Method and apparatus for fast other sector interference (OSI) adjustment

• US 8,670,777 B2
• Filed: 09/04/2007
• Issued: 03/11/2014
• Est. Priority Date: 09/08/2006
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Borran, Mohammad Jaber, Gorokhov, Alexei, Khandekar, Aamod, Ji, Tingfang, Kannan, Arumugam Chendamarai
• Primary Examiner(s): Karikari, Kwasi
• Application Number:
  US11/849,595
• Publication Number:
  US 20080117833A1
• Time in Patent Office: 2,380 Days
• Field of Search: 455/420, 455/522, 455/453, 455/509
• US Class Current: 455/452.2
• 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. An apparatus that facilities managing resources in a wireless communication system, the apparatus comprising:

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

means for receiving an other-sector interference (OSI) indication that corresponds to fast OSI from one or more APs in the monitor set and corresponds to an interference metric determined in a sub-superframe scale;

means for identifying the time-frequency resources corresponding to the OSI indication; and

means for adjusting an offset value associated with a communication resource according to the received OSI indication and the time-frequency resources identified as corresponding to the OSI indication.

2. The apparatus of claim 1, the sub-superframe time-scale corresponds to one selected from the group consisting of one or more frames and one or more symbols.

3. A computer product having a non-transitory computer-readable medium 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 identify wireless communication system time-frequency communication resources corresponding to the indication of excessive other-sector interference;

code for causing a computer to adjust an offset value associated with a communication resource assigned by an access point, based on the received indication of excessive other-sector interference and the identified time-frequency resources corresponding to the OSI indication; and

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

4. A method for managing interference in a wireless system having time-frequency communication resources, comprising:

determining a plurality of average interference metrics of the system time-frequency communication resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in time-frequency;

generating a cumulative probability distribution function (CDF) based on said plurality of average interference metrics;

determining an interference level based on the CDF;

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

transmitting the OSI indication.

5. The method of claim 4, wherein determining at least one of the average interference metrics 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.

6. The method of claim 4, wherein determining at least one of the average interference metrics includes averaging the interference metric in one or more frames over a set of subcarriers.

7. The method of claim 4, wherein determining at least one of the average interference metrics includes measuring an interference level in a subband and averaging the interference level over a set of interlaces.

8. The method of claim 4, wherein determining the CDF includes generating a time distribution of an average measured interference over a set of frequency resources.

9. The method of claim 4, wherein 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.

10. The method of claim 4, further comprising determining an effective interference metric, 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 a value of ƒ

(A) to the effective metric interference.

11. The method of claim 10, wherein measuring a plurality of interference levels on a set of time-frequency communication resources includes one selected from the group consisting of measuring an interference level on each member of said set, and measuring an average interference function on a subset of said set.

12. The method of claim 10, wherein the function of an interference level is one of a capacity function or a signal-to-interference value.

13. The method of claim 10, further comprising receiving the nominal value, or extracting the nominal value from a measurement or a data storage.

14. The method of claim 4, further comprising receiving at least one of a reference interference value and threshold performance metric value.

15. The method of claim 4, wherein determining an interference level includes measuring the interference level on a subband.

16. The method of claim 8, wherein generating an OSI indication includes detecting a tail value of the CDF, the tail value indicating a percentile position in the CDF, and comparing the tail value to a threshold interference value.

17. The method of claim 10, wherein generating an OSI indication includes contrasting the effective performance metric with a threshold value.

18. The method of claim 4, wherein the OSI indication is transmitted in a dedicated forward link.

19. An apparatus used in wireless communications, comprising:

means for determining a fast interference level of a wireless system time-frequency communication resource based on an interference metric, wherein said determining includes determining a percentile position in a cumulative probability distribution function (CDF) of a plurality of average interference metrics of the system frequency resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in frequency over a given fast other-sector interference (OSI) time span;

means for generating an indication of fast OSI according to the fast interference level; and

means for transmitting the generated OSI indication.

20. The apparatus of claim 19, 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, wherein

determining a slow interference level includes determining the effective interference metric, by determining a another percentile position in a CDF of a plurality of average interference metrics of the system time-frequency communication resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in frequency over a given slow OSI time span, longer than said fast OSI time span.

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

an integrated circuit configured to facilitate measurements of an interference level of wireless communication resources 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 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,

wherein the integrated circuit is further configured to compute the effective interference levels by determining a percentile position in a cumulative probability distribution function (CDF) of a plurality of average interference metrics of the wireless frequency resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in frequency over a given fast other-sector interference (OSI) time span.

22. The electronic appliance of claim 21, wherein the integrated circuit is further configured conduct the measurements at 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.

23. The electronic appliance of claim 21, wherein the integrated circuit is 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.

24. The electronic appliance of claim 21, wherein the integrated circuit is 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.

25. The electronic appliance of claim 21, the integrated circuit further configured to monitor a tail of a distribution of the CDF of the interference levels in time-domain, and to trigger an excess OSI indication when the tail values reach or exceed a threshold.

26. A method for controlling time-frequency resources of a wireless system, comprising

determining a fast interference level of a system communication resource based on an interference metric, wherein said determining includes

determining a plurality of average interference metrics of at least the system frequency communication resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in frequency over a given fast other-sector interference (OSI) time span, and

determining a percentile position in a cumulative probability distribution function (CDF) of the plurality of average interference metrics;

generating an indication of fast OSI according to the fast interference level; and

transmitting the generated OSI indication.

27. The method of claim 26, further comprising:

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

generating an indication of slow other-sector interference according to the slow interference level, wherein

determining a slow interference level includes determining the effective interference metric, by determining a another percentile position in a CDF of a plurality of average interference metrics of the system time-frequency communication resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in frequency over a given slow OSI time span, longer than said fast OSI time span.

28. A computer product having a non-transitory computer-readable medium having code for causing a computer to send control instructions to a wireless communication system having time-frequency communication resources, comprising:

code for causing a computer to determine a plurality of average interference metrics of the system time-frequency communication resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in time-frequency;

code for causing a computer to generate a cumulative probability distribution function (CDF) based on said plurality of average interference metrics;

code for causing a computer to determine an interference level based on the CDF;

code for causing a computer to generate an indication of other-sector interference (OSI) based on the determined interference level; and

code for causing a computer to transmit the OSI indication.

29. The computer product of claim 28, wherein the code for causing a computer to generate the CDF includes code for causing a computer to generate a CDF of an average measured interference over a set of frequency resources.

30. The computer product of claim 29, wherein the code for causing a computer to generate the OSI indication includes code for causing a computer to detect a tail value of the CDF, the tail value indicating a percentile position in the CDF, and compare the tail value to a threshold interference value.

31. A computer product having a non-transitory computer-readable medium, having code for causing a computer to control time-frequency communication resources of a wireless system, the code comprising:

code for causing a computer to determine a fast interference level of a system communication resource based on an interference metric, wherein determining a fast interference level includes

determining a plurality of average interference metrics of at least the system frequency communication resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in frequency over a given fast other-sector interference (OSI) time span, and

determining a percentile position in a cumulative probability distribution function (CDF) of the plurality of average interference metrics;

code for causing a computer to generate an indication of fast OSI according to the fast interference level; and

code for causing a computer to generate and transmit the generated OSI indication.

32. The computer product of claim 31, further comprising:

code for causing a computer to determine a slow interference level based on an effective interference metric; and

code for causing a computer to generate an indication of slow other-sector interference according to the slow interference level, wherein

determining a slow interference level includes determining the effective interference metric, by determining a another percentile position in a CDF of a plurality of average interference metrics of the system time-frequency communication resources, each of the average interference metrics based on a corresponding plurality of interference metrics, each of the interference metrics corresponding to a span in frequency over a given slow OSI time span, longer than said fast OSI time span.