Multi-Core Fiber Precoder Mitigates Crosstalk

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Multi-core fiber-based optical transmission systems face limitations due to core-dependent losses and crosstalk effects, which current solutions cannot optimally mitigate, leading to reduced performance and increased complexity.

Innovation Solution

An optical transmitter and receiver system that employs linear precoding techniques to precode information symbols using a precoding matrix determined by fiber parameters and misalignment loss values, reducing complexity and alleviating decoding operations without requiring channel state information or feedback links.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multi-core fiber is used to increase transmission capacity, then bandwidth capacity is improved, but core-dependent losses and crosstalk effects worsen

Engineering Contradiction:
Improvetransmission capacityVSAvoidsignal quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-calculating and pre-applying a precoding matrix at the transmitter before signal transmission. This precoding matrix is determined based on fiber parameters and misalignment loss values, allowing the system to compensate for core-dependent losses and crosstalk effects in advance, thereby maintaining signal quality while utilizing multi-core fiber for high capacity transmission

Inventive Principle:
Principle #10Preliminary action

2Reliability

If conventional solutions are used to mitigate core-dependent losses, then signal quality is improved, but system complexity increases

Engineering Contradiction:
Improvesignal qualityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying the transmission parameters through the precoding matrix, which is determined based on fiber parameters and misalignment loss values. This approach adjusts the signal parameters in a systematic way to compensate for losses without requiring complex additional hardware or multiple processing stages, thus improving signal quality while keeping system complexity manageable

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If channel state information feedback is used for precoding, then decoding performance is improved, but system complexity and overhead increase

Engineering Contradiction:
Improvedecoding performanceVSAvoidfeedback mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies self-service by determining the precoding matrix based on fiber parameters and misalignment loss values that are inherent to the transmission system itself, rather than requiring external feedback from channel state information. The system uses its own operational characteristics to generate the appropriate precoding, eliminating the need for complex feedback mechanisms while maintaining decoding performance

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3767841B1Methods and devices for multi-core fiber data transmission using data precoding
Publication Date: 2024.08.28 INSTITUT MINES TELECOM TELECOM BRETAGNE
  • EP3767841B1 patent drawingFigure 1~3
  • EP3767841B1 patent drawingFigure 4~5
  • EP3767841B1 patent drawingFigure 6~7

AI summary

The embodiments of the invention provide an optical transmitter (11) for transmitting a vector of information symbols over an optical fiber transmission channel (13) made of a multi-core fiber, optical signals carrying said vector of information symbols propagating along the multi-core fiber according to two or more cores, wherein the optical transmitter (11) comprises a precoder (87) configured to determine a precoding matrix depending on one or more fiber parameters associated with said multi-core fiber and to precode said vector of information symbols by multiplying the vector of information symbols by said precoding matrix.