Dynamically enabling dual default beams
Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for processing transmissions with multiple beams. For example, the techniques may be implemented in wireless systems in which any type of network entity (gNB or transmission reception points TRPs) send directional transmissions to user equipments (UEs) that receive the directional transmissions with receive beams.
1. A method for wireless communications by a user equipment (UE), comprising:
receiving a configuration indicating when the UE is to send a request to a network entity, to enable or disable a mode in which multiple default beams are used for physical downlink shared channel (PDSCH) transmission from multiple transmit receive points (TRPs), based on at least one condition;
sending the request if the at least one condition is met;
after sending the request, receiving dynamic signaling from the network entity of an indication that the mode is enabled or disabled; and
processing PDSCH transmissions from the multiple TRPs with one or more default beams in accordance with the indication.
2. The method of claim 1 , wherein the dynamic signaling comprises at least one of:
a downlink control information (DCI), a medium access control (MAC) control element (MAC CE), or radio resource control (RRC) signaling.
3. The method of claim 1 , wherein PDSCH transmission are processed using a single default beam if the indication is that the mode, in which multiple default beams are used for PDSCH transmission from multiple TRPs, is disabled.
4. The method of claim 1 , wherein, when the mode is enabled and PDSCH transmissions from the multiple TRPs are scheduled with multiple downlink control informations (DCIs):
each default beam is determined based on a spatially co-located reference signal (RS) of a certain command resource set (CORESET) ID among CORESETs with a common pool index.
5. The method of claim 1 , wherein, when the mode is enabled and PDSCH transmissions from the multiple TRPs are scheduled with a single downlink control information (DCI):
the default beams are determined based on active transmission configuration indicator (TCI) states mapped to certain TCI codepoint ID among TCI codepoints containing multiple TCI states.
6. The method of claim 1 , wherein the request is sent via at least one of:
a medium access control (MAC) control element (MAC CE) or radio resource control (RRC) signaling.
7. The method of claim 1 , wherein the request is sent with a request for a feature that involves multiple default beams for PDSCH transmissions from the multiple TRPs scheduled via single or multiple DCIs.
8. The method of claim 1 , wherein:
the at least one condition relates to battery life of the UE; and
the configuration indicates the UE is to send a request to disable the mode if the battery life is below a threshold value.
9. The method of claim 1 , wherein the UE provides a power saving related metric with the request for the network entity to consider with the request.
10. The method of claim 1 , wherein the dynamic signaling comprises a wake up signal (WUS) received while the UE is in a discontinuous reception (DRX) mode.
11. The method of claim 10 , wherein the indication is applied to one or more ON periods of the DRX mode after receiving the WUS.
12. The method of claim 1 , wherein:
the UE is configured with at least first and second bandwidth parts (BWPs) having different default beams.
13. The method of claim 12 , wherein:
the UE uses a single default PDSCH beam when the first BWP is active;
the UE uses multiple default PDSCH beams when the second BWP is active; and
the indication is received via a BWP switch between the first and second BWPs.
14. The method of claim 12 , wherein:
the UE is configured to use a single default PDSCH beam when the first BWP is configured as a dormant BWP;
the UE is configured to use multiple default PDSCH beams when the second BWP is configured as a non-dormant BWP; and
the indication is received via a switch of at least one of the first or second BWPs to or from a dormant or non-dormant BWP.
15. A method for wireless communications by a network entity, comprising:
sending a user equipment (UE) a configuration indicating when the UE is to send a request, to enable or disable a mode in which multiple default beams are used for physical downlink shared channel (PDSCH) transmission from multiple transmit receive points (TRPs), based on at least one condition;
receiving, from the UE, the request to enable or disable the mode;
after receiving the request, dynamically signaling the UE an indication that the mode is enabled or disabled; and
scheduling PDSCH transmissions from the multiple TRPs with one or more default beams in accordance with the indication.
16. The method of claim 15 , wherein the dynamic signaling comprises at least one of:
a downlink control information (DCI), a medium access control (MAC) control element (MAC CE), or radio resource control (RRC) signaling.
17. The method of claim 15 , wherein PDSCH transmission are processed using a single default beam if the indication is the mode is disabled.
18. The method of claim 15 , wherein, when the mode is enabled and PDSCH transmissions from the multiple TRPs are scheduled with multiple downlink control informations (DCIs):
each default beam is determined based on a spatially co-located reference signal (RS) of a certain command resource set (CORESET) ID among CORESETs with a common pool index.
19. The method of claim 15 , wherein, when the mode is enabled and PDSCH transmissions from the multiple TRPs are scheduled with a single downlink control information (DCI):
the default beams are determined based on active transmission configuration indicator (TCI) states mapped to certain TCI codepoint ID among TCI codepoints containing multiple TCI states.
20. The method of claim 15 , wherein the request is received via at least one of:
a medium access control (MAC) control element (MAC CE) or radio resource control (RRC) signaling.
21. The method of claim 15 , wherein the request is received with a request for a feature that involves multiple default beams for PDSCH transmissions from the multiple TRPs scheduled via single or multiple DCIs.
22. The method of claim 15 , wherein:
the at least one condition relates to battery life of the UE; and
the configuration indicates the UE is to send a request to disable the mode if the battery life is below a threshold value.
23. The method of claim 15 , wherein the UE provides a power saving related metric with the request for the network entity to consider with the request.
24. The method of claim 15 , wherein the dynamic signaling comprises a wake up signal (WUS) received while the UE is in a discontinuous reception (DRX) mode.
25. An apparatus for wireless communications by a user equipment (UE), comprising:
a transceiver configured to:
receive a configuration indicating when the UE is to send a request to a network entity, to enable or disable a mode in which multiple default beams are used for physical downlink shared channel (PDSCH) transmission from multiple transmit receive points (TRPs), based on at least one condition;
send the request if the at least one condition is met; and
after sending the request, receive dynamic signaling of an indication from the network entity that the mode is enabled or disabled; and
at least one processor configured to process PDSCH transmissions from the multiple TRPs with one or more default beams in accordance with the indication.
26. An apparatus for wireless communications by a network entity, comprising:
a transceiver configured to:
send a user equipment (UE) a configuration indicating when the UE is to send a request, to enable or disable a mode in which multiple default beams are used for physical downlink shared channel (PDSCH) transmission from multiple transmit receive points (TRPs), based on at least one condition;
receive, from the UE, the request to enable or disable the mode; and
after receiving the request, dynamically signal the UE an indication that the mode is enabled or disabled; and
at least one processor configured to schedule PDSCH transmissions from the multiple TRPs with one or more default beams in accordance with the indication.