Multi-Channel Voice Detection With Interference Cancellation
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Solution Overview
Problem
In modern wireless speaker systems, voice commands are difficult to recognize due to interference from audio content, which existing systems address by filtering out audio signals, but this approach can be inefficient and complex, especially in multi-channel setups where multiple speakers interfere with each other's microphone signals.
Innovation Solution
A multichannel audio system with adaptive filters that use reference signals from each speaker to cancel interference, enhancing voice signal clarity by subtracting speaker output from microphone signals, and utilizing multicast packets to efficiently distribute necessary information for complete interference cancellation across all speakers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If audio content is filtered out from microphone signals in single-channel systems, then voice signal clarity is improved, but system complexity and processing overhead increase significantly in multi-channel setups
Solution Approach 1:
The system divides the multi-channel audio environment into separate reference signal sources from each speaker. Each speaker's output is captured as an individual reference channel, allowing independent interference cancellation processing for each speaker-microphone pair rather than attempting to filter all interference simultaneously in a complex single-stage process.
Solution Approach 2:
Reference signals from each speaker act as intermediaries that carry information about the speaker output. These reference signals are used by the adaptive filters to identify and cancel the corresponding speaker's interference from microphone signals, enabling precise removal of audio content interference without requiring complex direct filtering of the mixed signal.
2Productivity
If traditional filtering methods are used to remove audio content from microphone signals, then voice recognition is enabled, but network loading and processing efficiency deteriorate in multi-channel systems
Solution Approach 1:
The system performs preliminary capture of speaker reference signals before they interfere with microphone signals. By having each speaker transmit its output signal as a reference channel in advance, the system prepares the necessary information for interference cancellation beforehand, enabling efficient real-time processing without requiring heavy post-processing of mixed signals.
Solution Approach 2:
The system changes the approach from direct signal filtering to adaptive filtering using reference signals. This parameter change enables the use of least-mean-squares (LMS) adaptive filtering algorithms that can efficiently identify and cancel speaker interference based on reference signal correlations, reducing computational complexity and network loading compared to traditional filtering methods.
3Adaptability or versatility
If multiple speakers operate simultaneously in a multi-channel system, then audio content coverage is improved, but interference cancellation becomes increasingly complex and computationally intensive
Solution Approach 1:
The system segments the multi-speaker interference problem into individual speaker contributions. Each speaker's reference signal is processed independently through its own adaptive filter to cancel its specific interference from the microphone signal, breaking down the complex multi-speaker problem into manageable single-speaker cancellation tasks that can be combined.
Solution Approach 2:
The adaptive filtering mechanism serves as a universal solution that works for any number of speakers in the system. The same reference signal capture and adaptive filtering approach applies regardless of whether there is one speaker or multiple speakers, providing a scalable multi-functional architecture that handles varying numbers of simultaneous speakers without requiring fundamentally different processing approaches.
Data Source
AI summary
A multichannel audio system with a plurality of multichannel speakers having microphones, where the system receives audio signals from multichannel speakers, an adaptive filter enhances the voice signal portion of the audio signal by canceling interference in the audio signals by eliminating the portion of the audio signal matching reference signals, and processing the voice signal into voice commands.