Adaptive estimation and compensation of clock drift in acoustic echo cancellers

A method implemented by a processor executing instructions stored in computer-readable storage media, the method comprising:

• receiving capture position information;
• receiving render position information, the render position information including a render read pointer and a render write pointer;
• calculating a render offset;
• calculating, by the processor, a raw error by comparing an actual difference between the render read pointer and the render write pointer with the calculated render offset;
• adjusting the render read pointer by adding an error value based upon the raw error to the render read pointer so that render data processed by an acoustic echo cancellation (AEC) component stays aligned in time with capture data processed by the AEC component to perform acoustic echo cancellation of the capture data using the render data;
• and
• employing the adjusted render read pointer and capture read pointer for acoustic echo cancellation.

A system, comprising:

• a render device having a digital-to-analog converter driven by a first clock signal;
• a capture device having an analog-to-digital converter driven by a second clock signal, wherein the second clock signal runs at a different rate than the first clock signal;
• an acoustic echo cancellation (AEC) component for controlling an acoustic echo;
• a capture buffer for buffering capture data received from the capture device according to the second clock signal, the capture buffer having a capture write pointer and a capture read pointer;
• a render buffer for buffering render data consumed by the render device according to the first clock signal, the render buffer having a render write pointer and a render read pointer;
• and
• a clock drift compensator implemented by a processor executing instructions stored in computer-readable storage media, the clock drift compensator compensating for clock drift between the first clock signal and the second clock signal by adjusting the render read pointer, wherein the render read pointer is adjusted by adding an error value to the render read pointer,
• wherein the error value is based on an actual difference between the render read pointer and the render write pointer, as compared with a calculated ideal render offset between the render read pointer and the render write pointer,
• wherein the render read pointer is adjusted by adding the error value to the render read pointer so that the render data processed by the AEC component from the render buffer stays aligned in time with the capture data processed by the AEC component from the capture buffer to perform acoustic echo cancellation of the capture data using the render data,
• wherein the AEC component performs acoustic echo cancellation of the capture data utilizing the adjusted render read pointer and capture read pointer.