REPORTING OF CHANNEL PROPERTIES IN HETEROGENEOUS NETWORKS

• US 20120076025A1
• Filed: 09/26/2011
• Published: 03/29/2012
• Est. Priority Date: 04/13/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: JI, TINGFANG, BARBIERI, ALAN
• Granted Patent: US 9,307,431 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/563 of the wireless resources

Abstract

Rank indicator and channel quality indicator (CQI) estimation and reporting functionalities are discussed with regard to heterogeneous networks to reduce the number of inconsistent CQI estimates transmitted to an evolved node B (eNB), where the CQI is defined as inconsistent when the rank indicator, on which the CQI is conditioned, is from a different subframe type than the subframe on which the CQI is to be estimated.

Claims

1. A method for wireless communication, comprising:

receiving a plurality of parameter values at a user equipment (UE) for reporting a plurality of channel properties associated with a resource;

estimating a first set of channel properties of the plurality of channel properties related to a first channel property, the estimating the first set using a first set of parameter values of the plurality of parameter values;

estimating a second set of channel properties of the plurality of channel properties related to a second channel property, the estimating the second set using a second set of parameter values of the plurality of parameter values, wherein the estimating of the first and second sets of the plurality of channel properties is performed in parallel; and

transmitting the plurality of estimated channel properties to an associated evolved node B (eNB).

2. The method of claim 1, wherein the plurality of parameter values include at least one of:

a periodicity; and

an offset.

3. The method of claim 1, wherein the first set of parameter values configures the estimating of the first set of channel properties for clean interlaces.

4. The method of claim 3, wherein the second set of parameter values configures the estimating of the second set of channel properties for unclean interlaces.

5. The method of claim 3, wherein the first set of parameter values that configure the estimating of the first set of channel properties for clean interlaces includes a reporting periodicity that is a multiple of an interlace period.

6. The method of claim 1, further comprising:

detecting a transmission collision of the first and second sets of channel properties scheduled for the transmitting in a same subframe; and

determining one of the first and second sets of channel properties to transmit during the same subframe.

7. The method of claim 6, wherein the determining comprises one of:

selecting the first set of channel properties;

selecting the one of the first and second sets of channel properties estimated from a clean subframe;

selecting the one of the first and second sets of estimated channel properties according to a configuration of the UE; and

selecting the one of the first and second sets of estimated channel properties according to collision parameters received from the associated eNB.

8. The method of claim 1, wherein the estimated channel properties comprise one or more of:

a rank indicator (RI);

a channel quality indicator (CQI); and

a precoding matrix indicator (PMI).

9. The method of claim 1,

wherein the channel properties include, at least, rank indicators and channel quality indicators (CQIs), and

wherein receiving the plurality of parameter values comprises:

receiving assignment of a reporting period to a rank indicator estimation process and a CQI estimation process,

receiving assignment of a first reporting offset to the rank indicator estimation process,

receiving assignment of a second reporting offset to the CQI estimation process, and

receiving assignment of a third reporting offset to the CQI estimation process, wherein, when combined with the second reporting offset, the third reporting offset causes the CQI estimated from the first reference subframe to be reported in a different subframe than the rank indicator estimated from the first reference subframe, and

wherein estimating the first set of channel properties comprises estimating a rank indicator with a rank estimation process at the UE;

wherein estimating the second set of channel properties comprises estimating the CQI with a CQI estimation process, wherein both the rank indicator and the CQI are estimated from a first reference subframe; and

wherein transmitting the plurality of estimated channel properties comprises,

transmitting the rank indicator to the eNB servicing the UE according to the reporting period and the first reporting offset; and

transmitting the CQI to the eNB according to the reporting period, the second reporting offset, and the third reporting offset.

10. The method of claim 1,

wherein the channel properties include, at least, rank indicators and channel quality indicators (CQIs), and

wherein receiving the plurality of parameter values comprises:

receiving assignment of a rate indicator reporting periodicity for a rate indicator estimation process, wherein the rate indicator reporting periodicity is not an integer multiple of an interlace period,

receiving assignment of the CQI reporting periodicity, the CQI reporting periodicity being smaller than the rate indicator reporting periodicity; and

wherein transmitting the plurality of estimated channel properties comprises;

reporting a first CQI to the eNB, the first CQI conditioned on a current-reported rank indicator;

reporting a second CQI to the eNB, the second CQI conditioned on a previously-reported;

reporting a third CQI to the eNB, the third CQI conditioned on the current-reported rank indicator; and

reporting a subsequent CQI to the eNB, the subsequent CQI conditioned on an opposite rank indicator, the opposite rank indicator opposite to the type of rank indicator previously used.

11. The method of claim 1,

wherein receiving the plurality of parameter values comprises receiving an assignment to alternate rank indicator reports between a first reference subframe type and a second reference subframe type;

and further comprising;

receiving semi-static resource partitioning information (SRPI) identifying a plurality of static interlace subframe assignments in an interlace period;

identifying a first reference subframe of the first reference subframe type using the SRPI, the first reference subframe identified for estimating a rank indicator;

identifying a next subframe of the second reference subframe type using the SRPI, the next subframe identified for estimating a next rank indicator;

identifying a first channel quality indicator (CQI) subframe and a corresponding rank indicator of the first reference subframe type using the SRPI, the first CQI subframe and the corresponding rank indicator identified for estimating a CQI associated with the first reference subframe type; and

identifying a next CQI subframe and a next corresponding rank indicator of the second reference subframe type using the SRPI, the next CQI subframe and the next corresponding rank indicator identified for estimating a next CQI associated with the second reference subframe type.

12. The method of claim 11 further-comprising:

decoding a plurality of adaptively assigned subframes of the interlace period to determine a subframe type of the plurality of adaptively assigned subframes, wherein the identifying also uses the subframe type determined for the plurality of adaptively assigned subframes.

13. The method of claim 1,

wherein the channel properties include, at least, rank indicators and channel quality indicators (CQI);

and

wherein receiving the plurality of parameter values comprises;

receiving a rank indicator assignment directing the UE to report rank indicators only for subframes of a first reference subframe type,

receiving a periodicity assignment for CQI reporting, wherein the periodicity assignment results in CQI reporting for all interlaces;

and further comprising;

responsive to a value of a rank indicator of the first reference subframe type indicating an unknown value of a rank indicator of a second reference subframe type on which a CQI estimate is to be conditioned, setting a value of the rank indicator of the second reference subframe type according to one of;

the value of the rank indicator of the second reference subframe type equals the value of the rank indicator of the first reference subframe type; and

the value of the rank indicator of the second reference subframe type equals a selected constant value.

14. The method of claim 13 wherein the selected constant value is selected by aperiodically estimating an aperiodic CQI for a subframe of the second reference subframe type, the selected constant value determined through the estimated aperiodic CQI, the aperiodic estimating periodically requested by the eNB associated with the UE.

15. The method of claim 1,

wherein the channel properties include, at least, rank indicators and channel quality indicators (CQI);

and

wherein receiving the plurality of parameter values comprises, wireless communication, comprising;

receiving an assignment directing the UE to alternate rank indicator (RI) reports and CQI reports between a first reference subframe type and a second reference subframe type;

and further comprising;

selecting a subframe for estimation of one of;

a RI and a CQI;

cancelling interference in the subframe;

responsive to the subframe being of the second reference subframe type and the estimating directed for the first reference subframe type, estimating the one of;

the RI and the CQI, after the cancelling; and

responsive to the subframe being of the second reference subframe type and the estimating directed for the second reference subframe type;

re-adding the cancelled interference to the subframe; and

estimating the one of;

the RI and the CQI, after the re-adding.

16. The method of claim 15, wherein the cancelling of interference comprises:

selecting one or more eNBs among at least one neighboring eNB detected by the UE, the selecting of one or more eNBs whose reference symbols collide with reference symbols from a serving eNB;

canceling interference due to the reference symbols transmitted from the selected one or more eNBs; and

computing a channel property using a remaining signal after the canceling.

17. The method of claim 16, wherein the selecting comprises one or more of:

receiving from the serving eNB a list of eNBs for cancelation; and

receiving from the serving eNB a list of eNBs for preserving.

18. An apparatus configured for wireless communication, comprising:

means for receiving a plurality of parameter values at a user equipment (UE) for reporting a plurality of channel properties associated with a resource;

means for estimating a first set of channel properties of the plurality of channel properties related to a first channel property, the means for estimating the first set using a first set of parameter values of the plurality of parameter values;

means for estimating a second set of channel properties of the plurality of channel properties related to a second channel property, the means for estimating the second set using a second set of parameter values of the plurality of parameter values, wherein the means for estimating the first and second sets of the plurality of channel properties is performed in parallel; and

means for transmitting the plurality of estimated channel properties to an associated evolved node B (eNB).

19. The apparatus of claim 18, wherein the plurality of parameter values include at least one of:

a periodicity; and

an offset.

20. The apparatus of claim 18, wherein the first set of parameter values configures the estimating of the first set of channel properties for clean interlaces.

21. The apparatus of claim 20, wherein the second set of parameter values configures the estimating of the second set of channel properties for unclean interlaces.

22. The apparatus of claim 20, wherein the first set of parameter values that configure the estimating of the first set of channel properties for clean interlaces includes a reporting periodicity that is a multiple of an interlace period.

23. The apparatus of claim 18, further comprising:

means for detecting a transmission collision of the first and second sets of channel properties scheduled for the means for transmitting in a same subframe; and

means for determining one of the first and second sets of channel properties to transmit during the same subframe.

24. The apparatus of claim 23, wherein the means for determining comprises one of:

means for selecting the first set of channel properties;

means for selecting the one of the first and second sets of channel properties estimated from a clean subframe;

means for selecting the one of the first and second sets of estimated channel properties according to a configuration of the UE; and

means for selecting the one of the first and second sets of estimated channel properties according to collision parameters received from the associated eNB.

25. The apparatus of claim 18, wherein the estimated channel properties comprise one or more of:

a rank indicator (RI);

a channel quality indicator (CQI); and

a precoding matrix indicator (PMI).

26. A computer program product for wireless communications in a wireless network, comprising:

a non-transitory computer-readable medium having program code recorded thereon, the program code comprising;

program code to receive a plurality of parameter values at a user equipment (UE) for reporting a plurality of channel properties associated with a resource;

program code to estimate a first set of channel properties of the plurality of channel properties related to a first channel property, the program code to estimate the first set using a first set of parameter values of the plurality of parameter values;

program code to estimate a second set of channel properties of the plurality of channel properties related to a second channel property, the program code to estimate the second set using a second set of parameter values of the plurality of parameter values, wherein the program code to estimate the first and second sets of the plurality of channel properties is performed in parallel; and

program code to transmit the plurality of estimated channel properties to an associated evolved node B (eNB).

27. The computer program product of claim 26, wherein the plurality of parameter values include at least one of:

a periodicity; and

an offset.

28. The computer program product of claim 26, wherein the first set of parameter values configures the program code to estimate the first set of channel properties for clean interlaces.

29. The computer program product of claim 28, wherein the second set of parameter values configures the program code to estimate the second set of channel properties for unclean interlaces.

30. The computer program product of claim 28, wherein the first set of parameter values that configures the program code to estimate the first set of channel properties for clean interlaces includes a reporting periodicity that is a multiple of an interlace period.

31. The computer program product of claim 26, further comprising:

program code to detect a transmission collision of the first and second sets of channel properties scheduled for use in the program code to transmit in a same subframe; and

program code to determine one of the first and second sets of channel properties to transmit during the same subframe.

32. The computer program product of claim 31, wherein the program code to determine comprises one of:

program code to select the first set of channel properties;

program code to select the one of the first and second sets of channel properties estimated from a clean subframe;

program code to select the one of the first and second sets of estimated channel properties according to a configuration of the UE; and

program code to select the one of the first and second sets of estimated channel properties according to collision parameters received from the associated eNB.

33. The computer program product of claim 26, wherein the estimated channel properties comprise one or more of:

a rank indicator (RI);

a channel quality indicator (CQI); and

a precoding matrix indicator (PMI).

34. An apparatus configured for wireless communication, comprising

at least one processor;

and

a memory coupled to the at least one processor, wherein the at least one processor is configured;

to receive a plurality of parameter values at a user equipment (UE) for reporting a plurality of channel properties associated with a resource;

to estimate a first set of channel properties of the plurality of channel properties related to a first channel property, the at least one processor configured to estimate the first set using a first set of parameter values of the plurality of parameter values;

to estimate a second set of channel properties of the plurality of channel properties related to a second channel property, the at least one processor configured estimate the second set using a second set of parameter values of the plurality of parameter values, wherein the estimation of the first and second sets of the plurality of channel properties is performed by the at least one processor in parallel; and

to transmit the plurality of estimated channel properties to an associated evolved node B (eNB).

35. The apparatus of claim 34, wherein the plurality of parameter values include at least one of:

a periodicity; and

an offset.

36. The apparatus of claim 34, wherein the first set of parameter values configures the at least one processor to estimate the first set of channel properties for clean interlaces.

37. The apparatus of claim 36, wherein the second set of parameter values configures the at least one processor to estimate the second set of channel properties for unclean interlaces.

38. The apparatus of claim 36, wherein the first set of parameter values that configures the program code to estimate the first set of channel properties for clean interlaces includes a reporting periodicity that is a multiple of an interlace period.

39. The apparatus of claim 34, wherein the at least one processor is further configured:

to detect a transmission collision of the first and second sets of channel properties scheduled for the transmission in a same subframe; and

to determine one of the first and second sets of channel properties to transmit during the same subframe.

40. The apparatus of claim 39, wherein the configuration of the at least one processor to determine comprises configuration of the at least one processor to one of:

select the first set of channel properties;

select the one of the first and second sets of channel properties estimated from a clean subframe;

select the one of the first and second sets of estimated channel properties according to a configuration of the UE; and

select the one of the first and second sets of estimated channel properties according to collision parameters received from the associated eNB.

41. The apparatus of claim 34, wherein the estimated channel properties comprise one or more of:

a rank indicator (RI);

a channel quality indicator (CQI); and

a precoding matrix indicator (PMI).

42. A method of wireless communication, comprising:

compiling a plurality of sets of scheduling parameter values, wherein each set of the plurality of sets includes a plurality of scheduling parameters designed to configure scheduling of a reporting engine of a user equipment (UE) for estimating channel properties of the UE, and wherein two or more of the plurality of sets are compiled for a specific UE; and

transmitting the plurality of sets of scheduling parameters values to a corresponding one or more UEs.

43. The method of claim 42, wherein at least one of the plurality of sets includes a plurality of scheduling parameters configuring the reporting engine to estimate channel properties for clean interlaces, and wherein at least another of the plurality of sets includes another plurality of scheduling parameters configuring the reporting engine to estimate channel properties for unclean interlaces.

44. The method of claim 42,

wherein the channel properties include, at least, rank indicators and channel quality indicators (CQIs), and

wherein compiling a plurality of sets of scheduling parameter values comprises:

assigning a reporting period to a rank indicator estimation process at the UE and a CQI estimation process at the UE, the reporting period being evenly divisible into an interlace period;

assigning a first reporting offset to the rank indicator estimation process;

assigning a second reporting offset to the CQI estimation process, wherein the first and second reporting offsets are different;

and further comprising;

receiving a rank indicator resulting from the rank indicator estimation process and a CQI resulting from the CQI estimation process during different ones of a plurality of subframes.

45. The method of claim 42,

wherein the channel properties include, at least, rank indicators and channel quality indicators (CQIs), and

wherein compiling a plurality of sets of scheduling parameter values comprises:

assigning a reporting period to a rank indicator estimation process at the UE and a CQI estimation process at the UE, wherein the reporting period and an interlace period have different prime values;

assigning a first reporting offset to the rank indicator estimation process;

assigning a second reporting offset to the CQI estimation process, wherein the first and second reporting offsets are selected to reduce a number of CQI estimates for a first reference subframe type produced by the CQI estimation process that are conditioned on a rate indicator based on a second reference subframe type different from the first reference subframe type, the rate indicator produced by the rate indicator estimation process;

and further comprising;

receiving a rank indicator resulting from the rank indicator estimation process and a CQI resulting from the CQI estimation process during different ones of a plurality of subframes.

46. The method of claim 42,

wherein the channel properties include, at least, rank indicators and channel quality indicators (CQIs), and

wherein compiling a plurality of sets of scheduling parameter values comprises:

assigning a reporting period to a rank indicator estimation process at the UE and a CQI estimation process at the UE, wherein the reporting period is greater than an interlace period but is not a multiple of the interlace period;

assigning a first reporting offset to the rank indicator estimation process;

assigning a second reporting offset to the CQI estimation process, wherein the first and second reporting offsets are selected so that when a rate indicator is estimated in a first reference subframe, a next CQI is estimated in a next subframe, the next subframe defined as the first reference subframe plus the interlace period;

and further comprising;

receiving a rank indicator resulting from the rank indicator estimation process and a CQI resulting from the CQI estimation process during different ones of a plurality of subframes.

47. An apparatus configured for wireless communication, comprising:

means for compiling a plurality of sets of scheduling parameter values, wherein each set of the plurality of sets includes a plurality of scheduling parameters designed to configure scheduling of a reporting engine of a user equipment (UE) for estimating channel properties of the UE, and wherein two or more of the plurality of sets are compiled for a specific UE; and

means for transmitting the plurality of sets of scheduling parameters values to a corresponding one or more UEs.

48. The apparatus of claim 47, wherein at least one of the plurality of sets includes a plurality of scheduling parameters configuring the reporting engine to estimate channel properties for clean interlaces, and wherein at least another of the plurality of sets includes another plurality of scheduling parameters configuring the reporting engine to estimate channel properties for unclean interlaces.

49. A computer program product for wireless communications in a wireless network, comprising:

a non-transitory computer-readable medium having program code recorded thereon, the program code comprising;

program code to compile a plurality of sets of scheduling parameter values, wherein each set of the plurality of sets includes a plurality of scheduling parameters designed to configure scheduling of a reporting engine of a user equipment (UE) for estimating channel properties of the UE, and wherein two or more of the plurality of sets are compiled for a specific UE; and

program code to transmit the plurality of sets of scheduling parameters values to a corresponding one or more UEs.

50. The computer program product of claim 49, wherein at least one of the plurality of sets includes a plurality of scheduling parameters configuring the reporting engine to estimate channel properties for clean interlaces, and wherein at least another of the plurality of sets includes another plurality of scheduling parameters configuring the reporting engine to estimate channel properties for unclean interlaces.

51. An apparatus configured for wireless communication, comprising

at least one processor;

and

a memory coupled to the at least one processor, wherein the at least one processor is configured;

to compile a plurality of sets of scheduling parameter values, wherein each set of the plurality of sets includes a plurality of scheduling parameters designed to configure scheduling of a reporting engine of a user equipment (UE) for estimating channel properties of the UE, and wherein two or more of the plurality of sets are compiled for a specific UE; and

to transmit the plurality of sets of scheduling parameters values to a corresponding one or more UEs.

52. The apparatus of claim 51, wherein at least one of the plurality of sets includes a plurality of scheduling parameters configuring the reporting engine to estimate channel properties for clean interlaces, and wherein at least another of the plurality of sets includes another plurality of scheduling parameters configuring the reporting engine to estimate channel properties for unclean interlaces.