title: Characterization of long-haul 112Gbit/s PDM-QAM-16 transmission with and without digital nonlinearity compensation.
abstract: In this paper long-haul, single channel, polarization multiplexed 16-state quadrature amplitude modulation (PDM-QAM-16) transmission at 112 Gbit/s is investigated. Novel digital signal processing techniques are used to perform carrier phase estimation and symbol estimation, in combination with nonlinear digital backpropagation. The results obtained demonstrate that the use of digital nonlinear backpropagation increases the optimum launch power from -4 dBm to -1 dBm with a consequent increase in maximum reach from 1440 km to 2400 km, which is a record transmission distance for QAM-16 reported to date for an SMF link with EDFAs only. Furthermore, experimental measurements are supported by simulations, based on the link used in the experiment.
authors.affiliation: Optical Networks Group, Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, UK. s.makovey@ee.ucl.ac.uk
authors.forename: Sergejs
authors.initials: S
authors.lastname: Makovejs
authors.forename: David S
authors.initials: DS
authors.lastname: Millar
authors.forename: Domanic
authors.initials: D
authors.lastname: Lavery
authors.forename: Carsten
authors.initials: C
authors.lastname: Behrens
authors.forename: Robert I
authors.initials: RI
authors.lastname: Killey
authors.forename: Seb J
authors.initials: SJ
authors.lastname: Savory
authors.forename: Polina
authors.initials: P
authors.lastname: Bayvel