Location-based detection of interference in cellular communications systems

• US 8,472,968 B1
• Filed: 08/03/2009
• Issued: 06/25/2013
• Est. Priority Date: 08/11/2008
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Kim, Kyungho
• Primary Examiner(s): Afshar, Kamran
• Assistant Examiner(s): Iqbal, Khawar
• Application Number:
  US12/534,361
• Time in Patent Office: 1,422 Days
• Field of Search: 455/63.1, 455/67.13, 455/68, 455/452.2, 4554561-4566, 455/522, 370231-233, 370/235
• US Class Current: 455/452.2
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 52/146 Uplink power control
• 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]
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

The present specification describes techniques and apparatus that enable location-based detection of interference. In one or more implementations, a neighboring cell generating interference for a mobile device is determined based at least in part on a location of the mobile device.

Claims

1. A method implemented in a first cellular base station located within a cell, the method comprising:

measuring, at the first cellular base station, signal-to-noise ratios of uplink signals received from multiple mobile devices to identify that interference for the multiple mobile devices exceeds a threshold amount when the signal-to-noise ratios are less than an interference threshold, the multiple mobile devices being managed by the first cellular base station; and

in response to the signal-to-noise ratios being less than the interference threshold for at least a particular amount of time,

determining, by array processing the uplink signals received from the multiple mobile devices, a direction from the first cellular base station to the multiple mobile devices in the cell,

determining, based on the direction to the multiple mobile devices and a cell topology of a cellular communications system that includes the first cellular base station, a neighboring cell generating the interference for the multiple mobile devices, and

communicating a request, from the first cellular base station to a second cellular base station managing the neighboring cell, effective to cause the second base station to reduce the interference for the multiple mobile devices.

2. A method as recited in claim 1, wherein the request to the second cellular base station is a request to alter operation of one or more mobile devices managed by the second cellular base station.

3. A method as recited in claim 2, wherein in response to the request, operation of the one or more mobile devices in the neighboring cell close to the cell managed by the first cellular base station are altered, while operation of other mobile devices in the neighboring cell remains unchanged.

4. A method as recited in claim 1, wherein the particular amount of time is dependent on a number of additional mobile devices being managed by the first cellular base station having uplink signals with signal-to-noise ratios that are less than the interference threshold.

5. A method as recited in claim 1, wherein determining the neighboring cell generating the interference comprises determining a path from the first cellular base stations to the multiple mobile devices and continuing the path past the multiple mobile devices to the next cell encountered in a direction of the path.

6. A method as recited in claim 1, wherein identifying when interference for the multiple mobile devices exceeds the threshold amount is based on a number of the multiple mobile devices that are within a threshold distance of each other.

7. A method as recited in claim 1, wherein the uplink signals are signals that are otherwise used by the mobile device for communication purposes.

8. A computing device of a cellular base station, the computing device comprising:

a receiver to receive uplink signals from multiple mobile devices being managed by the cellular base station, the multiple mobile devices within a cell associated with the cellular base station;

an analyzer to analyze signal-to-noise ratios of the uplink signals and identify that two or more of the multiple mobile devices within a threshold distance of each other are being interfered with by more than a threshold amount when the signal-to-noise ratios are less than an interference threshold;

a locator to determine, based on a location of the two or more of the multiple mobile devices and responsive to the signal-to-noise ratios being less than the interference threshold for at least a particular amount of time, another cell responsible for the interference; and

a transmitter to send a request to another cellular base station that manages other mobile devices in the other cell responsible for the interference, the request requesting that transmission power of the other mobile devices of the other cell be reduced.

9. A computing device as recited in claim 8, wherein the request requests that transmission power of some of the other mobile devices of the other cell to be reduced.

10. A computing device as recited in claim 8, wherein the analyzer is to generate the signal-to-noise ratios based on the uplink signals received from the multiple mobile devices.

11. A computing device as recited in claim 8, wherein the analyzer is to:

identify that uplink signals from another of the multiple mobile devices are being interfered with by greater than the threshold amount; and

reduce the particular amount of time that is exceeded to identify that uplink signals from the two or more of the multiple mobile devices are being interfered with.

12. A computing device as recited in claim 8, wherein the locator is to:

identify a direction from the cellular base station to the two or more of the multiple mobile devices;

compare the direction to the two or more of the multiple mobile devices to a cell topology of a cellular communications system that includes the cellular base station; and

identify the cell responsible for the interference as a closest cell to the two or more of the multiple mobile devices in the identified direction within the cell topology, the closest cell being a different cell than a cell managed by the cellular base station.

13. A computing device as recited in claim 8, wherein the uplink signals are signals that are otherwise used by the multiple mobile devices for communication purposes.

14. A method implemented in a first cellular base station, the method comprising:

receiving uplink signals from multiple mobile devices located in a first cell being managed by the first cellular base station;

identifying that the multiple mobile devices are being interfered with by more than a threshold amount when signal-to-noise ratios of the uplink signals are less than an interference threshold amount, the multiple mobile devices being within a threshold distance of each other;

determining, based on a direction from the first base station to the multiple mobile devices and responsive to the signal-to-noise ratios being less than the interference threshold for at least a particular amount of time, a second cell closest to the mobile device; and

requesting that a second cellular base station that manages the second cell cause mobile devices of the second cell to reduce their transmission power effective to reduce the interference.

15. A method as recited in claim 14 further comprising generating the signal-to-noise ratios of the uplink signals received from the multiple mobile devices, each of the signal-to-noise ratios being a measure of a power level of the uplink signals relative a power level of interference when the uplink signals are received at the first cellular base station.

16. A method as recited in claim 14, further comprising reducing the particular amount of time that is exceeded to determine that the uplink signals received from the multiple mobile devices are being interfered with in response to determining that signal-to-noise ratios of uplink signals received from another mobile device in the first cell are being interfered with are less than the interference threshold, the multiple mobile devices and the other mobile device being within the threshold distance of each other.

17. A method as recited in claim 14, wherein the uplink signals received from the multiple mobile devices are signals that are received from only mobile devices within a cell being managed by the first cellular base station.