METHODS AND APPARATUS FOR RANDOM ACCESS PROCEDURES WITH CARRIER AGGREGATION FOR LTE-ADVANCED SYSTEMS

• US 20120300714A1
• Filed: 05/02/2012
• Published: 11/29/2012
• Est. Priority Date: 05/06/2011
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Ng, Boon Loong, Zhang, Jianzhong, Nam, Young-Han, van Lieshout, Gerardus Johannes Petrus, Jeong, Kyeongin, Kim, Soenghun
• Application Number:
  US13/462,401
• Publication Number:
  US 20120300714A1
• Time in Patent Office: Days
• US Class Current: 370/329
• 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 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

An eNodeB is configured to perform a method for a random access procedure in an LTE-Advanced system. The method includes receiving from a user equipment a random access preamble message on a physical random access channel (PRACH) on a first cell, the PRACH associated with a random access radio network temporary identifier (RA-RNTI). The method also includes transmitting to the user equipment a random access response (RAR) message on a second cell. At least one of the RAR message and the RA-RNTI includes information configured to allow the user equipment to identify a target Timing Advance Group (TAG) or cell associated with the RAR message.

Claims

1. For use in an eNodeB, a method for a random access procedure, the method comprising:

receiving from a user equipment a random access preamble message on a physical random access channel (PRACH) on a first cell, the PRACH associated with a random access radio network temporary identifier (RA-RNTI); and

transmitting to the user equipment a random access response (RAR) message on a second cell,

wherein at least one of the RAR message and the RA-RNTI comprises information configured to allow the user equipment to identify a target Timing Advance Group (TAG) or cell associated with the RAR message.

2. The method of claim 1, wherein when cross-carrier scheduling is not configured, the second cell is a secondary cell and the first cell is the same as the second cell.

3. The method of claim 1, wherein when cross-carrier scheduling is configured, the first cell is different than the second cell.

4. The method of claim 1, wherein the RA-RNTI is determined based on an offset indicator, the offset indicator configured to identify the target TAG or cell.

5. The method of claim 4, wherein the RA-RNTI is determined according to the equation:

RA-RNTI=1+t_—

id+10*f_—

id+60*cell-offset,

where t_id is an index of a first subframe of a specified physical random access channel (PRACH), f_id is an index of the specified PRACH within the first subframe, and cell-offset is the offset indicator.

6. The method of claim 1, wherein the RAR message comprises a TAG indicator field (TIF) or carrier indicator field (CIF) configured to identify the target TAG or cell.

7. The method of claim 6, wherein the TIF or CIF is part of the medium access control (MAC) header or payload of the RAR.

8. The method of claim 1, wherein when the random access procedure is a contention-based random access procedure, the method further comprises:

transmitting a physical downlink control channel (PDCCH) order to the user equipment, the PDCCH order comprising a carrier indicator field (CIF), the CIF indicating the target cell in order to resolve the contention.

9. The method of claim 1, the method further comprising:

transmitting a physical downlink control channel (PDCCH) order to the user equipment, the PDCCH order comprising a TAG indicator field (TIF) or carrier indicator field (CIF), the TIF or CIF configured to identify the target TAG or cell.

10. An eNodeB configured for a random access procedure, the eNodeB comprising:

a controller configured to;

receive from a user equipment a random access preamble message on a physical random access channel (PRACH) on a first cell, the PRACH associated with a random access radio network temporary identifier (RA-RNTI), and

transmit to the user equipment a random access response (RAR) message on a second cell,

wherein at least one of the RAR message and the RA-RNTI comprises information configured to allow the user equipment to identify a target Timing Advance Group (TAG) or cell associated with the RAR message.

11. The eNodeB of claim 10, wherein when cross-carrier scheduling is not configured, the second cell is a secondary cell and the first cell is the same as the second cell.

12. The eNodeB of claim 10, wherein when cross-carrier scheduling is configured, the first cell is different than the second cell.

13. The eNodeB of claim 10, wherein the RA-RNTI is determined based on an offset indicator, the offset indicator configured to identify the target TAG or cell.

14. The eNodeB of claim 13, wherein the RA-RNTI is determined according to the equation:

RA-RNTI=1+t_—

id+10*f_—

id+60*cell-offset,

where t_id is an index of a first subframe of a specified physical random access channel (PRACH), f_id is an index of the specified PRACH within the first subframe, and cell-offset is the offset indicator.

15. The eNodeB of claim 10, wherein the RAR message comprises a TAG indicator field (TIF) or carrier indicator field (CIF) configured to identify the target TAG or cell.

16. The eNodeB of claim 15, wherein the TIF or CIF is part of the medium access control (MAC) header or payload of the RAR.

17. The eNodeB of claim 10, wherein when the random access procedure is a contention-based random access procedure, the controller transmits a physical downlink control channel (PDCCH) order to the user equipment, the PDCCH order comprising a carrier indicator field (CIF), the CIF indicating the target cell in order to resolve the contention.

18. The eNodeB of claim 10, the controller further configured to transmit a physical downlink control channel (PDCCH) order to the user equipment, the PDCCH order comprising a TAG indicator field (TIF) or carrier indicator field (CIF), the TIF or CIF configured to identify the target TAG or cell.

19. A user equipment configured for a random access procedure, the user equipment comprising:

a processor configured to;

transmit to an eNodeB a random access preamble message on a physical random access channel (PRACH) on a first cell, the PRACH associated with a random access radio network temporary identifier (RA-RNTI), and

receive from the eNodeB a random access response (RAR) message on a second cell,

wherein at least one of the RAR message and the RA-RNTI comprises information configured to allow the user equipment to identify a target Timing Advance Group (TAG) or cell associated with the RAR message.

20. The user equipment of claim 19, wherein when cross-carrier scheduling is not configured, the second cell is a secondary cell and the first cell is the same as the second cell.

21. The user equipment of claim 19, wherein when cross-carrier scheduling is configured, the first cell is different than the second cell.

22. The user equipment of claim 19, wherein the RA-RNTI is determined based on an offset indicator, the offset indicator configured to identify the target TAG or cell.

23. The user equipment of claim 22, wherein the RA-RNTI is determined according to the equation:

RA-RNTI=1+t_—

id+10*f_—

id+60*cell-offset,

where t_id is an index of a first subframe of a specified physical random access channel (PRACH), f_id is an index of the specified PRACH within the first subframe, and cell-offset is the offset indicator.

24. The user equipment of claim 19, wherein the RAR message comprises a TAG indicator field (TIF) or carrier indicator field (CIF) configured to identify the target TAG or cell.

25. The user equipment of claim 24, wherein the TIF or CIF is part of the medium access control (MAC) header or payload of the RAR.

26. The user equipment of claim 19, wherein when the random access procedure is a contention-based random access procedure, the processor receives a physical downlink control channel (PDCCH) order from the eNodeB, the PDCCH order comprising a carrier indicator field (CIF), the CIF indicating the target cell in order to resolve the contention.

27. The user equipment of claim 19, the processor further configured to receive a physical downlink control channel (PDCCH) order from the eNodeB, the PDCCH order comprising a TAG indicator field (TIF) or carrier indicator field (CIF), the TIF or CIF configured to identify the target TAG or cell.