Agradecimentos: The authors would like to thank Andr Souza and Lailson dos Santos for invaluable discussions concerning complexity calculations. The authors would like to thank the anonymous reviewers for important contributions to improve the paper quality. This work was supported by FUNTTEL/Finep, CNPq, and FAPESP under Grants 2015/24341-7 and 2015/24517-8 Ver menos

Abstract: In this paper, we evaluate the selective combination of algorithms for fiber nonlinearity compensation, transceiver impairments mitigation and variable-rate coding in unrepeatered optical transmission. A post-emphasis filter and a two-stage 44 multiple-input and multiple-output equalizer compensate the impact of bandwidth limitations and in-phase and quadrature skew. Nonlinear compensation is accomplished by a fast-converging adaptive digital back-propagation algorithm and maximum likelihood sequence estimation. Forward error correction is provided by a variable-rate spatially-coupled low-density parity-check code. The performance and complexity of the proposed digital subsystems are experimentally evaluated by the unrepeatered wavelength division multiplexing transmission of 17200-Gb/s (DP-16QAM 32-GBd) channels over 350-km of large effective area and low-loss single-mode fibers. The experimental results for different combinations of algorithms elucidate the trade-off of complexity and performance in unrepeatered optical transmission Ver menos