PUCCH RESOURCE DETERMINATION FOR EPDCCH

• US 20140133370A1
• Filed: 08/12/2013
• Published: 05/15/2014
• Est. Priority Date: 11/14/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Wanshi, Xu, Hao, Gaal, Peter
• Granted Patent: US 9,386,576 B2
• Time in Patent Office: Days
• US Class Current: 370/280
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

Methods, systems, and devices are described for indexing control channel elements to determine uplink channel resources. Downlink control messages may be monitored in a set of downlink subframes. The monitoring may include monitoring physical downlink control channel (PDCCH) messages in at least one of the subframes and monitoring enhanced physical downlink control channel (EPDCCH) messages in at least one of the subframes. A downlink control message may be received in at least one subframe. The downlink control message may include an EPDCCH message. An index for enhanced control channel elements (ECCEs) may be determined based at least in part on the set of downlink subframes. The determined index of the ECCEs may be used to identify uplink control channel resources. The ECCEs may be indexed in a manner that is specific to a cell in a wireless communication system, or which is configured for a particular mobile device.

Claims

1. A method of indexing control channel elements in wireless communications, comprising:

monitoring downlink control messages in a set of downlink subframes, where the monitoring comprises monitoring physical downlink control channel (PDCCH) messages in at least one of the subframes of the set and monitoring enhanced physical downlink control channel (EPDCCH) messages in at least one of the subframes of the set;

receiving at least one downlink control message in at least one subframe in the set of downlink subframes, the downlink control message comprising an EPDCCH message;

determining, based at least in part on the set of downlink subframes, an index for enhanced control channel elements (ECCEs) used to monitor the EPDCCH messages;

identifying uplink control channel resources based at least in part on the index of the ECCEs; and

transmitting an acknowledgement/negative acknowledgement (ACK/NACK) indication associated with the received downlink control message on the identified uplink control channel resources.

2. The method of claim 1, wherein determining the index for ECCEs is based upon a total number of subframes in the set of downlink subframes.

3. The method of claim 2, wherein the total number of subframes comprises subframes in which PDCCH messages are monitored and subframes in which EPDCCH messages are monitored.

4. The method of claim 1, wherein the transmitting the ACK/NACK indication comprises:

transmitting the ACK/NACK indication in a single uplink subframe, the single uplink subframe being a common uplink subframe for each of the subframes in the set of downlink subframes.

5. The method of claim 1, further comprising:

indexing the ECCEs used to monitor the EPDCCH messages.

6. The method of claim 5, wherein indexing the ECCEs comprises:

incrementing an index value in one or more subframes in the set of downlink subframes.

7. The method of claim 6, wherein the index value is incremented in each subframe in the set of downlink subframes.

8. The method of claim 6, further comprising:

receiving a configuration for a plurality of EPDCCH resource sets, each EPDCCH resource set comprising two or more physical resource block (PRB) pairs; and

incrementing the index value for each respective EPDCCH resource set in each subframe in the set of downlink subframes.

9. The method of claim 1, wherein each subframe in the set of downlink subframes comprises one of the PDCCH messages or the EPDCCH messages.

10. The method of claim 1, wherein each subframe in the set of downlink subframes comprises an EPDCCH message.

11. The method of claim 1, further comprising:

receiving at least one downlink control message in at least one subframe in the set of downlink subframes, the downlink control message comprising a PDCCH message.

12. The method of claim 11, further comprising:

determining, based at least in part on the set of downlink subframes, an index for control channel elements (CCEs) used to monitor the PDCCH messages;

identifying uplink control channel resources based at least in part on the index of the CCEs; and

transmitting an ACK/NACK indication for the received downlink control message comprising the PDCCH message on the identified uplink control channel resources.

13. The method of claim 12, wherein determining the index for CCEs is based upon a total number of subframes in the set of downlink subframes.

14. The method of claim 13, wherein the total number of subframes comprises subframes in which PDCCH messages are monitored and subframes in which EPDCCH messages are monitored.

15. The method of claim 1, further comprising:

identifying an index associated with the EPDCCH messages, the index based on all of the subframes in the set of downlink subframes.

16. The method of claim 15, wherein each of the subframes in the set of downlink subframes are contiguous downlink subframes.

17. The method of claim 1, wherein the wireless communications are performed in a wireless communication system that comprises a time division duplexed (TDD) long term evolution (LTE) system.

18. The method of claim 17, wherein the number of subframes in the set of downlink subframes depends at least in part on a downlink and uplink subframe configuration specified for the TDD LTE system.

19. The method of claim 1, wherein the downlink control message comprises a downlink control information (DCI) channel message.

20. The method of claim 1, wherein the EPDCCH messages are monitored in a search space specific to the mobile device.

21. The method of claim 1, wherein the EPDCCH messages are monitored in a search space common to two or more mobile devices.

22. An apparatus for indexing control channel elements in wireless communications, comprising:

means for monitoring downlink control messages in a set of downlink subframes, where the monitoring comprises monitoring physical downlink control channel (PDCCH) messages in at least one of the subframes of the set and monitoring enhanced physical downlink control channel (EPDCCH) messages in at least one of the subframe of the set;

means for receiving at least one downlink control message in at least one subframe in the set of downlink subframes, the downlink control message comprising an EPDCCH message;

means for determining, based at least in part on the set of downlink subframes, an index for enhanced control channel elements (ECCEs) used to monitor the EPDCCH messages;

means for identifying uplink control channel resources based at least in part on the index of the ECCEs; and

means for transmitting an acknowledgement/negative acknowledgement (ACK/NACK) indication associated with the received downlink control message on the identified uplink control channel resources.

23. The apparatus of claim 22, wherein the means for determining the index for ECCEs is based upon a total number of subframes in the set of downlink subframes.

24. The apparatus of claim 23, wherein the total number of subframes comprises subframes in which PDCCH messages are monitored and subframes in which EPDCCH messages are monitored.

25. The apparatus of claim 22, wherein the means for transmitting the ACK/NACK indication comprises:

means for transmitting the ACK/NACK indication in a single uplink subframe, the single uplink subframe being a common uplink subframe for each of the subframes in the set of downlink subframes.

26. The apparatus of claim 22, further comprising:

means for indexing the ECCEs used to monitor the EPDCCH messages.

27. The apparatus of claim 26, wherein the means for indexing the ECCEs comprises:

means for incrementing an index value in one or more subframes in the set of downlink subframes.

28. The apparatus of claim 27, wherein the index value is incremented in each subframe in the set of downlink subframes.

29. The apparatus of claim 27, further comprising:

means for receiving a configuration for a plurality of EPDCCH resource sets, each EPDCCH resource set comprising two or more physical resource block (PRB) pairs; and

means for incrementing the index value for each respective EPDCCH resource set in each subframe in the set of downlink subframes.

30. The apparatus of claim 22, wherein each subframe in the set of downlink subframes comprises one of the PDCCH messages or the EPDCCH messages.

31. The apparatus of claim 22, wherein each subframe in the set of downlink subframes comprises an EPDCCH message.

32. The apparatus of claim 22, further comprising:

means for receiving at least one downlink control message in at least one subframe in the set of downlink subframes, the downlink control message comprising a PDCCH message.

33. The apparatus of claim 22, further comprising:

means for determining, based at least in part on the set of downlink subframes, an index for control channel elements (CCEs) used to monitor the PDCCH messages;

means for identifying uplink control channel resources based at least in part on the index of the CCEs; and

means for transmitting an ACK/NACK indication for the received downlink control message comprising the PDCCH message on the identified uplink control channel resources.

34. The apparatus of claim 33, wherein the means for determining the index for CCEs is based upon a total number of subframes in the set of downlink subframes.

35. The apparatus of claim 34, wherein the total number of subframes comprises subframes in which PDCCH messages are monitored and subframes in which EPDCCH messages are monitored.

36. The apparatus of claim 22, further comprising:

means for identifying an index associated with the EPDCCH messages, the index based on all of the subframes in the set of downlink subframes.

37. The apparatus of claim 36, wherein each of the subframes in the set of downlink subframes are contiguous downlink subframes.

38. The apparatus of claim 22, wherein the wireless communications are performed in a wireless communication system that comprises a time division duplexed (TDD) long term evolution (LTE) system.

39. The apparatus of claim 38, wherein the number of subframes in the set of downlink subframes depends at least in part on a downlink and uplink subframe configuration specified for the TDD LTE system.

40. The apparatus of claim 22, wherein the downlink control message comprises a downlink control information (DCI) channel message.

41. The apparatus of claim 22, wherein the EPDCCH messages are monitored in a search space specific to the mobile device.

42. The apparatus of claim 22, wherein the EPDCCH messages are monitored in a search space common to two or more mobile devices.

43. An apparatus for indexing control channel elements in wireless communications, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

monitor downlink control messages in a set of downlink subframes, where the monitoring comprises monitoring physical downlink control channel (PDCCH) messages in at least one of the subframes of the set and monitoring enhanced physical downlink control channel (EPDCCH) messages in at least one of the subframe of the set;

receive at least one downlink control message in at least one subframe in the set of downlink subframes, the downlink control message comprising an EPDCCH message;

determine, based at least in part on the set of downlink subframes, an index for enhanced control channel elements (ECCEs) used to monitor the EPDCCH messages;

identify uplink control channel resources based at least in part on the index of the ECCEs; and

transmit an acknowledgement/negative acknowledgement (ACK/NACK) indication associated with the received downlink control message on the identified uplink control channel resources.

44. The apparatus of claim 43, wherein the instructions for determining the index for ECCEs are based upon a total number of subframes in the set of downlink subframes.

45. The apparatus of claim 44, wherein the total number of subframes comprises subframes in which PDCCH messages are monitored and subframes in which EPDCCH messages are monitored.

46. The apparatus of claim 43, wherein the instructions for transmitting the ACK/NACK indication are executable by the processor to:

transmit the ACK/NACK indication in a single uplink subframe, the single uplink subframe being a common uplink subframe for each of the subframes in the set of downlink subframes.

47. The apparatus of claim 43, wherein the instructions are executable by the processor to:

index the ECCEs used to monitor the EPDCCH messages.

48. The apparatus of claim 47, wherein the instructions for indexing the ECCEs are executable by the processor to:

increment an index value in one or more subframes in the set of downlink subframes.

49. The apparatus of claim 48, wherein the index value is incremented in each subframe in the set of downlink subframes.

50. The apparatus of claim 48, wherein the instructions are executable by the processor to:

receive a configuration for a plurality of EPDCCH resource sets, each EPDCCH resource set comprising two or more physical resource block (PRB) pairs; and

increment the index value for each respective EPDCCH resource set in each subframe in the set of downlink subframes.

51. The apparatus of claim 43, wherein each subframe in the set of downlink subframes comprises one of the PDCCH messages or the EPDCCH messages.

52. The apparatus of claim 43, wherein each subframe in the set of downlink subframes comprises an EPDCCH message.

53. A computer program product for indexing control channel elements in wireless communications, the computer program product comprising a non-transitory computer-readable medium storing instructions executable by a processor to:

monitor downlink control messages in a set of downlink subframes, where the monitoring comprises monitoring physical downlink control channel (PDCCH) messages in at least one of the subframes of the set and monitoring enhanced physical downlink control channel (EPDCCH) messages in at least one of the subframe of the set;

receive at least one downlink control message in at least one subframe in the set of downlink subframes, the downlink control message comprising an EPDCCH message;

determine, based at least in part on the set of downlink subframes, an index for enhanced control channel elements (ECCEs) used to monitor the EPDCCH messages;

identify uplink control channel resources based at least in part on the index of the ECCEs; and

transmit an acknowledgement/negative acknowledgement (ACK/NACK) indication associated with the received downlink control message on the identified uplink control channel resources.

54. The computer program product of claim 53, wherein the instructions for determining the index for ECCEs are based upon a total number of subframes in the set of downlink subframes.

55. The computer program product of claim 54, wherein the total number of subframes comprises subframes in which PDCCH messages are monitored and subframes in which EPDCCH messages are monitored.

56. The computer program product of claim 53, wherein the instructions for transmitting the ACK/NACK indication are executable by the processor to:

transmit the ACK/NACK indication in a single uplink subframe, the single uplink subframe being a common uplink subframe for each of the subframes in the set of downlink subframes.

57. The computer program product of claim 53, wherein the instructions are executable by the processor to:

index the ECCEs used to monitor the EPDCCH messages.