SEMI-STATIC RESOURCE ALLOCATION TO SUPPORT COORDINATED MULTIPOINT (COMP) TRANSMISSION IN A WIRELESS COMMUNICATION NETWORK

• US 20100177746A1
• Filed: 01/06/2010
• Published: 07/15/2010
• Est. Priority Date: 01/12/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Palanki, Ravi, Gorokhov, Alexei Y.
• Granted Patent: US 8,755,807 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• 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: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/03866 using scrambling
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0082 at predetermined intervals
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated

Abstract

Techniques for supporting Coordinated MultiPoint (CoMP) transmission are described. For CoMP transmission, multiple cells may simultaneously send one or more data streams to one or more UEs on the same time-frequency resources based on short-term channel feedback from at least one UE to at least two cells. In an aspect, a semi-static configuration may be used by a set of cells for CoMP transmission to a UE. The semi-static configuration may indicate resource elements available to the set of cells to send CoMP transmission to the UE. The available resource elements may be determined based on a maximum number of TDM control symbols for all cells in the set and resource elements used for cell-specific reference signals by the cells in the set. A cell in the set may send data on the available resource elements to the UE for the CoMP transmission.

Claims

1. A method for wireless communication, comprising:

determining a semi-static configuration comprising resource elements available to a set of cells to send Coordinated MultiPoint (CoMP) transmission to a user equipment (UE); and

sending data on the available resource elements to the UE for the CoMP transmission.

2. The method of claim 1, further comprising:

sending information indicative of the semi-static configuration to the UE, wherein the semi-static configuration is valid for a plurality of subframes in which the CoMP transmission is sent.

3. The method of claim 1, wherein the determining the semi-static configuration comprises

determining a maximum number of time division multiplexed (TDM) control symbols for all cells in the set, and

determining the available resource elements based on the maximum number of TDM control symbols.

4. The method of claim 3, wherein the maximum number of TDM control symbols for all cells in the set is determined based on a requested maximum number of TDM control symbols from each cell in the set.

5. The method of claim 3, further comprising:

sending up to the maximum number of TDM control symbols in each subframe in which the CoMP transmission is sent.

6. The method of claim 3, wherein the determining the semi-static configuration further comprises

determining resource elements used for cell-specific reference signals by the cells in the set, and

determining the available resource elements based further on the resource elements used for the cell-specific reference signals.

7. The method of claim 1, further comprising:

sending a cell-specific reference signal multiplexed with the data for the CoMP transmission, wherein the cells in the set transmit cell-specific reference signals aligned in time and frequency on a single set of resource elements.

8. The method of claim 1, wherein the cells in the set are assigned cell identities (IDs) that map to a single set of resource elements for cell-specific reference signals.

9. The method of claim 1, wherein a plurality of sets of cells are predefined, each set including cells with cell identities (IDs) that map to a single set of resource elements for cell-specific reference signals, and wherein the set of cells is one of the plurality of sets of cells.

10. The method of claim 1, wherein the set of cells is among a larger group of cells using a common set of resource elements for cell-specific reference signals.

11. The method of claim 1, further comprising:

sending a UE-specific reference signal for the CoMP transmission, wherein the cells in the set transmit UE-specific reference signals aligned in time and frequency on a single set of resource elements to the UE.

12. The method of claim 11, further comprising:

scrambling the UE-specific reference signal based on a scrambling code assigned to the set of cells for the UE.

13. The method of claim 1, wherein the sending data comprises sending the data on the available resource elements in a data zone of a multicast/broadcast single frequency network (MBSFN) subframe to the UE for the CoMP transmission, wherein the MBSFN subframe includes no cell-specific reference signals in the data zone.

14. The method of claim 1, wherein the sending data comprises sending the data on the available resource elements in a blank subframe to the UE for the CoMP transmission, wherein the blank subframe includes no cell-specific reference signals and no control information for other UEs.

15. An apparatus for wireless communication, comprising:

means for determining a semi-static configuration comprising resource elements available to a set of cells to send Coordinated MultiPoint (CoMP) transmission to a user equipment (UE); and

means for sending data on the available resource elements to the UE for the CoMP transmission.

16. The apparatus of claim 15, further comprising:

means for sending information indicative of the semi-static configuration to the UE, wherein the semi-static configuration is valid for a plurality of subframes in which the CoMP transmission is sent.

17. The apparatus of claim 15, wherein the means for determining the semi-static configuration comprises

means for determining a maximum number of time division multiplexed (TDM) control symbols for all cells in the set, and

means for determining the available resource elements based on the maximum number of TDM control symbols.

18. The apparatus of claim 17, wherein the means for determining the semi-static configuration further comprises

means for determining resource elements used for cell-specific reference signals by the cells in the set, and

means for determining the available resource elements based further on the resource elements used for the cell-specific reference signals.

19. The apparatus of claim 15, further comprising:

means for sending a cell-specific reference signal multiplexed with the data for the CoMP transmission, wherein the cells in the set transmit cell-specific reference signals aligned in time and frequency on a single set of resource elements.

20. The apparatus of claim 15, further comprising:

means for sending a UE-specific reference signal for the CoMP transmission, wherein the cells in the set transmit UE-specific reference signals aligned in time and frequency on a single set of resource elements to the UE.

21. An apparatus for wireless communication, comprising:

at least one processor configured to determine a semi-static configuration comprising resource elements available to a set of cells to send Coordinated MultiPoint (CoMP) transmission to a user equipment (UE), and to send data on the available resource elements to the UE for the CoMP transmission.

22. The apparatus of claim 21, wherein the at least one processor is configured to send information indicative of the semi-static configuration to the UE, and wherein the semi-static configuration is valid for a plurality of subframes in which the CoMP transmission is sent.

23. The apparatus of claim 21, wherein the at least one processor is configured to determine a maximum number of time division multiplexed (TDM) control symbols for all cells in the set, and to determine the available resource elements based on the maximum number of TDM control symbols.

24. The apparatus of claim 23, wherein the at least one processor is configured to determine resource elements used for cell-specific reference signals by the cells in the set, and to determine the available resource elements based further on the resource elements used for the cell-specific reference signals.

25. The apparatus of claim 21, wherein the at least one processor is configured to send a cell-specific reference signal multiplexed with the data for the CoMP transmission, and wherein the cells in the set transmit cell-specific reference signals aligned in time and frequency on a single set of resource elements.

26. The apparatus of claim 21, wherein the at least one processor is configured to send a UE-specific reference signal for the CoMP transmission, and wherein the cells in the set transmit UE-specific reference signals aligned in time and frequency on a single set of resource elements to the UE.

27. A computer program product, comprising:

a computer-readable medium comprising;

code for causing at least one computer to determine a semi-static configuration comprising resource elements available to a set of cells to send Coordinated MultiPoint (CoMP) transmission to a user equipment (UE), and

code for causing the at least one computer to send data on the available resource elements to the UE for the CoMP transmission.

28. A method for wireless communication, comprising:

receiving information indicative of a semi-static configuration comprising resource elements available to a set of cells to send Coordinated MultiPoint (CoMP) transmission to a user equipment (UE); and

receiving data sent on the available resource elements by at least two cells in the set of cells to the UE for the CoMP transmission.

29. The method of claim 28, wherein the available resource elements are determined based on a maximum number of time division multiplexed (TDM) control symbols for all cells in the set.

30. The method of claim 28, further comprising:

receiving cell-specific reference signals sent aligned in time and frequency by the at least two cells, wherein the available resource elements are determined based on resource elements used for the cell-specific reference signals; and

performing detection for the received data based on the cell-specific reference signals.

31. The method of claim 28, further comprising:

receiving UE-specific reference signals sent aligned in time and frequency by the at least two cells for the CoMP transmission; and

performing detection for the received data based on the UE-specific reference signals.

32. The method of claim 28, wherein the receiving data comprises receiving the data sent on the available resource elements in a data zone of a multicast/broadcast single frequency network (MBSFN) subframe by the at least two cells to the UE for the CoMP transmission, wherein the MBSFN subframe includes no cell-specific reference signals in the data zone.

33. The method of claim 28, wherein the receiving data comprises receiving the data sent on the available resource elements in a blank subframe by the at least two cells to the UE for the CoMP transmission, wherein the blank subframe includes no cell-specific reference signals and no control information for other UEs.

34. An apparatus for wireless communication, comprising:

means for receiving information indicative of a semi-static configuration comprising resource elements available to a set of cells to send Coordinated MultiPoint (CoMP) transmission to a user equipment (UE); and

means for receiving data sent on the available resource elements by at least two cells in the set of cells to the UE for the CoMP transmission.

35. The apparatus of claim 34, wherein the available resource elements are determined based on a maximum number of time division multiplexed (TDM) control symbols for all cells in the set.

36. The apparatus of claim 34, further comprising:

means for receiving cell-specific reference signals sent aligned in time and frequency by the at least two cells, wherein the available resource elements are determined based on resource elements used for the cell-specific reference signals; and

means for performing detection for the received data based on the cell-specific reference signals.

37. The apparatus of claim 34, further comprising:

means for receiving UE-specific reference signals sent aligned in time and frequency by the at least two cells for the CoMP transmission; and

means for performing detection for the received data based on the UE-specific reference signals.

38. The apparatus of claim 34, wherein the means for receiving data comprises means for receiving the data sent on the available resource elements in a data zone of a multicast/broadcast single frequency network (MBSFN) subframe by the at least two cells to the UE for the CoMP transmission, and wherein the MBSFN subframe includes no cell-specific reference signals in the data zone.

39. A method for wireless communication, comprising:

determining a multicast/broadcast single frequency network (MBSFN) subframe used by a set of cells for Coordinated MultiPoint (CoMP) transmission to a user equipment (UE); and

sending data in a data zone of the MBSFN subframe to the UE for the CoMP transmission, wherein the MBSFN subframe includes no cell-specific reference signals in the data zone.

40. The method of claim 39, further comprising:

sending a UE-specific reference signal in the data zone for the CoMP transmission.

41. A method for wireless communication, comprising:

determining a multicast/broadcast single frequency network (MBSFN) subframe used by a set of cells for Coordinated MultiPoint (CoMP) transmission to a user equipment (UE); and

receiving data sent in a data zone of the MBSFN subframe by at least two cells in the set of cells to the UE for the CoMP transmission, wherein the MBSFN subframe includes no cell-specific reference signals in the data zone.

42. The method of claim 41, further comprising:

receiving UE-specific reference signals sent in the data zone by the at least two cells for the CoMP transmission; and

performing detection for the received data based on the UE-specific reference signals.