Wireless Audio Playback Clock Drift Compensation
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Solution Overview
Problem
Achieving high audio quality in an environment is challenging due to improper placement of acoustic sources and listener positioning, leading to degraded acoustic quality and user satisfaction.
Innovation Solution
A coordination technique that adjusts electronic device clocks to synchronize playback operations within a predefined value, eliminating timing drift and facilitating surround sound or multi-channel sound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If wireless communication is used to transmit audio packets between devices, then device placement flexibility is improved, but timing synchronization deteriorates due to clock drift
Solution Approach 1:
The system continuously monitors timing differences between transmit and receive clocks by comparing timestamps in wireless packets. This feedback mechanism detects clock drift and enables dynamic adjustment of playback timing to maintain synchronization despite wireless transmission variations
Solution Approach 2:
The system dynamically adjusts the playback time parameter based on measured clock drift. By modifying the playback timestamp according to observed timing differences, the system compensates for clock drift and maintains precise timing synchronization in the wireless audio system
2Reliability
If clock adjustment is made to synchronize playback, then audio quality is improved, but system complexity increases
Solution Approach 1:
Each device in the wireless audio system autonomously monitors its own clock drift and adjusts its playback timing independently. The receiving device calculates timing corrections based on received timestamps and automatically modifies its playback schedule, eliminating the need for complex external synchronization control
3Manufacturing precision
If playback timing is modified to compensate for clock drift, then synchronization is improved, but timing precision deteriorates due to cumulative errors
Solution Approach 1:
The system performs preliminary clock synchronization by exchanging timing packets before actual audio playback begins. This preliminary timing alignment establishes an accurate baseline relationship between clocks, reducing cumulative timing errors during the subsequent audio reproduction phase
Data Source
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AI summary
An electronic device that coordinates a playback operation is described. In particular, an interface circuit in the electronic device may calculate, based on differences between transmit times when packets were transmitted by a second electronic device and receive times of the packets, relative drift as a function of time between a clock in the interface circuit and a second clock in the second electronic device. Then, the interface circuit may adjust, based on the relative drift, a clock circuit that provides the clock to eliminate the relative drift, and may determine a remaining time offset between the clock and the second clock. Next, the interface circuit may modify a future time when the electronic device is to perform the playback operation based on the remaining time offset to determine a corrected future time, and the electronic device may perform the playback operation at the corrected future time.