Target Constellation Diagram Determination for Nonlinear Optical Transmission

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Solution Overview

Problem

In long-haul coherent optical transmission systems, high nonlinear effects due to self-phase modulation and cross-phase modulation degrade transmission performance, as existing data sending and receiving methods are designed for lowly nonlinear conditions, leading to poor performance in highly nonlinear scenarios.

Innovation Solution

A target constellation diagram determining method that accurately reflects signal distribution under highly nonlinear effects by calculating cumulative distances between detection regions in an alternative constellation diagram, allowing for more accurate detection regions and improved data transmission performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If incident optical power is increased to improve OSNR and transmission distance, then transmission performance is improved, but nonlinear phase noise caused by SPM and XPM effects increases, degrading signal quality

Engineering Contradiction:
Improvetransmission performanceVSAvoidnonlinear phase noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements dynamic constellation diagram selection and detection region adjustment based on real-time channel conditions. The receiving device determines optimal detection regions for different constellation points by evaluating signal distribution characteristics under varying nonlinear effects, allowing the system to adapt to changing operating conditions and maintain performance across different optical power levels

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of the constellation diagram detection system by adjusting detection region boundaries based on the actual signal distribution. Instead of using fixed detection regions, the system dynamically modifies detection region parameters to match the distorted signal distribution caused by nonlinear effects, thereby improving detection accuracy under high optical power conditions

Inventive Principle:
Principle #35Parameter changes

2Reliability

If existing data sending and receiving methods designed for lowly nonlinear effects are used in highly nonlinear effects, then device complexity is low, but working performance becomes very poor

Engineering Contradiction:
Improveworking performanceVSAvoiddetection method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The receiving device performs self-optimization by automatically determining optimal detection regions based on the received training data and signal distribution characteristics. The system uses the transmitted training data to autonomously evaluate different detection region configurations and select the optimal ones without requiring external intervention or complex pre-programming

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements a feedback mechanism where the receiving device evaluates the performance of different detection region configurations using training data, selects the optimal configuration, and communicates this back to the sending device. This feedback loop enables continuous optimization of the detection process based on actual channel conditions

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method effectively improves data transmission performance in highly nonlinear effects by determining a target constellation diagram that reflects the centralized distribution of received data, resulting in better separation between detection regions and enhanced transmission accuracy.

Implementation Method 1

Self-phase modulation (Self-phase modulation, SPM for short) and cross-phase modulation (Cross-phase modulation, XPM for short) are two nonlinear effects that most greatly affect the transmission performance

Methodology Applied
Scientific EffectSelf-phase modulation:

Implementation Method 2

Self-phase modulation (Self-phase modulation, SPM for short) and cross-phase modulation (Cross-phase modulation, XPM for short) are two nonlinear effects that most greatly affect the transmission performance

Methodology Applied
Scientific EffectCross-phase modulation:

Data Source

PatentEP3490207B1Target constellation diagram determination method and apparatus
Publication Date: 2021.03.31 HUAWEI TECH CO LTD
  • EP3490207B1 patent drawingFigure 1a~1b
  • EP3490207B1 patent drawingFigure 1c~1d
  • EP3490207B1 patent drawingFigure 2

AI summary

A target constellation diagram determining method, a data sending method, and an apparatus are disclosed. The target constellation diagram determining method includes: receiving, by a receiving device, training data that is generated and sent by a sending device based on each constellation point in an alternative constellation diagram; determining a detection region of each constellation point based on a position of the training data in the alternative constellation diagram; obtaining a cumulative distance corresponding to the alternative constellation diagram based on a distance between the detection regions of the constellation points; and determining, based on cumulative distances corresponding to a plurality of alternative constellation diagrams, that an alternative constellation diagram with a largest cumulative distance is a target constellation diagram, and notifying the sending device of the target constellation diagram, so that the sending device modulates to-be-sent data based on the target constellation diagram. According to the method in embodiments of this application, data transmission performance can be effectively improved in a highly nonlinear effect.