Unified UL and DL beam indication

1. A user equipment (UE), the UE comprising:

a transmitter for performing uplink (UL) transmissions; and

a receiver for receiving a message comprising configuration information (CI) indicating that a reference signal (RS) is quasi-co-located (QCL) with an UL transmission, wherein the UE is configured to:

determine a spatial transmit (Tx) configuration for the UL transmission based on the RS associated with the received CI, where the RS is a downlink (DL) RS or an uplink (UL) RS, and

use the determined spatial Tx configuration to perform the UL transmission, wherein

if the RS is the DL RS, then the UE determines the spatial Tx configuration based on a spatial receive (Rx) configuration that was used to receive the DL RS, otherwise, the RS is the UL RS, and the UE determines the spatial Tx configuration based on a spatial Tx configuration that was used to transmit the UL RS.

2. The UE of claim 1 , wherein the message is a layer 2 message comprising the CI.

3. The UE of claim 1 , wherein the message is a Medium Access Control Control Element (MAC-CE) comprising the CI.

4. The UE of claim 1 , wherein the message is a Radio Resource Control (RRC) message comprising the CI.

5. The UE of claim 1 , wherein the message is a Downlink Control Information (DCI) message comprising the CI.

6. The UE of claim 5 , wherein

the DCI message comprises the CI, and

the DCI message further comprises an UL grant scheduling a Physical Uplink Shared Channel (PUSCH).

7. The UE of claim 1 , wherein

one or more RS sets are associated with the CI, and

the RS associated with the CI is in at least one of the RS sets associated with the CI.

8. The UE of claim 7 , wherein

the CI comprises a Transmission Configuration Indicator (TCI) and

the RS set(s) are associated with the TCI.

9. The UE of claim 1 , wherein the UE is configured to adjust the spatial Tx configuration such that the spatial configuration is reciprocal to a spatial configuration associated with the RS that is associated with the received CI.

10. The UE of claim 9 , wherein

the RS associated with the received CI is a downlink (DL) RS, and

the UE is configured to determine the spatial Tx configuration such that it is reciprocal to a spatial Rx configuration associated with the DL RS.

11. The UE of claim 9 , wherein

the RS associated with the received CI is an UL RS included in an RS set associated with the CI, and

the UE is configured to determine the spatial Tx configuration such that it is reciprocal to a second spatial Tx configuration associated with the UL RS.

12. The UE of claim 1 , wherein the transmission is a SRS transmission.

13. The UE of claim 1 , wherein the received CI is associated with i) a first RS set containing a first RS and ii) a second RS set containing a second RS, the UE adjusts a first spatial Tx configuration based on the first RS, the UE adjusts a second spatial Tx configuration based on the second RS, the UE uses the first spatial Tx configuration for transmission of PUCCH, and the UE uses the second spatial Tx configuration for transmission of PUSCH.

14. A method performed by a user equipment (UE), the method comprising:

receiving a message comprising configuration information (CI) indicating that a reference signal (RS) is quasi-co-located (QCL) with an uplink (UL) transmission;

determining a spatial transmit (Tx) configuration for the UL transmission based on the RS associated with the received CI, where the RS is a downlink (DL) RS or an uplink (UL) RS; and

using the determined spatial Tx configuration to perform the UL transmission, wherein

if the RS is the DL RS, then the UE determines the spatial Tx configuration based on a spatial receive (Rx) configuration that was used to receive the DL RS, otherwise, the RS is the UL RS, and the UE determines the spatial Tx configuration based on a spatial Tx configuration that was used to transmit the UL RS.

15. A computer program product comprising a non-transitory computer readable medium storing a computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method of claim 14 .