Echo Compensation Using Whitening Filters and Channel Segmentation

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Solution Overview

Problem

Vehicle communication systems face challenges in effectively compensating audio signal components due to noise, echoes, and reverberations, especially in surround sound modes, where existing echo compensation methods require high computational power and struggle with adapting to changes in audio signal characteristics, leading to suboptimal sound quality.

Innovation Solution

An echo compensation system using a combination of mono and multi-channel echo compensation units, time-dependent filter coefficients, and a dual echo compensation structure, which includes whitening filters, inverse filters, and adaptive algorithms to simulate the signal path and suppress audio signal components with variable time delays, allowing for effective echo compensation across different audio scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a long filter is used for echo compensation in surround sound mode, then echo compensation accuracy is improved, but computational power requirements increase

Engineering Contradiction:
Improveecho compensation accuracyVSAvoidcomputational power requirements
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The echo compensation filter is divided into multiple sub-filters corresponding to different audio channels. Each sub-filter processes a specific channel independently, allowing parallel computation that reduces overall computational burden while maintaining the effectiveness of long filter lengths for accurate echo compensation in surround sound mode.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts filter parameters and computation depth based on the detected audio mode (stereo vs. surround sound). In surround sound mode, the full-length filters are activated for high accuracy, while in stereo mode, simplified processing is used to reduce computational power consumption.

Inventive Principle:
Principle #15Dynamics

2Reliability

If echo compensation processing is applied to all audio modes, then sound quality is improved, but computational complexity increases

Engineering Contradiction:
Improvesound qualityVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The echo compensation system dynamically adapts its processing complexity based on the audio mode. In surround sound mode, full echo compensation with long filters is applied for high sound quality. In stereo mode, the system switches to a simplified processing path with reduced computational complexity, maintaining acceptable sound quality while reducing the burden on processing resources.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes key processing parameters such as filter length and processing depth according to the audio mode. This allows the same hardware to deliver high sound quality for surround sound while consuming fewer computational resources for stereo audio, effectively resolving the contradiction between quality and complexity.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If adaptive filters with long length are used for echo compensation, then echo suppression effectiveness is improved, but adaptation time increases

Engineering Contradiction:
Improveecho suppression effectivenessVSAvoidadaptation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The adaptive filter is segmented into multiple independent sub-filters for different audio channels. Each sub-filter can adapt independently and in parallel, which maintains the echo suppression effectiveness of long filters while reducing the overall adaptation time through concurrent processing of multiple channels.

Inventive Principle:
Principle #1Segmentation

4Measurement precision

If echo compensation is applied in surround sound mode with variable time delays, then echo accuracy is improved, but system complexity increases

Engineering Contradiction:
Improveecho accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The echo compensation system is segmented into separate processing paths for different audio channels, each with its own adaptive filter. This segmentation allows the system to handle variable time delays specific to each surround sound channel independently, improving echo accuracy for each channel while managing overall system complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS9111544B2Mono and multi-channel echo compensation from selective output
Publication Date: 2015.08.18 CERENCE OPERATING CO
  • US9111544B2 patent drawing
  • US9111544B2 patent drawing
  • US9111544B2 patent drawing

AI summary

A system and method for compensating audio signal components is disclosed. The method includes detecting, by a microphone, a sound signal. The sound signal comprises audio signal components resulting from reproducing an audio signal of an audio source and speech signal components corresponding to a speech signal from a person. The sound signal is filtered to whiten the sound signal. The audio signal components in the whitened sound signal are then compensated. The whitening of the compensated sound signal is removed. The filtering of the audio signal is performed using at least two filters in an alternating way, each filter using time-dependent filter coefficients.