Audio Signal Processing Echo Cancellation Beamformer Output
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Solution Overview
Problem
Existing systems face challenges in implementing both beamforming and echo cancellation simultaneously without compromising the performance of either technology, as they require complex computational processes and restrictive conditions on the beamformer's behavior.
Innovation Solution
A method that applies echo cancellation to the output of a beamformer, measuring the echo path gain from the strongest microphone signal and controlling the level of echo suppression based on this measurement, allowing for flexible beamformer behavior and reducing computational complexity by using a single echo canceller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If echo cancellation is applied to each microphone signal before beamforming, then echo suppression is achieved, but computational complexity increases significantly
Solution Approach 1:
The patent merges the echo cancellation operations by applying a single echo canceller to the beamformer output rather than implementing separate echo cancellers for each microphone signal. This consolidation reduces computational complexity while maintaining effective echo suppression through the combined signal processing approach.
2Device complexity
If echo canceller is applied to beamformer output, then computational complexity is reduced, but beamformer behavior must be slowly varying
Solution Approach 1:
The patent inverts the conventional processing order by applying the echo canceller after the beamformer rather than before it. This reversal allows the beamformer to operate with full adaptability and non-linear behavior without constraints, while the subsequent echo canceller handles echo suppression on the already-beamformed signal.
3Object-affected harmful factors
If beamforming and echo cancellation are implemented together, then both functions are achieved, but restrictive conditions are imposed on beamformer behavior
Solution Approach 1:
The patent removes restrictive conditions on beamformer behavior by inverting the processing order - applying the echo canceller after the beamformer. This allows the beamformer to operate freely with any behavior (linear or non-linear, adaptive or fixed) while the downstream echo canceller handles echo suppression without being affected by beamformer constraints.
Data Source
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AI summary
Method, device and computer program product for processing audio signals at the device, the device comprising audio output means for outputting audio signals. Audio signals are received at a plurality of microphones of the device. A characteristic of at least one of the audio signals received by the plurality of microphones is measured. A beamformer applies beamformer coefficients to the received audio signals, thereby generating a beamformer output. Echo cancelling means are applied to the beamformer output, thereby suppressing, from the beamformer output, an echo resulting from audio signals output from the audio output means, wherein an operating parameter of the echo cancelling means is controlled based on the measured characteristic of the at least one of the audio signals received by the plurality of microphones.