Inter-Channel Delay Estimation with Adaptive Cross-Correlation Weighting

Solution Overview

Problem

Existing audio coding devices inaccurately estimate inter-channel time differences due to excessive or insufficient smoothing of cross-correlation values, affecting the encoding and decoding quality of multi-channel signals.

Innovation Solution

A delay estimation method that uses an adaptive window function to weight cross-correlation coefficients based on delay track estimation values and smoothed inter-channel time difference information, enhancing accuracy by adjusting the smoothing according to the proximity of cross-correlation values to the delay track.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a uniform standard smoothing factor is used for all cross-correlation values, then the processing is simple, but some cross-correlation values are excessively smoothed while others are insufficiently smoothed, reducing estimation accuracy

Engineering Contradiction:

Improvesmoothing processing simplicityVSAvoidinter-channel time difference estimation accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies different smoothing factors to different cross-correlation values based on their proximity to the delay track estimation value. Cross-correlation values closer to the delay track estimation value use a first smoothing factor, while those farther away use a second smoothing factor, achieving localized adaptive smoothing that improves estimation accuracy without excessive complexity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically adjusts the smoothing factor based on the distance between each cross-correlation value and the delay track estimation value. This dynamic adaptation allows the smoothing process to respond to local characteristics of the cross-correlation function, preventing both excessive and insufficient smoothing

Inventive Principle:

Principle #15Dynamics

2Stability of the object's composition

If excessive smoothing is applied to cross-correlation values, then the processing is robust, but the inter-channel time difference estimation becomes inaccurate

Engineering Contradiction:

Improvesmoothing robustnessVSAvoidinter-channel time difference estimation accuracy

Core Design Contradiction:

Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent applies different smoothing factors to different cross-correlation values based on their proximity to the delay track estimation value. Cross-correlation values closer to the delay track estimation value use a first smoothing factor, while those farther away use a second smoothing factor, achieving localized adaptive smoothing that improves estimation accuracy without excessive complexity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the smoothing parameter (smoothing factor) based on the distance between cross-correlation values and the delay track estimation value. By adjusting this parameter locally rather than using a fixed value, the system achieves both robustness and accuracy in the estimation process

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If insufficient smoothing is applied to cross-correlation values, then the inter-channel time difference estimation maintains detail, but the processing becomes sensitive to noise and inaccuracies

Engineering Contradiction:

Improvecross-correlation value detail preservationVSAvoidestimation stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies different smoothing factors to different cross-correlation values based on their proximity to the delay track estimation value. Cross-correlation values closer to the delay track estimation value use a first smoothing factor, while those farther away use a second smoothing factor, achieving localized adaptive smoothing that improves estimation accuracy without excessive complexity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the smoothing parameter (smoothing factor) based on the distance between cross-correlation values and the delay track estimation value. By adjusting this parameter locally rather than using a fixed value, the system achieves both robustness and accuracy in the estimation process

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20260089454A1Delay Estimation Method and Apparatus

Publication Date: 2026.03.26 HUAWEI TECH CO LTD

AI summary

A delay estimation method includes determining a cross-correlation coefficient of a multi-channel signal of a current frame, determining a delay track estimation value of the current frame based on buffered inter-channel time difference information of at least one past frame, determining an adaptive window function of the current frame, performing weighting on the cross-correlation coefficient based on the delay track estimation value of the current frame and the adaptive window function of the current frame, to obtain a weighted cross-correlation coefficient, and determining an inter-channel time difference of the current frame based on the weighted cross-correlation coefficient.