number of steps, and show that the performance improvement saturates at approximately 20 steps per span, at which a 5 dB improvement in power tolerance is obtained with respect to linear compensation only. Furthermore, we show that coarse-step self-phase modulation compensation is inefficient in wavelength division multiplexed transmission.Optics Express 12/2011; 19(26):B805-10. DOI:10.1364/OE.19.00B805 · 3.53 Impact Factor
Article: Stochastic Digital Backpropagation[Show abstract] [Hide abstract]
ABSTRACT: In this paper, we propose a novel detector for single-channel long-haul coherent optical communications, termed stochastic digital backpropagation (SDBP), which takes into account noise from the optical amplifiers in addition to handling deterministic linear and nonlinear impairments. We discuss the design approach behind this detector, which is based on the maximum a posteriori (MAP) principle. As closed-form expressions of the MAP detector are not tractable for coherent optical transmission, we employ the framework of Bayesian graphical models, which allows a numerical evaluation of the proposed detector. Through simulations, we observe that by accounting for nonlinear signal-noise interactions, we achieve a significant improvement in system reach with SDBP over digital backpropagation (DBP) for systems with periodic inline optical dispersion compensation. In uncompensated links with high symbol rates, the performance difference in terms of system reach for SDBP over DBP is small. In the absence of noise, the proposed detector is equivalent to the well-known DBP detector.IEEE Transactions on Communications 01/2014; 62(11):3956-3968. DOI:10.1109/TCOMM.2014.2362534 · 1.98 Impact Factor