Calibration for multi-TRP coherent joint transmissions
Apparatuses and method for calibration for multiple transmission and reception point (multi-TRP) coherent joint transmissions. A method performed by a user equipment (UE) includes receiving configuration information about N downlink (DL) antenna port groups, N uplink (UL) antenna port groups, wherein the N DL antenna port groups are associated with the N UL antenna port groups, respectively and receiving an indicator to trigger M DL antenna port groups, where M≤N. The method further includes measuring a DL reference signal (RS) for the triggered M DL antenna port groups; determining, based on the measured DL RS, an UL precoder for each of M UL antenna port groups respectively associated with the triggered M DL antenna port groups; and transmitting, based on the UL precoder, an UL RS for the M associated UL antenna port groups.
1 . A user equipment (UE) comprising:
a processor; and
a transceiver operably coupled to the processor, the transceiver configured to:
receive, from a base station, a radio resource control (RRC) signaling configuring a channel state information (CSI) report, wherein the RRC signaling comprises first information on an associated sounding reference signal (SRS) resource for a CSI reference signal (CSI-RS) resource set and wherein the associated SRS resource is for a coherent joint transmission calibration (CJTC) for phase; and
transmit, to the base station, the CSI report.
2 . The UE of claim 1 , wherein an SRS resource set including the associated SRS resource is configured with a usage set to an antenna switching.
3 . The UE of claim 1 , wherein the RRC signaling further comprises second information configuring a plurality of single-port CSI-RS resources for the CSI-RS resource set.
4 . The UE of claim 1 , wherein the associated SRS resource is configured as aperiodic, semi-persistent, or periodic.
5 . The UE of claim 1 , wherein:
the CSI report includes phase offset values for each CSI-RS resource relative to a reference CSI-RS resource, and
the phase offset values are reported on a wideband basis or for subbands indicated by a parameter that corresponds to a number of subbands.
6 . A base station (BS) comprising:
a processor; and
a transceiver operably coupled to the processor, the transceiver configured to:
transmit, to a user equipment (UE), a radio resource control (RRC) signaling configuring a channel state information (CSI) report, wherein the RRC signaling comprises first information on an associated sounding reference signal (SRS) resource for a CSI reference signal (CSI-RS) resource set and wherein the associated SRS resource is for a coherent joint transmission calibration (CJTC) for phase; and
receive, from the UE, the CSI report.
7 . The BS of claim 6 , wherein an SRS resource set including the associated SRS resource is configured with a usage set to an antenna switching.
8 . The BS of claim 6 , wherein the RRC signaling further comprises second information configuring a plurality of single-port CSI-RS resources for the CSI-RS resource set.
9 . The BS of claim 6 , wherein the associated SRS resource is configured as aperiodic, semi-persistent, or periodic.
10 . The BS of claim 6 , wherein:
the CSI report includes phase offset values for each CSI-RS resource relative to a reference CSI-RS resource, and
the phase offset values are reported on a wideband basis or for subbands indicated by a parameter that corresponds to a number of subbands.
11 . A method performed by a user equipment (UE), the method comprising:
receiving, from a base station, a radio resource control (RRC) signaling configuring a channel state information (CSI) report, wherein the RRC signaling comprises first information on an associated sounding reference signal (SRS) resource for a CSI reference signal (CSI-RS) resource set and wherein the associated SRS resource is for a coherent joint transmission calibration (CJTC) for phase; and
transmitting to the base station, the CSI report.
12 . The method of claim 11 , wherein an SRS resource set including the associated SRS resource is configured with a usage set to an antenna switching.
13 . The method of claim 11 , wherein the RRC signaling further comprises second information configuring a plurality of single-port CSI-RS resources for the CSI-RS resource set.
14 . The method of claim 11 , wherein the associated SRS resource is configured as aperiodic, semi-persistent, or periodic.
15 . The method of claim 11 , wherein:
the CSI report includes phase offset values for each CSI-RS resource relative to a reference CSI-RS resource, and
the phase offset values are reported on a wideband basis or for subbands indicated by a parameter that corresponds to a number of subbands.