METHOD AND APPARATUS FOR FAST OTHER SECTOR INTERFERENCE (OSI) ADJUSTMENT

• US 20080117833A1
• Filed: 09/04/2007
• Published: 05/22/2008
• Est. Priority Date: 09/08/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kannan, Arumugam Chendamarai, Khandekar, Aamod, Gorokhov, Alexei, Ji, Tingfang, Borran, Mohammad Jaber
• Granted Patent: US 8,670,777 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

Systems and methods that facilitate management of interference and communication resources are provided. A differential approach is devised in which other-sector interference (OSI) and communication resources are managed by adjusting an offset (delta) value associated with the resources in response to receiving an indication of other-sector interference. An OSI indication can be issued based on a short and a long time scale, and effective interference metrics over time-frequency resources. The adjusted delta value is communicated to a serving access point, which reassigns communication resources in order to mitigate other-sector interference.

Claims

1. A method for resource management in a wireless system, the method comprising:

receiving an indication of other-sector interference (OSI);

determining whether a delta value associated with a communication resource should be adjusted in response to the received OSI indication;

the determination includes identifying the time-frequency resources corresponding to the OSI indication; and

adjusting the delta value associated with the communication resource.

2. The method of claim 1, wherein the adjusting the delta value includes randomly determining whether to increase, decrease, or preserve the delta value based on a probability distribution that depends on the received OSI indication, a current delta value, and a channel strength metric.

3. The method of claim 1, wherein the adjusting the delta value includes adopting a deterministic algorithm, wherein a weight function that depends on the received OSI indication, a current delta value, and a channel strength metric increases or decreases the delta value according to a specific discrete value.

4. The method of claim 1, further comprising retaining an adjusted delta value.

5. The method of claim 1, further comprising computing one or more delta values to serve as bounds for an adjusted delta value.

6. The method of claim 1, receiving the OSI indication takes place every superframe of a forward link.

7. The method of claim 1, receiving the OSI indication takes place upon decoding an interlace.

8. The method of claim 1, receiving the OSI indication takes place every frame of a forward link.

9. The method of claim 1, wherein receiving an OSI indication includes receiving a value of an interference metric averaged over one set selected from the group consisting of a set of subframes, a set of frames, and a set of subcarriers.

10. A wireless communication apparatus, comprising:

an integrated circuit configured to acquire a set of access points, to receive an indication of excessive other-sector interference (OSI) from an access point in a set of acquired access points, to adjust an offset value associated with a communication resource according to the excessive OSI indication, and to retain the adjusted offset value; and

a memory coupled to the integrated circuit for storing data.

11. The wireless communication apparatus of claim 10, the integrated circuit further configured to receive a resource assignment from a serving access point.

12. The wireless communication apparatus of claim 11, the integrated circuit further configured to transmit the adjusted offset value to the serving access point.

13. The wireless communication apparatus of claim 10, the integrated circuit further configured to facilitate a probabilistic algorithm to adjust the offset value.

14. The wireless communication apparatus of claim 10, the integrated circuit further configured to facilitate a deterministic algorithm to adjust the offset value, and even further configured to retrieve from the memory a set of parameters that define said algorithm.

15. The wireless communication apparatus of claim 10, the stored data includes computed values of an effective interference, an average interference, an interference that corresponds to a specific percentile of a distribution of interference levels, or any combination thereof

16. An apparatus that facilitates managing resources in a wireless communication system, the apparatus comprising:

means for establishing a set of non-serving access points (APs) to monitor for other-sector interference indications;

means for receiving an other-sector interference (OSI) indication from one or more APs in the monitor set; and

means for adjusting an offset value associated with a communication resource according to the received OSI indication.

17. The apparatus of claim 16, the OSI indication corresponds to fast other-sector interference, wherein an interference metric is determined in a sub-superframe time scale.

18. The apparatus of claim 17, the sub-superframe time-scale corresponds to one selected from the group consisting of one or more frames and one or more symbols.

19. A computer-readable mediums comprising:

code for causing a computer to receive an indication of excessive other-sector interference from a set of non-serving access points;

code for causing a computer to adjust an offset value associated with a communication resource assigned by an access point; and

code for causing a computer to communicate the adjusted offset value to an access point to update subsequent resource assignments.

20. A method for managing interference in a wireless system, comprising:

determining an interference level based on an interference metric;

generating an indication of other-sector interference (OSI) based on the determined interference level; and

transmitting the OSI indication.

21. The method of claim 20, wherein determining an interference level includes averaging the interference metric in one or more subcarriers over at least one set selected from a group consisting of a set of superframes and a set of frames.

22. The method of claim 20, wherein determining an interference level includes averaging the interference metric in one or more frames over a set of subcarriers.

23. The method of claim 20, determining an interference level includes measuring an interference level in a subband and averaging the interference level over a set of interlaces.

24. The method of claim 20, wherein determining an interference level comprises:

generating a time distribution of an average measured interference over a set of frequency resources, and monitoring a tail value of the distribution.

25. The method of claim 20, the interference metric is selected from the group consisting of a signal-to-noise ratio, a signal-to-interference ratio, a signal-to-interference-and-noise ratio, and a capacity.

26. The method of claim 20, determining an interference level includes computing an effective performance metric.

27. The method of claim 26, wherein an effective interference metric includes at least one metric selected from the group consisting of an average signal-to-noise ratio;

an average signal over time-frequency resources, an average interference over time-frequency resources, and their ratio; and

an effective signal-to-noise ratio extracted from a capacity measure.

28. The method of claim 26, wherein the effective interference metric is determined by performing the following acts:

measuring a plurality of interference levels on a set of time-frequency resources;

evaluating a function (ƒ

) of an interference level (I) for each interference level in the plurality of measured interference levels, and generating an average (A) of the evaluation results; and

evaluating the inverse function of ƒ

(I) with A as an argument value, and assigning the value ƒ

¹(A) to the effective metric interference.

29. The method of claim 28, measuring a plurality of interference levels on a set of time-frequency resources includes one selected from the group consisting of measuring an interference level on each member of said set, and measuring an average interference level on a subset of said set.

30. The method of claim 28, the function of an interference level is one of a capacity function or a signal-to-interference ratio.

31. The method of claim 28, further comprising receiving the nominal value, or extracting the nominal value from a measurement or a data storage.

32. The method of claim 20, further comprising receiving at least one of a reference interference value and threshold performance metric value.

33. The method of claim 20, determining an interference level includes measuring the interference level on a subband.

34. The method of claim 21, generating an OSI indication includes comparing the average value of the performance metric to a reference value.

35. The method of claim 24, generating an OSI indication includes comparing the tail value to a threshold interference value.

37. The method of claim 20, the OSI indication transmitted in a dedicated control channel in a forward link.

41. The computer-readable medium of claim 37, code for causing a computer to compute an effective interference level includes code for causing a computer to compute an average over a set selected from a group consisting of a frequency resources set and a time resources set, and extracting an effective interference level from a capacity measure.

36. The method of 26, generating an OSI indication includes contrasting the effective performance metric with a threshold value.

38. An apparatus used in wireless communications, comprising:

means for determining a fast interference level based on an interference metric;

means for generating an indication of fast other-sector interference (OSI) according to the fast interference level; and

means for transmitting the generated OSI indication.

39. The apparatus of claim 38, further comprising:

means for determining a slow interference level based on an effective interference metric; and

means for generating an indication of slow other-sector interference according to the slow interference level.

40. A computer-readable medium comprising:

code for causing a computer to measure interference levels on a frame time scale and a superframe time scale, the time scales dictated by a symbol numerology of a wireless system;

code for causing a computer to compute an effective interference level based on the interference level measurements; and

code for causing a computer to issue an excess other-sector interference indication according to the computed effective interference level.

43. The electronic appliance of claim 40, the disparate time scales selected from the group consisting of a fast time scale and a slow time scale, and specified by a numerology of the wireless communication environment.

44. The electronic appliance of claim 40, the integrated circuit further configured to compute effective interference levels based on a capacity measure, and to trigger an excess OSI indication when the effective interference level exceeds a threshold.

45. The electronic appliance of claim 40, the integrated circuit further configured to compute averages of measured interference levels on time-frequency resources, and to trigger an excess OSI indication when the average values surpass a threshold.

46. The electronic appliance of claim 40, the integrated circuit further configured to monitor a tail of a distribution of the measured interface levels in time-domain, and to trigger an excess OSI indication when the tail values reach or exceed a threshold.

48. The apparatus of claim 46, the integrated circuit further configured to communicate an algorithm to adjust the offset value associated with the assigned resource.

42. An electronic appliance that operates in a wireless communication environment, the appliance comprising:

an integrated circuit configured to facilitate measurements of an interference level in frequency-domain and time-domain, the measurements conducted at disparate time scales, to compute effective interference levels employing results of the measurements in slow and fast time regimes, and to broadcast an indication of excessive other-sector interference; and

a memory coupled to the integrated circuit to store measured and computed data.

47. An apparatus that facilitates wireless communications, the system comprising:

an integrated circuit configured to transmit a resource assignment, and to receive

an adjusted offset value associated with an assigned resource.

a memory coupled to the integrated circuit for storing data, the data includes the adjusted value of an offset associated with a communication resource.