APPARATUS AND METHODS FOR INTERCELL INTERFERENCE CANCELLATION VIA RNTI

• US 20100255852A1
• Filed: 03/18/2010
• Published: 10/07/2010
• Est. Priority Date: 03/20/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Montojo, Juan, Chen, Wanshi, Gorokhov, Alexei Y.
• Granted Patent: US 8,346,173 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

A method and system facilitate inter-cell interference cancellation in a wireless network. An RNTI component manages a set of radio network temporary identifiers (RNTIs) for a plurality of user equipment (UE). The RNTI component determines whether the UEs will likely cause interference with a neighboring cell and/or experience interference from a neighboring cell, based on a respective attribute of the UEs. The RNTI component includes a space splitting component that divides the set of RNTIs into at least two subsets based on the determination, and allocates a first group of the UEs that are determined to likely cause interference and/or experience interference to a first subset of the divided RNTIs, such that the UEs in the first group are allocated a corresponding one of the RNTIs among the first subset of RNTIs. An implicit broadcast component can implicitly broadcast the first subset of RNTIs to facilitate cancellation of interference possibly caused by the first group of UEs.

Claims

1. A method of facilitating inter-cell interference cancellation in a wireless network, comprising:

managing, in a terminal of the wireless network, a set of RNTIs (radio network temporary identifiers) for a set of user equipment (UE) being served by the terminal in the wireless network;

determining, in the terminal, whether the UEs will likely cause interference with at least one neighboring cell, based on at least one respective attribute of the UEs;

dividing, in the terminal, the set of RNTIs into at least one first subset for the UEs that are determined to likely cause interference, and into at least one second subset for the UEs that are not determined to likely cause interference; and

allocating, in the terminal, the UEs that are determined to likely cause interference to the at least one first subset of the RNTIs such that UEs that are determined to likely cause interference are respectively allocated a corresponding one of the RNTIs among the at least one first subset of RNTIs,

wherein each allocated RNTI uniquely identifies a corresponding one of the UEs.

2. The method of claim 1, further comprising communicating the allocated RNTIs to at least one UE being served in the at least one neighboring cell.

3. The method of claim 2, wherein the terminal serving the UEs that are determined to likely cause interference with the at least one neighboring cell communicates the allocated RNTIs to the at least one neighboring cell, and the at least one neighboring cell broadcasts the allocated RNTIs to at least one UE being served in the at least one neighboring cell and experiencing interference from transmission to at least one of the UEs allocated a corresponding one of the plurality of RNTIs.

4. The method of claim 1, wherein the terminal serving the UEs that are determined to likely cause interference with the at least one neighboring cell communicates the allocated RNTIs to the at least one neighboring cell.

5. The method of claim 1, further comprising:

managing, in the terminal, a plurality of sets of RNTIs respectively corresponding to a plurality of RNTIs selected from the group consisting of cell RNTIs (C-RNTIs), semi-persistent scheduling RNTIs (SRS-RNTIs), temporary cell RNTIs (T-RNTIs), system information RNTIs (S-RNTIs), paging RNTIs (P-RNTIs) and random access RNTIs (RA-RNTI),

dividing, in the terminal, the plurality of sets of RNTIs into at least one first subset for the UEs that are determined to likely cause interference, and into at least one second subset for the UEs that are not determined to likely cause interference; and

allocating, in the terminal, the UEs that are determined to likely cause interference to the at least one subset of the RNTIs such that UEs that are determined to likely cause interference are respectively allocated a corresponding one of the plurality of RNTIs among the at least one first subset of RNTIs.

6. The method of claim 5, wherein the terminal divides the plurality of sets of RNTIs into respectively different subsets for each one of the plurality of sets of RNTIs.

7. The method of claim 1, wherein each allocated RNTI is comprised of a first component uniquely identifying the at least one first subset of RNTIs, and a second component uniquely identifying a corresponding one of the UEs to which each RNTI is respectively allocated, and

wherein the method further comprises implicitly broadcasting the at least one first subset of RNTIs by broadcasting the first component of the RNTIs allocated among the at least one first subset of RNTIs.

8. The method of claim 7, wherein each RNTI is comprised of sixteen bits, and

wherein the first component of each RNTI is constituted by the first twelve bits of the sixteen bits, and the second component of each RNTI is constituted by four bits succeeding the first twelve bits of the first component, the four bits of the second component uniquely identifying a corresponding one of the UEs to which each RNTI is respectively allocated.

9. The method of claim 7, wherein the at least one first subset of RNTIs is broadcast via one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

10. The method of claim 7, comprising dynamically modifying a number of bits comprised in the first component of the RNTI and a number of bits comprised in the second component of the RNTI to accommodate changes in operating conditions of a cell in which the terminal is located.

11. The method of claim 1, further comprising allocating, in the terminal, the UEs that are not determined to likely cause interference to the at least one second subset of the RNTIs such that UEs that are not determined to likely cause interference are respectively allocated a corresponding one of the RNTIs among the at least one second subset of RNTIs.

12. The method of claim 1, wherein the at least one first subset of RNTIs represent inter-cell interference cancellation related RNTIs, and the at least one second subset of RNTIs represent non-inter-cell interference related RNTIs.

13. The method of claim 1, wherein the at least one respective attribute of the UEs comprises at least one of a respective proximity of the UEs to the terminal, a respective proximity of the UEs to an edge of a cell being served by the terminal, and a respective activity state of the UEs.

14. The method of claim 13, wherein the terminal determines that the UEs will likely cause interference with the at least one neighboring cell when the UEs are respectively in closer proximity to the edge of the cell than to the terminal.

15. The method of claim 13, wherein the terminal determines that the UEs will not likely cause interference with the at least one neighboring cell when the UEs are presently in an inactive state.

16. The method of claim 1, further comprising broadcasting the allocated RNTIs to the corresponding one of the UEs to which the RNTIs among the at least one first subset of RNTIs are respectively allocated via one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

17. The method of claim 1, further comprising scanning, in a UE being served by the at least one neighboring cell, the at least one first subset of the RNTIs to determine an interfering UE among the UEs to which a corresponding one of the at least one first subset of RNTIs is respectively allocated.

18. The method of claim 1, further comprising broadcasting each one of the allocated RNTIs among the at least one first subset of RNTIs to the corresponding one of the UEs to which the RNTIs of the at least one first subset of RNTIs are respectively allocated, to inform the corresponding one of the UEs that downlink is intended for the corresponding one of the UEs.

19. The method of claim 1, wherein each one of the allocated RNTIs among the at least one first subset of RNTIs constitutes a control channel for the corresponding one of the UEs to which the RNTIs of the at least one first subset of RNTIs are respectively allocated, and

wherein content in the control channel for the corresponding one of the UEs is scrambled in the RNTI allocated to the corresponding one of the UEs.

20. A computer-readable recording medium having a computer program recorded thereon that causes a computing device of the terminal to perform the method of claim 1.

21. A method of facilitating inter-cell interference cancellation in a wireless network, comprising:

managing, in a terminal of the wireless network, a set of RNTIs (radio network temporary identifiers) for a set of UE (user equipment) being served by the terminal in the wireless network;

dividing, in the terminal, the set of RNTIs into a plurality of subsets;

allocating, in the terminal, a first group of the UEs to a first subset among the plurality of divided subsets, based on at least one criterion, such that UEs in the first group of the UEs are respectively allocated a corresponding one of the RNTIs among the first subset of RNTIs, wherein each allocated RNTI among the first subset of RNTIs is comprised of a first component uniquely identifying the first subset of RNTIs, and a second component uniquely identifying a corresponding one of the first group of UEs to which each RNTI of the first subset of RNTIs is respectively allocated; and

implicitly broadcasting the first subset of RNTIs by broadcasting the first component of the RNTIs allocated among the first subset of RNTIs.

22. The method of claim 21, wherein the at least one criterion comprises whether the UEs being served by the terminal will likely cause interference with at least one neighboring cell.

23. The method of claim 22, wherein the terminal determines whether the UEs will likely cause interference with the at least one neighboring cell, based on at least one respective attribute of the UEs,

wherein the at least one respective attribute of the UEs comprises at least one of a respective proximity of the UEs to the terminal, a respective proximity of the UEs to an edge of a cell being served by the terminal, and a respective activity state of the UEs.

24. The method of claim 23, wherein the terminal determines that the UEs will likely cause interference with the at least one neighboring cell when the UEs are respectively in closer proximity to the edge of the cell than to the terminal.

25. The method of claim 23, wherein the terminal determines that the UEs will not likely cause interference with the at least one neighboring cell when the UEs are presently in an inactive state.

26. The method of claim 22, further comprising scanning, in a UE being served by the at least one neighboring cell, the first subset of RNTIs allocated to the first group of UEs to determine an interfering UE among the UEs of the first group of UEs to which a corresponding one of the first subset of RNTIs is respectively allocated.

27. The method of claim 21, further comprising:

determining whether the UEs will likely cause interference with the at least one neighboring cell; and

allocating a second group of the UEs to a second one of the subsets of RNTIs such that UEs in the second group of the UEs are respectively allocated a corresponding one of the RNTIs among the second subset of RNTIs,

wherein the second group of the UEs comprises the UEs which are not determined to likely cause interference with the at least one neighboring cell.

28. The method of claim 27, wherein the first subset of RNTIs represent inter-cell interference cancellation related RNTIs, and the second subset of RNTIs represent non-inter-cell interference related RNTIs.

29. The method of claim 21, wherein the allocating of the first group of UEs to the at least one first subset of RNTIs comprises broadcasting the allocated RNTIs to the corresponding one of the UEs of the first group of UEs to which the RNTIs among the first subset are respectively allocated via one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

30. The method of claim 21, wherein each one of the allocated RNTIs among the first subset of RNTIs is broadcast to the corresponding one of the first group of UEs to which the RNTIs of the first subset of RNTIs are respectively allocated, to inform the corresponding one of the UEs that downlink is intended for the corresponding one of the UEs.

31. The method of claim 21, wherein each one of the allocated RNTIs among the first subset of RNTIs constitutes a control channel for the corresponding one of the first group of UEs to which the RNTIs of the first subset of RNTIs are respectively allocated, and

wherein content in the control channel for the corresponding one of the UEs is scrambled in the RNTI allocated to the corresponding one of the UEs.

32. The method of claim 21, wherein each allocated RNTI is comprised of sixteen bits, and

wherein the first component of each RNTI is constituted by the first twelve bits of the sixteen bits, and the second component of each RNTI is constituted by four bits succeeding the first twelve bits of the first component.

33. A computer-readable recording medium having a computer program recorded thereon that causes a computing device of the terminal to execute the method of claim 21.

34. A computer processing device having at least one processor configured to facilitate inter-cell interference cancellation, the at least one processor comprising:

a first module configured to manage a set of RNTIs (radio network temporary identifiers) for a plurality of UE (user equipment) being served by a terminal in a wireless network;

a second module configured to determine whether the UEs will likely cause interference with at least one of neighboring cell, based on at least one respective attribute of the UEs;

a third module configured to divide the set of RNTIs into at least one first subset for the UEs that are determined to likely cause interference, and into at least one second subset for the UEs that are not determined to likely cause interference; and

a fourth module configured to allocate the UEs that are determined to likely cause interference to the at least one first subset of the RNTIs such that UEs that are determined to likely cause interference are respectively allocated a corresponding one of the RNTIs among the at least one first subset of RNTIs,

wherein each allocated RNTI uniquely identifies a corresponding one of the UEs.

35. The computer processing device of claim 34, wherein the processor further comprises a fifth module configured to cause the terminal to broadcast the allocated RNTIs to the corresponding one of the UEs to which the RNTIs among the at least one first subset of RNTIs are respectively allocated via one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

36. The computer processing device of claim 35, wherein the fifth module is configured to cause the terminal to broadcast each one of the allocated RNTIs among the at least one first subset of RNTIs to the corresponding one of the UEs to which the RNTIs of the at least one first subset of RNTIs are respectively allocated, to inform the corresponding one of the UEs that downlink is intended for the corresponding one of the UEs.

37. The computer processing device of claim 34, wherein the processor further comprises a fifth module configured to cause the terminal to communicate the allocated RNTIs of the at least one subset of RNTIs to at least one of another terminal serving the at least one neighboring cell, and to at least one UE being served in the at least one neighboring cell, to enable the at least one UE being served in the at least one neighboring cell to scan the first subset of the RNTIs to determine an interfering UE among the UEs to which a corresponding one of the at least one first subset of RNTIs is respectively allocated.

38. The computer processing device of claim 34, wherein the fourth module is configured to allocate the UEs that are not determined to likely cause interference to the at least one second subset of the RNTIs such that UEs that are not determined to likely cause interference are respectively allocated a corresponding one of the RNTIs among the at least one second subset of RNTIs.

39. The computer processing device of claim 34, wherein each allocated RNTI is comprised of a first component identifying the at least one first subset of RNTIs, and a second component uniquely identifying a corresponding one of the UEs to which each RNTI is respectively allocated, and

wherein the processor further comprises a fifth module configured to cause the terminal to implicitly broadcast the at least one first subset of RNTIs by broadcasting the first component of the RNTIs allocated among the at least one first subset of RNTIs.

40. The computer processing device of claim 39, wherein the fifth module is configured to cause the terminal to implicitly broadcast the at least one first subset of RNTIs via one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

41. The computer processing device of claim 34, wherein the at least one first subset of RNTIs represent inter-cell interference cancellation related RNTIs, and the at least one second subset of RNTIs represent non-inter-cell interference related RNTIs.

42. The computer processing device of claim 34, wherein the at least one respective attribute of the UEs comprise at least one of a respective proximity of the UEs to the terminal, a respective proximity of the UEs to an edge of a cell being served by the terminal, and a respective activity state of the UEs.

43. The computer processing device of claim 42, wherein the second module is configured to determine that the UEs will likely cause interference with the at least one neighboring cell when the UEs are respectively in closer proximity to the edge of the cell than to the terminal.

44. An apparatus, comprising:

means for managing a set of RNTIs (remote network temporary identifiers) for a set of UE (user equipment) being served by a terminal in a wireless network;

means for determining whether the UEs will likely cause interference with at least one of neighboring cell, based on at least one respective attribute of the UEs;

means for dividing the set of RNTIs into at least one first subset for the UEs that are determined to likely cause interference, and into at least one second subset for the UEs that not determined to likely cause interference; and

means for allocating the UEs that are determined to likely cause interference to the at least one first subset of the RNTIs such that UEs that are determined to likely cause interference are respectively allocated a corresponding one of the RNTIs among the at least one first subset of RNTIs,

wherein each allocated RNTI uniquely identifies a corresponding one of the UEs to which the RNTIs are respectively allocated.

45. The apparatus of claim 44, further comprising means for broadcasting the allocated RNTIs to the corresponding one of the UEs to which the RNTIs among the at least one first subset of RNTIs are respectively allocated via one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

46. The apparatus of claim 45, wherein the broadcasting means broadcasts each one of the allocated RNTIs among the at least one first subset of RNTIs to the corresponding one of the UEs to which the RNTIs of the at least one first subset of RNTIs are respectively allocated, to inform the corresponding one of the UEs that downlink is intended for the corresponding one of the UEs.

47. The apparatus of claim 44, further comprising means for communicating the allocated RNTIs of the at least one subset of RNTIs to at least one of another terminal serving the at least one neighboring cell, and to at least one UE being served in the at least one neighboring cell, to enable the at least one UE being served in the at least one neighboring cell to scan the first subset of the RNTIs to determine an interfering UE among the UEs to which a corresponding one of the at least one first subset of RNTIs is respectively allocated.

48. The apparatus of claim 44, wherein the allocating means allocates the UEs that are not determined to likely cause interference to the at least one second subset of the RNTIs such that UEs that are not determined to likely cause interference are respectively allocated a corresponding one of the RNTIs among the at least one second subset of RNTIs.

49. The apparatus of claim 44, wherein each allocated RNTI is comprised of a first component identifying the at least one first subset of RNTIs, and a second component uniquely identifying a corresponding one of the UEs to which each RNTI is respectively allocated, and

wherein the apparatus further comprises means for implicitly broadcasting the at least one first subset of RNTIs by broadcasting the first component of the RNTIs allocated among the at least one first subset of RNTIs.

50. The apparatus of claim 49, wherein the implicit broadcasting means implicitly broadcasts the at least one first subset of RNTIs via one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

51. The apparatus of claim 44, wherein the at least one first subset of RNTIs represent inter-cell interference cancellation related RNTIs, and the at least one second subset of RNTIs represent non-inter-cell interference related RNTIs.

52. The apparatus of claim 44, wherein the at least one respective attribute of the UEs comprise at least one of a respective proximity of the UEs to the terminal, a respective proximity of the UEs to an edge of a cell being served by the terminal, and a respective activity state of the UEs.

53. The apparatus of claim 52, wherein the determining means determines that the UEs will likely cause interference with the at least one neighboring cell when the UEs are respectively in closer proximity to the edge of the cell than to the terminal.

54. An apparatus, comprising:

a transmitter configured to broadcast content to a plurality of user equipment (UE) in a wireless network, the content transmitted from the transmitter containing an RNTI that is respectively unique to the UE to which the content is transmitted; and

a RNTI component that includes a space splitting component and an implicit broadcast component,

wherein the space splitting component is configured to maintain a set of RNTIs for the plurality of UEs, divide the set of RNTIs into a plurality of subsets based on at least one respective attribute of the plurality of UEs, allocate a first group of the plurality of UEs to a first subset of the divided RNTIs, based on the respective attribute of the UEs in the first group of UEs, such that UEs in the first group of UEs are respectively allocated a corresponding one of the RNTIs among the first subset of RNTIs, each allocated RNTI among the first subset of RNTIs comprising a first component uniquely identifying the first subset of RNTIs, and a second component uniquely identifying a corresponding one of the first group of UEs to which each RNTI of the first subset of RNTIs is respectively allocated, and

wherein the implicit broadcast component is configured to cause the transmitter to broadcast the first subset of RNTIs implicitly by broadcasting the first component of the RNTIs allocated among the first subset of RNTIs.

55. The apparatus of claim 54, wherein the at least one attribute comprises whether the UEs will at least one of likely cause interference with at least one neighboring cell.

56. The apparatus of claim 54, wherein the space splitting component is further configured to cause the transmitter to broadcast the allocated RNTIs to the corresponding one of the UEs to which the RNTIs among the first subset of RNTIs are respectively allocated via one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

57. The apparatus of claim 54, wherein:

the RNTI component is configured to determine whether the UEs will likely cause interference with at least one neighboring cell;

the space splitting component is further configured to allocate a second group of the UEs to a second one of the subsets of RNTIs such that UEs in the second group of the UEs are respectively allocated a corresponding one of the RNTIs among the second subset of RNTIs; and

the second group of the UEs comprising the UEs that are not determined to likely cause interference.

58. The apparatus of claim 57, wherein the first subset of RNTIs represent inter-cell interference cancellation related RNTIs, and the second subset of RNTIs represent non-inter-cell interference related RNTIs.

59. The apparatus of claim 54, wherein the space splitting component is further configured to cause the transmitter to communicate the allocated RNTIs of the at least one subset of RNTIs to at least one of a terminal serving at least one neighboring cell, and to at least one UE being served in the at least one neighboring cell, to enable the at least one UE being served in the at least one neighboring cell to scan the first subset of the RNTIs to determine an interfering UE among the UEs to which a corresponding one of the first subset of RNTIs is respectively allocated.

60. The apparatus of claim 54, wherein the implicit broadcast component is configured to cause the transmitter to implicitly broadcast the first subset of RNTIs to at least one of a terminal serving at least one neighboring cell, and to at least one UE being served in the at least one neighboring cell, to enable the at least one UE being served in the at least one neighboring cell to determine an interfering UE among the UEs to which a corresponding one of the first subset of RNTIs is respectively allocated, based on the first component contained in the implicitly broadcast first subset of RNTIs.

61. The apparatus of claim 54, wherein the RNTI component is configured to determine whether the UEs will likely cause interference with the at least one neighboring cell, and

wherein the space slitting component is configured to:

maintain a plurality of sets of RNTIs respectively corresponding to a plurality of RNTIs selected from the group consisting of cell RNTIs (C-RNTIs), semi-persistent scheduling RNTIs (SRS-RNTIs), temporary cell RNTIs (T-RNTIs), system information RNTIs (S-RNTIs), paging RNTIs (P-RNTIs) and random access RNTIs (RA-RNTI),

divide the plurality of sets of RNTIs into at least one first subset for the UEs that are determined to likely cause interference, and into at least one second subset for the UEs that are not determined to likely cause interference; and

allocate the UEs that are determined to likely cause interference to the at least one subset of the RNTIs such that UEs that are determined to likely cause interference are respectively allocated a corresponding one of the plurality of RNTIs among the at least one first subset of RNTIs.

62. The apparatus of claim 61, wherein the space splitting component is configured to divide the plurality of sets of RNTIs into respectively different subsets for each one of the plurality of sets of RNTIs.

63. A user equipment (UE) configured to be served a terminal in a wireless network, the UE comprising:

a reception unit configured to receive an RNTI (radio network temporary identifier) allocated to the UE to uniquely identify the UE in a cell served by the terminal, to receive content from the terminal, and to receive a subset of RNTIs respectively allocated to UEs in at least one neighboring cell that are likely to cause interference with the UE in the cell served by the terminal;

a processing unit configured to scan the received subset of RNTIs allocated to the UEs in the at least one neighboring cell to determine at least one interfering UE among the UEs in the at least one neighboring cell that is causing interference with the UE in the cell served by the terminal and that has been allocated a corresponding one of the received subset of RNTIs; and

a transmission unit configured to transmit an interference notification signal including an identity of the determined UE to at least one of the terminal and another terminal serving the at least one neighboring cell to initiate at least one of mitigation and cancellation of the interference caused by the determined UE.

64. The UE of claim 63, wherein:

the RNTIs in the subset of RNTIs allocated to the UEs in the at least one neighboring cell each comprise a first component uniquely identifying the subset of RNTIs allocated to the UEs in the at least one neighboring cell, and a second component uniquely identifying a corresponding one of the UEs in the at least one neighboring cell to which each RNTI of the subset of RNTIs is respectively allocated;

the reception unit is configured to receive the first component of the subset of RNTIs; and

the processing unit is configured to scan the RNTIs comprised in the received subset of RNTIs to determine the respective second component of the RNTIs allocated to a corresponding one of the UEs in the at least one neighboring cell based on the first component of the RNTIs, and to determine the at least one interfering UE in the at least one neighboring cell based on the determined respective second component of the RNTIs allocated to the UEs in the at least one neighboring cell.