Method and apparatus for dynamic beam indication mechanism

1. A user equipment (UE) comprising:

a transceiver configured to:

receive configuration information including a set of transmission configuration indicator (TCI) states, and

receive a medium access control-control element (MAC-CE) indicating activation of M TCI states from the set of TCI states, where M is a positive integer; and

a processor operably coupled to the transceiver, the processor configured to:

identify a medium for receiving an indication indicating a TCI state update, wherein the medium is the MAC-CE or a downlink control information (DCI), and the TCI state update is from the M activated TCI states,

determine a beam based on the TCI state update, and

apply the beam for a reception of both downlink (DL) control and data channels,

wherein:

the identification of the medium is based on a value of M,

a TCI state refers to at least one source reference signal (RS) with a corresponding quasi co-location (QCL) type,

the QCL type is a type of a QCL property associated with the at least one source RS, and

the beam refers to the QCL type being set to a spatial property used to receive or transmit the at least one source RS included in the TCI state update.

2. The UE of claim 1 , wherein the value of M is based on whether M≤t or M>t, where t is a threshold.

3. The UE of claim 2 , wherein t=1, and:

when M=1, the medium is the MAC-CE that activates the M TCI states, and the M activated TCI states corresponds to a single activated TCI state that also corresponds to the TCI state update; and

when M>1, the medium is the DCI.

4. The UE of claim 1 , wherein the medium is identified based on an information included in the configuration information.

5. The UE of claim 1 , wherein the TCI state update indicates a joint TCI state for both DL and uplink (UL), and the processor is configured to apply the beam for a transmission of both UL control and data channels.

6. The UE of claim 1 , wherein the TCI state update indicates two separate TCI states for DL and UL, a DL TCI state and an UL TCI state, respectively, and the processor is configured to:

determine the beam based on the DL TCI state,

determine an UL transmit beam based on the UL TCI state, and

apply the UL transmit beam for a transmission of both UL control and data channels,

wherein:

the UL TCI state is indicated from N UL TCI states that are activated via the MAC-CE,

the N UL TCI states are activated from a second set of TCI states, where N≥1, and

the identification of the medium is further based on a value of N.

7. A base station (BS) comprising:

a processor configured to:

generate configuration information including a set of transmission configuration indicator (TCI) states, and

generate a medium access control-control element (MAC-CE) indicating activation of M TCI states from the set of TCI states, where M is a positive integer; and

a transceiver operably coupled to the processor, the transceiver configured to:

transmit the configuration information,

transmit, via a medium, an indication indicating a TCI state update, the TCI state update indicating a beam from the M activated TCI states, wherein the medium is the MAC-CE or a downlink control information (DCI) identified based on a value of M, and

transmit downlink (DL) control and data channels for reception via the indicated beam,

wherein:

a TCI state refers to at least one source reference signal (RS) with a corresponding quasi co-location (QCL) type,

the QCL type is a type of a QCL property associated with the at least one source RS, and

the beam refers to the QCL type being set to a spatial property used to receive or transmit the at least one source RS included in the TCI state update.

8. The BS of claim 7 , wherein the value of M is based on whether M≤t or M>t, where t is a threshold.

9. The BS of claim 8 , wherein t=1, and:

when M=1, the medium is the MAC-CE that activates the M TCI states, and the M activated TCI states corresponds to a single activated TCI state that also corresponds to the TCI state update; and

when M>1, the medium is the DCI.

10. The BS of claim 7 , wherein the medium is indicated based on an information included in the configuration information.

11. The BS of claim 7 , wherein the TCI state update indicates a joint TCI state for both DL and uplink (UL), and the transceiver is configured to receive an UL control and data channels transmitted via the indicated beam.

12. The BS of claim 7 , wherein:

the TCI state update indicates two separate TCI states for DL and UL, a DL TCI state and an UL TCI state, respectively, and

the transceiver is configured to:

transmit DL control and data channels for reception via the beam indicated by the DL TCI state, and

receive UL control and data channels transmitted via an UL transmit beam indicated by the UL TCI state,

wherein:

the UL TCI state is indicated from N UL TCI states that are activated via the MAC-CE,

the N UL TCI states are activated from a second set of TCI states, where N≥1, and

identification of the medium is further based on a value of N.

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

receiving configuration information including a set of transmission configuration indicator (TCI) states;

receiving a medium access control-control element (MAC-CE) indicating activation of M TCI states from the set of TCI states, where M is a positive integer;

identifying a medium for receiving an indication indicating a TCI state update, wherein the medium is the MAC-CE or a downlink control information (DCI), and the TCI state update is from the M activated TCI states;

determining a beam based on the TCI state update; and

applying the beam for a reception of both downlink (DL) control and data channels,

wherein:

identification of the medium is based on a value of M,

a TCI state refers to at least one source reference signal (RS) with a corresponding quasi co-location (QCL) type,

the QCL type is a type of a QCL property associated with the at least one source RS, and

the beam refers to the QCL type being set to a spatial property used to receive or transmit the at least one source RS included in the TCI state update.

14. The method of claim 13 , wherein the value of M is based on whether M≤t or M>t, where t is a threshold.

15. The method of claim 14 , wherein t=1, and:

when M=1, the medium is the MAC-CE that activates the M TCI states, and the M activated TCI states corresponds to a single activated TCI state that also corresponds to the TCI state update; and

when M>1, the medium is the DCI.

16. The method of claim 13 , wherein the medium is identified based on an information included in the configuration information.

17. The method of claim 13 , wherein:

the TCI state update indicates a joint TCI state for both DL and uplink (UL), and

the method further comprises applying the beam for a transmission of both UL control and data channels.