Spectrally Shaped DP-16QAM Super-Channel Transmission with Multi-Channel Digital Back-Propagation

Abstract

The achievable transmission capacity of conventional optical fibre communication systems is limited by nonlinear distortions due to the Kerr effect and the difficulty in modulating the optical field to effectively use the available fibre bandwidth. In order to achieve a high information spectral density (ISD), while simultaneously maintaining transmission reach, multi-channel fibre nonlinearity compensation and spectrally efficient data encoding must be utilised. In this work, we use a single coherent super-receiver to simultaneously receive a DP-16QAM super-channel, consisting of seven spectrally shaped 10GBd sub-carriers spaced at the Nyquist frequency. Effective nonlinearity mitigation is achieved using multi-channel digital back-propagation (MC-DBP) and this technique is combined with an optimised forward error correction implementation to demonstrate a record gain in transmission reach of 85%; increasing the maximum transmission distance from 3190 km to 5890 km, with an ISD of 6.60 b/s/Hz. In addition, this report outlines for the first time, the sensitivity of MC-DBP gain to linear transmission line impairments and defines a trade-off between performance and complexity.

Digital nonlinearity compensation in high-capacity optical fibre communication systems: Performance and optimisation

“…compensating only for intra-channel nonlinearities (self-phase modulation), has been suggested as a low-complexity compensation scheme which may realise potential cost savings in newly deployed systems [29][30][31]. Nevertheless, for a substantial increase in the achievable information rates, multi-channel DBP (MC-DBP) has been widely considered as a promising approach as it compensates for both intra-channel and inter-channel fibre nonlinearities in dense wavelength division multiplexed (WDM) optical communication systems [32][33][34][35][36][37][38][39]. In this paper, the performance and the optimisation of MC-DBP is discussed from the perspectives of signal-to-noise ratio (SNR) and AIR enhancement in the compensated fibre-optic communication systems, where different high-cardinality modulation formats such as dual-polarisation quadrature phase shift keying (DP-QPSK), dual-polarisation 16-level quadrature amplitude modulation (DP-16QAM), DP-64QAM and DP-256QAM, are applied.…”

Analysis of Nonlinear Signal Interference to Optimize the Coherent Optical Transmission System

“…The expression for NLSI p in the case of multichannels is presented below [19] n s The effective length is calculated for using the following equation [15]:…”

Throughput Gains From Adaptive Transceivers in Nonlinear Elastic Optical Networks

“…The adaptation of the optical launch power [12], [13] and mitigation of nonlinear interference using, for example digital back propagation (DBP) [14], [15], can improve the properties of the light path. The use of flexible grids with adaptive signal bandwidth [16], superchannels and sliceable transceivers [17] allows the light path bandwidth to be better matched to the clients data requirements.…”