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Mitigation of intra-channel nonlinearities using a frequency-domain Volterra series equalizer

Guiomar, F. P. ; Reis, J.D. ; Teixeira, A. ; Pinto, A. N.

Optics Express Vol. 20, Nº 2, pp. 1360 - 1369, January, 2012.

ISSN (print): 1094-4087
ISSN (online): 1094-4087

Journal Impact Factor: 3,488 (in 2014)

Digital Object Identifier: 10.1364/OE.20.001360

We address the issue of intra-channel nonlinear compensation
using a Volterra series nonlinear equalizer based on an analytical closed-form solution for the 3rd order Volterra kernel in frequency-domain. The performance of the method is investigated through numerical simulations for a single-channel optical system using a 20 Gbaud NRZ-QPSK test signal propagated over 1600 km of both standard single-mode fiber and non-zero dispersion shifted fiber. We carry on performance and computational effort comparisons with the well-known backward propagation split-step Fourier (BP-SSF) method. The alias-free frequency-domain implementation of the Volterra series nonlinear equalizer makes it an attractive approach to work at low sampling rates, enabling to surpass the maximum performance of BP-SSF at 2x oversampling. Linear and nonlinear equalization can be treated independently, providing more flexibility to the equalization subsystem. The parallel structure of the algorithm is also a key advantage in
terms of real-time implementation.