Distributed Echo Cancellation via Synchronized Audio Signals
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Solution Overview
Problem
During Voice over Internet Protocol (VoIP) communication sessions, acoustic coupling between devices leads to feedback echo and artifacts, degrading audio quality and user experience due to the inability to effectively synchronize and cancel echo signals in real-time.
Innovation Solution
Implementing a distributed echo cancellation system that synchronizes microphone audio signals across devices and establishes bidirectional feedback links to generate a mixed microphone audio signal, allowing each device to perform echo cancellation using synchronized audio data, thereby reducing echo and improving audio quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acoustic coupling between devices is utilized for VoIP communication, then communication functionality is enabled, but feedback echo and artifacts occur degrading audio quality
Solution Approach 1:
The patent implements feedback links that transmit microphone audio signals between devices, enabling each device to receive and process the other's microphone signal. This feedback mechanism allows distributed echo cancellation by providing the necessary information to identify and remove echo components from the audio stream, directly addressing the feedback echo problem while maintaining communication functionality
Solution Approach 2:
The patent introduces synchronized microphone audio signals as an intermediary element that mediates between the acoustic coupling and the echo cancellation process. By synchronizing and transmitting these reference signals between devices, the system creates a bridge that enables each device to calculate and remove echo components without directly processing the problematic acoustic feedback loop
2Object-generated harmful factors
If echo cancellation is performed using traditional centralized methods, then echo reduction is achieved, but system complexity and synchronization requirements increase
Solution Approach 1:
The patent divides the echo cancellation function into distributed segments, where each device independently performs echo cancellation for its own outgoing audio stream. Instead of one device handling all echo cancellation centrally, the system segments the processing task across multiple devices, reducing the complexity and synchronization burden on any single device while maintaining effective echo reduction
Solution Approach 2:
Each device performs self-service echo cancellation by using its own outgoing audio signal and the received synchronized microphone signal from the other device to cancel echo in its incoming audio stream. This self-service approach eliminates the need for complex centralized coordination and synchronization, as each device independently manages its own echo cancellation process
Data Source
AI summary
A system configured to perform distributed echo cancellation processing to attenuate feedback echo from occurring when two devices are acoustically coupled during a communication session. To reduce the feedback echo, one of the devices is configured as a hub device and receives microphone signals, synchronizes the microphone signals, and generates a mixed microphone signal. To enable distributed echo cancellation, the system includes bidirectional feedback link(s) between the hub device and each device synchronized with the hub device. For example, a first bidirectional feedback link sends a microphone signal from a second device to the hub device and sends the mixed microphone signal from the hub device to the second device, which the second device uses to perform echo cancellation. In addition, a second bidirectional feedback link sends a playback signal from the hub device to the second device and sends the output of echo cancellation back to the hub device.