Channel state information (CSI) computation for effective isotropic radiated power (EIRP)-constrained transmissions

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

receiving a downlink transmission from a base station over a wireless channel, wherein the downlink transmission comprises an indication of a channel state information (CSI) computation mode;

receiving a scaling factor for the indicated CSI computation mode from the base station;

selecting, based at least in part on the indicated CSI computation mode, an effective isotropic radiated power (EIRP) constrained CSI computation mode for the wireless channel, wherein the EIRP constrained CSI computation mode is based at least in part on an EIRP constraint;

measuring a set of one or more CSI reference signals (CSI-RSs) from the base station to obtain a CSI measurement;

scaling the CSI measurement based at least in part on the selected EIRP constrained CSI computation mode according to the scaling factor; and

transmitting a CSI report to the base station wherein the CSI report is based at least in part on the selected EIRP constrained CSI computation mode and the CSI measurement, wherein the CSI report includes the scaled CSI measurement.

2. The method of claim 1 ,

wherein the indication of the CSI computation mode comprises a configuration of the CSI computation mode from the base station.

3. The method of claim 2 , wherein the downlink transmission comprises one or more of: a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE), or downlink control information (DCI) block.

4. The method of claim 3 , wherein the configuration of the CSI computation mode is based at least in part on one or more of: a number of antennas configured for the UE or a number of CSI ports configured for the UE.

5. The method of claim 1 , wherein the CSI measurement is scaled based at least in part on one or more of: a transmission rank of the base station or a number of antenna ports of the base station.

6. The method of claim 1 , further comprising:

identifying a precoder of the base station, the precoder based at least in part on a number of antenna ports in use by the base station, wherein the number of antenna ports in use by the base station is fewer than a total number of antenna ports of the base station; and

using the precoder to receive one or more of: the downlink transmission or a second downlink transmission.

7. The method of claim 1 , further comprising:

receiving from the base station a first rank parameter associated with a transport block size and a second rank parameter indicating a transmission rank;

determining the transport block size based at least in part on the received rank parameter; and

using the determined transport block size and the indicated transmission rank to receive one or more of: the downlink transmission or a second downlink transmission.

8. The method of claim 1 , further comprising:

using, based at least in part on the CSI computation mode, space time/frequency block coding (STBC/SFBC) to receive one or more of: the downlink transmission or a second downlink transmission.

9. The method of claim 1 , further comprising:

adjusting a measured pathloss of the base station based at least in part on the base station operating according to the EIRP constraint; and

setting an uplink power for a random access procedure with the base station based on the adjusting.

10. The method of claim 9 , further comprising:

receiving an offset parameter from the base station, wherein adjusting the measured pathloss is based at least in part on the received offset parameter.

11. An apparatus for wireless communications at a user equipment (UE), comprising: a processor, memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to:

receive a downlink transmission from a base station over a wireless channel, wherein the downlink transmission comprises an indication of a channel state information (CSI) computation mode;

receive a scaling factor for the indicated CSI computation mode from the base station;

select, based at least in part on the indicated CSI computation mode, an effective isotropic radiated power (EIRP) constrained CSI computation mode for the wireless channel, wherein the EIRP constrained CSI computation mode is based at least in part on an EIRP constraint;

measure a set of one or more CSI reference signals (CSI-RSs) from the base station to obtain a CSI measurement;

scale the CSI measurement based at least in part on the selected EIRP constrained CSI computation mode according to the scaling factor; and

transmit a CSI report to the base station wherein the CSI report is based at least in part on the selected EIRP constrained CSI computation mode and the CSI measurement, wherein the CSI report includes the scaled CSI measurement.

12. The apparatus of claim 11 ,

wherein the indication of the CSI computation mode comprises a configuration of the CSI computation mode from the base station.

13. The apparatus of claim 12 , wherein the downlink transmission comprises one or more of: a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE), or downlink control information (DCI) block.

14. The apparatus of claim 13 , wherein the configuration of the CSI computation mode is based at least in part on one or more of: a number of antennas configured for the UE or a number of CSI ports configured for the UE.

15. The apparatus of claim 11 , wherein the CSI measurement is scaled based at least in part on one or more of: a transmission rank of the base station or a number of antenna ports of the base station.

16. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

identify a precoder of the base station, the precoder based at least in part on a number of antenna ports in use by the base station, wherein the number of antenna ports in use by the base station is fewer than a total number of antenna ports of the base station; and

use the precoder to receive one or more of: the downlink transmission or a second downlink transmission.

17. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

receive from the base station a first rank parameter associated with a transport block size and a second rank parameter indicating a transmission rank;

determine the transport block size based at least in part on the received rank parameter; and

use the determined transport block size and the indicated transmission rank to receive one or more of: the downlink transmission or a second downlink transmission.

18. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

use, based at least in part on the CSI computation mode, space time/frequency block coding (STBC/SFBC) to receive one or more of: the downlink transmission or a second downlink transmission.

19. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

adjust a measured pathloss of the base station based at least in part on the base station operating according to the EIRP constraint; and

set an uplink power for a random access procedure with the base station based on the adjusting.

20. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

receive an offset parameter from the base station, wherein adjusting the measured pathloss is based at least in part on the received offset parameter; and

set an uplink power for a random access procedure with the base station based on the adjusting.

21. A non-transitory computer-readable medium storing code for wireless communications at a user equipment (UE), the code comprising instructions executable by a processor to:

receive a downlink transmission from a base station over a wireless channel, wherein the downlink transmission comprises an indication of a channel state information (CSI) computation mode;

receive a scaling factor for the indicated CSI computation mode from the base station;

select, based at least in part on the indicated CSI computation mode, an effective isotropic radiated power (EIRP) constrained CSI computation mode for the wireless channel, wherein the EIRP constrained CSI computation mode is based at least in part on an EIRP constraint;

measure a set of one or more CSI reference signals (CSI-RSs) from the base station to obtain a CSI measurement;

scale the CSI measurement based at least in part on the selected EIRP constrained CSI computation mode according to the scaling factor; and

transmit a CSI report to the base station wherein the CSI report is based at least in part on the selected EIRP constrained CSI computation mode and the CSI measurement, wherein the CSI report includes the scaled CSI measurement.

22. The non-transitory computer-readable medium of claim 21 ,

wherein the indication of the CSI computation mode comprises a configuration of the CSI computation mode from the base station.

23. The non-transitory computer-readable medium of claim 22 , wherein the downlink transmission comprises one or more of: a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE), or downlink control information (DCI) block.

24. The non-transitory computer-readable medium of claim 23 , wherein the configuration of the CSI computation mode is based at least in part on one or more of: a number of antennas configured for the UE or a number of CSI ports configured for the UE.

25. The non-transitory computer-readable medium of claim 21 , wherein the CSI measurement is scaled based at least in part on one or more of: a transmission rank of the base station or a number of antenna ports of the base station.