Methods and arrangements for CSI reporting

1. A method, in a wireless device, for reporting Channel State Information (CSI), the wireless device being comprised in a wireless communications system, the method comprising:

receiving a CSI process configuration and a request for CSI from a network node;

determining a CSI reference resource based on a numerical indicator indicating a total number of configured CSI processes; and reporting CSI for one or more CSI processes, wherein the CSI reflects a state of a channel for the CSI reference resource;

wherein determining the CSI reference resource comprises determining, as a function of how many CSI processes are configured for the wireless device, a location of the CSI reference resource in the time domain.

2. The method of claim 1 , wherein the determining the CSI reference resource comprises determining the CSI reference resource further based on a total number of configured CSI-RS resources configured for the wireless device.

3. The method of claim 1 , further comprising:

prioritizing a first CSI process over a second CSI process;

determining a rank indicator and/or a precoding matrix indicator for the first CSI process; and

reusing the determined rank indicator and/or precoding matrix indicator for the second CSI process.

4. The method of claim 1 , further comprising:

performing measurements on reference signal resources corresponding to the configured CSI processes; and

determining the CSI based on the measurements.

5. The method of claim 1 , wherein the CSI is determined based on measurements performed in and/or prior to the CSI reference resource.

6. The method of claim 1 , wherein the request for CSI is a request for a periodic CSI report.

7. The method of claim 1 , wherein the request for CSI is a request for an aperiodic CSI report.

8. The method of claim 1 , further comprising:

performing measurements on interference measurement resources corresponding to the configured CSI processes; and

determining the CSI based on the measurements.

9. The method of claim 1 , wherein each CSI process corresponds to a reference signal resource and an interference measurement resource.

10. A wireless device for reporting Channel State Information (CSI), the wireless device comprising:

memory comprising instructions;

processing circuitry operatively connected to the memory and configured, when executing the instructions, to cause the wireless device to:

receive, from a network node, a CSI process configuration and a request for CSI;

determine a CSI reference resource based on a numerical indicator indicating a total number of configured CSI processes; and report CSI for one or more CSI processes, wherein the CSI reflects a state of a channel for the CSI reference resource;

wherein the processing circuitry is operatively connected to the memory and is configured, when executing the instructions, to cause the wireless device to determine, as a function of how many CSI processes are configured for the wireless device, a location of the CSI reference resource in the time domain.

11. The wireless device of claim 10 , wherein the wireless device is a user equipment.

12. The wireless device of claim 10 , wherein the processing circuitry, when executing the instructions, is further configured to determine the CSI reference resource further based on a total number of configured CSI-RS resources configured for the wireless device.

13. The wireless device of claim 10 , wherein the processing circuitry, when executing the instructions, is further configured to:

prioritize a first CSI process over a second CSI process;

determine a rank indicator and/or a precoding matrix indicator for the first CSI process; and

reuse the determined rank indicator and/or precoding matrix indicator for the second CSI process.

14. The wireless device of claim 10 , wherein the processing circuitry, when executing the instructions, is further configured to:

perform measurements on reference signal resources corresponding to the configured CSI processes; and

determine the CSI based on the measurements.

15. The wireless device of claim 10 , wherein the processing circuitry, when executing the instructions, is further configured to determine the CSI based on measurements performed in and/or prior to the CSI reference resource.

16. The wireless device of claim 10 , wherein the processing circuitry, when executing the instructions, is further configured to:

perform measurements on interference measurement resources corresponding to the configured CSI processes; and

determine the CSI based on the measurements.

17. A computer program product stored on a non-transitory computer readable medium and comprising program instructions, which when executed by at least one processor, causes the at least one processor to:

receive, from a network node, a CSI process configuration and a request for CSI;

determine a CSI reference resource based on a numerical indicator indicating a total number of configured CSI processes; and

report CSI for one or more CSI processes, wherein the CSI reflects a state of a channel for the CSI reference resource;

wherein the at least one processor is configured, when executing the instructions, to cause a wireless device to determine, as a function of how many CSI processes are configured for the wireless device, a location of the CSI reference resource in the time domain.

18. The method of claim 1 ,

wherein the reporting CSI comprises transmitting the CSI report in a given subframe; and

wherein the determining a CSI reference resource comprises determining, based on the numerical indicator indicating a total number of configured CSI processes, the location of the CSI reference resource relative to the given subframe.