Far-field pickup device and method for collecting voice signal in far-field pickup device

Patent metadata

Field	Value
Publication number	US-2021021925-A1
Application number	US-202017032278-A
Country	US
Kind code	A1
Filing date	Sep 25, 2020
Priority date	Sep 29, 2018
Publication date	Jan 21, 2021
Grant date	—

Abstract

A far-field pickup device including a device body and a microphone pickup unit is provided. The microphone pickup unit is configured to collect user speech and an echo of a first sound signal output by the device body, and transmit, to the device body, a signal obtained through digital conversion of the collected user speech and the echo. The device body includes a signal playback source, a synchronizing signal generator, a horn, a delay determining unit, and an echo cancellation unit configured to perform echo cancellation on the signal transmitted by the microphone pickup unit to obtain a collected human voice signal.

First claim

What is claimed is:

1 . A far-field pickup device, comprising:
a device body; and a microphone pickup unit comprising at least one microphone, the at least one microphone configured to collect user speech and an echo of a first sound signal output by the device body, and the microphone pickup unit configured to transmit, to the device body, a signal obtained through digital conversion of the collected user speech and the echo, the device body comprising:
a signal playback source configured to generate a second sound signal;
a synchronizing signal generator, implemented by the at least one processor, configured to generate a synchronizing signal that is synchronized with the second sound signal and located in a second frequency band different from a first frequency band in which the second sound signal is located;
a horn configured to output a signal obtained by superimposing the second sound signal with the synchronizing signal, the signal output by the horn corresponding to the first sound signal;
a delay determining unit, implemented by the at least one processor, configured to determine a time delay between a second frequency band component in the signal transmitted by the microphone pickup unit and the synchronizing signal; and
an echo cancellation unit, implemented by the at least one processor, configured to perform echo cancellation on the signal transmitted by the microphone pickup unit, by using the second sound signal delayed according to the determined time delay, to obtain a collected human voice signal.

2 . The far-field pickup device according to claim 1 , wherein the device body further comprises:
a delay unit, implemented by the at least one processor, configured to delay the second sound signal by using the time delay determined by the delay determining unit.

3 . The far-field pickup device according to claim 1 , wherein the device body further comprises:
a filter configured to filter out the second frequency band component from the signal transmitted by the microphone pickup unit, and output the filtered second frequency band component to the delay determining unit.

4 . The far-field pickup device according to claim 1 , wherein the device body further comprises:
a down-sampler configured to convert, into a sampling frequency for human voice recognition, a sampling frequency of the signal transmitted by the microphone pickup unit, and output the sampling frequency to the echo cancellation unit.

5 . The far-field pickup device according to claim 1 , wherein the device body further comprises:
a receiver configured to receive the signal transmitted by the microphone pickup unit.

6 . The far-field pickup device according to claim 5 , wherein the microphone pickup unit has a transmitter configured to, in a transmission mode, transmit, to the device body, the collected user speech and the echo of the first sound signal output by the device body, the transmitter being switched from a standby mode to the transmission mode in response to the user speech being recognized from the collected user speech.

7 . The far-field pickup device according to claim 6 , wherein the microphone pickup unit further comprises a human voice recognition unit, and a cache,
the cache being configured to cache the user speech and the echo collected by the at least one microphone, and the human voice recognition unit being implemented by the at least one processor and configured to, in response to recognizing a human voice from an output of the at least one microphone, trigger the transmitter to enter into the transmission mode to transmit, to the device body, the user speech and the echo cached by the cache.

8 . The far-field pickup device according to claim 7 , wherein the at least one microphone comprises a plurality of microphones, one of the plurality of microphones being connected to the human voice recognition unit, and
wherein the human voice recognition unit is further configured to, in response to recognizing the human voice from an output of the connected microphone, trigger the transmitter to enter into the transmission mode to transmit, to the device body, the user speech and the echo collected by each of the plurality of microphones and cached by the cache.

9 . The far-field pickup device according to claim 8 , wherein the echo cancellation unit is further configured to perform the echo cancellation on the user speech collected by each of the plurality of microphones and received by the receiver, and
wherein the device body further comprises a speech enhancement unit, implemented by the at least one processor, and configured to combine human voice signals obtained by performing the echo cancellation on the user speech collected by each of the plurality of microphones, to obtain an enhanced human voice signal.

10 . The far-field pickup device according to claim 5 , wherein the receiver is further configured to switch from a standby mode to a receiving mode to receive the signal transmitted by the microphone pickup unit in response to sensing of a wireless signal.

11 . The far-field pickup device according to claim 1 , wherein the second frequency band is an ultrasonic frequency band, and the synchronizing signal is a pseudo-random sequence obtained after carrier modulation.

12 . The far-field pickup device according to claim 1 , wherein the device body further comprises:
a first cache configured to cache the second sound signal generated by the signal playback source and used in the echo cancellation by the echo cancellation unit; and a second cache configured to cache the synchronizing signal generated by the synchronizing signal generator and used in determining the time delay by the delay determining unit.

13 . The far-field pickup device according to claim 3 , wherein the delay determining unit is further configured to:
determine a time corresponding to a maximum value of a cross-correlation function between the second frequency band component in the signal transmitted by the microphone pickup unit and the synchronizing signal; and determine, as the time delay, a sum of the determined time and a delay caused by the filter.

14 . The far-field pickup device according to claim 5 , wherein the device body further comprises a processing device that is remotely located, and
wherein the signal playback source, the synchronizing signal generator, the delay determining unit, and the echo cancellation unit are located in the processing device.

15 . A method for collecting a human voice signal in a far-field pickup device, the far-field pickup device comprising a device body and a microphone pickup unit, the microphone pickup unit comprising at least one microphone, the method comprising:
generating, by the device body, a synchronizing signal that is synchronized with a first sound signal and in a second frequency band different from a first frequency band in which the first sound signal is located; outputting, by the device body, a second sound signal based on the synchronizing signal and the first sound signal; receiving, by the device body, an echo of the second sound signal output by the device body and user speech that are collected by the microphone pickup unit, and a signal obtained through digital conversion of the collected user speech and the echo; determining, by the device body, a time delay between a second frequency band component in the signal transmitted by the microphone pickup unit and the synchronizing signal; and performing, by the device body, echo cancellation on the signal transmitted by the microphone pickup unit, by using the first sound sign

Assignees

• Tencent Tech Shenzhen Company Ltd

Inventors

• Zheng ji meng
• Yu Meng
• Su Dan

Classifications

• G10L25/78

  Detection of presence or absence of voice signals (switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10) · CPC title

• H04R3/12

  for distributing signals to two or more loudspeakers {(specially adapted for hearing aids H04R25/407)} · CPC title

• H04R2430/00

  Signal processing covered by H04R, not provided for in its groups · CPC title

• H04R3/005

  for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407) · CPC title

• H04R1/406

  microphones · CPC title