Echo Cancellation via Acoustic Playback Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Acoustic echo cancellation in electronic devices is compromised by imprecise time alignment between playback audio data and microphone audio data due to variable delays, clock jitter, and other nonlinearities, leading to distortion and signal degradation during communication sessions.
Innovation Solution
A system generates reference audio data by isolating portions of microphone audio data correlated with playback audio data, using beamforming techniques to achieve precise time alignment and improve echo cancellation, substituting microphone audio data for playback audio data when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional acoustic echo cancellation is used with playback audio data, then echo cancellation is performed, but time alignment is imprecise due to variable delays and clock jitter causing distortion and signal degradation
Solution Approach 1:
The patent creates a reference audio signal by copying and processing the playback audio data through a simulated acoustic path that includes variable delays and clock jitter. This reference signal serves as a template for identifying and removing echo components from the microphone audio data, achieving precise time alignment despite system nonlinearities
Solution Approach 2:
The patent introduces an intermediary reference audio signal that mediates between the playback audio data and the microphone audio data. This reference signal acts as a bridge that accounts for variable delays and clock jitter, enabling accurate echo cancellation without directly comparing the original playback data with microphone data
2Object-affected harmful factors
If playback audio data is used for echo cancellation, then echo removal is attempted, but variable delays and nonlinearities cause imprecise alignment and distortion
Solution Approach 1:
The patent performs preliminary processing of the playback audio data by passing it through a simulated acoustic path that introduces variable delays and clock jitter before creating the reference audio signal. This preliminary action pre-compensates for system nonlinearities, ensuring that the reference signal accurately reflects the actual acoustic conditions and enables precise echo cancellation
3Adaptability or versatility
If wireless connection is used for playback audio data transmission, then flexibility is improved, but variable delays and dropped packets cause time alignment issues
Solution Approach 1:
The patent employs feedback mechanisms that continuously monitor the timing characteristics of the wireless transmission and dynamically adjust the reference audio signal to compensate for variable delays and dropped packets. This feedback loop ensures that time alignment is maintained despite fluctuations in wireless transmission conditions
Data Source
AI summary
A system configured to improve echo cancellation for nonlinear systems. The system generate reference audio data by isolating portions of microphone audio data that correspond to playback audio data. For example, the system may determine a correlation between the playback audio data and the microphone audio data in individual time-frequency bands in a frequency domain. In some examples, the system may substitute microphone audio data associated with output audio for the playback audio data. The system may generate the reference audio data based on portions of the microphone audio data that have a strong correlation with the playback audio data. The system may generate the reference audio data by selecting these portions of the microphone audio data or by performing beamforming. This results in precise time alignment between the reference audio data and the microphone audio data, improving performance of the echo cancellation.