COOPERATION AND OPERATION OF MACRO NODE AND REMOTE RADIO HEAD DEPLOYMENTS IN HETEROGENEOUS NETWORKS

• US 20120207105A1
• Filed: 01/12/2012
• Published: 08/16/2012
• Est. Priority Date: 02/11/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Geirhofer, Stefan, Ji, Tingfang, Gaal, Peter, Damnjanovic, Aleksandar, Montojo, Juan, Luo, Tao, Chen, Wanshi, Bhattad, Kapil
• Granted Patent: US 9,426,703 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 25/0226 sounding signals per se
• 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 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 36/0077 of access information of target access point

Abstract

A method, an apparatus, and a computer program product for wireless communication are provided for separating control transmissions and data transmissions within the coverage area of a plurality of transmission/reception points or points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node. Separating control transmissions and data transmissions in the macro node/RRH configuration may allow UEs to be associated with one set of transmission points for data transmissions and the same set or a different set of transmission points for common control signaling. Separating control transmissions and data transmissions may also allow for faster reconfiguration of antenna ports used for UE data transmission compared with reconfiguration via a handover process.

Claims

1. A method of a macro node and at least one remote radio head (RRH) coupled to the macro node, the macro node and the at least one RRH comprising a plurality of points that are geographically displaced, the method comprising:

transmitting control information with common reference signals (CRS) to a user equipment (UE) from a first subset of points; and

sending a data transmission based on UE-specific demodulation reference signals (DM-RS) to the UE from a second subset of points.

2. The method of claim 1, wherein the first subset of points has the same cell identifier and each point in the first subset of points transmits the same control information and CRS.

3. The method of claim 1, further comprising:

transmitting second control information and a second CRS from a designated point, the designated point being a point in the plurality of points but not in the first subset of points, and the designated point having a different cell identifier from any other point in the plurality of points.

4. The method of claim 1, further comprising transmitting channel state information reference signals (CSI-RS) to the UE from the second subset of points.

5. The method of claim 4, further comprising receiving a channel state information report from the UE based at least in part on the CSI-RS, the channel state information report comprising at least one of precoding matrix indicator (PMI), rank index (RI), or channel quality indicator (CQI) feedback.

6. The method of claim 5, wherein the received channel state information report, comprising PMI, RI, or CQI feedback, is based on channel conditions from the second subset of points to the UE and interference conditions at the UE.

7. The method of claim 1, wherein the control information is transmitted using at least one of a frequency division multiplexed (FDM) control channel or a relay physical downlink control channel (R-PDCCH).

8. The method of claim 1, wherein the first subset of points comprises the macro node and zero or more RRHs, and the second subset of points comprises the macro node and/or one or more RRHs.

9. The method of claim 1, further comprising:

receiving a sounding reference signal (SRS) from the UE at one or more points of the plurality of points;

determining channel strengths at each of the one or more points from the UE based on the SRS received by the one or more points;

receiving channel quality indicator (CQI) feedback from the UE;

determining a modulation and coding scheme (MCS) based on the determined channel strengths and the CQI; and

modulating and coding the data based on the MCS.

10. A method of a macro node and at least one remote radio head (RRH) coupled to the macro node, the macro node and the at least one RRH comprising a plurality of points that are geographically displaced, the method comprising:

transmitting control information with common reference signals (CRS) to a user equipment (UE) from a subset of points;

receiving a sounding reference signal (SRS) from the UE at one or more points of the plurality of points;

determining channel strengths at each of the one or more points from the UE based on the SRS received by the one or more points;

determining whether the UE is in close proximity to at least one point of the one or more points based on the determined channel strengths; and

sending a data transmission based on CRS to the UE from the at least one point when the UE is determined to be in close proximity to the at least one point based on the determined channel strengths,

wherein the data transmission based on CRS is sent to the UE from the at least one point independent of data transmissions from points not in close proximity to the UE.

11. A method of a user equipment (UE) communicating with a macro node and at least one remote radio head (RRH) coupled to the macro node, the macro node and the at least one RRH comprising a plurality of points that are geographically displaced, the method comprising:

receiving control information with a common reference signal (CRS) from a first subset of points;

receiving data transmitted based on UE-specific demodulation reference signals (DM-RS) from a second subset of points;

receiving channel state information reference signals (CSI-RS) from the second subset of points; and

transmitting a channel state information report based at least in part on the received CSI-RS, the channel state information report comprising at least one of precoding matrix indicator (PMI), rank index (RI), or channel quality indicator (CQI) feedback.

12. The method of claim 11, wherein the first subset of points comprises the macro node and zero or more RRHs, and the second subset of points comprises the macro node and/or one or more RRHs.

13. The method of claim 11, further comprising:

receiving an identifier from the first subset of points, the identifier being different from a cell identifier associated with the first subset of points; and

descrambling the received data from the second subset of points based on the received identifier.

14. The method of claim 11, wherein the transmitted channel state information report, comprising PMI, RI, or CQI feedback, is based on channel conditions from the second subset of points to the UE and interference conditions at the UE.

15. An apparatus for wireless communication comprising a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the apparatus further comprising:

means for transmitting control information with common reference signals (CRS) to a user equipment (UE) from a first subset of points; and

means for sending a data transmission based on UE-specific demodulation reference signals (DM-RS) to the UE from a second subset of points.

16. The apparatus of claim 15, wherein the first subset of points has the same cell identifier and each point in the first subset of points transmits the same control information and CRS.

17. The apparatus of claim 15, further comprising:

means for transmitting second control information and a second CRS from a designated point, the designated point being a point in the plurality of points but not in the first subset of points, and the designated point having a different cell identifier from any other point in the plurality of points.

18. The apparatus of claim 15, further comprising means for transmitting channel state information reference signals (CSI-RS) to the UE from the second subset of points.

19. The apparatus of claim 18, further comprising means for receiving a channel state information report from the UE based at least in part on the CSI-RS, the channel state information report comprising at least one of precoding matrix indicator (PMI), rank index (RI), or channel quality indicator (CQI) feedback.

20. The apparatus of claim 19, wherein the received channel state information report, comprising PMI, RI, or CQI feedback, is based on channel conditions from the second subset of points to the UE and interference conditions at the UE.

21. The apparatus of claim 15, wherein the control information is transmitted using at least one of a frequency division multiplexed (FDM) control channel or a relay physical downlink control channel (R-PDCCH).

22. The apparatus of claim 15, wherein the first subset of points comprises the macro node and zero or more RRHs, and the second subset of points comprises the macro node and/or one or more RRHs.

23. The apparatus of claim 15, further comprising:

means for receiving a sounding reference signal (SRS) from the UE at one or more points of the plurality of points;

means for determining channel strengths at each of the one or more points from the UE based on the SRS received by the one or more points;

means for receiving channel quality indicator (CQI) feedback from the UE;

means for determining a modulation and coding scheme (MCS) based on the determined channel strengths and the CQI; and

means for modulating and coding the data based on the MCS.

24. An apparatus for wireless communication comprising a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the apparatus further comprising:

means for transmitting control information with common reference signals (CRS) to a user equipment (UE) from a subset of points;

means for receiving a sounding reference signal (SRS) from the UE at one or more points of the plurality of points;

means for determining channel strengths at each of the one or more points from the UE based on the SRS received by the one or more points;

means for determining whether the UE is in close proximity to at least one point of the one or more points based on the determined channel strengths; and

means for sending a data transmission based on CRS to the UE from the at least one point when the UE is determined to be in close proximity to the at least one point based on the determined channel strengths,

wherein the data transmission based on CRS is sent to the UE from the at least one point independent of data transmissions from points not in close proximity to the UE.

25. An apparatus for wireless communication, the apparatus communicating with a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the apparatus comprising:

means for receiving control information with a common reference signal (CRS) from a first subset of points;

means for receiving data transmitted based on UE-specific demodulation reference signals (DM-RS) from a second subset of points;

means for receiving channel state information reference signals (CSI-RS) from the second subset of points; and

means for transmitting a channel state information report based at least in part on the received CSI-RS, the channel state information report comprising at least one of precoding matrix indicator (PMI), rank index (RI), or channel quality indicator (CQI) feedback.

26. The apparatus of claim 25, wherein the first subset of points comprises the macro node and zero or more RRHs, and the second subset of points comprises the macro node and/or one or more RRHs.

27. The apparatus of claim 25, further comprising:

means for receiving an identifier from the first subset of points, the identifier being different from a cell identifier associated with the first subset of points; and

means for descrambling the received data from the second subset of points based on the received identifier.

28. The apparatus of claim 25, wherein the transmitted channel state information report, comprising PMI, RI, or CQI feedback, is based on channel conditions from the second subset of points to the UE and interference conditions at the UE.

42. The apparatus of claim 25, wherein the transmitted channel state information report, comprising PMI, RI, or CQI feedback, is based on channel conditions from the second subset of points to the UE and interference conditions at the UE.

29. An apparatus for wireless communication comprising a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the apparatus further comprising:

a processing system configured to;

transmit control information with common reference signals (CRS) to a user equipment (UE) from a first subset of points; and

send a data transmission based on UE-specific demodulation reference signals (DM-RS) to the UE from a second subset of points.

30. The apparatus of claim 29, wherein the first subset of points has the same cell identifier and each point in the first subset of points transmits the same control information and CRS.

31. The apparatus of claim 29, wherein the processing system is further configured to:

transmit second control information and a second CRS from a designated point, the designated point being a point in the plurality of points but not in the first subset of points, and the designated point having a different cell identifier from any other point in the plurality of points.

32. The apparatus of claim 29, wherein the processing system is further configured to transmit channel state information reference signals (CSI-RS) to the UE from the second subset of points.

33. The apparatus of claim 32, wherein the processing system is further configured to receive a channel state information report from the UE based at least in part on the CSI-RS, the channel state information report comprising at least one of precoding matrix indicator (PMI), rank index (RI), or channel quality indicator (CQI) feedback.

34. The apparatus of claim 33, wherein the received channel state information report, comprising PMI, RI, or CQI feedback, is based on channel conditions from the second subset of points to the UE and interference conditions at the UE.

35. The apparatus of claim 29, wherein the control information is transmitted using at least one of a frequency division multiplexed (FDM) control channel or a relay physical downlink control channel (R-PDCCH).

36. The apparatus of claim 29, wherein the first subset of points comprises the macro node and zero or more RRHs, and the second subset of points comprises the macro node and/or one or more RRHs.

37. The apparatus of claim 29, wherein the processing system is further configured to:

receive a sounding reference signal (SRS) from the UE at one or more points of the plurality of points;

determine channel strengths at each of the one or more points from the UE based on the SRS received by the one or more points;

receive channel quality indicator (CQI) feedback from the UE;

determine a modulation and coding scheme (MCS) based on the determined channel strengths and the CQI; and

modulate and code the data based on the MCS.

38. An apparatus for wireless communication comprising a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the apparatus further comprising:

a processing system configured to;

transmit control information with common reference signals (CRS) to a user equipment (UE) from a subset of points;

receive a sounding reference signal (SRS) from the UE at one or more points of the plurality of points;

determine channel strengths at each of the one or more points from the UE based on the SRS received by the one or more points;

determine whether the UE is in close proximity to at least one point of the one or more points based on the determined channel strengths; and

send a data transmission based on CRS to the UE from the at least one point when the UE is determined to be in close proximity to the at least one point based on the determined channel strengths,

wherein the data transmission based on CRS is sent to the UE from the at least one point independent of data transmissions from points not in close proximity to the UE.

39. An apparatus for wireless communication, the apparatus communicating with a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the apparatus comprising:

a processing system configured to;

receive control information with a common reference signal (CRS) from a first subset of points;

receive data transmitted based on UE-specific demodulation reference signals (DM-RS) from a second subset of points;

receive channel state information reference signals (CSI-RS) from the second subset of points; and

transmit a channel state information report based at least in part on the received CSI-RS, the channel state information report comprising at least one of precoding matrix indicator (PMI), rank index (RI), or channel quality indicator (CQI) feedback.

40. The apparatus of claim 39, wherein the first subset of points comprises the macro node and zero or more RRHs, and the second subset of points comprises the macro node and/or one or more RRHs.

41. The apparatus of claim 39, wherein the processing system is further configured to:

receive an identifier from the first subset of points, the identifier being different from a cell identifier associated with the first subset of points; and

descramble the received data from the second subset of points based on the received identifier.

43. A computer program product for communicating with a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the computer program product comprising a computer-readable medium comprising code for:

transmitting control information with common reference signals (CRS) to a user equipment (UE) from a first subset of points; and

sending a data transmission based on UE-specific demodulation reference signals (DM-RS) to the UE from a second subset of points.

44. The computer program product of claim 43, wherein the first subset of points has the same cell identifier and each point in the first subset of points transmits the same control information and CRS.

45. The computer program product of claim 43, wherein the first subset of points comprises the macro node and zero or more RRHs, and the second subset of points comprises the macro node and/or one or more RRHs.

46. The computer program product of claim 43, the computer-readable medium further comprising code for:

receiving a sounding reference signal (SRS) from the UE at one or more points of the plurality of points;

determining channel strengths at each of the one or more points from the UE based on the SRS received by the one or more points;

receiving channel quality indicator (CQI) feedback from the UE;

determining a modulation and coding scheme (MCS) based on the determined channel strengths and the CQI; and

modulating and coding the data based on the MCS.

47. A computer program product for communicating with a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the computer program product comprising a computer-readable medium comprising code for:

transmitting control information with common reference signals (CRS) to a user equipment (UE) from a subset of points;

receiving a sounding reference signal (SRS) from the UE at one or more points of the plurality of points;

determining channel strengths at each of the one or more points from the UE based on the SRS received by the one or more points;

determining whether the UE is in close proximity to at least one point of the one or more points based on the determined channel strengths; and

sending a data transmission based on CRS to the UE from the at least one point when the UE is determined to be in close proximity to the at least one point based on the determined channel strengths,

wherein the data transmission based on CRS is sent to the UE from the at least one point independent of data transmissions from points not in close proximity to the UE.

48. A computer program product for communicating with a plurality of points that are geographically displaced, the plurality of points comprising a macro node and a plurality of remote radio heads (RRHs) coupled to the macro node, the computer program product comprising a computer-readable medium comprising code for:

receiving control information with a common reference signal (CRS) from a first subset of points;

receiving data transmitted based on demodulation reference signals (DM-RS) from a second subset of points;

receiving channel state information reference signals (CSI-RS) from the second subset of points; and

transmitting a channel state information report based at least in part on the received CSI-RS, the channel state information report comprising at least one of precoding matrix indicator (PMI), rank index (RI), or channel quality indicator (CQI) feedback.

49. The computer program product of claim 48, wherein the first subset of points comprises the macro node and zero or more RRHs, and the second subset of points comprises the macro node and/or one or more RRHs.

50. The computer program product of claim 48, the computer-readable medium further comprising code for:

receiving an identifier from the first subset of points, the identifier being different from a cell identifier associated with the first subset of points; and

descrambling the received data from the second subset of points based on the received identifier.