Accurate Non-Linearity Fully-Closed-Form Formula based on the GN/EGN Model and Large-Data-Set Fitting

Modulation Format Dependent, Closed-Form Formula for Estimating Nonlinear Interference in S+C+L Band Systems

“…To validate the proposed formula (3), a split-step simulation was performed for 452 × 40 GBd channels, occupying the entire S+C+L band (20 THz). This represents the first numerical validation of perturbation models such as [4,7,8,[10][11][12] over optical bandwidths of 20 THz. A Corning c SMF-28 c ULL fibre was considered with experimentally measured fibre data for attenuation coefficient, shown in Fig.…”

“…Numerically solving those integrals, typically taking a few minutes for a single transmission, quickly reaches unacceptable execution times, particularly for realtime optimisation and network modeling, where numerous configurations are analysed. To overcome this problem, modulation format independent closed-form approximations of the ISRS GN model have been proposed [6,10,11]. Recently, we upgraded the closed-form formula to account for non-Gaussian signals, increasing the prediction accuracy for real-world modulation formats [12].…”

A Closed-Form Expression for the Gaussian Noise Model in the Presence of Inter-Channel Stimulated Raman Scattering Extended for Arbitrary Loss and Fibre Length

“…These formulations must offer a fast, yet accurate, evaluation of the network characteristics, so that they can be widely used for network optimisation purposes [1,2]. The closed-form expressions derived using the ISRS Gaussian noise (GN) model [17] are a starting point due to their simplicity and efficiency in estimating NLI in UWB systems, and numerous closed-form equations have been developed to date [18,19,20,21].…”

A Closed-form Expression for the ISRS GN Model Supporting Distributed Raman Amplification

“…Of particular interest there are closedform expressions derived using the inter-channel stimulated Raman scattering (ISRS) Gaussian noise (GN) model [1], due to their simplicity and efficiency in estimating the NLI in UWB systems. This model includes the effect of ISRS and approximations in closed-form have been developed in [2], [3], [4]. However, among the weaknesses of these models are that the closed-form expressions do not support distributed Raman amplification (DRA), as they were developed for lumped amplifier solutions.…”