Acoustic Echo Cancellation Using Spatial Audio Components
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Solution Overview
Problem
Existing acoustic echo cancellation methods face performance degradation when using a large number of loudspeakers or high correlation between loudspeaker driving signals, particularly in multichannel audio systems, leading to undesirable fidelity loss.
Innovation Solution
A two-stage audio processing approach is employed, where a first stage generates a set of spatial audio components, which are further processed to obtain a second set of components for loudspeaker playback, and a spatial component combiner generates a deviated version of these components as a reference signal for echo cancellation, reducing computational complexity and improving suitability for adaptive filtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If loudspeaker driving signals are used as reference signal for echo cancellation, then echo cancellation can be performed, but performance degradation occurs when large number of loudspeakers are used or high correlation exists between loudspeaker driving signals
Solution Approach 1:
The audio processing is divided into two stages: first stage generates spatial audio components from multichannel audio signal, second stage processes these components to obtain final loudspeaker playback signals. The echo cancellation processor uses the first set of spatial audio components as reference signal instead of final loudspeaker signals, segmenting the reference signal generation process to avoid performance degradation.
Solution Approach 2:
The first set of spatial audio components acts as an intermediary signal between the multichannel audio input and the final loudspeaker playback. This intermediary signal is used as the reference signal for echo cancellation, providing a suitable reference that avoids the high correlation and performance degradation issues of direct loudspeaker driving signals.
2Reliability
If decorrelation methods are applied to reduce correlation between loudspeaker driving signals, then echo cancellation performance improves, but reproduction fidelity is reduced
Solution Approach 1:
The spatial audio components are generated in advance during the first stage of audio processing, before the final loudspeaker playback signals are created. These pre-generated spatial components are then used as the reference signal for echo cancellation, eliminating the need for post-processing decorrelation methods that would compromise reproduction fidelity.
3Reliability
If second set of spatial audio components (final playback signals) are used as reference signal, then echo cancellation can be performed, but computational complexity increases and suitability for adaptive filtering decreases
Solution Approach 1:
The echo cancellation processor uses only the first set of spatial audio components from the first processing stage, rather than processing through the complete two-stage pipeline to generate the second set of components. This partial action provides sufficient information for effective echo cancellation while reducing computational complexity and improving suitability for adaptive filtering.
Data Source
AI summary
An acoustic echo cancellation unit includes: an audio processor configured to receive a multichannel audio signal and including: a first stage which is configured to process the multichannel audio signal to obtain a first set of spatial audio components; and a second stage which is configured to process the first set of spatial audio components to obtain a second set of spatial audio components; an echo cancellation processor configured to perform echo cancellation by use of the first set of spatial audio components or a deviated version of the first set of spatial audio components as reference signal.