MAINTAINING TIME ALIGNMENT WITH MULTIPLE UPLINK CARRIERS

• US 20120008600A1
• Filed: 01/07/2011
• Published: 01/12/2012
• Est. Priority Date: 01/08/2010
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Marinier, Paul, Anepu, Bhaskar M., Pelletier, Ghyslain, Olesen, Robert L.
• Granted Patent: US 8,934,459 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H04L 27/2646 using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Maintaining time alignment with multiple carriers is contemplated. A group of uplink carriers (UL CC sets) that operate with a single Timing Advance (TA) may be determined, and a TA value may be applied to a specific UL CC set. A wireless transmit/receive unit'"'"'s (WTRU) capability of using multiple TAs may define a group index of a few bits for each UL CC set. A TA Command received in a Random Access Response message may be used to apply the TA value to each UL carrier of the UL CC set. The WTRU may determine which UL CC set the TA value applies to based on which DL carrier the command was transmitted from. The WTRU may determine which UL CC set the TA value applies to based on the Group Index being explicitly provided in the command. The WTRU may release multi-CC configurations upon Time Alignment Timer (TAT) expiry.

Claims

1. A wireless transmit/receive unit (WTRU), comprising:

a processor, the processor configured, at least in part to;

identify one or more uplink carriers with which the WTRU is capable of operating; and

determine one or more uplink component carrier sets (UL CC sets), each of the UL CC sets comprising one or more of the uplink carriers, each of the one or more uplink carriers that comprise a respective UL CC set being capable of operating with the same Timing Advance (TA).

2. The WTRU of claim 1, wherein the processor is further configured to determine the one or more UL CC sets based on a predetermined identification of which of the one or more uplink carriers correspond to the one or more UL CC sets.

3. The WTRU of claim 1, wherein the processor is further configured to receive at least one index, the at least one index corresponding to at least one of the one or more UL CC sets and the one or more uplink carriers that comprise the at least one of the one or more UL CC sets.

4. The WTRU of claim 1, wherein the processor is further configured to:

selecting at least one UL CC set;

identifying at least one of the one or more uplink carriers that are capable of random access channel (RACH) communication for the selected at least one UL CC set;

initiating a RACH communication on at least one of the identified one or more uplink carriers for the selected at least one UL CC set; and

receiving a TA value in response to the RACH communication.

5. The WTRU of claim 4, wherein the processor is further configured to apply the TA value to each of the one or more uplink carriers that comprise the selected at least on UL CC set.

6. The WTRU of claim 5, wherein the TA value is applied using a Timing Advance Command received in a Random Access Response message received in response to the RACH communication.

7. The WTRU of claim 5, wherein the selected at least one UL CC set has an associated Time Alignment Timer (TAT) and the processor is further configured to either start the TAT or restart the TAT.

8. The WTRU of claim 1, wherein the processor is further configured to:

receive a signal via a downlink carrier, the signal including a TA value;

identify at least one of the one or more uplink carriers that is paired with the downlink carrier;

identify at least one of the one or more UL CC sets that correspond to the at least one of the one or more uplink carriers that is paired with the downlink carrier; and

apply the TA value to each of the one or more uplink carriers that comprise the identified at least one of the one or more UL CC sets.

9. The WTRU of claim 1, wherein the signal includes a Timing Advance Command Medium Access Control (MAC) control element.

10. The WTRU of claim 1, wherein the one or more UL CC sets correspond to respective frequency bands, and the processor is further configured to:

receive a signal via a downlink carrier, the signal including a TA value;

identify a frequency band corresponding to the downlink carrier;

identify at least one of the one or more UL CC sets whose respective frequency band corresponds to the frequency band of the downlink carrier; and

apply the TA value to each of the one or more uplink carriers that comprise the identified at least one of the one or more UL CC sets.

11. The WTRU of claim 7, wherein the selected at least one UL CC set includes at least one uplink carrier with a dedicated physical uplink control channel (PUCCH) configuration, and the processor is further configured to cease transmitting on a resource corresponding to the PUCCH upon an expiration of the TAT.

12. The WTRU of claim 7, wherein the selected at least one UL CC set includes at least one uplink carrier with a dedicated physical uplink control channel (PUCCH) configuration, and the processor is further configured to remove at least a part of the PUCCH configuration upon an expiration of the TAT.

13. The WTRU of claim 7, wherein the processor is further configured to remove one or more RACH resources from the configuration of the selected at least one UL CC set upon an expiration of the TAT.

14. A method for establishing timing advance, comprising:

identifying one or more uplink carriers operating on a wireless communication network; and

determine one or more uplink component carrier sets (UL CC sets), each of the UL CC sets comprising one or more of the uplink carriers, each of the one or more uplink carriers that comprise a respective UL CC set being capable of operating with the same Timing Advance (TA).

15. The method of claim 14, further comprising:

selecting at least one UL CC set;

identifying at least one of the one or more uplink carriers that are capable of random access channel (RACH) communication for the selected at least one UL CC set;

initiating a RACH communication on at least one of the identified one or more uplink carriers for the selected at least one UL CC set; and

receiving a TA value in response to the RACH communication.

16. The method of claim 15, further comprising:

applying the TA value to each of the one or more uplink carriers that comprise the selected at least on UL CC set; and

executing at least one of a start or a restart of a Time Alignment Timer (TAT), the TAT being associated with the selected at least one UL CC set.

17. The method of claim 15, further comprising;

receiving a signal via a downlink carrier, the signal including a TA value;

identifying at least one of the one or more uplink carriers that is paired with the downlink carrier;

identifying at least one of the one or more UL CC sets that correspond to the at least one of the one or more uplink carriers that is paired with the downlink carrier; and

applying the TA value to each of the one or more uplink carriers that comprise the identified at least one of the one or more UL CC sets.

18. An evolved Node B (eNodeB), comprising:

a processor, the processor configured, at least in part, to;

identify one or more uplink carriers with which the eNodeB is capable of operating;

determine one or more indices, each of the one or more indices corresponding respectively to one or more uplink component carrier sets (UL CC sets), each of the UL CC sets comprising one or more of the uplink carriers, each of the one or more uplink carriers that comprise a respective UL CC set being capable of operating with the same Timing Advance (TA); and

transmit the one or more indices.

19. The eNodeB of claim 18, wherein the processor is further configured to:

receive a RACH communication on at least one of the one or more uplink carriers that comprise at least one of the one or more UL CC sets; and

transmit a TA value in response to the RACH communication, the TA value being applicable to each of the one or more uplink carriers that comprise the at least one of the one or more UL CC sets.

20. The eNode B of claim 18, wherein the processor is further configured to:

transmit a signal, the signal including a TA value and an indicator, the indicator indicating at least one of the one or more UL CC sets to which the TA value is applicable.