Signaling in RRC and MAC for PDSCH resource mapping for periodic and semipersistent reference signal assumptions

1. A method performed by a wireless device for activating a Semi-Persistent (SP) Zero Power (ZP) Channel State Information Reference Signal (CSI-RS), the method comprising:

receiving, from a base station, a configuration for the SP ZP CSI-RS that is independent of a second configuration for CSI-Interference Measurement (CSI-IM);

receiving, from the base station, a first control message that indicates activation of one or more SP ZP CSI-RS resources where the first control message is separate from a second control message indicating activation of SP Non-Zero Power (NZP) CSI-RS, SP CSI-IM, or CSI and the first and second control messages are Medium Access Control (MAC) Control Element (CE) based; and

activating, based on the first control message, the one or more SP ZP CSI-RS resources.

2. The method of claim 1 wherein the first control message comprises a bitmap, where each bit in the bitmap indicates if one SP ZP CSI-RS resource set is active or not.

3. The method of claim 2 wherein the SP ZP CSI-RS resource set to which the bitmap refers is a Radio Resource Control (RRC) configured list of SP ZP CSI-RS resources.

4. The method of claim 1 wherein the first control message comprises one or more identifiers, where each identifier identifies a preconfigured SP ZP CSI-RS resource set.

5. The method of claim 1 further comprising:

in response to activating the one or more SP ZP CSI-RS resources, Physical Downlink Shared Channel (PDSCH) resource mapping around the one or more SP ZP CSI-RS resources.

6. The method of claim 1 further comprising:

receiving, from the base station, a deactivation control message that indicates the deactivation of the one or more SP ZP CSI-RS resources where the deactivation control message is a MAC CE; and

deactivating, based on the deactivation control message, the one or more SP ZP CSI-RS resources.

7. The method of claim 6 further comprising:

in response to deactivating the one or more SP ZP CSI-RS resources, stopping Physical Downlink Shared Channel (PDSCH) resource mapping around resources for the one or more SP ZP CSI-RS.

8. A method performed by a base station for activating a Semi-Persistent (SP) Zero Power (ZP) Channel State Information Reference Signal (CSI-RS), the method comprising:

transmitting, to a wireless device, a configuration for the SP ZP CSI-RS that is independent of a second configuration for CSI-Interference Measurement (CSI-IM);

transmitting, to the wireless device, a first control message that indicates activation of one or more SP ZP CSI-RS resources where the first control message is separate from a second control message indicating activation of SP Non-Zero Power (NZP) CSI-RS, SP CSI IM, or CSI and the first and second control messages are Medium Access Control (MAC) Control Element (CE) based.

9. The method of claim 8 wherein the first control message comprises a bitmap, where each bit in the bitmap indicates if one SP ZP CSI-RS resource set is active or not.

10. The method of claim 9 wherein the one SP ZP CSI-RS resource set to which the bitmap refers is a Radio Resource Control (RRC) configured list of SP ZP CSI-RS resources.

11. The method of claim 8 wherein the first control message comprises one or more identifiers, where each identifier identifies a preconfigured SP ZP CSI-RS resource set.

12. The method of claim 8 further comprising:

in response to activating the one or more SP ZP CSI-RS resources, the wireless device Physical Downlink Shared Channel (PDSCH) resource maps around the one or more SP ZP CSI-RS resources.

13. The method of claim 8 further comprising:

transmitting, to the wireless device, a deactivation control message that indicates the deactivation of the one or more SP ZP CSI-RS resources where the deactivation control message is a MAC CE.

14. The method of claim 8 further comprising:

in response to deactivating the one or more SP ZP CSI-RS resources, the wireless device stops Physical Downlink Shared Channel (PDSCH) resource mapping around resources for the one or more SP ZP CSI-RS.

15. A wireless device for activating a Semi-Persistent (SP) Zero Power (ZP) Channel State Information Reference Signal (CSI-RS), comprising:

one or more network interfaces;

one or more processors; and

memory comprising instructions executable by the one or more processors whereby the wireless device is operable to:

receive, from a base station, a configuration for the SP ZP CSI-RS that is independent of a second configuration for CSI-Interference Measurement (CSI-IM);

receive, from the base station, a first control message that indicates activation of one or more SP ZP CSI-RS resources where the first control message is separate from a second control message indicating activation of SP Non-Zero Power (NZP) CSI-RS, SP CSI-IM, or CSI and the first and second control messages are Medium Access Control (MAC) Control Element (CE) based; and

activate, based on the first control message, the one or more SP ZP CSI-RS resources.

16. The wireless device of claim 15 wherein the first control message comprises a bitmap, where each bit in the bitmap indicates if one SP ZP CSI-RS resource set is active or not.

17. The wireless device of claim 16 wherein the one SP ZP CSI-RS resource set which the bitmap refers to is a Radio Resource Control (RRC) configured list of SP ZP CSI-RS resources.

18. The wireless device of claim 15 wherein the first control message comprises one or more identifiers, where each identifier identifies a preconfigured SP ZP CSI-RS resource set.

19. The wireless device of claim 15 further operable to:

in response to activating the one or more SP ZP CSI-RS resources, Physical Downlink Shared Channel (PDSCH) resource map around the one or more SP ZP CSI-RS resources.