System and method for flexible channel state information-reference signal transmission

1. A method by a wireless device for restricting channel state information, CSI, measurement comprises:

receiving, from a network node, information identifying a first subset of channel state information-reference signal, CSI-RS, resources comprising one or more parameters identifying a first subset of physical resource blocks (PRBs) to be used in performing CSI measurements, the first subset of CSI-RS resources being associated with a first portion of a frequency band that is less than all of the frequency band, wherein the information received from the network node further identifies a first CSI reporting type of a plurality of CSI reporting types for reporting the CSI associated with the first subset of CSI-RS resources; and

performing CSI measurements in the first subset of CSI-RS resources being associated with the first portion of the frequency band.

2. The method of claim 1 , wherein the frequency band comprises a system bandwidth in a CSI-RS subframe.

3. The method of claim 1 , further comprising:

transmitting, to the network node, CSI feedback comprising one or more values associated with the CSI measurements performed in the first subset of CSI-RS resources.

4. The method of claim 1 , wherein the frequency band consists of a plurality of PRBs.

5. The method of claim 1 , wherein the first portion of the frequency band consists of the first subset of PRBs.

6. The method of claim 1 , further comprising transmitting, to the network node, CSI feedback comprising:

one or more values associated with the CSI measurements performed in the first subset of CSI-RS resources.

7. The method of claim 3 , wherein the CSI feedback comprises a report of the first CSI reporting type.

8. The method of claim 1 , wherein:

the information identifying the first subset of CSI-RS resources comprises a set of antenna ports, and

performing the CSI measurements in the first subset of CSI-RS resources comprises performing the CSI measurements on the CSI-RS resources associated with the set of antenna ports.

9. The method of claim 1 , wherein:

the information identifying the first subset of CSI-RS resources comprises a set of even number PRBs or a set of odd number PRBs in the frequency band, and

based on the information received from the network node, performing the CSI measurements comprises performing the CSI-measurements on the first subset of CSI-RS resources configured on the set of even number PRBs or the set of odd number PRBs.

10. The method of claim 1 , wherein the information identifying the first subset of CSI-RS resources comprises every M PRBs in the frequency band, and wherein M is an integer and is greater than one.

11. The method of claim 1 , wherein the information identifying the first subset of CSI-RS resources is received in semi-static signaling.

12. The method of claim 1 , wherein the information identifying the first subset of CSI-RS resources is received in dynamic signaling.

13. The method of claim 12 , wherein the information is received as downlink control information, DCI, and wherein the DCI is received in a common control channel search space or UE specific search space.

14. The method of claim 1 , further comprising:

receiving, from the network node, information identifying a second subset of CSI-RS resources to be used in performing CSI measurements, the second subset of CSI-RS resources being associated with a second portion of the frequency band that is less than all of the frequency band and different from the first portion; and

performing the CSI measurements in the second subset of CSI-RS resources being associated with the second portion of the frequency band.

15. The method of claim 1 , wherein:

the information identifying the first subset of CSI-RS resources comprises a subset of precoding resource block groups, PRGs.

16. A wireless device for restricting channel state information, CSI, measurement, comprising:

processing circuitry, the processing circuitry configured to:

receive, from a network node, information identifying a first subset of channel state information reference-signal, CSI-RS, resources comprising one or more parameters identifying a first subset of physical resource blocks (PRBs) to be used in performing CSI measurements, the first subset of CSI-RS resources being associated with a first portion of a frequency band that is less than all of the frequency band, wherein the information received from the network node further identifies a first CSI reporting type of a plurality of CSI reporting types for reporting the CSI associated with the first subset of CSI-RS resources; and

perform CSI measurements in the first subset of CSI-RS resources being associated with the first portion of the frequency band.

17. A method by a network node for restricting channel state information, CSI, measurement comprises:

signaling, to a first wireless device, information identifying a first subset of channel state information-reference signal, CSI-RS, resources comprising one or more parameters identifying a first subset of physical resource blocks (PRBs) to be used in performing CSI measurements, the first subset of CSI-RS resources being associated with a first portion of a frequency band, the first portion being less than all of the frequency band, wherein the information signaled to the first wireless device further identifies a first CSI reporting type of a plurality of CSI reporting types for reporting the CSI associated with the first subset of CSI-RS resources; and

receiving, from the first wireless device, CSI feedback associated with the CSI measurements performed using the first subset of CSI-RS resources.