Audio Echo Cancellation Drift Compensation
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Solution Overview
Problem
Existing audio and video conferencing systems face challenges with acoustic echo cancellation due to variations in sampling frequencies across hardware and operating system components, leading to ineffective echo cancellation techniques despite accurate specifications.
Innovation Solution
The implementation of drift compensation and synchronization methods to adjust sampling frequencies and time alignment of audio signals, ensuring that far-end and near-end audio streams are sampled at the same frequency, facilitating accurate echo cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If software-based echo cancellation techniques are used, then echo cancellation functionality is provided, but the techniques fail to work well due to sampling frequency variations in real hardware systems
Solution Approach 1:
The patent applies parameter changes by detecting and compensating for sampling frequency drift in real-time. The system monitors actual sampling frequencies deviating from nominal values and adjusts the echo cancellation algorithm's expectations accordingly, allowing accurate echo cancellation despite hardware-induced frequency variations.
Solution Approach 2:
The patent implements feedback mechanisms where the system continuously monitors sampling frequency deviations and adjusts its operation accordingly. By comparing actual sampling frequencies against expected values and modifying echo cancellation parameters based on detected drift, the system maintains reliable performance under varying hardware conditions.
2Stability of the object's composition
If the same sampling frequency is specified throughout the system, then echo cancellation assumptions are met, but actual sampling frequencies vary due to hardware and operating system issues
Solution Approach 1:
The patent introduces dynamic adjustment capabilities to the echo cancellation system, allowing it to adapt sampling frequency expectations in real-time based on actual hardware behavior. This dynamic approach enables the system to maintain consistent effective sampling despite underlying hardware variations.
Solution Approach 2:
The patent replaces rigid mechanical assumptions about fixed sampling frequencies with a more flexible software-based detection and compensation mechanism. Instead of relying on hardware to maintain perfect frequency consistency, the system uses software algorithms to detect and correct for frequency variations.
3Measurement precision
If drift compensation and synchronization methods are implemented, then sampling frequency consistency is achieved, but system complexity increases
Solution Approach 1:
The patent implements self-service mechanisms where the system automatically detects and compensates for sampling frequency drift without requiring external intervention. The echo cancellation system monitors its own performance and adjusts itself, reducing the need for complex external synchronization hardware.
Solution Approach 2:
The patent designs a universal compensation mechanism that handles multiple types of sampling frequency deviations and synchronization issues through a single integrated approach, reducing overall system complexity compared to separate specialized solutions for each problem.
Data Source
AI summary
A new audio echo cancellation (AEC) approach is disclosed. To facilitate echo cancellation, the method adjusts for errors (called drift) in sampling rates for both capturing audio and playing audio. This ensures that the AEC module receives both the signals at precisely the same sampling frequency. Furthermore, the far-end signal and near-end mixed signal are time aligned to ensure that the alignment is suitable for application of AEC techniques. An additional enhancement to reduce errors utilizes a concept of native frequency. A by-product of drift compensation allows for excellent buffer control for capture/playback and buffer overflow/underflow errors from drift errors are eliminated.