ADAPTIVE CELLULAR POWER CONTROL

• US 20110300805A1
• Filed: 06/04/2010
• Published: 12/08/2011
• Est. Priority Date: 06/04/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Sen, Indranil, Gaikwad, Amit
• Granted Patent: US 8,588,696 B2
• Time in Patent Office: Days
• US Class Current: 455/63.1
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]

Abstract

A method of mitigating interference in a mobile wireless communication device by adaptively adjusting transmit power levels of a wireless cellular transceiver. A receive signal quality for a wireless non-cellular transceiver that includes interference from signals transmitted by the wireless cellular transceiver is estimated. The wireless non-cellular and wireless cellular transceivers are co-located in the mobile wireless communication device, and both transceivers are active. An actual transmit power of the wireless cellular transceiver is adjusted based on the estimated receive signal quality to a level less than a requested transmit power. The estimation of the receive signal quality and the adjusting of the actual transmit power is periodically repeated. The estimation accounts for operational properties of the wireless cellular and non-cellular transceivers as well as operational characteristics of wireless connections through the transceivers.

Claims

1. A method of mitigating interference in a mobile wireless communication device including a wireless cellular transceiver and a wireless non-cellular transceiver co-located in the mobile wireless communication device, the method comprising:

in the mobile wireless communication device,

when the wireless non-cellular and wireless cellular transceivers are active;

estimating a receive signal quality for the wireless non-cellular transceiver that includes interference from signals transmitted by the wireless cellular transceiver;

adjusting an actual transmit power of the wireless cellular transceiver based on the estimated receive signal quality; and

repeating periodically the estimating and adjusting;

wherein the actual transmit power of the wireless cellular transceiver is less than a requested transmit power for the wireless cellular transceiver.

2. The method as recited in claim 1, wherein a periodicity of the repeating depends on the method by which the mobile wireless communication device is powered and the amount of stored power available in the mobile wireless communication device.

3. The method as recited in claim 1, wherein a primary transmit frequency band of the wireless cellular transceiver and a primary receive frequency band of the wireless non-cellular transceiver do not overlap;

and

higher order harmonics of signals transmitted in the primary transmit frequency band of the wireless cellular transceiver overlap at least a portion of the primary receive frequency band of the wireless non-cellular transceiver.

4. The method as recited in claim 1, wherein estimating the receive signal quality for the wireless non-cellular transceiver depends on

the requested transmit power of signals transmitted by the wireless cellular transceiver,

an amount of radio frequency antenna isolation between the wireless cellular transceiver and the wireless non-cellular transceiver, and

a receiver sensitivity requirement of the wireless non-cellular transceiver.

5. The method as recited in claim 4, wherein estimating the receive signal quality for the wireless non-cellular transceiver further depends on the modulation type of the wireless cellular connection.

6. The method as recited in claim 1 wherein estimating the receive signal quality for the wireless non-cellular transceiver depends on

a connection state of the wireless non-cellular transceiver, and

a quality of service mode of connections through the wireless non-cellular transceiver.

7. The method as recited in claim 1, wherein adjusting the actual transmit power of the wireless cellular transceiver based on the estimated receive signal quality comprises:

when the receive signal quality for the wireless non-cellular transceiver is impacted by interference from signals transmitted by the wireless cellular transceiver and the requested transmit power for the wireless cellular transceiver exceeds a threshold,

adjusting the actual transmit power of the wireless cellular transceiver to a value at or below the threshold.

8. A mobile wireless communication device, comprising:

a first transceiver that receives signals through a wireless non-cellular connection;

a second transceiver that transmits signals through a wireless cellular connection; and

a control processor coupled to the first and second transceivers, wherein the control processor mitigates interference in the mobile wireless communication device by;

estimating a performance impact to signals received by the first transceiver from signals transmitted by the second transceiver;

adjusting an actual transmit power of the second transceiver based on the performance impact estimation; and

repeating periodically the estimating and adjusting while both the wireless non-cellular and wireless cellular connections are active;

wherein the actual transmit power of the second transceiver is less than a requested transmit power for an uplink of the wireless cellular connection.

9. The mobile wireless communication device as recited in claim 8,

wherein a periodicity at which the control processor repeats the estimating and adjusting depends on the method by which the mobile wireless communication device is powered and the amount of stored power available in the mobile wireless communication device.

10. The mobile wireless communication device as recited in claim 8,

wherein a primary transmit frequency band of the wireless cellular connection used by the second transceiver does not overlap a primary receive frequency band of the wireless non-cellular connection used by the first transceiver, and

higher order harmonics of transmissions in the primary transmit frequency band of the wireless cellular connection output by the second transceiver overlap at least a portion of the primary receive frequency band of the wireless non-cellular connection received by the first transceiver.

11. The mobile wireless communication device as recited in claim 8,

wherein the control processor estimates the performance impact to signals received by the first transceiver through the wireless non-cellular connection from signals transmitted by the second transceiver through the wireless cellular connection using

a requested transmit power level of signals transmitted by the second transceiver,

an amount of radio frequency antenna isolation between the first and second transceivers, and

a receiver sensitivity requirement of the first transceiver.

12. The mobile wireless communication device as recited in claim 8,

wherein the control processor estimates the performance impact to signals received by the first transceiver through the wireless non-cellular connection from signals transmitted by the second transceiver through the wireless cellular connection using

a connection state of the first transceiver, and

a quality of service mode of the wireless non-cellular connection.

13. The mobile wireless communication device as recited in claim 8, wherein adjusting the actual transmit power of the second transceiver based on the performance impact estimation comprises:

when the receive signal quality for the first transceiver is impacted by interference from signals transmitted by the second transceiver and the requested transmit power for the second transceiver exceeds a threshold,

adjusting the actual transmit power of the second transceiver to a value at or below the threshold.

14. Computer readable medium for storing computer program code executable by a processor for mitigating interference in a mobile wireless communication device comprising:

non-transitory computer program code for estimating a performance impact to signals received by a first transceiver of the mobile wireless communication device through a wireless non-cellular connection from signals transmitted by a second transceiver of the mobile wireless communication device through a wireless cellular connection;

non-transitory computer program code for adjusting an actual transmit power of the second transceiver based on the performance impact estimation; and

non-transitory computer program code for periodically repeating the estimating and adjusting while the wireless non-cellular and wireless cellular connections are active;

wherein the actual transmit power of the second transceiver is less than a requested transmit power for an uplink of the wireless cellular connection.

15. The computer readable medium as recited in claim 14 further comprising:

computer program code for estimating an amount of interference received by the first transceiver from the signals transmitted by the second transceiver over the wireless cellular connection based on

a power level and modulation type of the signals transmitted by the second transceiver over the wireless cellular connection, and

an amount of radio frequency antenna isolation between the first and second transceivers; and

computer program code for estimating the performance impact of the interference based on a receiver sensitivity requirement of the first transceiver.

16. The computer readable medium as recited in claim 14, wherein

estimating the performance impact to signals received by the first transceiver through the wireless non-cellular connection is based on

a connection state of the wireless non-cellular connection, and

a quality of service mode of the wireless non-cellular connection.

17. The computer readable medium as recited in claim 14, wherein

adjusting the actual transmit power of the second transceiver based on the performance impact estimation comprises:

determining an unadjusted digital gain setting for a variable gain transmit amplifier in the second transceiver based on one or more messages received through a downlink of the wireless cellular connection;

determining a digital gain adjustment value based on the performance impact estimation;

generating an adjusted digital gain setting for the variable gain transmit amplifier by combining the unadjusted digital gain setting and the digital gain adjustment value; and

setting a gain of the variable gain transmit amplifier using the adjusted digital gain setting.

18. An apparatus for adjusting transmit signals output by a cellular transceiver in a mobile wireless communication device, the apparatus comprising:

means for estimating a performance impact to signals received by a non-cellular transceiver of the mobile wireless communication device from signals transmitted by the cellular transceiver;

means for determining a requested transmit power level for the transmit signals output by the cellular transceiver, the requested transmit power level at least partially based on messages received from a network subsystem to which the cellular transceiver connects;

means for adjusting an actual transmit power level of the transmit signals to a value different than the requested transmit power level when the performance impact to signals received by the non-cellular transceiver exceeds a threshold; and

means for repeating the estimating, determining and adjusting periodically while the cellular and non-cellular transceivers are active.

19. The apparatus as recited in claim 18, wherein a periodicity of the repeating depends on the method by which the mobile wireless communication device is powered and the amount of stored power available in the mobile wireless communication device.

20. The apparatus as recited in claim 18 further comprising:

means for determining a transmit frequency for the transmit signals;

means for determining the actual transmit power level of the transmit signals;

means for determining an operating temperature of the cellular transceiver; and

means for adjusting the actual transmit power level based on an operational compensation value calculated using the determined transmit frequency, actual transmit power level and operating temperature.