Application time for DCI based update in cross-carrier scheduling
Certain aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for determining when to apply downlink control information (DCI) based updates using cross-component carrier (cross-CC) scheduling. A method that may be performed by a user equipment (UE) includes receiving, on a first component carrier (CC), a DCI indicating an update to be applied to at least one of an uplink (UL) transmission or a downlink (DL) transmission, determining an application time for applying the update based, at least in part, on a parameter associated with one or more second CCs, and applying the update in accordance with the determined application time.
1. A method for wireless communication by a user equipment (UE), the method comprising:
receiving radio resource control (RRC) configuring an application time parameter indicating a number of symbols;
receiving, on a first component carrier (CC), a downlink control information (DCI) indicating a transmission configuration indicator (TCI) state update to be applied to at least one of an uplink transmission or a downlink transmission;
transmitting an acknowledgment, on a second CC, for the DCI;
determining a common application time for applying the TCI state update for each of one or more second CCs on which the update is to be applied, wherein determining the common application time is based, at least in part, on the application time parameter and on a minimum subcarrier spacing (SCS) among SCSs associated with all of and only the one or more second CCs on which the TCI state update is to be applied; and
applying the TCI state update in a first slot after the determined application time from a last symbol of the acknowledgment transmission.
2. The method of claim 1 , wherein determining the application time comprises computing the application time using a multiplier determined based on:
an SCS associated with the first CC and the SCS associated with the one or more second CCs; and
a time constant based on the SCS associated with the first CC or the SCS associated with the one or more second CCs.
3. The method of claim 1 , wherein the minimum SCS is further from an SCS associated with the second CC on which the acknowledgement is transmitted.
4. The method of claim 1 , wherein the one or more second CCs are preconfigured by RRC signaling.
5. The method of claim 1 , further comprising using the TCI state update in an uplink power control algorithm for calculating transmit power for one or more uplink transmissions.
6. The method of claim 1 , wherein:
the TCI state update is to be applied to both uplink and downlink transmissions; and
determining the application time comprises determining separate application times for applying the TCI state update to the uplink and downlink transmissions.
7. A method for wireless communication by a network entity, the method comprising:
transmitting, to a user equipment (UE), radio resource control (RRC) configuring an application time parameter indicating a number of symbols;
transmitting, to the UE, on a first component carrier (CC), a downlink control information (DCI) indicating a transmission configuration indicator (TCI) state update to be applied to at least one of an uplink transmission or a downlink transmission;
receiving an acknowledgment, on a second CC, for the DCI;
determining a common application time for applying the TCI state update for each of one or more second CCs on which the update is to be applied, wherein determining the common application time is based, at least in part, on the application time parameter and on a minimum subcarrier spacing (SCS) among SCSs associated with all of and only the one or more second CCs on which the TCI state update is to be applied; and
applying the TCI state update in a first slot after the determined application time from a last symbol of the acknowledgment transmission.
8. The method of claim 7 , wherein determining the application time comprises computing the application time using a multiplier determined based on:
an SCS associated with the first CC and the SCS associated with the one or more second CCs; and
a time constant based on the SCS associated with the first CC or the SCS associated with the one or more second CCs.
9. The method of claim 7 , wherein the minimum SCS is further from an SCS associated with the second CC on which the acknowledgement is received.
10. The method of claim 7 , wherein determining the application time comprises computing the application time using a multiplier determined based on:
the SCS associated with the one or more second CCs and an SCS associated with one of the one or more second CCs on which an ACK is received; and
a time constant based on the SCS associated with the one or more second CCs or the SCS associated with the CC on which the ACK is received.
11. An apparatus for wireless communication, the apparatus comprising:
memory storing computer executable code; and
one or more processors coupled to the memory and configured to, individually or collectively, execute the computer executable code to cause the apparatus to:
receive radio resource control (RRC) configuring an application time parameter indicating a number of symbols;
receive, on a first component carrier (CC), a downlink control information (DCI) indicating a transmission configuration indicator (TCI) state update to be applied to at least one of an uplink transmission or a downlink transmission;
transmit an acknowledgment, on a second CC, for the DCI;
determine a common application time for applying the TCI state update for each of one or more second CCs on which the update is to be applied, wherein determining the common application time is based, at least in part, on the application time parameter and on a minimum subcarrier spacing (SCS) among SCSs associated with all of and only the one or more second CCs on which the TCI state update is to be applied; and
apply the TCI state update in a first slot after the determined application time from a last symbol of the acknowledgment transmission.
12. An apparatus for wireless communication, the apparatus comprising:
memory storing computer executable code; and
one or more processors coupled to the memory and configured to, individually or collectively, execute the computer executable code to cause the apparatus to:
transmit, to a user equipment (UE), radio resource control (RRC) configuring an application time parameter indicating a number of symbols;
transmit, to the UE, on a first component carrier (CC), a downlink control information (DCI) indicating a transmission configuration indicator (TCI) state update to be applied to at least one of an uplink transmission or a downlink transmission;
receive an acknowledgment, on a second CC, for the DCI;
determine a common application time for applying the TCI state update for each of one or more second CCs on which the update is to be applied, wherein determining the common application time is based, at least in part, on the application time parameter and on a minimum subcarrier spacing (SCS) among SCSs associated with all of and only the one or more second CCs on which the TCI state update is to be applied; and
apply the TCI state update in a first slot after the determined application time from a last symbol of the acknowledgment transmission.