SSYSTEMS AND METHODS FOR SELF-OPTIMIZATION IN WIRELESS BASE STATIONS BY DETECTION OF INTERFERENCE AT THE EDGE OF A RECEIVED RADIO FREQUENCY BAND

• US 20100214941A1
• Filed: 02/19/2010
• Published: 08/26/2010
• Est. Priority Date: 02/25/2009
• Status: Active Grant

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Eden Rock Communications LLC (Nokia Corporation)
• Inventors: Hoole, Elliott
• Granted Patent: US 9,225,620 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 2001/1045 Adjacent-channel interference
• CPC Class Codes: H04L 43/08 Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Systems and methods are described for reducing an interference level associated with frequency drift in a wireless base station. The base station monitors an interference level in a frequency resource caused by a first frequency resource colliding with a second frequency resource. If the interference level is outside of an expected range, the base station adjusts a parameter of the base station such as a reference oscillator frequency to compensate for frequency drift. This method may be used in a femtocell wireless base station.

Claims

1. A wireless communication system comprising:

a first base station using a first frequency resource; and

a second base station using a second frequency resource;

wherein the first base station is configured to;

monitor an interference level in a portion of the first frequency resource adjacent to the second frequency resource;

determine when the interference level indicates a frequency error; and

adjust a reference of the first base station to correct a frequency of the first frequency resource used by the first base station.

2. The system of claim 1, wherein adjusting the reference of the first base station further comprises adjusting a carrier frequency of the first frequency resource.

3. The system of claim 1, wherein adjusting the reference of the first base station reduces an interference level between the first frequency resource and the second frequency resource.

4. The system of claim 1, wherein monitoring an interference level further comprises:

receiving an uplink transmission from a mobile device including the first frequency resource; and

encountering interference from the second frequency resource.

5. The system of claim 1, wherein the first frequency resource is a first frequency band used by the first base station to wirelessly communicate with at least one mobile device, and

wherein the second frequency resource is a second frequency band used by the second base station to wirelessly communicate with at least one mobile device.

6. The system of claim 1, wherein the first base station is associated with a first coverage area and the second base station is associated with a second coverage area, and wherein at least a portion of the first coverage area and at least a portion of the second coverage spatially overlap.

7. The system of claim 1, wherein the first base station is a femtocell base station.

8. A computer implemented method for reducing wireless interference in a base station, comprising:

receiving a first frequency resource used by a first base station;

encountering interference from a second frequency resource used by a second base station;

monitoring an interference level in a portion of the first frequency resource adjacent to the second frequency resource;

determining when the interference level indicates a frequency error; and

adjusting a reference of the first base station to correct a frequency of the first frequency resource used by the first base station.

9. The method of claim 8, wherein adjusting the reference of the first base station further comprises adjusting a carrier frequency of the first frequency resource.

10. The method of claim 8, wherein adjusting the reference of the first base station reduces an interference level between the first frequency resource and the second frequency resource.

11. The method of claim 8, wherein receiving the first frequency resource comprises receiving an uplink transmission from a mobile device, and

wherein encountering interference from the second frequency resource comprises encountering adjacent channel interference.

12. The method of claim 8, wherein the first frequency resource is a first frequency band used by the first base station to wirelessly communicate with at least one mobile device, and

wherein the second frequency resource is a second frequency band used by the second base station to wirelessly communicate with at least one mobile device.

13. The method of claim 8, wherein the first base station is associated with a first coverage area and the second base station is associated with a second coverage area, and wherein at least a portion of the first coverage area and at least a portion of the second coverage spatially overlap.

14. The method of claim 8, wherein the adjusting is performed automatically by the first base station in response to the determination of the frequency error.

15. A computer readable medium encoded with computer-executable instructions for reducing wireless interference in a base station, which when executed, performs a method comprising:

receiving a first frequency resource used by a first base station;

encountering interference from a second frequency resource used by a second base station;

monitoring an interference level in a portion of the first frequency resource adjacent to the second frequency resource;

determining when the interference level indicates a frequency error; and

adjusting a reference of the first base station to correct a frequency of the first frequency resource used by the first base station.

16. The computer-readable medium of claim 15, wherein adjusting the reference of the first base station further comprises adjusting a carrier frequency of the first frequency resource.

17. The computer-readable medium of claim 15, wherein adjusting the reference of the first base station reduces an interference level between the first frequency resource and the second frequency resource.

18. The computer-readable medium of claim 15, wherein receiving the first frequency resource comprises receiving an uplink transmission from a mobile device, and

wherein encountering interference from the second frequency resource comprises encountering adjacent channel interference.

19. The computer-readable medium of claim 15, wherein the first frequency resource is a first frequency band used by the first base station to wirelessly communicate with at least one mobile device, and

wherein the second frequency resource is a second frequency band used by the second base station to wirelessly communicate with at least one mobile device.

20. The computer-readable medium of claim 15, wherein the first base station is associated with a first coverage area and the second base station is associated with a second coverage area, and wherein at least a portion of the first coverage area and at least a portion of the second coverage spatially overlap.