PDCCH SEARCH SPACE DESIGN FOR LTE-A MULTI-CARRIER OPERATION

• US 20110110316A1
• Filed: 04/29/2010
• Published: 05/12/2011
• Est. Priority Date: 04/30/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Montojo, Juan, Chen, Wanshi, Gaal, Peter
• Granted Patent: US 8,989,208 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A method, an apparatus, and a computer program product are provided in which a configuration for utilizing a plurality of carriers is received. In addition, a set of PDCCH candidates on a carrier of the plurality of carriers are determined for obtaining DCI for at least one carrier of the plurality of carriers. The number of PDCCH candidates is a function of a number of carriers of the at least one carrier.

Claims

1. A method of wireless communication, comprising:

receiving a configuration for utilizing a plurality of carriers; and

determining a set of physical downlink control channel (PDCCH) candidates on a carrier of the plurality of carriers for obtaining downlink control information (DCI) for at least one carrier of the plurality of carriers, the number of PDCCH candidates being a function of a number of carriers of said at least one carrier.

2. The method of claim 1, further comprising searching for the DCI in the carrier.

3. The method of claim 1, wherein a maximum of the number of the PDCCH candidates increases linearly based on the number of carriers of said at least one carrier.

4. The method of claim 1, wherein the number of the PDCCH candidates is also function of a control channel element (CCE) aggregation level.

5. The method of claim 1, wherein the determining the set of PDCCH candidates comprises determining at least one search space for obtaining the DCI, the PDCCH candidates being within the at least one search space.

6. The method of claim 5, wherein a number of the at least one search space is based on the number of carriers of said at least one carrier.

7. The method of claim 5, wherein the number of the at least one search space increases linearly based on the number of carriers of said at least one carrier.

8. The method of claim 5, wherein a starting control channel element (CCE) of the at least one search space on said carrier is randomly derived based on at least one of a user equipment (UE) specific identification (ID), a number of available CCEs on said at least one carrier, or a CCE aggregation level.

9. The method of claim 5, wherein the at least one search space comprises a first search space and the method further comprises determining a second search space on a second carrier for obtaining DCI for one or more of the plurality of carriers, wherein the first search space and the second search space are offset from each other by an offset.

10. The method of claim 9, wherein each search space for each CCE aggregation level has n control channel elements (CCEs) and the search spaces overlap or partially overlap each other such that an absolute value of the offset is less than n.

11. The method of claim 9, wherein the offset is a multiple of a control channel element (CCE) aggregation level for the search spaces including the PDCCH candidates.

12. The method of claim 9, wherein the offset is configured through one of statically, semi-statically through radio resource control (RRC) signaling, or dynamically.

13. The method of claim 5, wherein at least one of the search spaces is shared between at least two carriers and wherein the method further comprises monitoring said at least one of the search spaces for DCI applicable to any one of at least two carriers of the plurality of carriers.

14. A method of wireless communication, comprising:

configuring a user equipment with a plurality of carriers; and

determining a set of physical downlink control channel (PDCCH) candidates for transmitting downlink control information (DCI) for at least one carrier of the plurality of carriers, the number of PDCCH candidates being a function of a number of the plurality of carriers.

15. The method of claim 14, further comprising transmitting the DCI in the at least one carrier in order to schedule a PDCCH assignment.

16. An apparatus for wireless communication, comprising:

means for receiving a configuration for utilizing a plurality of carriers; and

means for determining a set of physical downlink control channel (PDCCH) candidates on a carrier of the plurality of carriers for obtaining downlink control information (DCI) for at least one carrier of the plurality of carriers, the number of PDCCH candidates being a function of a number of carriers of said at least one carrier.

17. The apparatus of claim 16, further comprising means for searching for the DCI in the carrier.

18. The apparatus of claim 16, wherein a maximum of the number of the PDCCH candidates increases linearly based on the number of carriers of said at least one carrier.

19. The apparatus of claim 16, wherein the number of the PDCCH candidates is also function of a control channel element (CCE) aggregation level.

20. The apparatus of claim 16, wherein the means for determining the set of PDCCH candidates determines at least one search space for obtaining the DCI, the PDCCH candidates being within the at least one search space.

21. The apparatus of claim 20, wherein a number of the at least one search space is based on the number of carriers of said at least one carrier.

22. The apparatus of claim 20, wherein the number of the at least one search space increases linearly based on the number of carriers of said at least one carrier.

23. The apparatus of claim 20, wherein a starting control channel element (CCE) of the at least one search space on said carrier is randomly derived based on at least one of a user equipment (UE) specific identification (ID), a number of available CCEs on said at least one carrier, or a CCE aggregation level.

24. The apparatus of claim 20, wherein the at least one search space comprises a first search space and the apparatus further comprises means for determining a second search space on a second carrier for obtaining DCI for one or more of the plurality of carriers, wherein the first search space and the second search space are offset from each other by an offset.

25. The apparatus of claim 24, wherein each search space for each CCE aggregation level has n control channel elements (CCEs) and the search spaces overlap or partially overlap each other such that an absolute value of the offset is less than n.

26. The apparatus of claim 24, wherein the offset is a multiple of a control channel element (CCE) aggregation level for the search spaces including the PDCCH candidates.

27. The apparatus of claim 24, wherein the offset is configured through one of statically, semi-statically through radio resource control (RRC) signaling, or dynamically.

28. The apparatus of claim 20, wherein at least one of the search spaces is shared between at least two carriers and wherein the apparatus further comprises means for monitoring said at least one of the search spaces for DCI applicable to any one of at least two carriers of the plurality of carriers.

29. An apparatus for wireless communication, comprising:

means for configuring a user equipment with a plurality of carriers; and

means for determining a set of physical downlink control channel (PDCCH) candidates for transmitting downlink control information (DCI) for at least one carrier of the plurality of carriers, the number of PDCCH candidates being a function of a number of the plurality of carriers.

30. The apparatus of claim 29, further comprising means for transmitting the DCI in the at least one carrier in order to schedule a PDCCH assignment.

31. A computer program product, comprising:

a computer-readable medium comprising code for;

receiving a configuration for utilizing a plurality of carriers; and

determining a set of physical downlink control channel (PDCCH) candidates on a carrier of the plurality of carriers for obtaining downlink control information (DCI) for at least one carrier of the plurality of carriers, the number of PDCCH candidates being a function of a number of carriers of said at least one carrier.

32. The computer program product of claim 31, wherein the computer-readable medium further comprises code for searching for the DCI in the carrier.

33. The computer program product of claim 31, wherein a maximum of the number of the PDCCH candidates increases linearly based on the number of carriers of said at least one carrier.

34. The computer program product of claim 31, wherein the number of the PDCCH candidates is also function of a control channel element (CCE) aggregation level.

35. The computer program product of claim 31, wherein the code for determining the set of PDCCH candidates determines at least one search space for obtaining the DCI, the PDCCH candidates being within the at least one search space.

36. The computer program product of claim 35, wherein a number of the at least one search space is based on the number of carriers of said at least one carrier.

37. The computer program product of claim 35, wherein the number of the at least one search space increases linearly based on the number of carriers of said at least one carrier.

38. The computer program product of claim 35, wherein a starting control channel element (CCE) of the at least one search space on said carrier is randomly derived based on at least one of a user equipment (UE) specific identification (ID), a number of available CCEs on said at least one carrier, or a CCE aggregation level.

39. The computer program product of claim 35, wherein the at least one search space comprises a first search space and the computer-readable medium further comprises code for determining a second search space on a second carrier for obtaining DCI for one or more of the plurality of carriers, wherein the first search space and the second search space are offset from each other by an offset.

40. The computer program product of claim 39, wherein each search space for each CCE aggregation level has n control channel elements (CCEs) and the search spaces overlap or partially overlap each other such that an absolute value of the offset is less than n.

41. The computer program product of claim 39, wherein the offset is a multiple of a control channel element (CCE) aggregation level for the search spaces including the PDCCH candidates.

42. The computer program product of claim 39, wherein the offset is configured through one of statically, semi-statically through radio resource control (RRC) signaling, or dynamically.

43. The computer program product of claim 35, wherein at least one of the search spaces is shared between at least two carriers and wherein the computer-readable medium further comprises code for monitoring said at least one of the search spaces for DCI applicable to any one of at least two carriers of the plurality of carriers.

44. A computer program product, comprising:

a computer-readable medium comprising code for;

configuring a user equipment with a plurality of carriers; and

determining a set of physical downlink control channel (PDCCH) candidates for transmitting downlink control information (DCI) for at least one carrier of the plurality of carriers, the number of PDCCH candidates being a function of a number of the plurality of carriers.

45. The computer program product of claim 44, wherein the computer-readable medium further comprises code for transmitting the DCI in the at least one carrier in order to schedule a PDCCH assignment.

46. An apparatus for wireless communication, comprising:

a processing system configured to;

receive a configuration for utilizing a plurality of carriers; and

determine a set of physical downlink control channel (PDCCH) candidates on a carrier of the plurality of carriers for obtaining downlink control information (DCI) for at least one carrier of the plurality of carriers, the number of PDCCH candidates being a function of a number of carriers of said at least one carrier.

47. The apparatus of claim 46, wherein the processing system is further configured to search for the DCI in the carrier.

48. The apparatus of claim 46, wherein a maximum of the number of the PDCCH candidates increases linearly based on the number of carriers of said at least one carrier.

49. The apparatus of claim 46, wherein the number of the PDCCH candidates is also function of a control channel element (CCE) aggregation level.

50. The apparatus of claim 46, wherein to determine the set of PDCCH candidates, the processing system is configured to determine at least one search space for obtaining the DCI, the PDCCH candidates being within the at least one search space.

51. The apparatus of claim 50, wherein a number of the at least one search space is based on the number of carriers of said at least one carrier.

52. The apparatus of claim 50, wherein the number of the at least one search space increases linearly based on the number of carriers of said at least one carrier.

53. The apparatus of claim 50, wherein a starting control channel element (CCE) of the at least one search space on said carrier is randomly derived based on at least one of a user equipment (UE) specific identification (ID), a number of available CCEs on said at least one carrier, or a CCE aggregation level.

54. The apparatus of claim 50, wherein the at least one search space comprises a first search space and the processing system is further configured to determine a second search space on a second carrier for obtaining DCI for one or more of the plurality of carriers, wherein the first search space and the second search space are offset from each other by an offset.

55. The apparatus of claim 54, wherein each search space for each CCE aggregation level has n control channel elements (CCEs) and the search spaces overlap or partially overlap each other such that an absolute value of the offset is less than n.

56. The apparatus of claim 54, wherein the offset is a multiple of a control channel element (CCE) aggregation level for the search spaces including the PDCCH candidates.

57. The apparatus of claim 54, wherein the offset is configured through one of statically, semi-statically through radio resource control (RRC) signaling, or dynamically.

58. The apparatus of claim 50, wherein at least one of the search spaces is shared between at least two carriers and wherein the processing system is further configured to monitor said at least one of the search spaces for DCI applicable to any one of at least two carriers of the plurality of carriers.

59. An apparatus for wireless communication, comprising:

a processing system configured to;

configure a user equipment with a plurality of carriers; and

determine a set of physical downlink control channel (PDCCH) candidates for transmitting downlink control information (DCI) for at least one carrier of the plurality of carriers, the number of PDCCH candidates being a function of a number of the plurality of carriers.

60. The apparatus of claim 59, wherein the processing system is further configured to transmit the DCI in the at least one carrier in order to schedule a PDCCH assignment.