Application of uplink transmission configuration indicator state with downlink reference signal to codebook based transmissions

1. A method of wireless communications by a user equipment (UE), comprising:

receiving, from a network entity, signaling of an uplink transmission configuration indicator (TCI) state for a target codebook based uplink transmission signal;

determining if the TCI state has a source downlink reference signal (RS); and

deciding how to process the codebook based uplink transmission based on the determination.

2. The method of claim 1 , wherein the codebook based uplink transmission comprises a physical uplink shared channel (PUSCH).

3. The method of claim 1 , wherein, if the determination is the uplink TCI state has a source downlink RS, the decision is to not apply the TCI state to the codebook based uplink transmission.

4. The method of claim 1 , wherein:

uplink transmission parameters have been determined based on a first downlink RS prior to receiving the TCI state;

the TCI state has a second downlink RS as a source downlink RS; and

deciding how to process the codebook based uplink transmission depends, at least in part, if the first downlink RS and second downlink RS are of a same type.

5. The method of claim 4 , wherein the type of first downlink RS and second downlink RS comprises one of:

a first QCL type that indicates QCL assumptions regarding Doppler shift, Doppler spread, average delay, and delay spread;

a second QCL type that indicates QCL assumptions regarding Doppler shift and Doppler spread;

a third QCL type that indicates Doppler shift and average delay; and

a fourth QCL type that indicates QCL assumptions regarding spatial relations.

6. The method of claim 4 , wherein the decision is to use the previously determined transmission parameters if the first and second downlink RS are the same type.

7. The method of claim 4 , wherein the decision is to use transmission parameters signaled with the uplink TCI state if the first and second downlink RS are of different types.

8. The method of claim 7 , wherein the uplink transmission parameters are indicated in the UL TCI in addition to the source downlink RS.

9. The method of claim 4 , further comprising: determining the uplink transmission parameters based on a first downlink RS prior to receiving the TCI state.

10. The method of claim 4 , wherein the first and the second downlink RS are the same downlink RS.

11. The method of claim 1 , further comprising:

transmitting sounding reference signals (SRS) to the network entity prior to receiving the uplink TCI state; and

receiving uplink transmission parameters from the network entity based on the SRS;

wherein the decision is to apply the uplink transmission parameters and UL TCI state for the codebook based uplink transmission.

12. The method of claim 11 , wherein at least some of the uplink transmission parameters are signaled separately from the UL TCI state.

13. The method of claim 11 , wherein the uplink transmission parameters are indicated in the UL TCI in addition to the source downlink RS.

14. The method of claim 4 , wherein the uplink transmission parameters comprise at least one of a transmission rank indication (TRI), transmit precoding matrix indicator (TPMI), or SRS resource indicator (SRI).

15. A method of wireless communications by a network entity, comprising:

sending, to a user equipment (UE), signaling of an uplink transmission configuration indicator (TCI) state for a target codebook based uplink transmission signal;

determining how the UE processed the codebook based uplink transmission, based on whether the TCI state has a source downlink reference signal (RS); and

processing the codebook based uplink transmission in accordance with the determination.

16. The method of claim 15 , wherein the codebook based uplink transmission comprises a physical uplink shared channel (PUSCH).

17. The method of claim 15 , wherein, if the uplink TCI state has a source downlink RS, the determination is that the UE did not apply the TCI state to the codebook based uplink transmission.

18. The method of claim 15 , wherein:

uplink transmission parameters have been determined based on a first downlink RS prior to sending the TCI state;

the TCI state has a second downlink RS as a source downlink RS; and

determining how the UE processed the codebook based uplink transmission depends, at least in part, if the first downlink RS and second downlink RS are of a same type.

19. The method of claim 18 , wherein the type of first downlink RS and second downlink RS comprises one of:

a first QCL type that indicates QCL assumptions regarding Doppler shift, Doppler spread, average delay, and delay spread;

a second QCL type that indicates QCL assumptions regarding Doppler shift and Doppler spread;

a third QCL type that indicates Doppler shift and average delay; and

a fourth QCL type that indicates QCL assumptions regarding spatial relations.

20. The method of claim 18 , wherein the determination is the UE used the previously determined transmission parameters if the first and second downlink RS are the same type.

21. The method of claim 18 , wherein the determination is the UE used transmission parameters signaled with the uplink TCI state if the first and second downlink RS are of different types.

22. The method of claim 21 , wherein the network entity indicates the uplink transmission parameters in the uplink TCI in addition to the source downlink RS.

23. The method of claim 18 , wherein the UE determines the uplink transmission parameters based on a first downlink RS prior to receiving the TCI state.

24. The method of claim 18 , wherein the first and the second downlink RS are the same downlink RS.

25. The method of claim 15 , further comprising:

receiving sounding reference signals (SRS) from the UE prior to sending the uplink TCI state; and

transmitting uplink transmission parameters to the UE based on the SRS;

wherein the determination is the UE applied the uplink transmission parameters and UL TCI state for the codebook based uplink transmission.

26. The method of claim 25 , wherein at least some of the uplink transmission parameters are signaled separately from the UL TCI state.

27. The method of claim 25 , wherein the uplink transmission parameters are indicated in the UL TCI in addition to the source downlink RS.

28. The method of claim 18 , wherein the uplink transmission parameters comprise at least one of a transmission rank indication (TRI), transmit precoding matrix indicator (TPMI), or SRS resource indicator (SRI).

29. An apparatus of wireless communications, comprising:

at least one processor; and

memory coupled to the at least one processor, the memory comprising code executable by the at least one processor to cause the apparatus to:

receive, from a network entity, signaling of an uplink transmission configuration indicator (TCI) state for a target codebook based uplink transmission signal;

determine if the TCI state has a source downlink reference signal (RS); and

decide how to process the codebook based uplink transmission based on the determination.

30. An apparatus of wireless communications, comprising:

at least one processor; and

memory coupled to the at least one processor, the memory comprising code executable by the at least one processor to cause the apparatus to:

send, to a user equipment (UE), signaling of an uplink transmission configuration indicator (TCI) state for a target codebook based uplink transmission signal;

determine how the UE processed the codebook based uplink transmission, based on whether the TCI state has a source downlink reference signal (RS); and

process the codebook based uplink transmission in accordance with the determination.