# US 2013/0155816 A1 · Systems and methods for predicting an expected blockage of a signal path of an ultrasound signal

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- Number: US 2013/0155816 A1
- Document ID: US20130155816A1
- Status: Published application
- Kind: A1
- Application number: 13/712,159
- Filed: 2012-12-12
- Published: 2013-06-20
- Earliest claimed: 2011-12-16
- Assignees: QUALCOMM Incorporated
- Inventors: Ren Li; Hui-ya L. Nelson; Joseph R. Fitzgerald
- Web page: https://patentgrep.com/patent/US20130155816A1

## CPC

- G06F 3/0418: {for error correction or compensation, e.g. based on parallax, calibration or alignment}
- G01S 3/80: using ultrasonic, sonic or infrasonic waves
- G06F 3/043: using propagating acoustic waves
- G06F 3/0433: {in which the acoustic waves are either generated by a movable member and propagated within a surface layer or propagated within a surface layer and captured by a movable member}
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES

## Abstract

A method includes detecting a signal at a first set of receivers of a plurality of receivers of a device. The plurality of receivers includes the first set of receivers and a second set of receivers. The first set of receivers corresponds to selected receivers and the second set of receivers corresponds to non-selected receivers. The method includes predicting, based on the signal, an expected blockage of a signal path between a source of the signal and a first selected receiver of the first set of receivers, and selecting a particular receiver of the second set of receivers as a newly selected receiver in response to predicting the expected blockage.

## Claims

### Claim 1

A method comprising:
detecting a signal at a first set of receivers of a plurality of receivers of a device, the plurality of receivers including the first set of receivers and a second set of receivers, wherein the first set of receivers corresponds to selected receivers and wherein the second set of receivers corresponds to non-selected receivers;
predicting, based on the signal, an expected blockage of a signal path between a source of the signal and a first selected receiver of the first set of receivers; and
selecting a particular receiver of the second set of receivers as a newly selected receiver in response to predicting the expected blockage.

### Claim 2 (depends on 1)

The method of claim 1, wherein the source comprises an ultrasound transmitter.

### Claim 3 (depends on 1)

The method of claim 1, further comprising:
predicting a travel path of the source of the signal in response to predicting the expected blockage of the signal path; and
determining the particular receiver of the second set of receivers based on the predicted travel path of the source of the signal.

### Claim 4 (depends on 3)

The method of claim 3, wherein the particular receiver is selected from a look-up table based on information related to other receivers of the first set of receivers, based on information regarding the predicted travel path, based on information regarding a location of the source, or any combination thereof.

### Claim 5 (depends on 1)

The method of claim 1, wherein the particular receiver of the second set of receivers is selected before the signal path is blocked.

### Claim 6 (depends on 1)

The method of claim 1, wherein the expected blockage is a result of movement of the source of the signal, movement of an object, or any combination thereof.

### Claim 7 (depends on 1)

The method of claim 1, wherein the signal is an ultrasound signal.

### Claim 8 (depends on 1)

The method of claim 1, wherein predicting an expected blockage of the first receiver comprises calculating a signal-to-noise ratio (SNR) value associated with the first receiver and determining whether the SNR value is below an SNR threshold.

### Claim 9 (depends on 1)

The method of claim 1, wherein predicting an expected blockage of the first receiver comprises calculating a phase output of a phase-locked loop (PLL) associated with the first receiver and determining whether the phase output is exceeds an output threshold.

### Claim 10 (depends on 1)

The method of claim 1, further comprising de-selecting the first receiver in response to predicting the expected blockage.

### Claim 11 (depends on 10)

The method of claim 10, wherein the first receiver is de-selected before the signal path is blocked.

### Claim 12 (depends on 1)

The method of claim 1, wherein the source is located at a location that is not bounded by the plurality of receivers.

### Claim 13 (depends on 1)

The method of claim 1, wherein the source is a pen device comprising a transmitter that generates the signal.

### Claim 14 (depends on 1)

The method of claim 1, further comprising determining a location of the source of the signal based on a time difference of arrival, at two or more receivers of the first set of receivers, of the signal.

### Claim 15 (depends on 14)

The method of claim 14, further comprising selecting two or more receivers of the second set of receivers in response to predicting the expected blockage and in response to determining that the location of the source is within a particular region.

### Claim 16 (depends on 1)

The method of claim 1, further comprising:
after selecting the particular receiver as the newly selected receiver, determining whether a second signal path between the source and the newly selected receiver is blocked; and
when the second signal path is determined to be blocked, activating another particular receiver of the second set of receivers as a second selected receiver and de-selecting the newly selected receiver.

### Claim 17

An apparatus comprising:
a plurality of receivers including a first set of receivers and a second set of receivers;
a processor; and
a memory storing instructions executable by the processor to:
receive signals from the first set of receivers, wherein the first set of receivers corresponds to selected receivers, and wherein the signals received from the first set of receivers are indicative of acoustic signals detected by the first set of receivers;
predict, based on a signal, an expected blockage of a signal path between a source of the acoustic signals detected by the first set of receivers and a first receiver of the first set of receivers; and
select at least one receiver of the second set of receivers in response to predicting the expected blockage, wherein the second set of receivers corresponds to non-selected receivers.

### Claim 18 (depends on 17)

The apparatus of claim 17, wherein the source of the acoustic signals corresponds to a transmitter of a pen configured to write on a surface, and wherein the acoustic signals have a frequency in excess of twenty (20) kiloHertz (kHz).

### Claim 19 (depends on 18)

The apparatus of claim 18, wherein the instructions are further executable by the processor to detect a state of the pen based on at least one of the signals received from the first set of receivers, wherein the pen has a first state when the pen is operational but not writing and a second state with the pen is operational and writing.

### Claim 20 (depends on 17)

The apparatus of claim 17, wherein the plurality of receivers includes at least one microphone configured to detect the acoustic signals, and wherein the acoustic signals are outside a human auditory range.

### Claim 21 (depends on 17)

The apparatus of claim 17, wherein the instructions are further executable by the processor to generate a first clock signal based on the signals received from the first set of receivers, and wherein the plurality of receivers are synchronized based on the first clock signal.

### Claim 22 (depends on 17)

The apparatus of claim 17, wherein the memory further stores a look-up table, and wherein the instructions are further executable by the processor to select the at least one receiver of the second set of receivers based at least in part on the look-up table.

### Claim 23 (depends on 17)

The apparatus of claim 17, wherein the plurality of receivers comprises a plurality of microphones configured to detect the acoustic signals and to generate the signal for use by the processor to estimate a distance and direction to the source of the acoustic signals based on time difference of arrival of the acoustic signals at a set of microphones of the plurality of microphones, wherein the set of microphones corresponds to the first set of receivers.

### Claim 24 (depends on 17)

The apparatus of claim 17, wherein the plurality of receivers, the processor, and the memory are integrated into one of a mobile communication device, a smart phone, a cellular phone, a laptop computer, a computer, a tablet, a personal digital assistant, a display device, a television, a gaming console, a music player, a radio, a digital video player, a digital video disc (DVD) player, a tuner, a camera, and a navigation device.

### Claim 25 (depends on 17)

The apparatus of claim 17, wherein the plurality of receivers includes at least one microphone configured to detect acoustic signals both inside and outside a human auditory range.

### Claim 26

A computer-readable medium comprising instructions executable by a processor to cause the processor to perform operations including:
receiving signals from a first set of receivers of a plurality of receivers of a device, the plurality of receivers including the first set of receivers and a second set of receivers, wherein the first set of receivers correspond to selected receivers, wherein the second set of receivers correspond to non-selected receivers, and wherein the signals received from the first set of receivers are indicative of acoustic signals detected by the first set of receivers;
predicting, based on a signal, an expected blockage of a signal path between a source of the acoustic signals and a first receiver of the first set of receivers; and
selecting a particular receiver of the second set of receivers as a newly selected receiver in response to predicting the expected blockage.

### Claim 27 (depends on 26)

The computer-readable medium of claim 26, wherein the plurality of receivers includes at least one microphone.

### Claim 28 (depends on 26)

The computer-readable medium of claim 26, wherein the plurality of receivers includes at least one microphone configured to detect acoustic signals having a frequency in excess of twenty (20) kiloHertz (kHz), and at least one microphone configured to detect acoustic signals having a frequency between twenty (20) Hertz (Hz) and twenty (20) kHz.

### Claim 29 (depends on 26)

The computer-readable medium of claim 26, wherein the operations further comprise:
predicting a travel path of the source of the acoustic signals in response to predicting the expected blockage of the signal path; and
determining the particular receiver of the second set of receivers based on the predicted travel path of the source of the acoustic signals.

### Claim 30 (depends on 29)

The computer-readable medium of claim 29, wherein the particular receiver is selected from a look-up table based on information related to other receivers of the first set of receivers, based on information regarding the predicted travel path, based on information regarding a location of the source, or any combination thereof.

### Claim 31 (depends on 26)

The computer-readable medium of claim 26, wherein the operations further comprise de-selecting the first receiver in response to predicting the expected blockage.

### Claim 32 (depends on 26)

The computer-readable medium of claim 26, wherein the operations further comprise determining a location of the source of the signal based on a time difference of arrival, at two or more receivers of the first set of receivers, of the acoustic signals.

### Claim 33 (depends on 26)

The computer-readable medium of claim 26, wherein the plurality of receivers includes at least one microphone configured to detect acoustic signals both inside and outside a human auditory range.

### Claim 34

An apparatus comprising:
multiple receiving means for receiving a signal, the multiple receiving means including a first set of receiving means and a second set of receiving means, wherein the first set of receiving means correspond to selected receiving means, and wherein the second set of receiving means correspond to non-selected receiving means;
means for predicting, based on a received signal, an expected blockage of a signal path between a source of the received signal and a first receiving means of the first set of receiving means; and
means for selecting a particular receiving means of the second set of receiving means as a newly selected receiving means in response to predicting the expected blockage.

### Claim 35 (depends on 34)

The apparatus of claim 34, wherein the multiple receiving means, the means for predicting, and the means for selecting are integrated in a computer.

### Claim 36 (depends on 34)

The apparatus of claim 34, wherein the multiple receiving means, the means for predicting, and the means for selecting are integrated in a mobile communication device.

### Claim 37 (depends on 34)

The apparatus of claim 34, wherein the multiple receiving means comprise a plurality of microphones, wherein at least one microphone of the plurality of microphones is configured to detect ultrasound signals, and wherein the received signal corresponds to an ultrasound signal.

### Claim 38 (depends on 34)

The apparatus of claim 34, further comprising means for de-selecting the first receiving means in response to predicting the expected blockage.

### Claim 39 (depends on 34)

The apparatus of claim 34, further comprising means for determining a location of the source of the received signal based on a time difference of arrival, at two or more receiving means of the first set of receiving means, of the received signals.

### Claim 40 (depends on 34)

The apparatus of claim 34, further comprising:
means for predicting a travel path of the source of the received signal in response to predicting the expected blockage of the signal path; and
means for determining the particular receiving means of the second set of receiving means based on the predicted travel path of the source of the signal.

### Claim 41 (depends on 34)

The apparatus of claim 34, wherein the multiple receiving means includes at least one microphone configured to detect acoustic signals both inside and outside a human auditory range.