Method to determine spatial quasi co-location (QCL) assumption for channel state information reference signal (CSI-RS) in new radio (NR)

1. A user equipment (UE), comprising:

one or more processors configured to:

process a physical downlink shared channel (PDSCH) scheduling signal, received from a base station (BS), wherein the PDSCH scheduling signal is configured to schedule a PDSCH transmission and wherein the PDSCH scheduling signal comprises a first transmission configuration indicator (TCI) state indicative of a first channel state information reference signal (CSI-RS) resource;

determine a PDSCH receive (Rx) beam to be utilized for a reception of the PDSCH transmission based on the first CSI-RS resource based at least in part on whether the first CSI-RS resource is aperiodically transmitted within a predefined time period before the scheduled PDSCH transmission; and

generate a beam pattern of an aperiodic transmission of the first CSI-RS resource within the predefined time period as the PDSCH Rx beam, in response to the first CSI-RS resource being aperiodically transmitted within the predefined time period before the scheduled PDSCH transmission.

2. The UE of claim 1 , wherein the one or more processors is configured to determine the PDSCH Rx beam based on the first CSI-RS resource, when a scheduling offset between the PDSCH scheduling signal and the scheduled PDSCH transmission is greater than or equal to a predefined PDSCH scheduling threshold, wherein the predefined time period comprises a plurality of symbols/slots.

3. The UE of claim 2 , wherein, when the scheduling offset between the PDSCH scheduling signal and the PDSCH transmission is less than the predefined PDSCH scheduling threshold, the one or more processors is configured to determine the PDSCH Rx beam based on a predefined default PDSCH RX beam, irrespective of the first CSI-RS resource.

4. The UE of claim 1 , wherein, when the first CSI-RS resource is not aperiodically transmitted within the predefined time period before the PDSCH transmission, the PDSCH Rx beam follows an existing spatial quasi co-located (QCL) assumption for the first CSI-RS resource.

5. The UE of claim 1 , wherein the PDSCH Rx beam comprises a beam pattern of a most recent aperiodic transmission of the first CSI-RS resource that is transmitted before a predefined time period before the PDSCH transmission.

6. The UE of claim 1 , wherein the PDSCH Rx beam comprises a beam pattern of a most recent aperiodic transmission of the first CSI-RS resource with a CSI-RS scheduling offset that is greater than or equal to a CSI-RS scheduling threshold and that is transmitted before a predefined time period before the PDSCH transmission.

7. The UE of claim 1 , wherein the PDSCH Rx beam comprises a beam pattern of a reference signal that is configured in a quasi co-location (QCL) information of a triggering state associated with a most recent aperiodic transmission of the first CSI-RS resource that is transmitted before a predefined time period before the PDSCH transmission.

8. The UE of claim 1 , wherein the PDSCH Rx beam comprises a beam pattern of a latest transmission of the first CSI-RS resource, irrespective of whether the latest transmission of the first CSI-RS resource is aperiodic, periodic or semi-persistent.

9. The UE of claim 8 , wherein the latest transmission of the first CSI-RS resource comprises the latest transmission of the first CSI-RS resource that has a measured signal quality that is greater than a predefined CSI-RS signal quality threshold.

10. The UE of claim 1 , wherein the one or more processors is further configured to process a physical downlink control channel (PDCCH) configuration signal received from the BS associated therewith, wherein the PDCCH configuration signal is configured to configure PDCCH transmission and wherein the PDCCH configuration signal comprises a second transmission configuration indicator (TCI) state indicative of a second channel state information reference signal (CSI-RS) resource that is triggered aperiodically; and

determine a receive (Rx) beam to be utilized for a reception of the PDCCH transmission, that forms a PDCCH Rx beam, based on the second CSI-RS resource.

11. The UE of claim 10 , wherein determining the PDCCH Rx beam comprises determining whether the second CSI-RS resource is aperiodically transmitted within a predefined time period before the PDCCH transmission and utilizing a beam pattern of an aperiodic transmission of the second CSI-RS resource within the predefined time period as the PDCCH Rx beam, when the second CSI-RS resource is aperiodically transmitted within the predefined time period before the PDCCH transmission.

12. The UE of claim 11 , wherein, when the second CSI-RS resource is not aperiodically transmitted within the predefined time period before the PDCCH transmission, the PDCCH Rx beam follows an existing spatial quasi co-located (QCL) assumption for the second CSI-RS resource.

13. The UE of claim 1 , wherein the PDSCH scheduling signal comprises a physical downlink control channel (PDCCH).

14. The UE of claim 10 , wherein the PDCCH configuration signal comprises medium access control (MAC) layer signaling.

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

processing a physical downlink shared channel (PDSCH) scheduling signal, received from a base station (BS), at one or more processors associated with the UE, wherein the PDSCH scheduling signal is configured to schedule a PDSCH transmission and wherein the PDSCH scheduling signal comprises a transmission configuration indicator (TCI) state indicative of a channel state information reference signal (CSI-RS) resource;

determining, at the one or more processors, a PDSCH receive (Rx) beam to be utilized for a reception of the PDSCH transmission based on the CSI-RS resource based at least in part on whether the CSI-RS resource is aperiodically transmitted within a predefined time period comprising a plurality of symbols / slots before the PDSCH transmission; and

generating a beam pattern of an aperiodic transmission of the CSI-RS resource within the predefined time period as the PDSCH Rx beam, in response to the CSI-RS resource being aperiodically transmitted within the predefined time period before the PDSCH transmission.

16. The method of claim 15 , further comprising determining, at the one or more processors, the PDSCH Rx beam based on a predefined default PDSCH RX beam, irrespective of the CSI-RS resource, when a scheduling offset between the PDSCH scheduling signal and the PDSCH transmission is less than a predefined PDSCH scheduling threshold.

17. A baseband processor configured to:

process a physical downlink shared channel (PDSCH) scheduling signal, received from a base station (BS) associated therewith, wherein the PDSCH scheduling signal is configured to schedule a PDSCH transmission and wherein the PDSCH scheduling signal comprises a transmission configuration indicator (TCI) state indicative of a channel state information reference signal (CSI-RS) resource;

determine a PDSCH receive (Rx) beam to be utilized for a reception of the scheduled PDSCH transmission based on the CSI-RS resource, when a scheduling offset between the PDSCH scheduling signal and the PDSCH transmission is greater than or equal to a predefined PDSCH scheduling threshold based at least in part on whether the CSI-RS resource is aperiodically transmitted within a predefined time period comprising a plurality of symbols/slots before the scheduled PDSCH transmission; and

generate a beam pattern of an aperiodic transmission of the CSI-RS resource within the predefined time period as the PDSCH Rx beam, in response to the CSI-RS resource being aperiodically transmitted within the predefined time period before the scheduled PDSCH transmission.

18. The baseband processor of claim 17 , further configured to determine the PDSCH Rx beam based on a predefined default PDSCH RX beam, irrespective of the CSI-RS resource, when the scheduling offset between the PDSCH scheduling signal and the PDSCH transmission is less than the predefined PDSCH scheduling threshold.