Microphone Array Echo Cancellation Linear Phase Compatibility

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing two-way communication systems face challenges in integrating residual echo suppression and center clipping with sound source localization and microphone array processing due to non-linear phase effects, which adversely affect the performance of subsequent processes.

Innovation Solution

Alternative architectures are proposed that separate non-linear phase processes from linear phase processes, such as using a beam forming type microphone array process and modifying residual echo suppression and center clipping processes to ensure linear phase compatibility, allowing for effective integration with sound source localization and microphone arrays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If residual echo suppression and center clipping processes are integrated with sound source localization and microphone array processing, then echo and noise reduction is improved, but non-linear phase effects adversely affect the performance of subsequent processes

Engineering Contradiction:

Improveecho and noiseVSAvoidperformance of sound source localization and microphone array processes

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The system separates echo suppression processing into independent residual echo suppression (RES) and center clipping (CC) modules that operate before the microphone array process. This segmentation allows each module to handle specific aspects of echo reduction while maintaining compatibility with subsequent sound source localization and beamforming operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An intermediary processing stage is introduced between the echo cancellation and microphone array processes. This intermediary stage includes the RES and CC modules that prepare the signal in a way that is compatible with the linear phase requirements of the microphone array process, acting as a bridge between non-linear echo suppression and linear beamforming operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If non-linear phase processes are used for echo suppression, then echo reduction is achieved, but the linear phase compatibility required for microphone array processes is compromised

Engineering Contradiction:

ImproveechoVSAvoidlinear phase compatibility

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The system changes the parameters of the echo suppression processes by implementing RES and CC in a manner that preserves linear phase characteristics. This is achieved by carefully designing the filtering and signal processing operations to maintain phase linearity, thereby enabling compatibility with subsequent microphone array operations that require linear phase input.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7773743B2Integration of a microphone array with acoustic echo cancellation and residual echo suppression

Publication Date: 2010.08.10 MICROSOFT TECHNOLOGY LICENSING LLC

AI summary

Acoustic echo cancellation, residual echo suppression and sound-source localization/microphone array processes are combined in a two-way voice communication system that uses a microphone array to capture local speech. The processes can be configured according to various alternative architectures and enhancements made to the processes to avoid the adverse effects of non-linear operations in the residual echo suppression on the sound-source localization/microphone array process.