# Signaling on the Continuous Spectrum of Nonlinear Optical fiber

## TL;DR

This paper explores various signaling techniques on the nonlinear Fourier spectrum of optical fibers, analyzing their performance, noise effects, and optimizing data rate and reach distance for high-capacity fiber-optic communication.

## Contribution

It introduces and compares three novel signaling methods on the nonlinear spectral domain, optimizing bandwidth and data rate, and demonstrating a 7100 km reach at 9.6 Gbps.

## Key findings

- Optimal bandwidth minimizes temporal signal duration.
- Proposed methods improve error performance and distance reach.
- Achieved 7100 km transmission at 9.6 Gbps.

## Abstract

This paper studies different signaling techniques on the continuous spectrum (CS) of nonlinear optical fiber defined by nonlinear Fourier transform. Three different signaling techniques are proposed and analyzed based on the statistics of the noise added to CS after propagation along the nonlinear optical fiber. The proposed methods are compared in terms of error performance, distance reach, and complexity. Furthermore, the effect of chromatic dispersion on the data rate and noise in nonlinear spectral domain is investigated. It is demonstrated that, for a given sequence of CS symbols, an optimal bandwidth (or symbol rate) can be determined so that the temporal duration of the propagated signal at the end of the fiber is minimized. In effect, the required guard interval between the subsequently transmitted data packets in time is minimized and the effective data rate is significantly enhanced. Moreover, by selecting the proper signaling method and design criteria a reach distance of 7100 km is reported by only singling on the CS at a rate of 9.6 Gbps.