Methods and apparatuses for physical layer beam indications

A base station (BS) comprising:

• a transceiver configured to transmit one or more first transmission configuration indicator (TCI) state identifiers (IDs);
• and
• a processor operably coupled to the transceiver, the processor configured to determine one or more TCI states and corresponding one or more second TCI state identifier (IDs),
• wherein, the transceiver is further configured to:
• transmit, in a downlink control information (DCI) format on a physical downlink control channel (PDCCH), the one or more second TCI state IDs using a quasi colocation (QCL) based on the one or more first TCI state IDs;
• and
• receive an acknowledgement in response to the transmission of the DCI format on the PDCCH,
• wherein the processor is further configured to:
• determine a time to apply the one or more TCI states;
• and
• update one or more spatial filters and the QCL based on the one or more TCI states,
• wherein the time to apply is based on a time of the transmission of the acknowledgement, and
• wherein the transceiver is further configured, based on the acknowledgment, to transmit and receive data on downlink (DL) channels and uplink (UL) channels, respectively, using the one or more spatial filters and the QCL starting at the determined time.

A method for operating a user equipment (UE), the method comprising:

• receiving one or more first transmission configuration indicator (TCI) state identifiers (IDs);
• receiving, in a downlink control information (DCI) format included in a physical downlink control channel (PDCCH), one or more second TCI state IDs using a quasi colocation (QCL) based on the one or more first TCI state IDs;
• transmitting, in response to reception of the DCI format included in the PDCCH, an acknowledgement;
• determining, based on the one or more second TCI state IDs, one or more TCI states;
• determining a time to apply the one or more TCI states;
• updating one or more spatial filters and the QCL based on the one or more TCI states, wherein the time to apply is based on a time of the transmission of the acknowledgement;
• and
• receiving and transmitting data on downlink (DL) channels and uplink (UL) channels, respectively, using the one or more spatial filters and the QCL starting at the determined time.