Channel state information reporting for partial bands

1 . A method for wireless communication at a user equipment (UE), comprising:

receiving, from a network node, a configuration message comprising an indication of one or more partial bands for channel state information reporting and an indication of one or more antenna ports for each partial band of the one or more partial bands, wherein each partial band of the one or more partial bands is less than a system bandwidth and comprises a plurality of frequency domain units, and wherein each frequency domain unit of the plurality of frequency domain units is associated with a precoder;

selecting, by the UE, one or more antenna ports for each partial band of the one or more partial bands based at least in part on the configuration message and the indication of the one or more antenna ports;

calculating channel state information comprising a linear combination of the selected one or more antenna ports for each partial band, based at least in part on receiving the configuration message; and

transmitting the channel state information comprising at least an indication of the selected one or more antenna ports and linear combination coefficients for each partial band of the one or more partial bands in accordance with the indication of the one or more antenna ports.

2 . The method of claim 1 , wherein the one or more antenna ports comprise channel state information reference signal (CSI-RS) ports, and wherein selecting the one or more antenna ports comprises:

selecting a subset of a total number of antenna ports for each partial band of the one or more partial bands in accordance with the indication of the one or more antenna ports.

3 . The method of claim 2 , wherein selecting the subset of the total number of antenna ports for each partial band comprises:

selecting a same subset of one or more CSI-RS ports for each different partial band of the one or more partial bands.

4 . The method of claim 1 , wherein:

calculating the channel state information comprises separately precoding each partial band of the one or more partial bands.

5 . The method of claim 1 , wherein the indication of the one or more partial bands for channel state information reporting comprises one or more of a numerical quantity of partial bands for which the UE is to perform channel state measurements, or a partial band size for which the UE is to perform the channel state measurements, or a ratio of partial band size to frequency domain unit size.

6 . The method of claim 5 , further comprising:

transmitting, to the network node, a capability message indicating a numerical quality of partial bands for which the UE is capable of performing the channel state measurements, wherein the configuration message is based at least in part on the capability message.

7 . The method of claim 5 , wherein the indication of the one or more partial bands is dependent on an indication of a numerical quantity of antenna ports to select for each partial band of the one or more partial bands or a numerical quantity of total antenna ports, and wherein selecting the one or more antenna ports for each partial band is based at least in part on the indicated numerical quantity of antenna ports or the indicated numerical quantity of total antenna ports.

8 . The method of claim 1 , wherein:

the one or more antenna ports comprise channel state information reference signal (CSI-RS) ports and the configuration message further comprises an indication of partial bands and a numerical quantity of the CSI-RS ports; and

selecting the one or more antenna ports for each partial band is based at least in part on the indication of the partial bands and the numerical quantity of the CSI-RS ports.

9 . The method of claim 8 , wherein the indication of the partial bands and the numerical quantity of the CSI-RS ports comprises one or more of: a number of partial bands, a partial band size, or a ratio of partial bands to frequency unit size; and

the indication of the partial bands and the numerical quantity of the CSI-RS ports further comprises one or more of: a number of total CSI-RS ports or a number of CSI-RS ports to be selected for each partial band.

10 . The method of claim 1 , further comprising:

transmitting, to the network node, a report of the one or more antenna ports selected for each partial band of the one or more partial bands, wherein the report comprises an indication of a first set of antenna ports common to all partial bands of the one or more partial bands and, for each partial band of the one or more partial bands, an indication of a respective second set of antenna ports independently selected for that partial band, wherein the one or more respective second sets of antenna ports for each partial band are from the first set of antenna ports.

11 . The method of claim 10 , further comprising:

receiving, from the network node, a configuration of a size of the first set of antenna ports and a size of the respective second set of antenna ports.

12 . The method of claim 1 , further comprising:

transmitting, to the network node, a report of a resource selection for a channel state measurement for each partial band of the one or more partial bands.

13 . The method of claim 1 , further comprising:

receiving, from the network node, a configuration of frequency domain restriction for channel measurements; and

determining that a frequency domain restriction for channel measurements is in place based at least in part on the configuration of the frequency domain restriction for channel measurements, wherein calculating the channel state information for each partial band of the one or more partial bands comprises restricting channel state measurements to non-zero power channel state information reference signals within each partial band.

14 . The method of claim 1 , further comprising:

receiving, from the network node, a configuration of a frequency domain restriction for interference measurements; and

determining that the frequency domain restriction for interference measurements is in place based at least in part on the configuration of the frequency domain restriction for interference measurements, wherein performing interference measurements for each partial band of the one or more partial bands comprises restricting the interference measurements to non-zero power interference measurement resources within each partial band.

15 . The method of claim 1 , wherein a frequency domain unit of the plurality of frequency domain units corresponds to a subband size for channel quality indicator (CQI) reporting.

16 . A method for wireless communication at a network node, comprising:

transmitting, to a user equipment (UE), a configuration message comprising an indication of one or more partial bands for channel state information reporting and an indication of one or more antenna ports for each partial band of the one or more partial bands, wherein each partial band of the one or more partial bands is less than a system bandwidth and comprises a plurality of frequency domain units, and wherein each frequency domain unit of the plurality of frequency domain units is associated with a precoder;

receiving channel state information comprising an indication of the one or more antenna ports and linear combination coefficients for each partial band of the one or more partial bands based at least in part on transmitting the configuration message and channel state measurements; and

communicating with the UE based at least in part on receiving the channel state information for each partial band of the one or more partial bands.

17 . The method of claim 16 , wherein the indication of the one or more partial bands for channel state information reporting comprises one or more of a numerical quantity of partial bands for which the UE is to perform the channel state measurements, or a partial band size for which the UE is to perform the channel state measurements, or a ratio of partial band size to frequency domain unit size.

18 . The method of claim 17 , wherein the indication of the one or more partial bands is dependent on an indication of a numerical quantity of antenna ports to select for each partial band of the one or more partial bands or a numerical quantity of total antenna ports.

19 . The method of claim 16 , further comprising:

receiving a capability message from the UE indicating a numerical quality of partial bands for which the UE is capable of performing the channel state measurements, wherein the configuration message is based at least in part on the capability message.

20 . The method of claim 16 , wherein:

the antenna ports comprise channel state information reference signal (CSI-RS) ports and the configuration message further comprises an indication of partial bands and a numerical quantity of the CSI-RS ports.

21 . The method of claim 20 , wherein the indication of the partial bands and the numerical quantity of the CSI-RS ports comprises one or more of: a number of partial bands, a partial band size, or a ratio of partial bands to frequency unit size; and

the indication of the partial bands and the numerical quantity of the CSI-RS ports further comprises one or more of: a number of total CSI-RS ports or a number of CSI-RS ports to be selected for each partial band.

22 . The method of claim 16 , further comprising:

receiving a report from the UE of one or more antenna ports selected for each partial band of the one or more partial bands, wherein the report comprises an indication of a first set of antenna ports common to all partial bands of the one or more partial bands and, for each partial band of the one or more partial bands, an indication of a respective second set of antenna ports independently selected for that partial band, wherein the one or more respective second sets of antenna ports for each partial band are from the first set of antenna ports.

23 . The method of claim 22 , further comprising:

transmitting, to the UE, a configuration of a size of the first set of antenna ports and a size of the respective second set of antenna ports.

24 . The method of claim 16 , further comprising:

receiving, from the UE, a report of a resource selection for the channel state measurements for each partial band of the one or more partial bands.

25 . The method of claim 16 , further comprising:

transmitting, to the UE, a configuration of a frequency domain restriction for channel measurements; and

receiving the channel state information based at least in part on channel state measurements of non-zero power channel state information reference signals within each partial band.

26 . The method of claim 16 , further comprising:

transmitting, to the UE, a configuration of a frequency domain restriction for interference measurement; and

receiving the channel state information based at least in part on an interference measurement of interference measurement resources within each partial band.

27 . An apparatus for wireless communication at a user equipment (UE), comprising:

one or more processors,

one or more memories coupled with the one or more processors; and

instructions stored in the one or more memories and executable by the one or more processors to cause the apparatus to:

receive, from a network node, a configuration message comprising an indication of one or more partial bands for channel state information reporting and an indication of one or more antenna ports for each partial band of the one or more partial bands, wherein each partial band of the one or more partial bands is less than a system bandwidth and comprises a plurality of frequency domain units, and wherein each frequency domain unit of the plurality of frequency domain units is associated with a precoder;

select, by the UE, one or more antenna ports for each partial band of the one or more partial bands based at least in part on the configuration message and the indication of the one or more antenna ports;

calculate channel state information comprising a linear combination of the selected one or more antenna ports for each partial band, based at least in part on receiving the configuration message; and

transmit the channel state information comprising at least an indication of the selected one or more antenna ports and linear combination coefficients for each partial band of the one or more partial bands in accordance with the indication of the one or more antenna ports.

28 . The apparatus of claim 27 , wherein the one or more antenna ports comprise channel state information reference signal (CSI-RS) ports, and wherein the instructions to select the one or more antenna ports are executable by the one or more processors to cause the apparatus to:

select a subset of a total number of antenna ports for each partial band of the one or more partial bands in accordance with the indication of the one or more antenna ports.

29 . The apparatus of claim 28 , wherein the instructions to select the subset of the total number of antenna ports for each partial band comprise instructions executable by the one or more processors to cause the apparatus to:

select a same subset of one or more CSI-RS ports for each different partial band of the one or more partial bands.

30 . The apparatus of claim 27 , wherein the instructions to calculate the channel state information comprise instructions executable by the one or more processors to separately precode each partial band of the one or more partial bands.

31 . An apparatus for wireless communication at a network node comprising, comprising:

one or more processors,

one or more memories coupled with the one or more processors; and

instructions stored in the one or more memories and executable by the one or more processors to cause the apparatus to:

transmit to a user equipment (UE) a configuration message comprising an indication of one or more partial bands for channel state information reporting and an indication of one or more antenna ports for each partial band of the one or more partial bands, wherein each partial band of the one or more partial bands is less than a system bandwidth and comprises a plurality of frequency domain units, and wherein each frequency domain unit of the plurality of frequency domain units is associated with a precoder;

receive channel state information comprising an indication of the one or more antenna ports and linear combination coefficients for each partial band of the one or more partial bands based at least in part on transmitting the configuration message and channel state measurements; and

communicate with the UE based at least in part on receiving the channel state information for each partial band of the one or more partial bands.

32 . The apparatus of claim 31 , wherein the indication of the one or more partial bands for channel state information reporting comprises one or more of a numerical quantity of partial bands for which the UE is to perform channel state measurement, or a partial band size for which the UE is to perform the channel state measurements, or a ratio of partial band size to frequency domain unit size.

33 . The apparatus of claim 32 , wherein the indication of the one or more partial bands is dependent on an indication of a numerical quantity of antenna ports to select for each partial band of the one or more partial bands or a numerical quantity of total antenna ports.

34 . An apparatus for wireless communication at a user equipment (UE), comprising:

means for receiving, from a network node, a configuration message comprising an indication of one or more partial bands for channel state information reporting and an indication of one or more antenna ports for each partial band of the one or more partial bands, wherein each partial band of the one or more partial bands is less than a system bandwidth and comprises a plurality of frequency domain units, and wherein each frequency domain unit of the plurality of frequency domain units is associated with a precoder;

means for selecting, by the UE, one or more antenna ports for each partial band of the one or more partial bands based at least in part on the configuration message and the indication of the one or more antenna ports;

means for calculating channel state information comprising a linear combination of the selected one or more antenna ports for each partial band, based at least in part on receiving the configuration message; and

means for transmitting the channel state information comprising at least an indication of the selected one or more antenna ports and linear combination coefficients for each partial band of the one or more partial bands in accordance with the indication of the one or more antenna ports.

35 . The apparatus of claim 34 , wherein the means for selecting the one or more antenna ports comprises:

means for selecting a subset of a total number of antenna ports for each partial band of the one or more partial bands in accordance with the indication of the one or more antenna ports.