Using inertial sensors to trigger transmit power management

• US 8,989,792 B1
• Filed: 06/24/2010
• Issued: 03/24/2015
• Est. Priority Date: 01/22/2010
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Depew, John
• Primary Examiner(s): Safaipour, Bobbak
• Application Number:
  US12/823,074
• Time in Patent Office: 1,734 Days
• Field of Search: 455/522, 455/575.1, 455/575.2, 455/575.3, 455/575.4, 455/117
• US Class Current: 455/522
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H04B 1/3838 Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

A user device obtains motion data from an inertial sensor included in the user device. The user device receives a command to transmit information at a specified transmit power level. The user device determines, based on the motion data, whether the presence of a human body part is detected. When the presence of a human body part is detected, the user device reduces a current transmit power level below the specified transmit power level.

Claims

1. A method comprising:

obtaining, by a user device, motion data from an inertial sensor included in the user device;

receiving a command to transmit information at a specified transmit power level;

determining, based on the motion data, whether a human body part is detected to be in contact with the user device, the determining comprising at least one of a) determining whether a tilt angle of the user device is beyond a tilt angle threshold, b) determining whether an angular acceleration of the user device is above an angular acceleration threshold, or c) determining whether a linear acceleration of the user device is above a linear acceleration threshold; and

responsive to determining that the human body part is in contact with the user device, reducing a current transmit power level below the specified transmit power level for future transmissions.

2. The method of claim 1, further comprising:

determining the tilt angle of the user device based on the motion data; and

responsive to a determination that the tilt angle is beyond the tilt angle threshold, reducing the transmit power level for the future transmissions.

3. The method of claim 1, wherein the human body part is detected to be in contact with the user device responsive to a determination that the motion data comprises angular accelerations above the angular acceleration threshold and linear accelerations above the linear acceleration threshold.

4. The method of claim 1, further comprising:

filtering the motion data based on an identified moving vehicle filter; and

using the filtered motion data to determine whether the human body part is detected.

5. The method of claim 4, further comprising:

comparing the motion data to motion signatures of one or more moving vehicle filters; and

responsive to a determination that the motion data matches a motion signature of the identified moving vehicle filter, selecting the identified moving vehicle filter to filter the motion data.

6. The method of claim 1, further comprising:

obtaining the motion data after receiving the command to transmit the information at the specified transmit power level; and

performing the determining after a specified amount of motion data is obtained.

7. The method of claim 1, further comprising:

periodically obtaining and storing the motion data;

determining whether the human body part is detected prior to receiving the command to transmit the information at the specified transmit power level; and

responsive to the human body part being detected, automatically reducing the current transmit power level responsive to receiving the command to transmit the information.

8. The method of claim 1, the method further comprising:

determining, based on the motion data, whether the human body part is in contact with the user device within a threshold distance of an antenna of the user device; and

reducing the current transmit power responsive to determining that the human body part is in contact with the user device within the threshold distance of the antenna.

9. The method of claim 1, further comprising:

obtaining additional data from a proximity sensor included in the user device; and

determining whether the human body part is detected based on a combination of the motion data and on the additional data.

10. A user device comprising:

one or more inertial sensors;

a processor to receive motion data from the one or more inertial sensors and to determine, based on the motion data, whether a human body part is detected to be in contact with the user device, the determination comprising at least one of a) determining whether a tilt angle of the user device is beyond a tilt angle threshold, b) determining whether an angular acceleration of the user device is above an angular acceleration threshold, or c) determining whether a linear acceleration of the user device is above a linear acceleration threshold; and

a power manager, configured to be executed from a memory by the processor, to reduce a current power output of one or more antennas for future transmissions responsive to a determination that the human body part is in contact with the user device.

11. The user device of claim 10, further comprising:

at least one modem, connected to the one or more antennas, to control the power output of the one or more antennas, wherein the at least one modem comprises the power manager.

12. The user device of claim 10, wherein the one or more inertial sensors comprise at least one of an accelerometer or a gyroscope.

13. The user device of claim 10, further comprising:

the processor to determine the tilt angle of the user device based on the motion data, and to reduce the current power output of the one or more antennas responsive to the tilt angle being greater than the tilt angle threshold.

14. The user device of claim 10, wherein the human body part is detected to be in contact with the user device responsive to a determination that the motion data includes angular accelerations above the angular acceleration threshold and linear accelerations above the linear acceleration threshold.

15. The user device of claim 10, further comprising:

the processor to filter the motion data based on an identified moving vehicle filter, and to use the filtered motion data to determine whether the human body part is detected.

16. The user device of claim 15, further comprising:

the processor to compare the motion data to motion signatures of one or more moving vehicle filters, and responsive to a determination that the motion data matches a motion signature of the identified moving vehicle filter, select the identified moving vehicle filter to filter the motion data.

17. The user device of claim 10, wherein the processor is further to receive the motion data after receiving a command to transmit information at a specified transmit power level, and to perform the determining after a predefined amount of the motion data is received.

18. The user device of claim 10, further comprising:

a motion data cache to store the motion data over a sample period;

wherein the processor is further to determine whether the human body part is detected to be in contact with the user device prior to the user device receiving a command to transmit information at a specified transmit power level; and

wherein the power manager automatically reduces the current transmit power level below the specified transmit power level responsive to the user device receiving the command to transmit the information when the human body part is detected.

19. The user device of claim 10, further comprising:

the processor to determine, based on the motion data, whether the human body part is in contact with the user device within a threshold distance of the one or more antennas of the user device; and

the power manager to reduce the current power output level responsive to determining that the human body part is in contact with the user device within the threshold distance of the antenna.

20. The user device of claim 10, further comprising:

a proximity sensor;

wherein the processor is further to receive additional data from the proximity sensor and to determine, based on the motion data and the additional data, whether the human body part is detected.