METHODS AND ARRANGEMENTS IN RADIO COMMUNICATION SYSTEMS

• US 20110200032A1
• Filed: 02/11/2011
• Published: 08/18/2011
• Est. Priority Date: 02/15/2010
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: BOSTRÖM, Lisa, PEISA, Janne, LINDSTRÖM, Magnus, SAGFORS, Mats, WIEMANN, Henning
• Granted Patent: US 9,137,765 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• 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

Abstract

Methods and arrangements for adjusting timing of transmissions in a radio communication system in which aggregation of component carriers is employed are disclosed. A base station sends a first TA command applicable to a first component carrier to a user equipment. A need to maintain different uplink transmission timing for the first user equipment component carrier and second uplink component carrier is detected by the base station. The base station then sends a second TA command based on the detected need to maintain different uplink transmission timing. The second TA command is applicable to uplink transmissions on the first component carrier and/or the second component carrier. The user equipment adjusts uplink transmissions on the first component carrier and/or the second uplink component carrier based on the second timing advance command.

Claims

1. A method in a base station for adjusting timing of transmissions in a radio communication system in which aggregation of component carriers is employed, the base station being configured to receive data from a user equipment, UE, over a plurality of uplink component carriers, the method comprising

sending a first timing advance command to the UE, wherein the first timing advance command is applicable to transmissions on a first component carrier,

sending a second timing advance command to the UE based on a detected need to maintain different uplink transmission timing for the first component carrier and at least a second component carrier, wherein the second timing advance is applicable to uplink transmissions on at least one of the first component carrier or the second component carrier.

2. The method according to claim 1, wherein the first timing advance command comprises a reference timing advance or a timing adjustment.

3. The method according to claim 1, wherein the second timing advance command comprises a timing advance or a timing adjustment based on the detected need to maintain different uplink transmission timing.

4. The method according to claim 1, wherein the detecting the need to maintain different uplink transmission timing for the first and the second component carrier comprises detecting that uplink transmissions on the second uplink carrier is received with an offset relative uplink transmissions on the first component carrier.

5. The method according to claim 1, wherein the detecting the need to maintain different uplink transmission timing for the first and the second component carrier comprises ordering the UE to perform a random access on the second uplink component carrier and detecting if uplink transmissions on the second uplink carrier is received with an offset relative uplink transmissions on the first component carrier.

6. The method according to claim 1, wherein the second timing advance command is based on the offset relative uplink transmissions on the first component carrier.

7. The method according to claim 1, wherein the second timing advance command is applicable to several of the plurality of uplink component carriers.

8. The method according to claim 1, wherein the second timing advance command comprises multiple adjustment commands applicable to several of the plurality of uplink component carriers.

9. The method according to claim 8, wherein the multiple adjustment commands provide relative time adjustments in relation to a previous timing advance command applied to at least one of the plurality of uplink component carriers.

10. The method according to claim 8, wherein the multiple adjustment commands provide relative time adjustments in relation to the first timing advance command.

11. The method according to claim 1, wherein the timing advance command is implemented in a medium access control protocol.

12. The method according to claim 11, wherein the timing advance command comprises at least a carrier identifier field or carrier group identifier field and at least a time-alignment field.

13. The method according to claim 12, wherein the timing advance is included in the time-alignment field and a carrier indicator associated with the component carrier, to which the timing advance is applicable, is included in the carrier identifier field.

14. A method in a user equipment for adjusting timing of transmissions in a radio communication system in which aggregation of component carriers is employed, the user equipment being configured to transmit data to a base station comprised in the radio communication system over a plurality of uplink component carriers, the method comprising

receiving a first timing advance command from the base station, wherein the first timing advance command is applicable to transmissions on a first component carrier,

receiving a second timing advance command from the base station, wherein the second timing advance command is based on a detected need to maintain different uplink transmission timing for the first component carrier and at least a second component carrier and is applicable to transmissions on at least one of the first component carrier and the second uplink component carrier;

and

adjusting uplink transmissions on at least one of the first component carrier and the second uplink component carrier based on the second timing advance command.

15. The method according to claim 14, wherein the first timing advance command comprises a reference timing advance or a timing adjustment.

16. The method according to claim 14, wherein the second timing advance command comprises a timing advance or a timing adjustment based on the detected need to maintain different uplink transmission timing.

17. The method according to claim 14, wherein the second timing advance command is based on an offset relative uplink transmissions on the first component carrier.

18. The method according to claim 14, wherein the second timing advance command is applicable to several of the plurality of uplink component carriers.

19. The method according to claim 14, wherein the second timing advance command comprises multiple adjustment commands applicable to several of the plurality of uplink component carriers.

20. The method according to claim 19, wherein the multiple adjustment commands provide relative time adjustments in relation to a previous timing advance command applied to at least one of the plurality of uplink component carriers.

21. The method according to claim 19, wherein the multiple adjustment commands provide relative time adjustments in relation to the first timing advance command.

22. The method according to claim 14, wherein the user equipment comprises a time alignment timer, the method further comprising

starting the time alignment timer.

23. The method according to claim 14, wherein the user equipment is configured with a time alignment timer, the method further comprising

starting the time alignment timer when the second timing advance command is applicable to the first component carrier.

24. The method according to claim 14, wherein the timing advance command is implemented in a medium access control protocol.

25. The method according to claim 24, wherein the timing advance command comprises at least a carrier identifier field or carrier group identifier field and at least a time-alignment field.

26. The method according to claim 25, wherein the timing advance is included in the time-alignment field and a carrier indicator associated with the component carrier, to which the timing advance is applicable, is included in the carrier identifier field.

27. A base station for adjusting timing of transmissions in a radio communication system in which aggregation of component carriers is employed, the base station being configured to receive data from a user equipment, UE, over a plurality of uplink component carriers, the base station comprises

a transmitter unit adapted to send a first timing advance command to the UE, wherein the first timing advance command is applicable to transmissions on a first component carrier,

a detecting unit adapted to detect a need to maintain different uplink transmission timing for the first component carrier and at least a second component carrier;

and

the transmitter unit further adapted to send a second timing advance command to the UE, wherein the second timing advance command is based on the detected need to maintain different uplink transmission timing and is applicable to uplink transmissions on at least one of the first component carrier and the second component carrier.

28. The base station according to claim 27, wherein the first timing advance command comprises a reference timing advance or a timing adjustment.

29. The base station according to claim 27, wherein the second timing advance command comprises a timing advance or a timing adjustment based on the detected need to maintain different uplink transmission timing.

30. The base station according to claim 27, wherein the detecting unit is further adapted to detect that uplink transmissions on the second uplink carrier are received with an offset relative uplink transmissions on the first component carrier.

31. The base station according to claim 27, wherein the base station further comprises an ordering unit adapted to order the UE to perform a random access on the second uplink component carrier, and wherein the detecting unit is further adapted to detect that uplink transmissions on the second uplink carrier is received with an offset relative uplink transmissions on the first component carrier.

32. The base station according to claim 27, wherein the second timing advance command is based on the offset relative uplink transmissions on the first component carrier.

33. The base station according to claim 27, wherein the second timing advance command is applicable to several of the plurality of uplink component carriers.

34. The base station according to claim 27, wherein the second timing advance command comprises multiple adjustment commands applicable to several of the plurality of uplink component carriers.

35. The base station according to claim 34, wherein the multiple adjustment commands provide relative time adjustments in relation to a previous timing advance command applied to at least one of the plurality of uplink component carriers.

36. The base station according to claim 34, wherein the multiple adjustment commands provide relative time adjustments in relation to the first timing advance command.

37. The base station according to claim 27, wherein the timing advance command is implemented in a medium access control protocol.

38. The base station according to claim 37, wherein the timing advance command comprises at least a carrier identifier field or carrier group identifier field and at least a time-alignment field.

39. The base station according to claim 38, wherein the timing advance is included in the time-alignment field and a carrier indicator associated with the component carrier, to which the timing advance is applicable, is included in the carrier identifier field.

40. A user equipment for adjusting timing of transmissions in a radio communication system in which aggregation of component carriers is employed, the user equipment being configured to transmit data to a base station comprised in the radio communication system over a plurality of uplink component carriers, the user equipment comprises

a receiver unit adapted to receive a first timing advance command from the base station, wherein the first timing advance command is applicable to transmissions on a first component carrier,

the receiver unit further adapted to receive a second timing advance command from the base station, wherein the second timing advance command is based on a detected need to maintain different uplink transmission timing for the first component carrier and at least a second component carrier, wherein the second timing advance command is applicable to transmissions on at least one of the first component carrier and the second uplink component carrier;

and

an adjustment unit adapted to adjust uplink transmissions on at least one of the first component carrier and the second uplink component carrier based on the second timing advance command.

41. The user equipment according to claim 40, wherein the first timing advance command comprises a reference timing advance and the reference timing advance is a timing advance or a timing adjustment.

42. The user equipment according to claim 40, wherein the second timing advance command comprises a timing advance or a timing adjustment based on the detected need to maintain different uplink transmission timing.

43. The user equipment according to claim 40, wherein the second timing advance command is based on an offset relative uplink transmissions on the first component carrier.

44. The user equipment according to claim 40, wherein the second timing advance command is applicable to several of the plurality of uplink component carriers.

45. The user equipment according to claim 40, wherein the second timing advance command comprises multiple adjustment commands applicable to several of the plurality of uplink component carriers.

46. The user equipment according to claim 45, wherein the multiple adjustment commands provide relative time adjustments in relation to a previous timing advance command applied to at least one of the plurality of uplink component carriers.

47. The user equipment according to claim 45, wherein the multiple adjustment commands provide relative time adjustments in relation to the first timing advance command.

48. The user equipment according to claim 40, wherein the user equipment comprises a time alignment timer, the user equipment further comprises

a starter unit adapted to start the time alignment timer.

49. The user equipment according to claim 40, wherein the user equipment is configured with a time alignment timer, the user equipment further comprises

a starter unit adapted to start the time alignment timer when the second timing advance command is applicable to the first component carrier.

50. The user equipment according to claim 40, wherein the timing advance command is implemented in a medium access control protocol.

51. The user equipment according to claim 50, wherein the timing advance command comprises at least a carrier identifier field or carrier group identifier field and at least a time-alignment field.

52. The user equipment according to claim 51, wherein the timing advance is included in the time-alignment field and a carrier indicator associated with the component carrier, to which the timing advance is applicable, is included in the carrier identifier field.