Techniques for handling channel state information (CSI) in ultra low latency (ULL) LTE

1. A method of reporting channel state information (CSI) to a network entity, comprising:

detecting a CSI reporting trigger for reporting CSI to the network entity;

identifying, based on detection of the CSI reporting trigger, whether a subframe region of a subframe, associated with one or more symbols for which the CSI is to be generated is a control region defined by at least a first symbol of the subframe during which transmissions occur via one or more control channels, a data region defined by at least a second symbol of the subframe during which transmissions occur exclusively via one or more data channels, or a grey region defined by at least a third symbol of the subframe, wherein each of the control region, the data region, and the grey region is included in the subframe;

where the subframe region is identified as the control region, generating the CSI based on a first measurement;

where the subframe region is identified as the data region, generating the CSI based on a second measurement;

where the subframe region is identified as the grey region, generating the CSI based on a third measurement; and

transmitting the CSI to the network entity,

wherein the control region, the data region, and the grey region are defined according to a first wireless communication technology that is based on a transmission time interval (TTI) having a duration of the subframe, and wherein transmitting the CSI comprises transmitting the CSI based on a second wireless communication technology and in a TTI having a duration less than the subframe.

2. The method of claim 1 , wherein the subframe region is identified as the control region, the control region including at least one symbol during which information is transmitted via one or more control channels.

3. The method of claim 2 , further comprising receiving at least one common reference signal (CRS) in the control region, and wherein generation of the CSI based on the first measurement includes generating the CSI based on the at least one CRS received in the control region.

4. The method of claim 1 , wherein the subframe region is identified as the data region, the data region including at least one symbol during which information is transmitted via one or more data channels.

5. The method of claim 4 , further comprising performing an Interference Measurement Resource (IMR) measurement of an IMR, and wherein generation of the CSI based on the second measurement includes generating the CSI based on the IMR measurement.

6. The method of claim 1 , wherein the subframe region is identified as the grey region, the grey region including at least one symbol during which information is transmitted via one or both of one or more control channels or one or more data channels.

7. The method of claim 6 , further comprising identifying one or more resource element groups (REGs) in the grey region for interference measurement; and

measuring interference associated with the one or more REGs to obtain an interference measurement,

wherein generation of the CSI based on the third measurement further includes generating the CSI based on the interference measurement.

8. The method of claim 1 , further comprising determining whether the CSI reporting trigger is associated with a first transmit time interval (TTI), wherein the first TTI is less than a second TTI, and wherein legacy communications with the network entity use the second TTI.

9. The method of claim 8 , wherein generation of the CSI is performed over a plurality of subbands, where a subband size for the CSI is larger than a subband size associated with generation of CSI for the second TTI.

10. The method of claim 8 , wherein the CSI for the first TTI is restricted compared with the CSI for the second TTI, wherein the first TTI is restricted by implementing one or more of a reduced set of ranks, a reduced set of precoding matrix indicators, a reduced set of CSI reporting types, or a reduced performance requirement for the first TTI.

11. The method of claim 8 , further comprising determining that a prior CSI transmitted to the network entity was based on a prior CSI reporting trigger associated with the second TTI, and wherein generation of the CSI comprises generating a differential CSI relative to the prior CSI.

12. The method of claim 1 , wherein the CSI reporting trigger is at least one of a configuration for periodic CSI reporting or an indication in a control channel for aperiodic CSI reporting.

13. An apparatus for reporting channel state information (CSI) to a network entity, comprising:

means for detecting a CSI reporting trigger for reporting CSI to the network entity;

means for identifying, based on detection of the CSI reporting trigger, whether a subframe region of a subframe, associated with one or more symbols for which the CSI is to be generated is a control region defined by at least a first symbol of the subframe during which transmissions occur via one or more control channels, a data region defined by at least a second symbol of the subframe during which transmissions occur exclusively via one or more data channels, or a grey region defined by at least a third symbol of the subframe, wherein each of the control region, the data region, and the grey region is included in the subframe;

where the subframe region is identified as the control region, means for generating the CSI based on a first measurement;

where the subframe region is identified as the data region, means for generating the CSI based on a second measurement;

where the subframe region is identified as the grey region, means for generating the CSI based on a third measurement; and

means for transmitting the CSI to the network entity,

wherein the control region, the data region, and the grey region are defined according to a first wireless communication technology that is based on a transmission time interval (TTI) having a duration of the subframe, and wherein the means for transmitting the CSI transmits the CSI based on a second wireless communication technology and in a TTI having a duration less than the subframe.

14. The apparatus of claim 13 , wherein the subframe region is identified as the grey region, the grey region including at least one symbol during which information is transmitted via one or more control channels, one or more data channels, or any combination thereof, and further comprising:

means for identifying one or more resource element groups (REGs) in the grey region for interference measurement; and

means for measuring interference associated with the one or more REGs to obtain an interference measurement,

wherein the means for generating the CSI based on the third measurement comprise means for generating the CSI based on the interference measurement.

15. A non-transitory computer-readable medium storing computer-executable code for reporting channel state information (CSI) to a network entity, the code comprising instructions executable to:

detect a CSI reporting trigger for reporting CSI to the network entity;

identify, based on detection of the CSI reporting trigger, whether a subframe region of a subframe, associated with one or more symbols for which the CSI is to be generated is a control region defined by at least a first symbol of the subframe during which transmissions occur via one or more control channels, a data region defined by at least a second symbol of the subframe during which transmissions occur exclusively via one or more data channels, or a grey region defined by at least a third symbol of the subframe, wherein each of the control region, the data region, and the grey region is included in the subframe;

where the subframe region is identified as the control region, generate the CSI based on a first measurement;

where the subframe region is identified as the data region, generate the CSI based on a second measurement;

where the subframe region is identified as the grey region, generate the CSI based on a third measurement; and

transmit the CSI to the network entity,

wherein the control region, the data region, and the grey region are defined according to a first wireless communication technology that is based on a transmission time interval (TTI) having a duration of the subframe, and wherein the code is executable to transmit the CSI based on a second wireless communication technology and in a TTI having a duration less than the subframe.

16. The computer-readable medium of claim 15 , wherein the subframe region is identified as the grey region, the grey region including at least one symbol during which information is transmitted via one or more control channels, one or more data channels, or any combination thereof, and the code comprising instructions executable to:

identify one or more resource element groups (REGs) in the grey region for interference measurement; and

measure interference associated with the one or more REGs to obtain an interference measurement,

wherein the instructions executable to generate the CSI based on the third measurement comprise instructions executable to generate the CSI based on the interference measurement.

17. An apparatus for reporting channel state information (CSI) to a network entity, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to:

detect a CSI reporting trigger for reporting CSI to the network entity;

identify, based on detection of the CSI reporting trigger, whether a subframe region of a subframe, associated with one or more symbols for which the CSI is to be generated is a control region defined by at least a first symbol of the subframe during which transmissions occur via one or more control channels, a data region defined by at least a second symbol of the subframe during which transmissions occur exclusively via one or more data channels, or a grey region defined by at least a third symbol of the subframe, wherein each of the control region, the data region, and the grey region is included in the subframe;

where the subframe region is identified as the control region, generate the CSI based on a first measurement;

where the subframe region is identified as the data region, generate the CSI based on a second measurement;

where the subframe region is identified as the grey region, generate the CSI based on a third measurement; and

transmit the CSI to the network entity,

wherein the control region, the data region, and the grey region are defined according to a first wireless communication technology that is based on a transmission time interval (TTI) having a duration of the subframe, and wherein the instructions are executable to transmit the CSI based on a second wireless communication technology and in a TTI having a duration less than the subframe.

18. The apparatus of claim 17 , wherein the subframe region is the control region including at least one symbol during which information is transmitted via one or more control channels.

19. The apparatus of claim 18 , wherein the instructions further comprise instructions being executable by the processor to receive at least one common reference signal (CRS) in the control region, and wherein the instructions executable to generate the CSI based on the first measurement comprise instructions executable by the processor to generate the CSI based on the at least one CRS received in the control region.

20. The apparatus of claim 17 , wherein the subframe region is identified as the data region, the data region including at least one symbol during which information is transmitted via one or more data channels.

21. The apparatus of claim 20 , wherein the instructions further comprise instructions being executable by the processor to perform an Interference Measurement Resource (IMIR) measurement of an IMIR, and wherein the instructions executable to generate the CSI based on the second measurement comprise instructions executable by the processor to generate the CSI based on the IMIR measurement.

22. The apparatus of claim 17 , wherein the subframe region is identified as the grey region, the grey region comprising at least one symbol during which information is transmitted via one or both of one or more control channels or one or more data channels.

23. The apparatus of claim 22 , wherein the instructions further comprise instructions being executable by the processor to:

identify one or more resource element groups (REGs) in the grey region for interference measurement; and

measure interference associated with the one or more REGs to obtain an interference measurement,

wherein the instructions executable to generate the CSI based on the third measurement further comprise instructions being executable by the processor to generate the CSI based on the interference measurement.

24. The apparatus of claim 17 , wherein the instructions further comprise instructions being executable by the processor to determine whether the CSI reporting trigger is associated with a first transmit time interval (TTI), wherein the first TTI is less than a second TTI, and wherein legacy communications with the network entity use the second TTI.

25. The apparatus of claim 24 , wherein the instructions executable to generate the CSI comprise instructions executable by the processor to generate the CSI over a plurality of subbands, where a subband size for the CSI is larger than a subband size associated with generation of CSI for the second TTI.

26. The apparatus of claim 24 , wherein the CSI for the first TTI is restricted compared with the CSI for the second TTI, wherein the first TTI is restricted by implementing one or more of a reduced set of ranks, a reduced set of precoding matrix indicators, a reduced set of CSI reporting types, or a reduced performance requirement for the first TTI.

27. The apparatus of claim 24 , wherein the instructions further comprise instructions being executable by the processor to determine that a prior CSI transmitted to the network entity was based on a prior CSI reporting trigger associated with the second TTI, and wherein the instructions executable to generate the CSI comprise instructions executable by the processor to generate a differential CSI relative to the prior CSI.

28. The apparatus of claim 17 , wherein the CSI reporting trigger is at least one of a configuration for periodic CSI reporting or an indication in a control channel for aperiodic CSI reporting.