Transparent frequency shift Solution for Comp

• US 20120176982A1
• Filed: 08/14/2009
• Published: 07/12/2012
• Est. Priority Date: 08/14/2009
• Status: Active Grant

• Current Assignee: HMD Global Oy
• Original Assignee: HMD Global Oy
• Inventors: Zirwas, Wolfgang, Chmiel, Mieszko, Kiiski, Matti Tapani, Schilz, Egon
• Granted Patent: US 10,454,645 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal

Abstract

A method is described, which includes controlling a coordinated transmission between network control elements and terminals on resource elements, detecting whether a resource element includes a specific element, and selecting a resource element for the coordinated transmission, when it is detected that the resource element does not include a specific element. The application also describes some further aspects to improve a coordinated transmission such as a coordinated multipoint transmission is improved.

Claims

1. A method comprising

controlling a coordinated transmission between network control elements and terminals on resource elements,

detecting whether a resource element comprises a specific element, and selecting a resource element for the coordinated

transmission, when it is detected that the resource element does not comprise a specific element.

2. The method according to claim 1, wherein the specific element is a reference signal.

3. The method according to claim 2, further comprising

canceling interference caused by a transmission of a reference signal in a resource element not selected for coordinated transmission.

4. The method according to claim 3, wherein the canceling is carried out in a terminal by subtracting known interference.

5. The method according to claim 2, wherein the method is carried out by a central network control element by applying precompensation.

7. The method according to claim 2, wherein the reference signal is a common reference signal.

8. The method according to claim 1, wherein the specific element is a control channel symbol used for a control channel.

9. The method according to claim 8, wherein the detecting is performed by detecting the number of control channel symbols assigned to a particular subframe in a cell.

10. The method according to claim 9, wherein the number is detected by referring to a control format indicator.

11. The method according to claim 8, wherein a predetermined number of transmission points on resource elements are scheduled for the coordinated transmission, the method further comprising applying, in case the number of transmission points which are used for the coordinated transmission is less than the predetermined number, a precompensation for the transmission, and/or interleaving of the transmission and/or applying a different modulation and coding scheme per symbol in the transmission .

12. The method according to claim 8, wherein the resource elements used in a subframe which do not contain a control channel symbol are used for a shared channel for transmitting data.

13. The method according to claim 8, wherein all the resource elements constitute OFDM symbols, the control channel is a physical downlink control channel and the shared channel is a physical downlink shared channel.

62. The method according to claim 1, wherein the coordinated transmission is a multipoint coordinated (CoMP) transmission or a multi-user multiple input multiple output (MU-MIMO) transmission.

64. A computer program product including a program for a processing device, comprising software code portions for performing the steps of claim 1 when the program is run on the processing device.

65. The computer program product according to claim 64, wherein the computer program product comprises a computer-readable medium on which the software code portions are stored.

66. The computer program product according to claim 64, wherein the program is directly loadable into an internal memory of the processing device.

6. A method comprising

receiving a coordinated transmission from network control elements on resource elements, and

canceling interference caused by a transmission of a reference signal in a resource element not selected for the coordinated transmission, by subtracting known interference.

14. An apparatus comprising

a transmission controller configured to control a

coordinated transmission between network control elements and terminals on resource elements,

a detector configured to detect whether a resource element comprises a specific element, and

a selector configured to select a resource element for the coordinated transmission, when it is detected that the

resource element does not comprise a specific element.

15. The apparatus according to claim 14, wherein the specific element is a reference signal.

16. The apparatus according to claim 15, further comprising a cancelling unit configured to cancel interference caused by a transmission of a reference signal in a resource element not selected for the coordinated transmission.

17. The apparatus according to claim 16, wherein the apparatus is configured to perform the cancellation by applying precompensation.

19. The apparatus according to claim 15, wherein the reference signal is a common reference signal.

20. The apparatus according to claim 14, wherein the specific element is a control channel symbol used for a control channel.

21. The apparatus according to claim 20, wherein the detector is configured to detect the number of control channel symbols assigned to a particular subframe in a cell.

22. The apparatus according to claim 21, wherein the detector is configured to detect the number by referring to a control format indicator.

23. The apparatus according to claim 20, wherein a predetermined number of transmission points on resource elements are scheduled for the coordinated transmission,

wherein the controller is configured to apply, in case the number of transmission points which are used for the coordinated transmission is less than the predetermined number, a precompensation for the transmission points, and/or interleaving of the transmission points and/or applying a different modulation and coding scheme per symbol in the transmission points.

24. The apparatus according to claim 20, wherein the resource elements used in a subframe which do not contain a control channel symbol are used for a shared channel for transmitting data.

25. The apparatus according to claim 20, wherein all the resource elements constitute OFDM symbols, the control channel is a physical downlink control channel and the shared channel is a physical downlink shared channel.

63. The apparatus according to claim 14, wherein the coordinated transmission is a multipoint coordinated (CoMP) transmission or a multi-user multiple input multiple output (MU-MIMO) transmission.

18. An apparatus comprising

a receiver configured to receive a coordinated transmission from network control elements on resource elements, and

a controller configured to cancel interference caused by a transmission of a common reference signal in a resource element not selected for the coordinated transmission, by subtracting known interference.

26. (canceled)

27. (canceled)

28. (canceled)

29. (canceled)

30. (canceled)

31. (canceled)

32. (canceled)

33. (canceled)

34. (canceled)

35. (canceled)

36. (canceled)

37. (canceled)

38. (canceled)

39. (canceled)

40. (canceled)

41. (canceled)

42. (canceled)

43. (canceled)

44. (canceled)

45. (canceled)

46. (canceled)

47. (canceled)

48. (canceled)

49. (canceled)

50. (canceled)

51. (canceled)

52. (canceled)

53. (canceled)

54. (canceled)

55. (canceled)

56. (canceled)

57. (canceled)

58. (canceled)

59. (canceled)

60. (canceled)

61. (canceled)