Beam-specific virtual power headroom reporting
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit, to a base station, a virtual power headroom report (PHR) that is based at least in part on a beam-specific pathloss reference signal (PLRS). The UE may receive, from the base station, a downlink transmission based at least in part on the virtual PHR. Numerous other aspects are described.
1. An apparatus for wireless communication at a user equipment (UE), comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, configured to:
transmit, to a base station, a virtual power headroom report (PHR) that is based at least in part on a beam-specific pathloss reference signal (PLRS), wherein the beam-specific PLRS is associated with a synchronization signal (SS) or physical broadcast channel (PBCH) resource block indicator (SSBRI) or a channel state information reference signal (CSI-RS) resource indicator (CRI), wherein the SSBRI or CRI is associated with a radio resource control (RRC) configured candidate pool of SSBRIs or CRIs, and wherein the virtual PHR indicates an actual beam-specific maximum permissible exposure value associated with the SSBRI or the CRI.
2. The apparatus of claim 1 , wherein the virtual PHR is associated with the SSBRI or the CRI.
3. The apparatus of claim 2 , wherein the candidate pool is based at least in part on a synchronization signal block set, a transmission configuration indicator (TCI) state pool, a medium access control control element activated TCI state pool, or a PLRS set.
4. The apparatus of claim 1 , wherein:
the beam-specific PLRS is associated with a measured synchronization signal block or a measured channel state information reference signal; or
the beam-specific PLRS is a default PLRS.
5. The apparatus of claim 1 , wherein the beam-specific PLRS corresponds to a PLRS associated with a transmission configuration indicator (TCI), and wherein the TCI is associated with the SSBRI or the CRI.
6. The apparatus of claim 5 , wherein the one or more processors, to transmit the virtual PHR, are configured to transmit a PHR medium access control control element that indicates the virtual PHR, the SSBRI or the CRI, and a maximum permissible exposure (MPE) value, wherein the SSBRI or the CRI is associated with a beam index, and wherein the beam index is associated with the virtual PHR and the MPE value.
7. The apparatus of claim 1 , wherein the one or more processors, to transmit the virtual PHR, are configured to transmit a channel state information (CSI) report that indicates a quantity of virtual PHRs and a quantity of resource indices corresponding to the quantity of virtual PHRs.
8. The apparatus of claim 7 , wherein the one or more processors are further configured to:
transmit, to the base station, a capability message indicating a maximum value associated with the quantity of virtual PHRs and the quantity of resource indices.
9. The apparatus of claim 7 , wherein the CSI report is associated with a reference signal resource, wherein the reference signal resource is a source reference signal in a configured transmission configuration indicator (TCI) or an activated TCI, or wherein the reference signal resource is a reference signal with a configured TCI or an activated TCI.
10. The apparatus of claim 7 , wherein the one or more processors are further configured to:
transmit, to the base station, a capability message indicating a maximum quantity of activated transmission configuration indicators for a candidate maximum permissible exposure measurement in the CSI report.
11. The apparatus of claim 7 , wherein:
the CSI report is an aperiodic CSI report, a semi-persistent CSI report, or a periodic CSI report;
the CSI report is carried on a physical uplink control channel or a physical uplink shared channel; and
the CSI report is scheduled by the base station or is an event triggered CSI report.
12. The apparatus of claim 1 , wherein the virtual PHR is based at least in part on a power management maximum power reduction (P-MPR) value associated with a maximum permissible exposure, wherein the P-MPR value is associated with a synchronization signal block (SSB) or CSI-RS.
13. The apparatus of claim 12 , wherein the beam-specific PLRS is based at least in part on a reference signal received power value measured from the SSB or CSI-RS.
14. The apparatus of claim 1 , wherein the virtual PHR is based at least in part on a beam-specific power control-adjustment state.
15. The apparatus of claim 14 , wherein accumulative transmit power control (TPC) is enabled.
16. An apparatus for wireless communication at a base station, comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, configured to:
receive, from a user equipment (UE), a virtual power headroom report (PHR) that is based at least in part on a beam-specific pathloss reference signal (PLRS), wherein the beam-specific PLRS is associated with a synchronization signal (SS) or physical broadcast channel (PBCH) resource block indicator (SSBRI) or a channel state information reference signal (CSI-RS) resource indicator (CRI), wherein the SSBRI or CRI is associated with a radio resource control (RRC) configured candidate pool of SSBRIs or CRIs, and wherein the virtual PHR indicates an actual beam-specific maximum permissible exposure value associated with the SSBRI or the CRI.
17. The apparatus of claim 16 , wherein the virtual PHR is associated with the SSBRI or the CRI.
18. The apparatus of claim 17 , wherein the candidate pool is based at least in part on a synchronization signal block set, a transmission configuration indicator (TCI) state pool, a medium access control control element activated TCI state pool, or a PLRS set.
19. The apparatus of claim 16 , wherein:
the beam-specific PLRS is associated with a measured synchronization signal block or a measured channel state information reference signal; or
the beam-specific PLRS is a default PLRS.
20. The apparatus of claim 16 , wherein the beam-specific PLRS corresponds to a PLRS associated with a transmission configuration indicator (TCI), and wherein the TCI is associated with the SSBRI or the CRI.
21. The apparatus of claim 20 , wherein the one or more processors, to receive the virtual PHR, are configured to receive a PHR medium access control control element that indicates the virtual PHR, the SSBRI or the CRI, and a maximum permissible exposure (MPE) value, wherein the SSBRI or the CRI is associated with a beam index, and wherein the beam index is associated with the virtual PHR and the MPE value.
22. The apparatus of claim 16 , wherein the one or more processors, to receive the virtual PHR, are configured to receive a channel state information (CSI) report that indicates a quantity of virtual PHRs and a quantity of resource indices corresponding to the quantity of virtual PHRs.
23. The apparatus of claim 22 , wherein the one or more processors are further configured to receive, from the UE, a capability message indicating a maximum value associated with the quantity of virtual PHRs and the quantity of resource indices.
24. The apparatus of claim 22 , wherein the CSI report is associated with a reference signal resource, wherein the reference signal resource is a source reference signal in a configured transmission configuration indicator (TCI) or an activated TCI, or wherein the reference signal resource is a reference signal with a configured TCI or an activated TCI.
25. The apparatus of claim 22 , wherein the one or more processors are further configured to:
receive, from the UE, a capability message indicating a maximum quantity of activated transmission configuration indicators for a candidate maximum permissible exposure measurement in the CSI report.
26. The apparatus of claim 22 , wherein:
the CSI report is an aperiodic CSI report, a semi-persistent CSI report, or a periodic CSI report;
the CSI report is carried on a physical uplink control channel or a physical uplink shared channel; and
the CSI report is scheduled by the base station or is an event triggered CSI report.
27. The apparatus of claim 16 , wherein the virtual PHR is based at least in part on a power management maximum power reduction (P-MPR) value associated with a maximum permissible exposure, wherein the P-MPR value is associated with a synchronization signal block (SSB) or CSI-RS resource.
28. The apparatus of claim 27 , wherein the beam-specific PLRS is based at least in part on a reference signal received power value measured from the SSB or CSI-RS.
29. A method of wireless communication performed by a user equipment (UE), comprising:
transmitting, to a base station, a virtual power headroom report (PHR) that is based at least in part on a beam-specific pathloss reference signal (PLRS), wherein the beam-specific PLRS is associated with a synchronization signal (SS) or physical broadcast channel (PBCH) resource block indicator (SSBRI) or a channel state information reference signal (CSI-RS) resource indicator (CRI), wherein the SSBRI or CRI is associated with a radio resource control (RRC) configured candidate pool of SSBRIs or CRIs, and wherein the virtual PHR indicates an actual beam-specific maximum permissible exposure value associated with the SSBRI or the CRI.
30. A method of wireless communication performed by a base station, comprising:
receiving, from a user equipment (UE), a virtual power headroom report (PHR) that is based at least in part on a beam-specific pathloss reference signal (PLRS), wherein the beam-specific PLRS is associated with a synchronization signal (SS) or physical broadcast channel (PBCH) resource block indicator (SSBRI) or a channel state information reference signal (CSI-RS) resource indicator (CRI), wherein the SSBRI or CRI is associated with a radio resource control (RRC) configured candidate pool of SSBRIs or CRIs, and wherein the virtual PHR indicates an actual beam-specific maximum permissible exposure value associated with the SSBRI or the CRI.