Systems and methods for reliable dynamic indication for semi-persistent CSI-RS

1. A method in a wireless device for initiating semi-persistent channel state information, CSI, measurements, the method comprising:

receiving, from a network node, dynamic allocation signaling, the dynamic allocation signaling triggering the wireless device to commence measurement on a semi-persistent channel state information-reference signal, CSI-RS, resource;

in response to receiving the dynamic allocation signaling, performing a first measurement on the semi-persistent CSI-RS resource;

receiving, from the network node, an aperiodic CSI report trigger message triggering an aperiodic CSI report, the aperiodic CSI report trigger message being different than the dynamic allocation signaling;

transmitting, to the network node, the aperiodic CSI report based only on the first measurement for which measurement was triggered on the semi-persistent CSI-RS resource by the dynamic allocation signaling;

receiving, from the network node, a semi-persistent CSI report trigger message that is different than the dynamic allocation signaling and the aperiodic CSI report trigger message, the semi-persistent CSI report trigger message triggering semi-persistent CSI reporting; and

initiating semi-persistent CSI reporting based on subsequent measurements of the semi-persistent CSI-RS resource.

2. The method according to claim 1 , wherein the dynamic allocation signaling comprises a MAC control element, MAC CE.

3. The method according to claim 1 , wherein the semi-persistent CSI report trigger message comprises downlink control information, DCI.

4. The method according to claim 1 , wherein initiating semi-persistent CSI reporting comprises transmitting a plurality of semi-persistent CSI reports.

5. The method according to claim 4 , further comprising:

ceasing transmission of the plurality of semi-persistent CSI-RS reports after a predetermined length of time.

6. The method according to claim 1 , where the first CSI report is an aperiodic report.

7. The method according to claim 1 , where the first CSI report is a semi-persistent report.

8. The method according to claim 1 , wherein the dynamic allocation signaling comprises at least one of the following:

an indication of semi-persistent CSI-RS measurement initiation;

an indication of semi-persistent CSI-RS resource configuration index/indices; and

an uplink resource allocation and associated modulation and coding rate.

9. The method according to claim 1 , wherein the semi-persistent CSI-RS resource comprises a CSI-RS resource that is configured with at least a CSI-RS transmission periodicity and for which at least one wireless device assumption on transmission and cessation of CSI-RS transmission applies.

10. The method according to claim 1 wherein:

the semi-persistent CSI-RS resource is configured for transmission of CSI-RS at a configured periodicity for a limited time duration; and

receipt of the dynamic allocation is required to trigger to transmission of the semi-persistent CSI-RS on the semi-persistent CSI-RS resource.

11. The method according to claim 1 , further comprising:

receiving dynamic deallocation signaling to terminate the measurement of on the semi-persistent CSI-RS resource; and

in response to the dynamic deallocation signaling, ceasing the semi-persistent measurements on the semi-persistent CSI-RS resource.

12. A wireless device for initiating semi-persistent channel state information, CSI, measurements, the wireless device comprising:

a memory storing instructions; and

processing circuitry operable to execute the instructions to cause the wireless device to:

in response to receiving the dynamic allocation signaling, receive, from a network node, dynamic allocation signaling, the dynamic allocation signaling triggering the wireless device to commence measurement on a semi-persistent channel state information-reference signal, CSI-RS, resource;

perform a first measurement on the semi-persistent CSI-RS resource;

receive, from the network node, an aperiodic CSI report trigger message triggering an aperiodic CSI report, the aperiodic CSI report trigger message being different than the dynamic allocation signaling;

transmit, to the network node, the aperiodic CSI report based only on the first measurement for which measurement was triggered on the semi-persistent CSI-RS resource by the dynamic allocation signaling;

receive, from the network node, a semi-persistent CSI report trigger message that is different than the dynamic allocation signaling and the aperiodic CSI report trigger message, the semi-persistent CSI report trigger message triggering semi-persistent CSI reporting; and

initiate semi-persistent CSI reporting based on subsequent measurements of the semi-persistent CSI-RS resource.

13. The wireless device according to claim 12 , wherein the dynamic allocation signaling comprises a MAC control element, MAC CE.

14. The wireless device according to claim 12 , wherein the semi-persistent CSI report trigger message comprises downlink control information, DCI.

15. The wireless device according to claim 12 , wherein initiating semi-persistent CSI reporting comprises transmitting a plurality of semi-persistent CSI reports.

16. The wireless device according to claim 15 , wherein the processing circuitry is operable to execute the instructions to cause the wireless device to:

cease transmission of the plurality of semi-persistent CSI-RS reports after a predetermined length of time.

17. A method in a network node for initiating semi-persistent channel state information, CSI, measurements, the method comprising:

transmitting, to the wireless device, dynamic allocation signaling, the dynamic allocation signaling triggering the wireless device to initiate measurement on a semi-persistent channel state information-reference signal, CSI-RS, resource for which the wireless device is not currently performing measurements;

transmitting, to the wireless device, an aperiodic CSI report trigger message triggering an aperiodic CSI report, the aperiodic CSI report trigger message being different than the dynamic allocation signaling;

receiving, from the wireless device, the aperiodic CSI report based only on a first measurement for which measurement was triggered on the semi-persistent CSI-RS resource by the dynamic allocation signaling; and

transmitting, to the wireless device, a semi-persistent CSI report trigger message that is different from the dynamic allocation signaling and the aperiodic CSI report trigger message, the semi-persistent CSI report trigger message triggering semi-persistent CSI reporting; and

receiving semi-persistent CSI reporting based on subsequent measurements of the semi-persistent CSI-RS resource by the wireless device.

18. The method according to claim 17 , wherein the dynamic allocation signaling comprises a MAC control element, MAC CE.

19. The method of claim 17 , further comprising:

based on receiving the aperiodic CSI report, determining that the wireless device successfully received the dynamic allocation signaling; and

wherein the semi-persistent CSI report trigger message is transmitted to the wireless device to trigger semi-persistent CSI reporting in response to determining that the wireless device successfully received the dynamic allocation signaling.

20. The method according to claim 17 , wherein the semi-persistent CSI report trigger message comprises downlink control information, DCI.

21. The method according to claim 17 , wherein the dynamic allocation signaling comprises at least one of the following:

an indication of semi-persistent CSI-RS measurement initiation;

an indication of semi-persistent CSI-RS resource configuration index/indices; and

an uplink resource allocation and associated modulation and coding rate.

22. The method according to claim 17 , wherein the semi-persistent CSI-RS resource comprises a CSI-RS resource that is configured with at least a CSI-RS transmission periodicity and for which at least one wireless device assumption on transmission and cessation of CSI-RS transmission applies.

23. The method according to claim 17 wherein:

the semi-persistent CSI-RS resource is configured for transmission of CSI-RS at a configured periodicity for a limited time duration; and

receipt of the dynamic allocation is required to trigger to transmission of the semi-persistent CSI-RS on the semi-persistent CSI-RS resource.

24. The method according to claim 17 , further comprising:

transmitting dynamic deallocation signaling to terminate the measurement on the semi-persistent CSI-RS resource by the wireless device;

determine whether a second CSI report is transmitted by the wireless device in response to the dynamic deallocation signaling; and

take an action based on whether the second CSI report is transmitted by the wireless device in response to the dynamic allocation signaling.

25. A network node for initiating semi-persistent channel state information, CSI, measurements, the network node comprising:

a memory storing instructions; and

processing circuitry operable to execute the instructions to cause the network node to:

transmit, to the wireless device, dynamic allocation signaling, the dynamic allocation signaling triggering the wireless device to initiate measurement on a semi-persistent channel state information-reference signal, CSI-RS, resource for which the wireless device is not currently performing measurements;

transmit, to the wireless device, an aperiodic CSI report trigger message triggering an aperiodic CSI report, the aperiodic CSI report trigger message being different than the dynamic allocation signaling;

receive, from the wireless device, the aperiodic CSI report based only on a first measurement for which measurement was triggered on the semi-persistent CSI-RS resource by the dynamic allocation signaling;

transmit, to the wireless device, a semi-persistent CSI report trigger message that is different from the dynamic allocation signaling and the aperiodic CSI report trigger message, the semi-persistent CSI report trigger message triggering semi-persistent CSI reporting; and

receive semi-persistent CSI reporting based on subsequent measurements of the semi-persistent CSI-RS resource by the wireless device.