SYSTEMS, METHODS, AND APPARATUS FOR ESTIMATING DIRECTION OF ARRIVAL

• US 20130272097A1
• Filed: 03/15/2013
• Published: 10/17/2013
• Est. Priority Date: 04/13/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kim, Lae-Hoon, Visser, Erik
• Granted Patent: US 9,354,295 B2
• Time in Patent Office: Days
• US Class Current: 367/129
• CPC Class Codes: G01B 21/00 Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
• CPC Class Codes: G01S 15/86 Combinations of sonar systems with lidar systems; Combinations of sonar systems with systems not using wave reflection
• CPC Class Codes: G01S 15/876 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S15/872 takes precedence
• CPC Class Codes: G01S 3/80 using ultrasonic, sonic or infrasonic waves
• CPC Class Codes: G01S 3/8006 Multi-channel systems specially adapted for direction-finding, i.e. having a single aerial system capable of giving simultaneous indications of the directions of different signals
• CPC Class Codes: G01S 3/8083 determining direction of source
• CPC Class Codes: G01S 5/18 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: G01S 5/186 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49
• CPC Class Codes: G06F 1/1633 Constructional details or arrangements of portable computers not specific to the type of enclosures covered by groups G06F1/1615 - G06F1/1626
• CPC Class Codes: G06F 16/433 using audio data
• CPC Class Codes: G06F 3/04817 using icons graphical or visual programming using iconic symbols G06F8/34
• CPC Class Codes: G06F 3/0484 for the control of specific functions or operations, e.g. selecting or manipulating an object, an image or a displayed text element, setting a parameter value or selecting a range
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: G06F 3/167 Audio in a user interface, e.g. using voice commands for navigating, audio feedback
• CPC Class Codes: G10L 17/00 Speaker identification or verification techniques
• CPC Class Codes: G10L 2021/02166 Microphone arrays; Beamforming
• CPC Class Codes: H04R 1/08 Mouthpieces; Microphones; Attachments therefor
• CPC Class Codes: H04R 3/00 Circuits for transducers , loudspeakers or microphones
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04S 7/40 Visual indication of stereophonic sound image

Abstract

Systems, methods, and apparatus for matching pair-wise differences (e.g., phase delay measurements) to an inventory of source direction candidates, and application of pair-wise source direction estimates, are described.

Claims

1. A method of processing a multichannel signal, said method comprising:

for a first pair of channels of the multichannel signal, calculating a first plurality of directional fitness measures, wherein each among the first plurality of directional fitness measures is based on a corresponding different one among a plurality of candidate directions;

for a second pair of channels of the multichannel signal that is different than the first pair, calculating a second plurality of directional fitness measures, wherein each among the second plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions; and

based on the first plurality of directional fitness measures and the second plurality of directional fitness measures, selecting a first direction from among the plurality of candidate directions,

wherein each of the first plurality of directional fitness measures is based on a difference, at a first frequency component of the multichannel signal, between the channels of the first pair, and

wherein each of the second plurality of directional fitness measures is based on a difference, at the first frequency component, between the channels of the second pair.

2. The method according to claim 1, wherein said selecting the first direction from among the plurality of candidate directions comprises determining a minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures.

3. The method according to claim 1, wherein, for each of the first plurality of directional fitness measures, said difference between the channels of the first pair is a difference between a phase of the first frequency component in one channel of the first pair and a phase of the frequency component in another channel of the first pair.

4. The method according to claim 1, wherein said channels of the multichannel signal are based on signals produced by a linear array of microphones such that each among said channels of the multichannel signal is based on a signal produced by a different microphone of said linear array.

5. The method according to claim 4, wherein a first channel of the first pair corresponds to a first microphone of the array, a second channel of the first pair corresponds to a second microphone of the array, a first channel of the second pair corresponds to the first microphone, and a second channel of the second pair corresponds to a third microphone of the array.

6. The method according to claim 4, wherein each channel of the first pair of channels is based on a signal produced by a corresponding microphone of a first pair of microphones of said linear array, and

wherein each channel of the second pair of channels is based on a signal produced by a corresponding microphone of a second pair of microphones of said linear array, and wherein the microphones of said first pair of microphones are separated by a first distance, and

wherein the microphones of said second pair of microphones are separated by a second distance that is different than the first distance.

7. The method according to claim 6, wherein said first frequency component has a wavelength that is less than twice the first distance and less than twice the second distance.

8. The method according to claim 1, wherein said method comprises:

for the first pair of channels of the multichannel signal, calculating a third plurality of directional fitness measures, wherein each among the third plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions;

for the second pair of channels of the multichannel signal, calculating a fourth plurality of directional fitness measures, wherein each among the fourth plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions; and

based on the third plurality of directional fitness measures and the fourth plurality of directional fitness measures, selecting a second direction from among the plurality of candidate directions,

wherein each of the third plurality of directional fitness measures is based on a difference, at a second frequency component of the multichannel signal that is different than the first frequency component, between the channels of the first pair, and

wherein each of the fourth plurality of directional fitness measures is based on a difference, at the second frequency component, between the channels of the second pair.

9. The method according to claim 8, wherein said method comprises indicating a direction of arrival for the multichannel signal, based on said selected first one among the plurality of candidate directions and said selected second one among the plurality of candidate directions.

10. The method according to claim 8, wherein said selecting the first direction from among the plurality of candidate directions comprises determining a minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures, and

wherein said selecting the second direction from among the plurality of candidate directions comprises determining a minimum directional error among the third plurality of directional fitness measures and the fourth plurality of directional fitness measures.

11. The method according to claim 10, wherein said minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures corresponds to said first pair of channels of the multichannel signal, and

wherein said minimum directional error among the third plurality of directional fitness measures and the fourth plurality of directional fitness measures corresponds to said second pair of channels of the multichannel signal.

12. The method according to claim 8, wherein said selected first direction and said selected second direction are the same direction.

13. The method according to claim 8, wherein said selected first direction is a different direction than said selected second direction.

40. A non-transitory computer-readable data storage medium having tangible features that cause a machine reading the features to perform a method according to claim 1.

14. An apparatus for processing a multichannel signal, said apparatus comprising:

means for calculating, for a first pair of channels of the multichannel signal, a first plurality of directional fitness measures, wherein each among the first plurality of directional fitness measures is based on a corresponding different one among a plurality of candidate directions;

means for calculating, for a second pair of channels of the multichannel signal that is different than the first pair, a second plurality of directional fitness measures, wherein each among the second plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions; and

means for selecting a first direction from among the plurality of candidate directions, based on the first plurality of directional fitness measures and the second plurality of directional fitness measures,

wherein each of the first plurality of directional fitness measures is based on a difference, at a first frequency component of the multichannel signal, between the channels of the first pair, and

wherein each of the second plurality of directional fitness measures is based on a difference, at the first frequency component, between the channels of the second pair.

15. The apparatus according to claim 14, wherein said selecting the first direction from among the plurality of candidate directions comprises determining a minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures.

16. The apparatus according to claim 14, wherein, for each of the first plurality of directional fitness measures, said difference between the channels of the first pair is a difference between a phase of the first frequency component in one channel of the first pair and a phase of the frequency component in another channel of the first pair.

17. The apparatus according to claim 14, wherein said channels of the multichannel signal are based on signals produced by a linear array of microphones such that each among said channels of the multichannel signal is based on a signal produced by a different microphone of said linear array.

18. The apparatus according to claim 17, wherein a first channel of the first pair corresponds to a first microphone of the array, a second channel of the first pair corresponds to a second microphone of the array, a first channel of the second pair corresponds to the first microphone, and a second channel of the second pair corresponds to a third microphone of the array.

19. The apparatus according to claim 17, wherein each channel of the first pair of channels is based on a signal produced by a corresponding microphone of a first pair of microphones of said linear array, and

wherein each channel of the second pair of channels is based on a signal produced by a corresponding microphone of a second pair of microphones of said linear array, and wherein the microphones of said first pair of microphones are separated by a first distance, and

wherein the microphones of said second pair of microphones are separated by a second distance that is different than the first distance.

20. The apparatus according to claim 19, wherein said first frequency component has a wavelength that is less than twice the first distance and less than twice the second distance.

21. The apparatus according to claim 14, wherein said method comprises:

means for calculating, for the first pair of channels of the multichannel signal, a third plurality of directional fitness measures, wherein each among the third plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions;

means for calculating, for the second pair of channels of the multichannel signal, a fourth plurality of directional fitness measures, wherein each among the fourth plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions; and

means for selecting a second direction from among the plurality of candidate directions, based on the third plurality of directional fitness measures and the fourth plurality of directional fitness measures,

wherein each of the third plurality of directional fitness measures is based on a difference, at a second frequency component of the multichannel signal that is different than the first frequency component, between the channels of the first pair, and

wherein each of the fourth plurality of directional fitness measures is based on a difference, at the second frequency component, between the channels of the second pair.

22. The apparatus according to claim 21, wherein said apparatus comprises means for indicating a direction of arrival for the multichannel signal, based on said selected first one among the plurality of candidate directions and said selected second one among the plurality of candidate directions.

23. The apparatus according to claim 21, wherein said selecting the first direction from among the plurality of candidate directions comprises determining a minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures, and

wherein said selecting the second direction from among the plurality of candidate directions comprises determining a minimum directional error among the third plurality of directional fitness measures and the fourth plurality of directional fitness measures.

24. The apparatus according to claim 23, wherein said minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures corresponds to said first pair of channels of the multichannel signal, and

wherein said minimum directional error among the third plurality of directional fitness measures and the fourth plurality of directional fitness measures corresponds to said second pair of channels of the multichannel signal.

25. The apparatus according to claim 21, wherein said selected first direction and said selected second direction are the same direction.

26. The apparatus according to claim 21, wherein said selected first direction is a different direction than said selected second direction.

27. An apparatus for processing a multichannel signal, said apparatus comprising:

a measure calculator configured to

calculate, for a first pair of channels of the multichannel signal, a first plurality of directional fitness measures, wherein each among the first plurality of directional fitness measures is based on a corresponding different one among a plurality of candidate directions, and to

calculate, for a second pair of channels of the multichannel signal that is different than the first pair, a second plurality of directional fitness measures, wherein each among the second plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions; and

a selector configured to select a first direction from among the plurality of candidate directions, based on the first plurality of directional fitness measures and the second plurality of directional fitness measures,

wherein each of the first plurality of directional fitness measures is based on a difference, at a first frequency component of the multichannel signal, between the channels of the first pair, and

wherein each of the second plurality of directional fitness measures is based on a difference, at the first frequency component, between the channels of the second pair.

28. The apparatus according to claim 27, wherein said error calculator is configured to determine a minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures.

29. The apparatus according to claim 27, wherein, for each of the first plurality of directional fitness measures, said difference between the channels of the first pair is a difference between a phase of the first frequency component in one channel of the first pair and a phase of the frequency component in another channel of the first pair.

30. The apparatus according to claim 27, wherein said channels of the multichannel signal are based on signals produced by a linear array of microphones such that each among said channels of the multichannel signal is based on a signal produced by a different microphone of said linear array.

31. The apparatus according to claim 30, wherein a first channel of the first pair corresponds to a first microphone of the array, a second channel of the first pair corresponds to a second microphone of the array, a first channel of the second pair corresponds to the first microphone, and a second channel of the second pair corresponds to a third microphone of the array.

32. The apparatus according to claim 30, wherein each channel of the first pair of channels is based on a signal produced by a corresponding microphone of a first pair of microphones of said linear array, and

wherein each channel of the second pair of channels is based on a signal produced by a corresponding microphone of a second pair of microphones of said linear array, and

wherein the microphones of said first pair of microphones are separated by a first distance, and

wherein the microphones of said second pair of microphones are separated by a second distance that is different than the first distance.

33. The apparatus according to claim 32, wherein said first frequency component has a wavelength that is less than twice the first distance and less than twice the second distance.

34. The apparatus according to claim 27, wherein said measure calculator is configured to

calculate, for the first pair of channels of the multichannel signal, a third plurality of directional fitness measures, wherein each among the third plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions, and to

calculate, for the second pair of channels of the multichannel signal, a fourth plurality of directional fitness measures, wherein each among the fourth plurality of directional fitness measures is based on a corresponding different one among the plurality of candidate directions, and

wherein said selector is configured to select a second direction from among the plurality of candidate directions, based on the third plurality of directional fitness measures and the fourth plurality of directional fitness measures, and

wherein each of the third plurality of directional fitness measures is based on a difference, at a second frequency component of the multichannel signal that is different than the first frequency component, between the channels of the first pair, and

wherein each of the fourth plurality of directional fitness measures is based on a difference, at the second frequency component, between the channels of the second pair.

35. The apparatus according to claim 34, wherein said apparatus comprises an indicator configured to indicate a direction of arrival for the multichannel signal, based on said selected first one among the plurality of candidate directions and said selected second one among the plurality of candidate directions.

36. The apparatus according to claim 34, wherein said selector is configured to determine a minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures and to determine a minimum directional error among the third plurality of directional fitness measures and the fourth plurality of directional fitness measures.

37. The apparatus according to claim 36, wherein said minimum directional error among the first plurality of directional fitness measures and the second plurality of directional fitness measures corresponds to said first pair of channels of the multichannel signal, and

wherein said minimum directional error among the third plurality of directional fitness measures and the fourth plurality of directional fitness measures corresponds to said second pair of channels of the multichannel signal.

38. The apparatus according to claim 34, wherein said selected first direction and said selected second direction are the same direction.

39. The apparatus according to claim 34, wherein said selected first direction is a different direction than said selected second direction.