Capacity of a discrete-time model of optical fiber described by thesplit-step Fourier method (SSFM) as a function of the average input power$\mathcal P$ and the number of segments in distance $K$ is considered . The capacity of the resulting continuous-space lossless model is lower bounded by $o(1)$ . The number of DoFs in thecontinuous-space model is at least half of the input dimension $n$Intensity-modulation and direct detection achieves this rate . The lower bound when $K{=}\mathcal{P}^{1/\delta}$ is generally characterized interms of $delta$. We consider the SSFM model where the dispersion matrix does not depend on$K$. The capacity is $1.2(1+\text{SNR)+ o(1), for example, for example . The pre-log inthe lower bound is $K is $2.3$ for any $K\rightarrow\infty$ is $

**Author(s) :**Milad Sefidgaran, Mansoor Yousefi

**Links :**PDF - Abstract

**Code :**

https://github.com/SergeyVYakhontov/PeqNPApp

Keywords : model - capacity - bound - ssfm - space -