Partitioned Block Frequency Domain Adaptive Filter Device Comprising Adaptation Modules and Correction Modules

Simple SummaryContent extracted from patent full text and abstract with AI.

This invention describes a partitioned block frequency domain adaptive filter device designed to process signals—such as audio signals—by efficiently updating filter coefficients in the frequency domain. The core innovation involves breaking the adaptive filter into separate blocks and applying a novel two-stage adaptation and correction process, using simplified (lower-complexity) mathematical operations to approximate and then accurately correct filter updates. This approach significantly lowers computational complexity while maintaining high performance, particularly for applications like echo cancellation.

Use CasesContent extracted from patent full text and abstract with AI.

• Acoustic echo cancellation in telecommunication devices (e.g. hands-free calls, conferencing systems)
• Noise reduction in audio recording or speech processing systems
• System identification tasks in control systems
• Channel equalization in wireless or wired communication systems
• Real-time digital signal processing in consumer electronic devices
• Hearing aids and audio enhancement systems
• Voice recognition and smart assistant devices

BenefitsContent extracted from patent full text and abstract with AI.

• Significantly reduces computational complexity and processing time compared to traditional methods.
• Maintains high adaptation accuracy and fast convergence, even with simplifications in processing.
• Highly flexible—filter block size and correction intervals can be adjusted dynamically for different environments or performance needs.
• Enables fully parallelizable processing, making it ideal for modern hardware and multi-threaded implementations.
• Improves power efficiency, suitable for battery-operated or embedded devices.
• Can be adapted and expanded for a variety of signal processing applications beyond echo cancellation.

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Patent Abstract

Partitioned block frequency domain adaptive filter device comprising: a frequency domain adaptive filter configured for filtering a frequency domain representation of a time domain input signal depending on a set of filter coefficients consisting of a plurality of blocks of filter coefficients in order to produce a filtered signal; a plurality of parallel arranged filter update blocks, each of the filter update blocks being configured for updating one of the blocks of filter coefficients based on an update signal gathered by a circular correlation of a block of the frequency domain representation signal and a frequency domain control signal comprising a representation of the filtered signal; wherein each of the filter update blocks comprises an adaptation module configured for executing an adaptation sequence comprising the steps of calculating an approximation of a constrained gradient update for the filter coefficients of the respective block of filter coefficients by applying an approximated constraining matrix having a lesser complexity than a constraining matrix to an unconstrained gradient update for the filter coefficients of the respective block of filter coefficients, wherein the unconstrained gradient update is derived from the update signal, and calculating a cumulative error introduced on the unconstrained gradient update by applying the approximated constraining matrix to the unconstrained gradient update; wherein each of the filter update blocks comprises a correction module configured for executing a correction sequence comprising the steps of calculating a corrected constrained gradient update for the filter coefficients of the respective block of filter coefficients by applying the frequency domain constraining matrix to a sum of the approximation of the constrained gradient update and the cumulative error.