WIRELESS INTERFERENCE MITIGATION

• US 20110237246A1
• Filed: 03/26/2010
• Published: 09/29/2011
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Sen, Indranil
• Granted Patent: US 8,805,397 B2
• Time in Patent Office: Days
• US Class Current: 455/426.1
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

Mitigating interference in a mobile wireless communication device by using an estimation of the performance impact of interfering signals generated by a wireless cellular transmitter and received by a co-located wireless local area network receiver. Wireless local area network frequency band usage is modified based on the performance impact estimation and the state of the wireless cellular and wireless local area network connections. The estimation accounts for properties of the wireless cellular transmitter and wireless local area network receiver as well as operational characteristics of the wireless cellular and wireless local area network connections.

Claims

1. A method of mitigating interference in a mobile wireless communication device, the method comprising:

estimating a performance impact to signals received in a first frequency band by a first transceiver of the mobile wireless communication device through a wireless local area network connection with a first wireless local area network partner device from signals transmitted by a second transceiver of the mobile wireless communication device through a wireless cellular connection;

changing the wireless local area network connection to use a second frequency band based on the performance impact estimation; and

repeating periodically the estimating and changing while the wireless local area network and wireless cellular connections are active.

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 higher order harmonics of transmissions in a third frequency band of the wireless cellular connection output by the second transceiver overlap at least a portion of the first frequency band of the wireless local area network connection received by the first transceiver.

4. The method as recited in claim 1 wherein the active wireless local area connection operates in an ad hoc mode and further comprising:

requesting the first wireless local area network partner device to use the second frequency band instead of the first frequency band.

5. The method as recited in claim 1 wherein a proprietary communication mode exists between the first transceiver in the mobile wireless communication device and a partner device over the wireless local area network connection and further comprising:

requesting the first wireless local area network partner device to use the second frequency band instead of the first frequency band.

6. The method as recited in claim 1 further comprising:

estimating a performance impact to signals received in the second frequency band by the first transceiver of the mobile wireless communication device by signals transmitted by the second transceiver of the mobile wireless communication device through the wireless cellular connection; and

moving the wireless local area network connection from the first frequency band with the first wireless local area network partner device to the second frequency band with a second wireless local area network partner device.

7. The method as recited in claim 1 wherein estimating the performance impact to signals received by the first transceiver through the wireless local area network connection by signals transmitted by the second transceiver through the wireless cellular connection depends on

a 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.

8. The method as recited in claim 7 wherein estimating the performance further depends on the modulation type of the wireless cellular connection.

9. The method as recited in claim 1 wherein estimating the performance impact to signals received by the first transceiver through the wireless local area network connection by signals transmitted by the second transceiver through the wireless cellular connection depends on

a connection state of the wireless local area network connection, and

a quality of service mode of the wireless local area network connection.

10. A mobile wireless communication device, comprising:

a first transceiver that receives signals through a wireless local area network 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;

changing the wireless local area network connection to use a second frequency band based on the performance impact estimation; and

repeating periodically the estimating and changing while the first and second wireless connections are active.

11. The mobile wireless communication device as recited in claim 10 wherein a periodicity at which the control processor repeats the estimating and changing 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.

12. The mobile wireless communication device as recited in claim 10 wherein

the first frequency band of the wireless local area network connection used by the first wireless transceiver does not overlap a third frequency band of the wireless cellular connection used by the second wireless transceiver, and

higher order harmonics of transmissions in the third frequency band of the wireless cellular connection output by the first transceiver overlap at least a portion of the first frequency band of the wireless local area network connection received by the second transceiver.

13. The mobile wireless communication device as recited in claim 10 wherein the control processor estimates the performance impact to signals received by the first transceiver through the wireless local area network connection from signals transmitted by the second transceiver through the wireless cellular connection using

a 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.

14. The mobile wireless communication device as recited in claim 10 wherein the control processor estimates the performance impact to signals received by the first transceiver through the wireless local area network connection from signals transmitted by the second transceiver through the wireless cellular connection using on

a connection state of the wireless local area network connection, and

a quality of service mode of the wireless local area network connection.

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

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

computer program code for changing the wireless local area network connection to use a second frequency band based on the performance impact estimation; and

computer program code for periodically repeating the estimating the performance impact and changing the wireless local area network connection while the wireless local area network and wireless cellular connections are active.

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

computer program code for estimating an amount of interference received by the first transceiver in the first frequency band based on

a power level and modulation type of 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.

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

computer program code for estimating the performance impact of interference received by the first transceiver from signals transmitted by the second transceiver based on

a connection state of the wireless local area network connection, and

a quality of service mode of the wireless local area network connection.

18. An apparatus for mitigating interference in a mobile wireless communication device, the apparatus comprising:

means for estimating a performance impact to signals received in a first frequency band by a first transceiver of the mobile wireless communication device through a wireless local area network connection with a first wireless local area network partner device from signals transmitted by a second transceiver of the mobile wireless communication device through a wireless cellular connection;

means for changing the wireless local area network connection to use a second frequency band based on the performance impact estimation; and

means for periodically the estimating and changing while the wireless local area network and wireless cellular connections 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 wherein higher order harmonics of transmissions in a third frequency band of the wireless cellular connection output by the second transceiver overlap at least a portion of the first frequency band of the wireless local area network connection received by the first transceiver.

21. The apparatus as recited in claim 18 wherein the active wireless local area connection operates in an ad hoc mode and further comprising:

means for requesting the first wireless local area network partner device to use the second frequency band instead of the first frequency band.

22. The apparatus as recited in claim 18 wherein a proprietary communication mode exists between the first transceiver in the mobile wireless communication device and a partner device over the wireless local area network connection and further comprising:

means for requesting the first wireless local area network partner device to use the second frequency band instead of the first frequency band.

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

means for estimating a performance impact to signals received in the second frequency band by the first transceiver of the mobile wireless communication device by signals transmitted by the second transceiver of the mobile wireless communication device through the wireless cellular connection; and

means for moving the wireless local area network connection from the first frequency band with the first wireless local area network partner device to the second frequency band with a second wireless local area network partner device.

24. The apparatus as recited in claim 18 wherein the means for estimating the performance impact to signals received by the first transceiver through the wireless local area network connection by signals transmitted by the second transceiver through the wireless cellular connection depends on

a 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.