Ultrasonic echo canceler-based technique to detect participant presence at a video conference endpoint
First Claim
1. A method comprising:
- transmitting an ultrasonic signal into a spatial region;
transducing ultrasonic sound, including an echo of the transmitted ultrasonic signal, received from the spatial region at a microphone into a received ultrasonic signal;
transforming the ultrasonic signal and the received ultrasonic signal into respective time-frequency domains that cover respective ultrasound frequency ranges;
computing an error signal, representative of an estimate of an echo-free received ultrasonic signal, based on the transformed ultrasonic signal and the transformed received ultrasonic signal;
computing power estimates of the error signal over time; and
detecting a change in people presence in the spatial region over time based on a change in the power estimates of the error signal over time.
1 Assignment
0 Petitions
Accused Products
Abstract
A loudspeaker transmits an ultrasonic signal into a spatial region. A microphone transduces ultrasonic sound, including an echo of the transmitted ultrasonic signal, received from the spatial region into a received ultrasonic signal. A controller transforms the ultrasonic signal and the received ultrasonic signal into respective time-frequency domains that cover respective ultrasound frequency ranges. The controller computes an error signal, representative of an estimate of an echo-free received ultrasonic signal, based on the transformed ultrasonic signal and the transformed received ultrasonic signal. The controller computes power estimates of the error signal over time, and detects a change in people presence in the spatial region based on a change in the power estimates of the error signal over time.
-
Citations
20 Claims
-
1. A method comprising:
-
transmitting an ultrasonic signal into a spatial region; transducing ultrasonic sound, including an echo of the transmitted ultrasonic signal, received from the spatial region at a microphone into a received ultrasonic signal; transforming the ultrasonic signal and the received ultrasonic signal into respective time-frequency domains that cover respective ultrasound frequency ranges; computing an error signal, representative of an estimate of an echo-free received ultrasonic signal, based on the transformed ultrasonic signal and the transformed received ultrasonic signal; computing power estimates of the error signal over time; and detecting a change in people presence in the spatial region over time based on a change in the power estimates of the error signal over time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. An apparatus comprising:
-
a loudspeaker configured to transmit an ultrasonic signal into a spatial region; a microphone configured to transduce ultrasonic sound, including an echo of the transmitted ultrasonic signal, received from the spatial region into a received ultrasonic signal; a processor coupled to the loudspeaker and the microphone and configured to; transform the ultrasonic signal and the received ultrasonic signal into respective time-frequency domains; compute an error signal, representative of an estimate of an echo-free received ultrasonic signal, based on the transformed ultrasound signal and the transformed received ultrasonic signals; compute power estimates of the error signal over time; and detect a change in people presence in the spatial region over time based on a change in the power estimates of the error signal over time. - View Dependent Claims (12, 13, 14, 15, 16)
-
-
17. A non-transitory processor readable medium storing instructions that, when executed by a processor, cause the processor to:
-
cause a loudspeaker to transmit an ultrasonic signal into a spatial region; access a received ultrasonic signal representative of transduced ultrasonic sound, including an echo of the transmitted ultrasonic signal, received from the spatial region at a microphone; transform the ultrasonic signal and the received ultrasonic signal into respective time-frequency domains that cover respective ultrasound frequency ranges; compute an error signal, representative of an estimate of an echo-free received ultrasonic signal, based on the transformed ultrasonic signal and the transformed received ultrasonic signal; compute power estimates of the error signal over time; and detect a change in people presence in the spatial region over time based on a change in the power estimates of the error signal over time. - View Dependent Claims (18, 19, 20)
-
Specification