Echo Cancellation Using Digital Reference Signal
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Solution Overview
Problem
Existing echo cancellation techniques in voice interaction systems, particularly in smart speakers, face limitations due to the inability to accurately extract echo reference signals, leading to suboptimal performance in recognizing user voice commands amidst played audio echoes.
Innovation Solution
An electronic device with an improved echo cancellation method that includes a loudspeaker, microphone, analog-to-digital converter, and echo canceller, where the analog audio signal is converted into a digital echo reference signal to approximate the audio signal played, enabling effective echo cancellation through adaptive filtering and non-linear processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional echo cancellation techniques are used, then the system can perform basic echo cancellation, but the echo reference signal extraction is inaccurate leading to poor user voice recognition performance
Solution Approach 1:
The patent uses a copy of the original audio signal (played through the loudspeaker) as the echo reference signal. The audio signal is captured from the loudspeaker output, converted to digital format, and used as a reference template for echo cancellation, enabling accurate extraction and subtraction of echo components from the mixed audio signal.
Solution Approach 2:
The patent introduces an intermediary processing chain between the audio signal generation and echo cancellation. The audio signal passes through the loudspeaker, is captured by the microphone, converted to digital signal, and then processed through the echo canceller using the extracted reference signal. This intermediary processing enables accurate echo separation.
2Ease of operation
If the microphone collects both played audio and user voice, then the system can capture user commands, but the mixed acoustic signal makes voice recognition difficult
Solution Approach 1:
The patent extracts and removes the echo component from the mixed acoustic signal using adaptive filtering. The echo reference signal is used to generate an estimated echo signal that is subtracted from the mixed signal, effectively taking out the harmful echo information while preserving the user voice signal for accurate recognition.
Solution Approach 2:
The patent converts the harmful echo signal into a useful reference for cancellation. By capturing the played audio signal and using it as a reference template, the system can accurately model and subtract the echo, transforming the problematic echo into a tool for improving voice recognition accuracy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances echo cancellation performance, allowing for better recognition of user voice commands and improving the overall voice interaction experience by accurately isolating user audio signals from mixed acoustic signals.
Implementation Method 1
a loudspeaker which is configured to play an acoustic signal corresponding to an analog audio signal
Implementation Method 2
a microphone which is configured to convert a mixed acoustic signal received into a mixed audio signal
Implementation Method 3
an analog-to-digital convertor which is configured to convert the analog audio signal into a digital signal as an echo reference signal
Data Source
AI summary
Embodiments of the present disclosure provide a method and a device for cancelling an echo, and a computer readable storage medium. The device includes a loudspeaker configured to play an acoustic signal corresponding to an analog audio signal. The device further includes a microphone configured to convert a mixed acoustic signal received into a mixed audio signal. The mixed acoustic signal includes an echo of the acoustic signal played and an acoustic signal from a user. The device further includes an analog-to-digital converter configured to convert the analog audio signal into a digital signal as an echo reference signal. The device further includes an echo canceller, configured to cancel an echo component from the mixed audio signal using the echo reference signal to obtain a user audio signal corresponding to the acoustic signal from the user.