Beamformer Time Delay Determination via Deviation Thresholds
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Solution Overview
Problem
Existing beamformer systems require frequent recalculations of time delays to align with moving sound sources, leading to computational inefficiencies and impaired signal quality due to frequent re-adaptation of adaptive systems.
Innovation Solution
A method that determines time delays for microphone signals in a beamformer arrangement by checking if the instantaneous estimate of a sound source's position or direction of arrival deviates from a preset estimate by a predetermined threshold, allowing for less frequent recalculations and reducing the need for adaptive system re-adaptation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequent recalculations of time delays are performed to align with moving sound sources, then the alignment accuracy with the sound source is improved, but the computational efficiency deteriorates
Solution Approach 1:
The system dynamically adjusts the recalculation frequency of time delays based on the movement characteristics of the sound source. Instead of fixed frequent recalculations, the system calculates time delays only when the sound source position changes significantly, optimizing the balance between alignment accuracy and computational efficiency.
Solution Approach 2:
The invention changes the parameter of time delay recalculation from a fixed frequent schedule to a variable schedule based on position deviation thresholds. When the instantaneous position estimate deviates from the preset estimate beyond a threshold, recalculation is triggered; otherwise, the previous values are maintained, reducing unnecessary computations.
2Measurement precision
If frequent recalculations of time delays are performed, then the alignment with the sound source is improved, but the signal quality stability deteriorates due to frequent re-adaptation
Solution Approach 1:
The system dynamically determines when to recalculate time delays based on actual sound source movement rather than following a fixed schedule. This dynamic approach prevents frequent re-adaptation of the beamformer, thereby maintaining signal quality stability while still responding to genuine position changes.
Solution Approach 2:
The system uses position deviation thresholds as a preliminary filter to prevent unnecessary time delay recalculations. By checking whether the instantaneous position estimate deviates beyond the threshold before triggering recalculation, the system avoids the harmful effect of frequent re-adaptation that would destabilize signal quality.
3Speed
If time delay recalculation is performed at every time step, then the responsiveness to sound source movement is improved, but the computational cost increases
Solution Approach 1:
The invention changes the parameter of recalculation timing from continuous (every time step) to event-driven (only when position deviation exceeds threshold). This maintains responsiveness to actual sound source movement while dramatically reducing computational cost by eliminating recalculations during periods of stable position.
Solution Approach 2:
Instead of continuous periodic recalculation at every time step, the system implements conditional periodic action where recalculation occurs only when necessary (when position deviation threshold is exceeded). This reduces computational cost while maintaining appropriate responsiveness to sound source movement.
Data Source
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AI summary
The invention provides a method for determining a time delay for time delay compensation of a microphone signal from a microphone array in a beamformer arrangement, comprising the steps of: determining, for a given time, an instantaneous estimate of a position of a wanted sound source and/or of a direction of arrival of a signal originating from the wanted sound source, determining whether the instantaneous estimate deviates from a preset estimate of a position of the wanted sound source and/or of a direction of arrival of a signal originating from the wanted sound source according to a predetermined criterion, wherein the predetermined criterion comprises a check whether the instantaneous estimate deviates from the preset estimate by at least a predetermined deviation threshold, and if the predetermined criterion is fulfilled: setting the instantaneous estimate for the given time as the preset estimate, and determining the time delay for time delay compensation of the microphone signal based on the instantaneous estimate.