Adaptive ANC Duty Cycle Control for Power Reduction
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Solution Overview
Problem
Existing active noise cancellation (ANC) systems in portable devices consume excessive processing resources and power due to constant processing of input frames, even when significant acoustic changes occur infrequently.
Innovation Solution
Adaptive ANC processing is modified to occur on a subset of input frames based on the difference between filter parameters, adjusting the duty cycle to conserve power and resources by discarding or processing frames accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If adaptive ANC processing is performed on each input frame at a constant rate, then fast adaptation to acoustic changes is achieved, but power consumption and processing resources increase significantly
Solution Approach 1:
The system dynamically adjusts the processing rate of adaptive ANC based on the detected acoustic change rate. When acoustic changes are detected (through analyzing filter parameter differences between frames), the system increases the processing rate to maintain fast adaptation. When acoustic changes are minimal, the system reduces the processing rate to conserve power, thus making the adaptation speed dynamic rather than constant.
Solution Approach 2:
The system changes the processing parameter (frame processing rate) based on the acoustic environment. By monitoring the difference in filter parameters between consecutive frames, the system determines whether to process each frame or skip frames, effectively changing the processing rate parameter to optimize between adaptation speed and power consumption.
2Use of energy by moving object
If adaptive ANC processing is performed on a subset of input frames to reduce power consumption, then battery life is improved, but adaptation speed may be reduced
Solution Approach 1:
The system uses feedback from the acoustic environment monitoring to control the processing rate. By continuously analyzing the difference between filter parameters of consecutive frames, the system receives feedback about the acoustic change rate and adjusts the frame processing subset accordingly, ensuring adaptation speed is maintained when needed while saving power when possible.
Solution Approach 2:
The processing rate is made dynamic by adjusting the subset of frames processed based on real-time acoustic conditions. The system transitions between different processing modes (processing every frame vs. processing subset of frames) depending on whether acoustic changes are detected, optimizing the balance between power consumption and adaptation speed.
3Use of energy by moving object
If the duty cycle of adaptive ANC processing is adjusted based on acoustic change rate, then power consumption is reduced, but system complexity increases
Solution Approach 1:
The system performs self-service by automatically detecting acoustic changes through filter parameter analysis and autonomously adjusting its own processing rate. The ANC system monitors its own filter parameter differences and uses this information to control when to process frames, eliminating the need for external control mechanisms and reducing overall system complexity despite the adaptive behavior.
Data Source
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AI summary
A method of audio signal processing includes determining a difference between a first set of filter parameters of a first input frame of an active noise cancellation (ANC) filter and a second set of filter parameters of a second input frame of the ANC filter. The method further includes selectively modifying a duty cycle of adaptive ANC processing associated with the ANC filter based on the difference between the first set of filter parameters and the second set of filter parameters.