Always-On Low-Power Keyword spotting

• US 20140281628A1
• Filed: 06/24/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Nigam, Vivek, Doy, Anthony Stephen, Wang, Yadong, Moore, Todd D.
• Granted Patent: US 9,703,350 B2
• Time in Patent Office: Days
• US Class Current: 713/323
• CPC Class Codes: G06F 1/3206 Monitoring of events, devices or parameters that trigger a change in power modality
• CPC Class Codes: G10L 2015/088 Word spotting

Abstract

The invention relates to an electronic device that includes a wake-up system that operates at a substantially low power level and is applied to wake up the electronic device from a sleep mode. The wake-up system comprises a sound transducer that converts a received sound signal to an electrical signal and a keyword detection logic that preliminarily identifies a speech energy profile that corresponds to at least one of a plurality of keywords in a part of the electrical signal. In some embodiments, a keyword finder is further activated to identify with an enhanced accuracy whether the at least one keyword exists in the part of the electrical signal, and generates a wake-up control to activate a host of the electronic device from its sleep mode.

Claims

1. A wake-up system that wakes up an electronic device from a sleep mode, comprising:

a sound transducer that receives a sound signal and converts the sound signal to an electrical signal, wherein the sound transducer is re-tasked from a conventional loudspeaker.

a keyword detection logic, coupled to the sound transducer, the keyword detection logic preliminarily identifying in a part of the electrical signal a speech energy profile that corresponds to at least one of a plurality of keywords and generating a first wake-up control, the first wake-up control being further applied to activate a host in the electronic device from the sleep mode.

2. The wake-up system according to claim 1, wherein the wake-up system is constantly powered with a substantially low power level regardless of whether the host of the electronic device is at the sleep mode or not.

3. The wake-up system according to claim 1, wherein the wake-up system further comprises a buffer to temporarily store the part of the electrical signal.

4. The wake-up system according to claim 1, wherein the first wake-up control is first used to activate a keyword finder in the host from the sleep mode, the keyword finder further identifying the at least one of the plurality of keywords with an enhanced accuracy and generating a second wake-up control to activate the complete host functionality.

5. The wake-up system according to claim 4, wherein the keyword detection logic adopts a simpler sound processing method and consumes less power than the keyword finder does.

6. The wake-up system according to claim 4, wherein the sound transducer operates at two modes to reduce power consumption, the sound signal being captured to simply generate the electrical signal sufficient for preliminary sound identification in the keyword detection logic in a first mode, the part of the sound signal being accurately captured for enhanced sound identification in the keyword finder in a second mode.

7. The wake-up system according to claim 1, wherein the at least one of the plurality of keywords is distinguished from a regular conventional talk or a piece of background noise like music.

8. The wake-up system according to claim 1, wherein the sound signal includes a voice wake-up command that further includes the at least one of the plurality of keywords, and upon receiving the voice wake-up command, the wake-up system wakes up the host of the electronic device from the sleep mode.

9. The wake-up system according to claim 1, wherein the host sends back a response upon receiving the first wake-up control, such that the user may rely on the wake-on system to identify the location of the electronic device.

10. The wake-up system according to claim 1, wherein the sound signal is associated with a pressure wave that adopts a frequency outside an audible frequency range.

11. A method of waking up an electronic device from a sleep mode, comprising the steps of:

converting a sound signal received by a sound transducer to an electrical signal, wherein the sound transducer is re-tasked from a conventional loudspeaker.

preliminarily detecting in a part of the electrical signal a speech energy profile that corresponds to at least one of a plurality of keywords;

activating a keyword finder from the sleep mode to further identify the at least one of the plurality of keywords with an enhanced accuracy; and

generating a wake-up control to activate a host of the electronic device from the sleep mode.

12. The method of waking up the electronic device according to claim 11, wherein the at least one of the plurality of keywords is distinguished from a regular conventional talk or a piece of background noise like music.

13. The method of waking up the electronic device according to claim 11, wherein the sound transducer operates at two modes to reduce power consumption, the sound signal being captured to simply generate the electrical signal sufficient for preliminary sound detection in a first mode, the part of the sound signal being accurately captured for enhanced sound identification in the keyword finder in a second mode.

14. The method of waking up the electronic device according to claim 11, wherein the sound signal is associated with a pressure wave that adopts a frequency outside an audible frequency range.

15. The method of waking up the electronic device according to claim 11, wherein the speech energy profile is bi-modal as the at least one of the plurality of keywords is associated with a pair of keywords separated by a time interval.

16. An electronic device, comprising:

a wake-up system that is constantly powered at a substantially low power level, further comprising (1) a sound transducer that receives a sound signal and converts the sound signal to an electrical signal, wherein the sound transducer is re-tasked from a conventional loudspeaker, and (2) a keyword detection logic, coupled to the sound transducer, the keyword detection logic preliminarily detecting in a part of the electrical signal a speech energy profile that corresponds to at least one of a plurality of keywords and initiating a data transfer; and

a keyword finder, coupled to the wake-up system, the keyword finder further identifying the at least one of the plurality of keywords with an enhanced accuracy and generating a wake-up control to activate a host of the electronic device.

17. The electronic device according to claim 16, wherein in the sleep mode, the electronic device adopts different activity levels to disable different programs and deactivate different hardware units.

18. The electronic device according to claim 16, wherein the host sends back a response upon receiving the first wake-up control, such that the user may rely on the wake-on system to identify the location of the electronic device.

19. The electronic device according to claim 16, wherein the wake-up system further comprises a buffer to temporarily store the part of the electrical signal.

20. The electronic device according to claim 16, wherein the sound signal is associated with a pressure wave that adopts a frequency outside an audible frequency range.