Method and apparatus for performing coordinated multipoint feedback under multiple channel and interference assumptions

1. A method for wireless communications by a user equipment (UE), comprising:

receiving signaling indicating at least:

one or more interference measurement resources (IMRs) from a network, and

one or more subframe sets;

performing interference measurements according to the one or more signaled IMRs;

transmitting one or more channel state information (CSI) feedback reports that correspond to the interference measurements, wherein the one or more CSI feedback reports comprise CSI restricted to IMRs that occur in a same subframe set of the one or more signaled subframe sets;

receiving further signaling indicating a deactivation of one or more of the IMRs; and

discontinuing performing interference measurements or transmitting CSI feedback corresponding to the deactivated IMRs.

2. The method of claim 1 , wherein the signaling further comprises a configuration with one or more non-zero power reference signal (NZP-RS) resources in which one or more base stations transmit a reference signal (RS), and wherein the one or more NZP-RS signal resources comprise one or more non-zero power channel state information reference signal (NZP-CSI-RS) resources and wherein the RS transmitted by the one or more base stations comprises a CSI-RS.

3. The method of claim 1 , wherein the one or more IMRs correspond to a single IMR.

4. The method of claim 2 , wherein the performing comprises performing separate interference measurements at least on a per-IMR basis in one or more subframes by forming a baseline interference estimate based on the IMR and forming separate interference estimates based on adding interference from selected NZP-RS resources to the baseline interference estimate, and wherein the adding of the interference from the selected NZP-CSI-RS resources is subject to specific, separately signaled, precoding assumptions.

5. The method of claim 4 , wherein the one or more IMRs correspond to two or more IMRs.

6. The method of claim 5 , wherein the per-IMR interference measurements are performed on a single subframe.

7. The method of claim 1 , wherein the CSI feedback is transmitted to one or more base stations.

8. The method of claim 7 , wherein the CSI feedback is transmitted using uplink transmission formats with a higher payload.

9. The method of claim 1 , further comprising receiving further signaling indicating codebook subset restrictions for one or more reporting configurations.

10. The method of claim 9 , wherein the restrictions for the one or more reporting configurations comprises restrictions for the one or more IMRs.

11. The method of claim 1 , further comprising:

generating a rank indicator (RI) report based on a number of CSI-RS ports across one or more channel measurement resources (CMRs).

12. An apparatus for wireless communications by a user equipment (UE), comprising:

means for receiving signaling indicating at least:

one or more interference measurement resources (IMRs) from a network, and

one or more subframe sets;

means for performing interference measurements according to the one or more signaled IMRs;

means for transmitting one or more channel state information (CSI) feedback reports that correspond to the interference measurements, wherein the one or more CSI feedback reports comprise CSI restricted to IMRs that occur in a same subframe set of the one or more signaled subframe sets;

means for receiving further signaling indicating a deactivation of one or more of the IMRs; and

means for discontinuing performing interference measurements or transmitting CSI feedback corresponding to the deactivated IMRs.

13. The apparatus of claim 12 , wherein the signaling further comprises a configuration with one or more non-zero power reference signal (NZP-RS) resources in which one or more base stations transmit a reference signal (RS), and wherein the one or more NZP-RS signal resources comprise one or more non-zero power channel state information reference signal (NZP-CSI-RS) resources and wherein the RS transmitted by the one or more base stations comprises a CSI-RS.

14. The apparatus of claim 12 , wherein the one or more IMRs correspond to a single IMR.

15. The apparatus of claim 13 , wherein the means for performing comprises means for performing separate interference measurements at least on a per-IMR basis in one or more subframes by forming a baseline interference estimate based on the IMR and means for forming separate interference estimates based on adding interference from selected NZP-RS resources to the baseline interference estimate, and wherein the adding of the interference from the selected NZP-CSI-RS resources is subject to specific, separately signaled, precoding assumptions.

16. The apparatus of claim 15 , wherein the one or more IMRs correspond to two or more IMRs.

17. The apparatus of claim 16 , wherein the per-IMR interference measurements are performed on a single subframe.

18. The apparatus of claim 12 , wherein the CSI feedback is transmitted to one or more base stations.

19. The apparatus of claim 18 , wherein the CSI feedback is transmitted using uplink transmission formats with a higher payload.

20. The apparatus of claim 12 , further comprising means for receiving further signaling indicating codebook subset restrictions for one or more reporting configurations.

21. The apparatus of claim 20 , wherein the restrictions for the one or more reporting configurations comprises restrictions for the one or more IMRs.

22. The apparatus of claim 12 , further comprising:

means for generating a rank indicator (RI) report based on a number of CSI-RS ports across one or more channel measurement resources (CMRs).

23. An apparatus for wireless communications by a user equipment (UE), comprising:

at least one processor configured to:

receive signaling indicating at least:

one or more interference measurement resources (IMRs) from a network, and

one or more subframe sets;

perform interference measurements according to the one or more signaled IMRs; and

transmit one or more channel state information (CSI) feedback reports that correspond to the interference measurements, wherein the one or more CSI feedback reports comprise CSI restricted to IMRs that occur in a same subframe set of the one or more signaled subframe sets;

receive further signaling indicating a deactivation of one or more of the IMRs; and

discontinue performing interference measurements or transmitting CSI feedback corresponding to the deactivated IMRs; and

a memory coupled to the at least one processor.

24. A non-transitory computer-readable medium having code stored thereon, the code executable by one or more processors for:

receiving signaling indicating at least:

one or more interference measurement resources (IMRs) from a network, and

one or more subframe sets;

performing interference measurements according to the one or more signaled IMRs;

transmitting one or more channel state information (CSI) feedback reports that correspond to the interference measurements, wherein the one or more CSI feedback reports comprise CSI restricted to IMRs that occur in a same subframe set of the one or more signaled subframe sets;

receiving further signaling indicating a deactivation of one or more of the IMRs; and

discontinuing performing interference measurements or transmitting CSI feedback corresponding to the deactivated IMRs.

25. A method for wireless communications by a base station, comprising:

transmitting signaling indicating at least:

one or more interference measurement resources (IMRs), and

one or more subframe sets;

transmitting at least signals or data transmissions such that interference conditions encountered by a user equipment (UE) on the one or more IMRs include only interference from a subset of transmission points;

receiving one or more channel state information (CSI) feedback reports that correspond to separate interference measurements performed at the UE at least on a per-IMR basis in one or more subframes, wherein the one or more CSI feedback reports comprise CSI restricted to IMRs that occur in a same subframe set of the one or more signaled subframe sets; and

transmitting signaling indicating a deactivation of one or more of the IMRs, the signaling indicating that interference measurements are not to be performed or CSI feedback is not to be transmitted corresponding to the deactivated one or more IMRs.

26. The method of claim 25 , wherein a configuration with one or more non-zero power reference signal (NZP-RS) resources in which the base station transmits a reference signal (RS), and wherein the one or more NZP-RS resources comprise one or more non-zero power channel state information reference signal (NZP-CSI-RS) resources and wherein the RS transmitted by the base station comprises a CSI-RS.

27. The method of claim 25 , wherein the one or more IMRs correspond to a single IMR.

28. The method of claim 26 , wherein the CSI reports correspond to separate interference estimates based on adding interference from selected NZP-RS resources to a baseline interference estimate based on the IMR, and wherein the adding of the interference from the selected NZP-CSI-RS resources is subject to specific, separately signaled, precoding assumptions.

29. The method of claim 27 , wherein the base station avoids creating interference on the IMR by configuring one or more ZP-CSI-RS resources on resource elements comprising the IMR.

30. The method of claim 25 , wherein the one or more IMRs correspond to two or more IMRs.

31. The method of claim 30 , wherein the interference measurements performed at the UE at least on a per-IMR basis are performed on a single subframe.

32. The method of claim 30 , wherein the base station avoids creating interference on a specific IMR by configuring one or more ZP-CSI-RS resources on resource elements comprising the IMR.

33. An apparatus for wireless communications by a base station, comprising:

means for transmitting signaling indicating at least:

one or more interference measurement resources (IMRs), and

one or more subframe sets;

means for transmitting at least signals or data transmissions such that interference conditions encountered by a user equipment (UE) on the one or more IMRs include only interference from a subset of transmission points;

means for receiving one or more channel state information (CSI) feedback reports that correspond to separate interference measurements performed at the UE at least on a per-IMR basis in one or more subframes, wherein the one or more CSI feedback reports comprise CSI restricted to IMRs that occur in a same subframe set of the one or more signaled subframe sets; and

means for transmitting signaling indicating a deactivation of one or more of the IMRs, the signaling indicating that interference measurements are not to be performed or CSI feedback is not to be transmitted corresponding to the deactivated one or more IMRs.

34. The method of claim 33 , wherein a configuration with one or more non-zero power reference signal (NZP-RS) resources in which the base station transmits a reference signal (RS), and wherein the one or more NZP-RS resources comprise one or more non-zero power channel state information reference signal (NZP-CSI-RS) resources and wherein the RS transmitted by the base station comprises a CSI-RS.

35. The apparatus of claim 33 , wherein the one or more IMRs correspond to a single IMR.

36. The apparatus of claim 34 , wherein the CSI reports correspond to separate interference estimates based on adding interference from selected NZP-RS resources to a baseline interference estimate based on the IMR, and wherein the adding of the interference from the selected NZP-CSI-RS resources is subject to specific, separately signaled, precoding assumptions.

37. The apparatus of claim 35 , wherein the base station avoids creating interference on the IMR by configuring one or more ZP-CSI-RS resources on resource elements comprising the IMR.

38. The apparatus of claim 33 , wherein the one or more IMRs correspond to two or more IMRs.

39. The apparatus of claim 38 , wherein the interference measurements performed at the UE at least on a per-IMR basis are performed on a single subframe.

40. The apparatus of claim 38 , wherein the base station avoids creating interference on a specific IMR by configuring one or more ZP-CSI-RS resources on resource elements comprising the IMR.

41. An apparatus for wireless communications by a base station, comprising:

at least one processor configured to:

transmit signaling indicating at least:

one or more interference measurement resources (IMRs), and

one or more subframe sets;

transmit at least signals or data transmissions such that interference conditions encountered by a user equipment (UE) on the one or more IMRs include only interference from a subset of transmission points;

receive one or more channel state information (CSI) feedback reports that correspond to separate interference measurements performed at the UE at least on a per-IMR basis in one or more subframes, wherein the one or more CSI feedback reports comprise CSI restricted to IMRs that occur in a same subframe set of the one or more signaled subframe sets; and

transmit signaling indicating a deactivation of one or more of the IMRs, the signaling indicating that interference measurements are not to be performed or CSI feedback is not to be transmitted corresponding to the deactivated one or more IMRs; and

a memory coupled to the at least one processor.

42. A non-transitory computer-readable medium having code stored thereon, the code executable by one or more processors for:

transmitting signaling indicating at least:

one or more interference measurement resources (IMRs), and

one or more subframe sets;

transmitting at least signals or data transmissions such that interference conditions encountered by a user equipment (UE) on the one or more IMRs include only interference from a subset of transmission points;

receiving one or more channel state information (CSI) feedback reports that correspond to separate interference measurements performed at the UE at least on a per-IMR basis in one or more subframes, wherein the one or more CSI feedback reports comprise CSI restricted to IMRs that occur in a same subframe set of the one or more signaled subframe sets; and

transmitting signaling indicating a deactivation of one or more of the IMRs, the signaling indicating that interference measurements are not to be performed or CSI feedback is not to be transmitted corresponding to the deactivated one or more IMRs.