Noise-induced signal corruption in nonlinear Fourier-based optical transmission system in the presence of discrete eigenvalues

We present the numerical analysis of the correlation properties of the amplifier spontaneous emission (ASE) noise transformed into the nonlinear Fourier (NF) domain, addressing the noise-induced corruptions in the communication systems employing the nonlinear Fourier transform (NFT) based signal processing. In our current work we deal with the orthogonal frequency division multiplexing (OFDM) modulation of a continuous NF spectrum and account for the presence of discrete (soliton) eigenvalues. This approach is aimed at extending our previous studies that referred to the modulation of continuous NF spectrum only. The effective noise covariance functions are obtained from numerical simulations for a range of propagation distances, values of discrete eigenvalue, and different effective signal power levels. We report the existence of the correlations between the continuous and discrete parts of the NF spectrum.