Far-Field Pickup Device Echo Cancellation via Modular Segmentation
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Solution Overview
Problem
Far-field pickup devices face challenges in synchronizing sound signals and echo reference signals, leading to decreased speech recognition performance due to echo clipping, saturation, and interference noise, especially when the microphone and horn are integrated closely and the user is far away.
Innovation Solution
A far-field pickup device with a microphone unit that transmits digital signals to a device body, which generates a synchronizing signal in a different frequency band, determines the time delay between the signal and echo, and performs echo cancellation using the delayed sound signal to improve speech recognition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the microphone and horn are integrated closely on the main body, then the device structure is compact and simple, but the echo signal becomes clipped and saturated causing significant decrease in echo cancellation performance
Solution Approach 1:
The patent divides the device into two separate functional modules: a sound output module (horn) and a sound collection module (microphone pickup unit). This segmentation allows the horn and microphone to be spatially separated, preventing echo clipping while maintaining compact overall device structure through modular design.
2Reliability
If the microphone is placed far from the horn, then echo clipping and saturation are reduced, but the user is far away from the microphone causing low input signal quality and decreased speech recognition performance
Solution Approach 1:
The patent resolves the spatial conflict by transitioning from a single-location constraint to a multi-dimensional arrangement. The microphone pickup unit can be positioned at an optimal distance from the horn while the user interacts with the device from a different spatial position, allowing both echo cancellation and speech recognition requirements to be satisfied simultaneously.
3Reliability
If the microphone pickup unit transmits sound signals wirelessly to the main body, then the distance between microphone and horn can be increased to reduce echo clipping, but the sound signal and echo reference signal cannot be synchronized decreasing application performance
Solution Approach 1:
The patent implements a feedback mechanism where the sound signal transmitted from the microphone pickup unit is used to generate an echo reference signal in the main body. This feedback loop ensures that the echo reference signal accurately reflects the actual sound signal received, enabling precise echo cancellation even when the microphone is positioned at an optimal distance from the horn.
4Device complexity
If the horn and microphone are integrated on the main body, then the device is compact, but when the user is far away the interference noise in the environment is large causing low input signal noise and decreased speech recognition performance
Solution Approach 1:
The patent introduces a separate microphone pickup unit as an intermediary between the user and the main body. This intermediary can be positioned closer to the user while the main body remains compact, effectively isolating the microphone from environmental interference noise while maintaining the integrated device structure.
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 solution enhances speech recognition performance by preventing echo clipping and saturation, improving noise cancellation, and ensuring accurate synchronization of sound signals, even when the user is far from the microphone.
Implementation Method 1
a microphone pickup unit including at least one microphone, the at least one microphone configured to collect user speech and an echo of a first sound signal output by the device body, and the microphone pickup unit configured to transmit, to the device body, a signal obtained through digital conversion of the collected user speech and the echo
Data Source
AI summary
A far-field pickup device including a device body and a microphone pickup unit is provided. The microphone pickup unit is configured to collect user speech and an echo of a first sound signal output by the device body, and transmit, to the device body, a signal obtained through digital conversion of the collected user speech and the echo. The device body includes a signal playback source, a synchronizing signal generator, a horn, a delay determining unit, and an echo cancellation unit configured to perform echo cancellation on the signal transmitted by the microphone pickup unit to obtain a collected human voice signal.