Fiber Nonlinearity Compensation via Frequency Domain Perturbation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current fiber-optical transmission systems face challenges in accurately modeling and mitigating nonlinear interference due to the inherent nonlinearity of fiber-optical channels, which limits the effectiveness of existing transmission schemes optimized for linear channels.
Innovation Solution
A discrete-time end-to-end fiber-optical channel model based on a first-order perturbation approach is developed, transforming data signals from the time domain to the frequency domain to determine spectral interference coefficients, allowing for the representation of self- and cross-channel nonlinear interactions and enabling novel algorithms for low-complexity fiber nonlinearity compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a first-order perturbation approach is used to model fiber-optical channel, then computational complexity is reduced, but modeling accuracy of nonlinear interference may be compromised
Solution Approach 1:
The patent transforms the nonlinear fiber-optical channel model from the time domain to the frequency domain by changing the representation parameters. This allows the use of first-order perturbation theory while maintaining accurate modeling of nonlinear interference through spectral coefficients, resolving the contradiction between computational simplicity and modeling accuracy
Solution Approach 2:
The patent replaces the traditional time-domain mechanical/mathematical model with a frequency-domain equivalent model. By substituting the representation domain from time to frequency, the system achieves both computational efficiency and accurate nonlinear interference characterization
2Ease of operation
If existing transmission schemes optimized for linear channels are used, then implementation simplicity is maintained, but transmission performance over nonlinear fiber-optical channels deteriorates
Solution Approach 1:
The patent introduces spectral interference coefficients as an intermediary element that bridges linear transmission schemes and nonlinear fiber-optical channel characteristics. These coefficients enable compensation for nonlinear effects while maintaining the simplicity of existing transmission schemes
Solution Approach 2:
The patent segments the nonlinear interference into individual spectral coefficients corresponding to different frequency channels. This segmentation allows selective compensation of nonlinear effects in each channel while maintaining overall system simplicity
Data Source
AI summary
An apparatus for determining an interference in a transmission medium during a transmission of a data input signal according to an embodiment has a transform module configured to transform the data input signal from a time domain to a frequency domain comprising a plurality of frequency channels to obtain a frequency-domain data signal comprising a plurality of spectral coefficients, wherein each spectral coefficient is assigned to one of the frequency channels, an analysis module configured to determine the interference by determining one or more spectral interference coefficients, wherein each spectral interference coefficient is assigned to one frequency channel. The analysis module is configured to determine each spectral interference coefficient depending on the spectral coefficients, and depending on a transfer function, wherein the transfer function is configured to receive two or more argument values, wherein each of the argument values indicates one frequency channel, and wherein the transfer function is configured to return a return value depending on the argument values.