ABSTRACT
This chapter aims to present the general framework of how to estimate the capacity for the channel defined inside the nonlinear Fourier (NF) domain. It addresses already specifically the transmission in the NF domain, and explores the equations further for the definition of discrete input-output channel for the NF data and the forthcoming analysis of the resulting channel capacity. The original idea of using the NF spectrum for modulation and transmission was first proposed in the currently well-recognized work by Hasegawa and Nyu “Eigenvalue communication”. The chapter describes a theoretical approach based on the perturbation theory for the NF data for the asymptotical estimate of capacity limits of the nonlinear Fourier transform (NFT)-based optical transmission. The burst mode of the NFT-based methods brings about the noticeable degradation of the effective spectral efficiency of a system measured in the optical domain, which means that the NFT-based systems require further development and optimization.
