FALLBACK OPERATION FOR CROSS-CARRIER SIGNALING IN MULTI-CARRIER OPERATION

• US 20120009923A1
• Filed: 12/22/2010
• Published: 01/12/2012
• Est. Priority Date: 12/29/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Wanshi, Damnjanovic, Jelena M., Gaal, Peter, Montojo, Juan, Damnjanovic, Aleksandar
• Granted Patent: US 9,124,406 B2
• Time in Patent Office: Days
• US Class Current: 455/434
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path

Abstract

Techniques for supporting fallback operation in a multi-carrier communication system are described. In one aspect, a UE may determine at least one first downlink control information (DCI) format to monitor on a first carrier. The UE may monitor for the first DCI format(s) on the first carrier to detect DCI sent to the UE. The UE may receive a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling, and may determine at least one second DCI format to monitor on the first carrier based on the reconfiguration message. The UE may monitor for the first DCI format(s) and the second DCI format(s) on the first carrier after receiving the reconfiguration message.

Claims

1. A method of wireless communication, comprising:

determining at least one first downlink control information (DCI) format to monitor on a first carrier at a user equipment (UE);

monitoring for the at least one first DCI format on the first carrier to detect DCI sent to the UE;

receiving at the UE a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling;

determining at least one second DCI format to monitor on the first carrier at the UE based on the reconfiguration message; and

monitoring for the at least one first DCI format and the at least one second DCI format on the first carrier after receiving the reconfiguration message to detect DCI sent to the UE.

2. The method of claim 1, wherein each second DCI format comprises a corresponding first DCI format and at least one additional field supporting cross-carrier signaling.

3. The method of claim 2, wherein the at least one additional field comprises a cross-carrier indication field (CIF) indicating a carrier on which a data transmission is scheduled.

4. The method of claim 1, wherein the at least one first DCI format has a first size, and wherein the at least one second DCI format has a second size different from the first size.

5. The method of claim 1, further comprising:

determining a third DCI format to monitor on the first carrier prior to receiving the reconfiguration message, the third DCI format being associated with a transmission mode of the UE on the first carrier;

monitoring for the third DCI format on the first carrier prior to receiving the reconfiguration message to detect DCI sent to the UE;

determining a fourth DCI format to monitor on the first carrier after receiving the reconfiguration message, the fourth DCI format being associated with the transmission mode of the UE on the first carrier; and

monitoring for the fourth DCI format to detect DCI sent to the UE and not monitoring for the third DCI format on the first carrier after receiving the reconfiguration message.

6. The method of claim 1, further comprising:

monitoring for the at least one second DCI format but not the at least one first DCI format on a second carrier after receiving the reconfiguration message.

7. The method of claim 1, further comprising:

monitoring for the at least one first DCI format and the at least one second DCI format on a subset of the plurality of carriers after receiving the reconfiguration message, the subset of the plurality of carriers including the first carrier; and

monitoring for the at least one second DCI format and not monitoring for the at least one first DCI format on remaining ones of the plurality of carriers after receiving the reconfiguration message.

8. The method of claim 1, wherein the monitoring for the at least one first DCI format and the at least one second DCI format comprises monitoring for the at least one second DCI format in all search spaces for the UE on the first carrier.

9. The method of claim 1, wherein the monitoring for the at least one first DCI format and the at least one second DCI format comprises monitoring for the at least one second DCI format in a UE-specific search space and not monitoring for the at least one second DCI format in a common search space of the UE on the first carrier.

10. The method of claim 1, wherein the monitoring for the at least one first DCI format and the at least one second DCI format comprises:

determining a plurality of Physical Downlink Control Channel (PDCCH) candidates for the UE on the first carrier, and

decoding the plurality of PDCCH candidates based on the at least one first DCI format and the at least one second DCI format.

11. The method of claim 1, wherein the monitoring for the at least one first DCI format and the at least one second DCI format comprises:

determining a first set of Physical Downlink Control Channel (PDCCH) candidates for the UE on the first carrier,

determining a second set of PDCCH candidates for the UE on the first carrier,

decoding the first set of PDCCH candidates for the at least one first DCI format but not the at least one second DCI format, and

decoding the second set of PDCCH candidates for the at least one first DCI format and the at least one second DCI format.

12. The method of claim 11, wherein the first set of PDCCH candidates is for a common search space on the first carrier, and wherein the second set of PDCCH candidates is for a UE-specific search space on the first carrier.

13. The method of claim 11, wherein the first and second sets of PDCCH candidates correspond to different parts of a search space for the UE on the first carrier.

14. The method of claim 11, wherein the first and second sets of PDCCH candidates correspond to different parts of an aggregation level for a search space for the UE on the first carrier.

15. The method of claim 1, further comprising:

determining a third DCI format to monitor on the first carrier prior to receiving the reconfiguration message, the third DCI format being associated with a transmission mode of the UE on the first carrier;

monitoring for the third DCI format on the first carrier prior to receiving the reconfiguration message to detect DCI sent to the UE; and

monitoring for the at least one first DCI format and the at least one second DCI format, and not monitoring for the third DCI format, on the first carrier during a transition interval for reconfiguration of the UE based on the reconfiguration message.

16. The method of claim 15, further comprising:

determining a start of the transition interval based on a time at which the reconfiguration message is received by the UE.

17. The method of claim 15, further comprising:

sending a reconfiguration complete message by the UE;

receiving an acknowledgement for the reconfiguration complete message; and

determining an end of the transition interval based on a time at which the reconfiguration complete message is sent by the UE or a time at which the acknowledgement for the reconfiguration complete message is received by the UE.

18. The method of claim 17, wherein the determining the end of the transition interval comprises determining the end of the transition interval based further on a timer, wherein the timer is started at the time at which the reconfiguration complete message is sent or at the time at which the acknowledgement for the reconfiguration complete message is received.

19. The method of claim 1, further comprising:

receiving data on a single carrier by the UE prior to receiving the reconfiguration message; and

receiving data on the plurality of carriers with cross-carrier signaling by the UE after receiving the reconfiguration message.

20. The method of claim 1, further comprising:

receiving data on the plurality of carriers without cross-carrier signaling by the UE prior to receiving the reconfiguration message; and

receiving data on the plurality of carriers with cross-carrier signaling by the UE after receiving the reconfiguration message.

21. The method of claim 1, wherein the at least one first DCI format includes DCI format 1A for downlink grants, or DCI format 0 for uplink grants, or both.

22. The method of claim 1, wherein the at least one second DCI format includes DCI format 1A′

comprising DCI format 1A and a cross-carrier indication field (CIF), or DCI format 0′

comprising DCI format 0 and the CIF, or both.

23. An apparatus for wireless communication, comprising:

means for determining at least one first downlink control information (DCI) format to monitor on a first carrier at a user equipment (UE);

means for monitoring for the at least one first DCI format on the first carrier to detect DCI sent to the UE;

means for receiving at the UE a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling;

means for determining at least one second DCI format to monitor on the first carrier at the UE based on the reconfiguration message; and

means for monitoring for the at least one first DCI format and the at least one second DCI format on the first carrier after receiving the reconfiguration message to detect DCI sent to the UE.

24. The apparatus of claim 23, further comprising:

means for monitoring for the at least one first DCI format and the at least one second DCI format on a subset of the plurality of carriers after receiving the reconfiguration message, the subset of the plurality of carriers including the first carrier; and

means for monitoring for the at least one second DCI format but not the at least one first DCI format on remaining ones of the plurality of carriers after receiving the reconfiguration message.

25. The apparatus of claim 23, wherein the means for monitoring for the at least one first DCI format and the at least one second DCI format comprises means for monitoring for the at least one second DCI format in a UE-specific search space but not a common search space for the UE on the first carrier.

26. The apparatus of claim 23, wherein the means for monitoring for the at least one first DCI format and the at least one second DCI format comprises:

means for determining a first set of Physical Downlink Control Channel (PDCCH) candidates for the UE on the first carrier,

means for determining a second set of PDCCH candidates for the UE on the first carrier,

means for decoding the first set of PDCCH candidates for the at least one first DCI format but not the at least one second DCI format, and

means for decoding the second set of PDCCH candidates for the at least one first DCI format and the at least one second DCI format.

27. An apparatus for wireless communication, comprising:

at least one processor configured to;

determine at least one first downlink control information (DCI) format to monitor on a first carrier at a user equipment (UE),

monitor for the at least one first DCI format on the first carrier to detect DCI sent to the UE,

receive at the UE a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling,

determine at least one second DCI format to monitor on the first carrier at the UE based on the reconfiguration message, and

monitor for the at least one first DCI format and the at least one second DCI format on the first carrier after receiving the reconfiguration message to detect DCI sent to the UE; and

a memory coupled to the at least one processor.

28. The apparatus of claim 27, wherein the at least one processor is configured to monitor for the at least one first DCI format and the at least one second DCI format on a subset of the plurality of carriers after receiving the reconfiguration message, the subset of the plurality of carriers including the first carrier, and to monitor for the at least one second DCI format but not the at least one first DCI format on remaining ones of the plurality of carriers after receiving the reconfiguration message.

29. The apparatus of claim 27, wherein the at least one processor is configured to monitor for the at least one second DCI format in a UE-specific search space but not a common search space for the UE on the first carrier.

30. The apparatus of claim 27, wherein the at least one processor is configured to determine a first set of Physical Downlink Control Channel (PDCCH) candidates for the UE on the first carrier, to determine a second set of PDCCH candidates for the UE on the first carrier, to decode the first set of PDCCH candidates for the at least one first DCI format but not the at least one second DCI format, and to decode the second set of PDCCH candidates for the at least one first DCI format and the at least one second DCI format.

31. A computer program product, comprising:

a non-transitory computer-readable medium comprising;

code for causing at least one computer to determine at least one first downlink control information (DCI) format to monitor on a first carrier at a user equipment (UE),

code for causing the at least one computer to monitor for the at least one first DCI format on the first carrier to detect DCI sent to the UE,

code for causing the at least one computer to receive at the UE a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling,

code for causing the at least one computer to determine at least one second DCI format to monitor on the first carrier at the UE based on the reconfiguration message, and

code for causing the at least one computer to monitor for the at least one first DCI format and the at least one second DCI format on the first carrier after receiving the reconfiguration message to detect DCI sent to the UE.

32. A method of wireless communication, comprising:

determining at least one first downlink control information (DCI) format monitored by a user equipment (UE) on a first carrier;

sending DCI on the first carrier to the UE based on the at least one first DCI format;

sending to the UE a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling;

determining at least one second DCI format monitored by the UE on the first carrier in response to the reconfiguration message; and

sending DCI on the first carrier to the UE based on the at least one first DCI format and the at least one second DCI format after sending the reconfiguration message.

33. The method of claim 32, further comprising:

determining a third DCI format monitored by the UE on the first carrier prior to sending the reconfiguration message, the third DCI format being associated with a transmission mode of the UE on the first carrier;

sending DCI on the first carrier to the UE based further on the third DCI format prior to sending the reconfiguration message;

determining a fourth DCI format monitored by the UE on the first carrier after sending the reconfiguration message, the fourth DCI format being associated with the transmission mode of the UE on the first carrier; and

sending DCI on the first carrier to the UE based further on the fourth DCI format but not the third DCI format after sending the reconfiguration message.

34. The method of claim 32, further comprising:

sending DCI to the UE on a second carrier based on the at least one second DCI format but not the at least one first DCI format after sending the reconfiguration message.

35. The method of claim 32, further comprising:

sending DCI to the UE based on the at least one first DCI format and the at least one second DCI format on a subset of the plurality of carriers after sending the reconfiguration message; and

sending DCI to the UE based on the at least one second DCI format but not the at least one first DCI format on remaining ones of the plurality of carriers after sending the reconfiguration message.

36. The method of claim 32, wherein the sending DCI on the first carrier to the UE based on the at least one first DCI format and the at least one second DCI format comprises sending DCI to the UE based on the at least one second DCI format in a UE-specific search space but not a common search space on the first carrier.

37. The method of claim 32, wherein the sending DCI on the first carrier to the UE based on the at least one first DCI format and the at least one second DCI format comprises:

sending DCI based on the at least one first DCI format but not the at least one second DCI format in a first set of Physical Downlink Control Channel (PDCCH) candidates for the UE on the first carrier, and

sending DCI based on the at least one first DCI format and the at least one second DCI format in a second set of PDCCH candidates for the UE on the first carrier.

38. The method of claim 37, wherein the first set of PDCCH candidates is for a common search space on the first carrier, and wherein the second set of PDCCH candidates is for a UE-specific search space for the UE on the first carrier.

39. The method of claim 37, wherein the first and second sets of PDCCH candidates correspond to different parts of a search space for the UE on the first carrier.

40. The method of claim 37, wherein the first and second sets of PDCCH candidates correspond to different parts of an aggregation level for a search space for the UE on the first carrier.

41. The method of claim 32, further comprising:

sending data on a single carrier to the UE prior to sending the reconfiguration message; and

sending data on the plurality of carriers with cross-carrier signaling to the UE after sending the reconfiguration message.

42. The method of claim 32, further comprising:

sending data on the plurality of carriers without cross-carrier signaling to the UE prior to sending the reconfiguration message; and

sending data on the plurality of carriers with cross-carrier signaling to the UE after sending the reconfiguration message.

43. The method of claim 32, wherein the at least one first DCI format includes DCI format 1A for downlink grants, or DCI format 0 for uplink grants, or both.

44. The method of claim 43, wherein the at least one second DCI format includes DCI format 1A′

comprising DCI format 1A and a cross-carrier indicator field (CIF), or DCI format 0′

comprising DCI format 0 and the CIF, or both.

45. The method of claim 32, further comprising:

generating a first grant for a data transmission to the UE based on one of the at least one first DCI format;

generating a second grant for the data transmission to the UE based on one of the at least one second DCI format; and

sending the first and second grants to the UE.

46. An apparatus for wireless communication, comprising:

means for determining at least one first downlink control information (DCI) format monitored by a user equipment (UE) on a first carrier;

means for sending DCI on the first carrier to the UE based on the at least one first DCI format;

means for sending to the UE a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling;

means for determining at least one second DCI format monitored by the UE on the first carrier in response to the reconfiguration message; and

means for sending DCI on the first carrier to the UE based on the at least one first DCI format and the at least one second DCI format after sending the reconfiguration message.

47. The apparatus of claim 46, further comprising:

means for sending DCI to the UE based on the at least one first DCI format and the at least one second DCI format on a subset of the plurality of carriers after sending the reconfiguration message; and

means for sending DCI to the UE based on the at least one second DCI format but not the at least one first DCI format on remaining ones of the plurality of carriers after sending the reconfiguration message.

48. The apparatus of claim 46, wherein the means for sending DCI on the first carrier to the UE based on the at least one first DCI format and the at least one second DCI format comprises means for sending DCI to the UE based on the at least one second DCI format in a UE-specific search space but not a common search space on the first carrier.

49. The apparatus of claim 46, wherein the means for sending DCI on the first carrier to the UE based on the at least one first DCI format and the at least one second DCI format comprises:

means for sending DCI based on the at least one first DCI format but not the at least one second DCI format in a first set of Physical Downlink Control Channel (PDCCH) candidates for the UE on the first carrier, and

means for sending DCI based on the at least one first DCI format and the at least one second DCI format in a second set of PDCCH candidates for the UE on the first carrier.

50. An apparatus for wireless communication, comprising:

at least one processor configured to;

determine at least one first downlink control information (DCI) format monitored by a user equipment (UE) on a first carrier,

send DCI on the first carrier to the UE based on the at least one first DCI format,

send to the UE a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling,

determine at least one second DCI format monitored by the UE on the first carrier in response to the reconfiguration message, and

send DCI on the first carrier to the UE based on the at least one first DCI format and the at least one second DCI format after sending the reconfiguration message; and

a memory coupled to the at least one processor.

51. A computer program product, comprising:

a non-transitory computer-readable medium comprising;

code for causing at least one computer to determine at least one first downlink control information (DCI) format monitored by a user equipment (UE) on a first carrier,

code for causing the at least one computer to send DCI on the first carrier to the UE based on the at least one first DCI format,

code for causing the at least one computer to send to the UE a reconfiguration message related to communication on a plurality of carriers by the UE with cross-carrier signaling,

code for causing the at least one computer to determine at least one second DCI format monitored by the UE on the first carrier in response to the reconfiguration message, and

code for causing the at least one computer to send DCI on the first carrier to the UE based on the at least one first DCI format and the at least one second DCI format after sending the reconfiguration message.