BYOD Acoustic Echo Cancellation via Distributed Timing Sync
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Acoustic echo cancellation in video conferencing systems with Bring Your Own Devices (BYODs) is challenging due to dynamic changes in the number of devices, varying network delays, and differing microphone and speaker sampling clocks, which can overwhelm the audio system's computation power.
Innovation Solution
A conference system controller synchronizes timing information with BYODs through a network timing protocol, enabling each BYOD to perform local acoustic echo cancellation, reducing the computational burden on the system and ensuring accurate alignment of microphone and speaker signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acoustic echo cancellation is performed for both array microphones and BYOD microphones centrally in the audio system, then echo cancellation effectiveness is improved, but computation power requirement increases beyond system capacity
Solution Approach 1:
The patent divides the echo cancellation computation into two segments: (1) BYOD devices perform self-echo cancellation on their own microphone signals using their local processors, and (2) the audio system performs echo cancellation only on the combined signals from array microphones. This segmentation distributes the computational burden, allowing effective echo cancellation without overwhelming the audio system's processing capacity.
2Adaptability or versatility
If multiple BYODs with different network delays and sampling clocks are connected, then system adaptability is improved, but signal alignment accuracy deteriorates
Solution Approach 1:
The patent applies preliminary timing adjustment to align the sampling clocks of multiple BYOD devices and the audio system before echo cancellation processing. Each BYOD device's microphone signal is resampled or buffered to synchronize with the audio system's master clock, ensuring accurate signal alignment despite varying network delays and different native sampling rates.
3Adaptability or versatility
If the number of BYODs changes dynamically during a meeting, then system flexibility is improved, but computation power fluctuation increases
Solution Approach 1:
The patent implements self-service echo cancellation where each BYOD device independently performs echo cancellation on its own microphone signal using its local processor. This eliminates the need for the audio system to dynamically adjust computation resources when devices join or leave, as each device handles its own processing requirements independently, resulting in stable overall system computation power consumption.
Data Source
AI summary
A controller for the conference session generates a speaker signal for speakers in a conference room. The controller correlates the speaker signal with network timing information and generates speaker timing information. The controller transmits the correlated speaker signal and timing information to a mobile device participating in the conference session. The mobile device generates an echo cancelled microphone signal from a microphone of the mobile device, and transmits the echo cancelled signal back to the controller. The controller also receives array microphone signals associated with an array of microphones at known positions in the room. The controller estimates a relative location of the mobile device within the conference room. The controller dynamically selects as audio output corresponding to the mobile device location either the echo cancelled microphone signal from the mobile device or an echo cancelled array microphone signal associated with the relative location of the mobile device.