Activating transmission configuration indicator codepoints
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, an indication that indicates whether a medium access control control element (MAC-CE)-based implicit transmission configuration indicator (TCI) update rule is enabled. The UE may receive, from the base station, a MAC-CE that activates one or more TCI codepoints based at least in part on the indication. Numerous other aspects are described.
1 . A user equipment (UE) for wireless communication, comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, and configured to:
receive an indication that indicates whether a medium access control control element (MAC-CE)-based implicit transmission configuration indicator (TCI) update rule is enabled; and
receive a MAC-CE that activates one or more TCI codepoints based at least in part on the indication,
wherein one or more applied TCI states according to the MAC-CE based implicit TCI update rule can be overwritten or cannot be overwritten by one or more TCI states later selected by a TCI-updating downlink control information.
2 . The UE of claim 1 , wherein the MAC-CE that activates the one or more TCI codepoints is based at least in part on the MAC-CE based implicit TCI update rule when the indication indicates that the MAC-CE based implicit TCI update rule is enabled.
3 . The UE of claim 1 , wherein the MAC-CE that activates the one or more TCI codepoints is based at least in part on a MAC-CE based TCI activation rule when the indication indicates that the MAC-CE based implicit TCI update rule is not enabled.
4 . The UE of claim 3 , wherein the MAC-CE based TCI activation rule is associated with applying a TCI state to a set of channels or reference signals associated with a TCI codepoint, after a MAC-CE activation time, when a MAC-CE activates the TCI codepoint mapped to the TCI state.
5 . The UE of claim 1 , wherein one or more predetermined activated TCI codepoints are applied to one or more predetermined sets of channels or reference signals when the MAC-CE based implicit TCI update rule is enabled.
6 . The UE of claim 1 , wherein the one or more processors, to receive the indication, are configured to receive the indication via a radio resource control flag or an indicator in a MAC-CE that is used for TCI activation.
7 . The UE of claim 1 , wherein the one or more processors, to receive the indication, are configured to receive the indication via an indicator in downlink control information (DCI), wherein the DCI is associated with a TCI update that includes or does not include a downlink/uplink transmission, or wherein the DCI is not associated with the TCI update and is used for scheduling the downlink/uplink transmission.
8 . The UE of claim 1 , wherein the MAC-CE based implicit TCI update rule is associated with applying one predetermined activated TCI codepoint to a plurality of channels or reference signals.
9 . The UE of claim 1 , wherein the MAC-CE based implicit TCI update rule is associated with applying multiple predetermined activated TCI codepoints to multiple predetermined sets of channels or reference signals.
10 . The UE of claim 1 , wherein the MAC-CE based implicit TCI update rule is associated with applying multiple TCI states mapped to a predetermined activated TCI codepoint to multiple predetermined sets of channels or reference signals.
11 . The UE of claim 1 , wherein the MAC-CE based implicit TCI update rule is associated with applying multiple TCI states mapped to a predetermined activated TCI codepoint to multiple TCI states originally configured or indicated for a channel or reference signal.
12 . The UE of claim 1 , wherein the indication instructs the UE to use the MAC-CE based implicit TCI update rule or a MAC-CE based TCI activation rule, and wherein the indication is signaled via radio resource control signaling, a MAC-CE, or downlink control information.
13 . The UE of claim 1 , wherein one or more predetermined activated TCI codepoints associated with the MAC-CE based implicit TCI update rule are determined based at least in part on TCI codepoints mapped to a quantity of TCI states.
14 . The UE of claim 1 , wherein one or more predetermined activated TCI codepoints associated with the MAC-CE based implicit TCI update rule are mapped to a quantity of TCI states.
15 . The UE of claim 1 , wherein an applied channel or reference signal associated with the MAC-CE based implicit TCI update rule includes one or more of a physical downlink control channel, a physical downlink shared channel, a channel state information reference signal, a physical uplink control channel, a physical uplink shared channel, or a sounding reference signal, and wherein the applied channel or reference signal is based at least in part on originally configured or indicated channels or reference signals with a quantity of TCI states.
16 . The UE of claim 1 , wherein an activated TCI state associated with the MAC-CE based implicit TCI update rule includes one or more of a joint downlink/uplink TCI state, a separate downlink common TCI state, a separate uplink common TCI state, a legacy single-channel downlink TCI state, or a legacy single-channel uplink spatial relation.
17 . The UE of claim 1 , wherein the one or more applied TCI states according to the MAC-CE based implicit TCI update rule can be overwritten by the one or more TCI states later selected by the TCI-updating downlink control information.
18 . The UE of claim 1 , wherein the one or more applied TCI states according to the MAC-CE based implicit TCI update rule cannot be overwritten by the one or more TCI states later selected by the TCI-updating downlink control information.
19 . A user equipment (UE) for wireless communication, comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, and configured to:
receive an indication that indicates whether a medium access control control element (MAC-CE)-based implicit transmission configuration indicator (TCI) update rule is enabled; and
receive a MAC-CE that activates one or more TCI codepoints based at least in part on the indication,
wherein the MAC-CE based implicit TCI update rule is associated with applying a first activated TCI codepoint to a plurality of channels or reference signals to prevent a transmission of additional downlink control information.
20 . A method of wireless communication performed by a user equipment (UE), comprising:
receiving an indication that indicates whether a medium access control control element (MAC-CE)-based implicit transmission configuration indicator (TCI) update rule is enabled; and
receiving a MAC-CE that activates one or more TCI codepoints based at least in part on the indication
wherein the MAC-CE based implicit TCI update rule is associated with applying a first activated TCI codepoint to a plurality of channels or reference signals to prevent a transmission of additional downlink control information.
21 . A method of wireless communication performed by a user equipment (UE), comprising:
receiving an indication that indicates whether a medium access control control element (MAC-CE)-based implicit transmission configuration indicator (TCI) update rule is enabled; and
receiving a MAC-CE that activates one or more TCI codepoints based at least in part on the indication,
wherein one or more applied TCI states according to the MAC-CE based implicit TCI update rule are overwritten or cannot be overwritten by one or more TCI states later selected by a TCI-updating downlink control information.
22 . The method of claim 21 , wherein the one or more applied TCI states according to the MAC-CE based implicit TCI update rule are overwritten by the one or more TCI states later selected by the TCI-updating downlink control information.
23 . The method of claim 21 , wherein the one or more applied TCI states according to the MAC-CE based implicit TCI update rule cannot be overwritten by the one or more TCI states later selected by the TCI-updating downlink control information.