DELAY ESTIMATION FOR ECHO CANCELLATION USING ULTRASONIC MARKERS

摘要

A far end signal is received at a device, a marker signal is inserted into the far end signal and the far end signal with the marker signal is played on a speaker. A near end signal is received via a microphone and the marker signal is detected in said received near end signal. The detected marker signal is used to determine a delay that is then used to cancel at least some of an echo in the near end signal. The marker may be ultrasonic. The echo canceller and other processing may run at a lower sampling frequency than the marker detection.

主权项

1. A method comprising, at a device:
(A) receiving a far end signal; (B) inserting a marker signal into said far end signal; (C) rendering said far end signal with said marker signal on a speaker; (D) receiving a near end signal via a microphone; (E) attempting to detect said marker signal in said received near end signal; (F) based on said attempting to detect in (E), determining a delay; and (G) attempting to cancel at least some of an echo in said near end signal using said delay.