Adaptive Equalizer Tap Coefficient Centering

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Solution Overview

Problem

In high-speed optical transmission systems, the adaptive equalizer's tap coefficients can deviate from their center position due to time-varying channel impairments, leading to increased error rates and unstable system operation, as existing methods risk moving the tap coefficient with the second largest energy out of bounds or causing it to recur at the boundaries, resulting in decreased filter performance.

Innovation Solution

A method and device that adjust the center position of tap coefficients by acquiring energy at each boundary, calculating a total energy amount, setting proportionality coefficients, comparing energies, and adjusting the center position based on these calculations to prevent tap coefficients with greater energy from being moved out of bounds and to avoid recurrence, ensuring stable filter performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the tap coefficient with the largest energy is moved to the center position, then the center position adjustment is achieved, but the tap coefficient with the second largest energy may be moved out of bounds or recur at boundaries, causing filter performance degradation

Engineering Contradiction:
Improvecenter position accuracyVSAvoidfilter performance stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies local quality by differentiating the treatment of tap coefficients based on their energy levels. High-energy tap coefficients are prioritized for centering while low-energy coefficients are protected from boundary movements. The adjustment mechanism selectively applies different operations (centering vs. boundary protection) to different regions of the tap coefficient spectrum, ensuring that only coefficients that would benefit from centering are moved, while others remain stable.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements preliminary action by performing energy level assessment and boundary condition checks before executing the centering operation. The system预先 identifies which tap coefficients are high-energy and would benefit from centering, and which are low-energy and should be protected. This preliminary classification prevents harmful movements before they occur, maintaining filter performance stability.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the tap coefficients are adjusted to track channel characteristics, then the adaptive equalization performance is improved, but the system error rate increases sharply when coefficients deviate to boundaries

Engineering Contradiction:
Improvechannel tracking capabilityVSAvoidsystem error rate
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent employs feedback mechanisms by continuously monitoring the energy levels of tap coefficients and their positions within the coefficient queue. The system uses this feedback to dynamically adjust the centering operation, ensuring that coefficients remain in optimal positions for channel tracking while preventing boundary deviations that would cause error rate increases. The feedback loop maintains the balance between adaptability and reliability.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If the center position is adjusted frequently to track time-varying channels, then the adaptability is improved, but the filter performance becomes unstable due to coefficient oscillation

Engineering Contradiction:
Improvetime-varying channel trackingVSAvoidfilter performance stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies partial action by performing centering adjustments only when necessary - specifically, only for high-energy tap coefficients that have deviated from their optimal positions. The system avoids excessive centering operations on low-energy coefficients that would cause unnecessary oscillation and performance instability. This selective partial adjustment maintains stability while providing sufficient adaptability for time-varying channels.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3509257B1Tap coefficient adjustment method and device, and computer storage medium
Publication Date: 2021.11.17 SANECHIPS TECH CO LTD
  • EP3509257B1 patent drawingFigure 1~2
  • EP3509257B1 patent drawingFigure 3~4
  • EP3509257B1 patent drawingFigure 5~6

AI summary

The present invention provides a tap coefficient adjustment method. The adjustment method includes: acquiring energy of T+1 tap coefficients at each boundary in a tap coefficient queue of tap coefficients of an adaptive equalizer, and calculating a total amount of energy of the tap coefficients in the tap coefficient queue; setting a proportionality coefficient corresponding to each boundary based on the number T+1 of tap coefficients at the each boundary, and calculating a product of the total amount of energy and the proportionality coefficient corresponding to each boundary; comparing energy of each of T+1 tap coefficients at a first boundary with the product corresponding to the first boundary, comparing a total amount of energy of T tap coefficients at a second boundary with the product corresponding to the second boundary, comparing energy of a (T+1)-th tap coefficient from the second boundary with the product corresponding to the second boundary, and generating a comparison result; and adjusting a center position in the tap coefficients according to the comparison result. The present invention further provides a tap coefficient adjustment device and a computer storage medium.