Intra-cell common reuse for a wireless communication system

• US 20050272432A1
• Filed: 10/20/2004
• Published: 12/08/2005
• Est. Priority Date: 06/08/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Agrawal, Avneesh, Ji, Tingfang
• Granted Patent: US 8,014,781 B2
• Time in Patent Office: Days
• US Class Current: 455/449
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

To avoid or reduce intra-cell interference, each sector of a cell is associated with a sector-specific set of system resources (e.g., subbands) and at least one non-overlapping common set of system resources. Each common set for each sector includes system resources observing little or no interference from at least one other sector in the cell. The channel condition for a terminal in a given sector x is ascertained based on forward and/or reverse link measurements for the terminal. The terminal is assigned system resources from a common set or a sector-specific set for sector x based on the terminal'"'"'s channel condition. For example, if the terminal observes high interference from another sector y, then the terminal is assigned system resources from a common set that observes little or no interference from sector y. The techniques may be used for an OFDMA system that uses frequency hopping.

Claims

1. A method of assigning system resources in a wireless communication system, comprising:

determining channel condition for a terminal; and

assigning the terminal with system resources from a first set or a common set based at least on the channel condition for the terminal, the first set and the common set being non-overlapping and including different system resources, the first set including system resources allocable to terminals in a first sector of a cell, and the common set including system resources with little interference, if any, from the first sector and at least one other sector in the cell.

2. The method of claim 1, further comprising:

classifying the terminal into one of a plurality of groups based at least on the channel condition for the terminal, each group being associated with a different set of system resources, and wherein the terminal is assigned system resources based at least on the group in which the terminal is classified.

3. The method of claim 2, wherein the terminal is classified into one of the plurality of groups further based on amounts of system resources in the first and common sets, or number of other terminals sharing the system resources in the first and common sets, or both.

4. The method of claim 1, wherein the terminal is assigned system resources further based on information for quality of service (QoS), system loading, fairness requirement, or any combination thereof.

5. The method of claim 1, wherein the system resources are frequency subbands, and wherein the terminal is assigned at least one frequency subband from the first set or the common set.

6. The method of claim 1, wherein the system resources are time slots, and wherein the terminal is assigned at least one time slot from the first set or the common set.

7. The method of claim 1, wherein the system resources are radio frequency (RF) channels, and wherein the terminal is assigned at least one RF channel from the first set or the common set.

8. The method of claim 1, wherein the system resources in the common set are allocable to terminals in softer handoff and communicating with the first sector and the at least one other sector.

9. The method of claim 1, wherein the system resources in the common set are allocable to terminals located on a boundary between the first sector and the at least one other sector.

10. The method of claim 1, wherein the cell includes the first sector and second and third sectors, and wherein the common set includes system resources with little interference, if any, from the first, second, and third sectors in the cell.

11. The method of claim 1, wherein the cell includes the first sector and second and third sectors, and wherein the common set includes system resources with little interference, if any, from the first and second sectors in the cell.

12. The method of claim 11, wherein the system resources in the common set are included in a second set of system resources allocable to terminals in the third cell.

13. The method of claim 1, wherein the determining the channel condition for the terminal comprises

obtaining pilot measurements for the terminal, and

determining amount of interference observed by the terminal from the at least one other sector based on the pilot measurements, and wherein the terminal is assigned system resources from the common set if the terminal observes high interference from the at least one other sector.

14. The method of claim 1, wherein the determining the channel condition for the terminal comprises

obtaining received signal quality estimates for the first set and the common set, and wherein the terminal is assigned system resources from the first set or the common set based on the received signal quality estimates.

15. The method of claim 1, wherein the wireless communication system utilizes orthogonal frequency division multiplexing (OFDM), and wherein the system resources in the first set and the common set are frequency subbands obtained via OFDM.

16. The method of claim 1, wherein the wireless communication system is an orthogonal frequency division multiple access (OFDMA) system utilizing frequency hopping, wherein a first plurality of frequency hopping (FH) patterns are defined for the first set and a second plurality of frequency hopping (FH) patterns are defined for the common set, and wherein the terminal is assigned an FH pattern selected from the first or second plurality of FH patterns.

17. A method of allocating frequency subbands in an orthogonal frequency division multiple access (OFDMA) system utilizing frequency hopping (FH), comprising:

determining channel condition for a terminal; and

assigning the terminal with an FH pattern from a first plurality of FH patterns or a second plurality of FH patterns based at least on the channel condition for the terminal, the first plurality of FH patterns being defined for a first set of frequency subbands and the second plurality of FH patterns being defined for a common set of frequency subbands, the first set and the common set being non-overlapping and including different frequency subbands, the first set including frequency subbands allocable to terminals in a first sector of a cell, and the common set including frequency subbands with little interference, if any, from the first sector and at least one other sector in the cell.

18. The method of claim 17, further comprising:

classifying the terminal into one of a plurality of groups based at least on the channel condition for the terminal, number of FH patterns in the first and second pluralities of FH patterns, number of other terminals to be assigned FH patterns in the first and second pluralities of FH patterns, or any combination thereof, and wherein the terminal is assigned the FH pattern based at least on the group in which the terminal is classified.

19. An apparatus in a wireless communication system, comprising:

a controller operable to determine channel condition for a terminal; and

a scheduler operable to assign the terminal with system resources from a first set or a common set based at least on the channel condition for the terminal, the first set and the common set being non-overlapping and including different system resources, the first set including system resources allocable to terminals in a first sector of a cell, and the common set including system resources with little interference, if any, from the first sector and at least one other sector in the cell.

20. The apparatus of claim 19, wherein the cell includes the first sector and second and third sectors, and wherein the common set includes system resources with little interference, if any, from the first, second, and third sectors in the cell.

21. The apparatus of claim 19, wherein the cell includes the first sector and second and third sectors, and wherein the common set includes system resources with little interference, if any, from the first and second sectors in the cell.

22. An apparatus in a wireless communication system, comprising:

means for determining channel condition for a terminal; and

means for assigning the terminal with system resources from a first set or a common set based at least on the channel condition for the terminal, the first set and the common set being non-overlapping and including different system resources, the first set including system resources allocable to terminals in a first sector of a cell, and the common set including system resources with little interference, if any, from the first sector and at least one other sector in the cell.

23. The apparatus of claim 22, wherein the cell includes the first sector and second and third sectors, and wherein the common set includes system resources with little interference, if any, from the first, second, and third sectors in the cell.

24. The apparatus of claim 22, wherein the cell includes the first sector and second and third sectors, and wherein the common set includes system resources with little interference, if any, from the first and second sectors in the cell.

25. A method of allocating system resources in a wireless communication system, comprising:

forming at least one common set of system resources from among total system resources available for a cell, each common set being defined for a different combination of at least two sectors in the cell and including system resources with little interference, if any, from the at least two sectors; and

forming a sector-specific set of system resources for each sector in the cell, the sector-specific set for each sector including all of the total system resources except for system resources in each common set defined for the sector, and

wherein terminals in the cell are assigned system resources in the sector-specific set for each sector and the at least one common set based at least on channel conditions for the terminals.

26. The method of claim 25, wherein the wireless communication system utilizes orthogonal frequency division multiplexing (OFDM), and wherein the total system resources are a plurality of frequency subbands obtained via OFDM.

27. The method of claim 26, wherein the cell includes first, second, and third sectors, and wherein each sector is associated with a first common set of frequency subbands with little interference, if any, from the first, second, and third sectors.

28. The method of claim 27, wherein the first sector is further associated with second and third common sets, the second common set including frequency subbands with little interference, if any, from the first and second sectors, and the third common set including frequency subbands with little interference, if any, from the first and third sectors.

29. An apparatus in a wireless communication system, comprising:

means for forming at least one common set of system resources from among total system resources available for a cell, each common set being defined for a different combination of at least two sectors in the cell and including system resources with little interference, if any, from the at least two sectors; and

means for forming a sector-specific set of system resources for each sector in the cell, the sector-specific set for each sector including all of the total system resources except for system resources in each common set defined for the sector, and

wherein terminals in the cell are assigned system resources in the sector-specific set for each sector and the at least one common set based at least on channel conditions for the terminals.

30. A method of transmitting data in a wireless communication system, comprising:

obtaining an assignment of system resources for a terminal, the system resources assigned to the terminal being selected from a first set or a common set based at least on channel condition for the terminal, the first set and the common set being non-overlapping and including different system resources, the first set including system resources allocable to terminals in a first sector of a cell, and the common set including system resources with little interference, if any, from the first sector and at least one other sector in the cell; and

generating a control indicative of the system resources assigned to the terminal.

31. The method of claim 30, further comprising:

processing data for the terminal to obtain data symbols; and

mapping the data symbols onto the system resources assigned to the terminal based on the control.

32. The method of claim 30, further comprising:

processing a received data transmission to obtain received symbols; and

demapping received symbols from the system resources assigned to the terminal based on the control.

33. The method of claim 30, wherein the terminal is assigned system resources from the common set, and wherein data is sent to the terminal from at least two base stations for at least two sectors.

34. The method of claim 33, further comprising:

receiving data transmissions from the at least two base stations;

processing the received data transmission from each base station to obtain soft-decision symbols for the base station;

combining soft-decision symbols obtained for the at least two base stations; and

decoding combined soft-decision symbols to obtain decoded data for the terminal.

35. The method of claim 30, wherein the terminal is assigned system resources from the common set, and wherein data is sent by the terminal to at least two base stations for at least two sectors.

36. The method of claim 35, further comprising:

receiving a data transmission from the terminal by the at least two base stations;

processing the received data transmission at each base station to obtain soft-decision symbols for the terminal;

combining soft-decision symbols obtained for the terminal by the at least two base stations; and

decoding the combined soft-decision symbols to obtain decoded data for the terminal.

37. The method of claim 30, wherein the wireless communication system utilizes orthogonal frequency division multiplexing (OFDM), and wherein the system resources assigned to the terminal comprise at least one frequency subband.

38. The method of claim 30, wherein the wireless communication system is an orthogonal frequency division multiple access (OFDMA) system utilizing frequency hopping (FH), and wherein the control indicates different frequency subbands to use for data transmission in different time intervals.

39. An apparatus in a wireless communication system, comprising:

a controller operable to obtain an assignment of system resources for a terminal and to generate a control indicative of the system resources assigned to the terminal, the system resources assigned to the terminal being selected from a first set or a common set based at least on channel condition for the terminal, the first set and the common set being non-overlapping and including different system resources, the first set including system resources allocable to terminals in a first sector of a cell, and the common set including system resources with little interference, if any, from the first sector and at least one other sector in the cell.

40. The apparatus of claim 39, further comprising:

a data processor operable to process data for the terminal to obtain data symbols; and

a mapper operable to map the data symbols onto the system resources assigned to the terminal based on the control.

41. The apparatus of claim 39, further comprising:

a demodulator operable to process a received data transmission to obtain received symbols; and

a demappper operable to demap the received symbols from the system resources assigned to the terminal based on the control.

42. An apparatus in a wireless communication system, comprising:

means for obtaining an assignment of system resources for a terminal, the system resources assigned to the terminal being selected from a first set or a common set based at least on channel condition for the terminal, the first set and the common set being non-overlapping and including different system resources, the first set including system resources allocable to terminals in a first sector of a cell, and the common set including system resources with little interference, if any, from the first sector and at least one other sector in the cell; and

means for generating a control indicative of the system resources assigned to the terminal.

43. The apparatus of claim 42, further comprising:

means for processing data for the terminal to obtain data symbols; and

means for mapping the data symbols onto the system resources assigned to the terminal based on the control.

44. The apparatus of claim 42, further comprising:

means for processing a received data transmission to obtain received symbols; and

means for demapping the received symbols from the system resources assigned to the terminal based on the control.