Methods and arrangements in radio communication systems

• US 9,137,765 B2
• Filed: 02/11/2011
• Issued: 09/15/2015
• Est. Priority Date: 02/15/2010
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lindstrm, Magnus, Bostrm, Lisa, Peisa, Janne, Sgfors, Mats, Wiemann, Henning
• Primary Examiner(s): Patel, Parth
• Application Number:
  US13/025,893
• Publication Number:
  US 20110200032A1
• Time in Patent Office: 1,677 Days
• Field of Search: 370/280, 370/336, 370/329, 370/350
• US Class Current: 1/1
• 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 performed by a base station for adjusting timing of uplink 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;

receiving uplink transmissions from the UE, on the uplink carrier components, wherein the UE transmits uplink transmissions on the first component carrier according to the first timing advance command, and uses predetermined timings relative to the uplink transmissions on the first component carrier, for the uplink transmissions on the uplink carrier components other than the first component carrier, respectively;

detecting a need to adjust the predetermined timings based on the uplink transmissions received from the UE using the predetermined timings; and

sending a second timing advance command to the UE based on the detected need,

wherein the second timing advance command is applicable to uplink transmissions on at least one of the first component carrier or a second component carrier among the uplink carrier components, the second timing advance command specifying an offset of uplink transmissions on the second component carrier relative to uplink transmissions on the first 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.

4. The method according to claim 1, wherein detecting the need comprises:

detecting that uplink transmissions on the second uplink carrier are received at the base station with an offset relative to receiving uplink transmissions on the first component carrier.

5. The method according to claim 1, wherein detecting the need comprises:

ordering the UE to perform a random access on the second uplink component carrier and detecting if uplink transmissions on the at least a second uplink carrier are received with an offset relative to uplink transmissions on the first component carrier.

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

7. 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.

8. The method according to claim 7, 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.

9. The method according to claim 7, wherein the multiple adjustment commands provide relative time adjustments in relation to the first timing advance command.

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

11. The method according to claim 10, wherein the timing advance command comprises:

at least a carrier identifier field or carrier group identifier field and at least a time-alignment field.

12. The method according to claim 11, 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.

13. 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,

sending uplink transmissions on the first component carrier according to the first timing advance command, and uplink transmissions on the uplink carrier components other than the first component carrier using predetermined timing offsets relative to the uplink transmissions on the first carrier, respectively;

receiving a second timing advance command from the base station, wherein the second timing advance command is based on a need to adjust the predetermined timings, which need is detected based on the uplink transmissions sent on the carrier components using the predetermined timing offsets, the second timing advance command being applicable to transmissions on at least one of the first component carrier and a second uplink component carrier among the uplink component carriers; and

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

wherein the second timing advance command specifies an offset of uplink transmissions on the second uplink component carrier relative to uplink transmissions on the first component carrier.

14. The method according to claim 13, wherein the first timing advance command comprises:

a reference timing advance or a timing adjustment.

15. The method according to claim 13, wherein the second timing advance command comprises:

a timing advance or a timing adjustment based on the detected need.

16. The method according to claim 13, wherein the second timing advance command is applicable to several of the plurality of uplink component carriers.

17. The method according to claim 13, wherein the second timing advance command comprises:

multiple adjustment commands applicable to several of the plurality of uplink component carriers.

18. The method according to claim 17, 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.

19. The method according to claim 17, wherein the multiple adjustment commands provide relative time adjustments in relation to the first timing advance command.

20. The method according to claim 13, wherein the user equipment further includes a time alignment timer, the method further comprising:

starting the time alignment timer.

21. The method according to claim 13, 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.

22. The method according to claim 13, wherein the timing advance command is implemented in a medium access control protocol.

23. The method according to claim 22, wherein the timing advance command comprises:

at least a carrier identifier field or carrier group identifier field and at least a time-alignment field.

24. The method according to claim 23, 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.

25. 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 comprising:

a transmitter unit configured 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 receiver configured to receive uplink transmissions from the UE, on the uplink carrier components, wherein the UE transmits uplink transmissions on the first component carrier according to the first timing advance command, and uses predetermined timings relative to uplink transmissions on the first component carrier for the uplink transmissions on the uplink carrier components other than the first component carrier, respectively; and

a detecting unit configured to detect a need to adjust timing of uplink transmissions based on the received uplink transmissions from the UE using the predetermined timings, and

wherein the transmitter unit is further configured to send a second timing advance command to the UE, wherein the second timing advance command is based on the detected need, and

wherein the second timing advance command specifies an offset of uplink transmissions on a second component carrier relative to uplink transmissions on the first component carrier.

26. The base station according to claim 25, wherein the first timing advance command comprises:

a reference timing advance or a timing adjustment.

27. The base station according to claim 25, wherein the second timing advance command comprises:

a timing advance or a timing adjustment based on the detected need.

28. The base station according to claim 25, wherein the detecting unit is further adapted to detect that uplink transmissions on the second uplink carrier are received with an offset relative to uplink transmissions on the first component carrier.

29. The base station according to claim 25, 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 are received with an offset relative uplink transmissions on the first component carrier.

30. The base station according to claim 25, wherein the second timing advance command is applicable to several of the plurality of uplink component carriers.

31. The base station according to claim 25, wherein the second timing advance command comprises:

multiple adjustment commands applicable to several of the plurality of uplink component carriers.

32. The base station according to claim 31, 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.

33. The base station according to claim 31, wherein the multiple adjustment commands provide relative time adjustments in relation to the first timing advance command.

34. The base station according to claim 25, wherein the timing advance command is implemented in a medium access control protocol.

35. The base station according to claim 34, wherein the timing advance command comprises:

at least a carrier identifier field or carrier group identifier field and at least a time-alignment field.

36. The base station according to claim 35, 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.

37. 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 in the radio communication system over a plurality of uplink component carriers, the user equipment comprising:

a receiver unit configured 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,

a transmission unit configured to send uplink transmissions from the UE transmitting uplink transmissions on the first component carrier according to the first timing advance command, and using predetermined timings relative to the uplink transmissions on the first component carrier for the uplink transmissions on the carrier components other than the first component carrier, respectively,

wherein the receiver unit is further configured to receive a second timing advance command from the base station, wherein the second timing advance command is based on a detected need to adjust the predetermined timings based on the uplink transmissions received from the UE using the predetermined timings,

wherein the second timing advance command is applicable to transmissions on at least one of the first component carrier and a second component carrier among the components carriers and specifies an offset of uplink transmissions on the second component carrier relative to uplink transmissions on the first component carrier; and

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

38. The user equipment according to claim 37, wherein the first timing advance command comprises:

a reference timing advance and the reference timing advance is a timing advance or a timing adjustment.

39. The user equipment according to claim 37, wherein the second timing advance command comprises:

a timing advance or a timing adjustment based on the detected need.

40. The user equipment according to claim 37, wherein the second timing advance command is applicable to several of the plurality of uplink component carriers.

41. The user equipment according to claim 37, wherein the second timing advance command comprises:

multiple adjustment commands applicable to several of the plurality of uplink component carriers.

42. The user equipment according to claim 41, 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.

43. The user equipment according to claim 41, wherein the multiple adjustment commands provide relative time adjustments in relation to the first timing advance command.

44. The user equipment according to claim 37, wherein the user equipment further comprises:

a time alignment timer; and

a starter unit adapted to start the time alignment timer.

45. The user equipment according to claim 37, wherein the user equipment is configured with a time alignment timer, the user equipment further comprising:

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

46. The user equipment according to claim 37, wherein the timing advance command is implemented in a medium access control protocol.

47. The user equipment according to claim 46, wherein the timing advance command comprises:

at least a carrier identifier field or carrier group identifier field and at least a time-alignment field.

48. The user equipment according to claim 47, 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.