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EP-4736338-A1 - UE INITIATED BEAM SWITCHING

EP4736338A1EP 4736338 A1EP4736338 A1EP 4736338A1EP-4736338-A1

Abstract

Systems, methods and apparatuses perform UE initiated beam switching. A UE (110) receives (304), from a network entity (120), a UE initiated beam switching configuration indicating a plurality of reference signals (RSs) associated with a plurality of beams. The UE receives (308), from the network entity, one or more RSs associated with one or more beams. The UE transmits (312), to the network entity, an indication to switch from communicating via at least one first beam to communicating via at least one second beam based on the one or more RSs. The UE and the network entity communicate (318) with one another via the at least one second beam.

Inventors

  • LIOU, JIA-HONG
  • ZHANG, YUSHU

Assignees

  • Google LLC

Dates

Publication Date
20260506
Application Date
20230811

Claims (18)

  1. A method for wireless communications by a user equipment (UE) (110) , comprising: receiving (304) , from a network entity (120) , a UE initiated beam switching configuration indicating a plurality of reference signals (RSs) associated with a plurality of beams; receiving (308) , from the network entity, one or more RSs associated with one or more beams; transmitting (312) , to the network entity, an indication to switch from communicating via at least one first beam to communicating via at least one second beam based on the one or more RSs; and communicating (318) with the network entity via the at least one second beam.
  2. The method of claim 1, wherein the UE initiated beam switching configuration includes one of more of: an indicator indicating whether a beam report is for beam switching; a number of reported synchronization signal block (SSB) resource indicators (SSBRIs) , channel state information reference signal (CSI-RS) resource indicators (CRIs) , or transmission configuration indicator (TCI) indexes; a first uplink resource for a beam report for beam switching; a report quantity for the beam report for beam switching; target uplink channels or downlink channels for beam switching; a first set of one or more SSBs or CSI-RSs for beam measurement; a second set of CSI-RSs for tracking reference signals (TRSs) for quasi-colocation (QCL) TypeA parameter identification; an action delay for the beam switching; a set of uplink power control parameters for uplink power control after the beam switching; a number of requested SSBRIs, CRIs, or TCI indexes; a first threshold to identify the at least one second beam; a second threshold to determine a beam quality for the at least one first beam; a number of beam switching request events to trigger a beam switching request; a detection interval for beam switching event detection; an indicator indicating whether to include a beam quality indicator with a SSBRI, CRI, or TCI index associated with a beam; a second uplink resource to transmit a beam switching request; a scheduling request (SR) to request an uplink grant for a beam switching request transmission; a maximum number of retransmissions of beam switching request; or a monitoring window for a response to the beam switching request.
  3. The method of claim 1 or 2, further comprising detecting (310) , by the UE, at least one beam switching event based on the one or more RSs; wherein the transmitting the indication to switch is in response to the detecting the at least one beam switching event.
  4. The method of claims 3, further comprising: calculating one or more beam quality measurements associated with one or more beams of the plurality of beams, the one or more beam quality measurements including at least one first beam quality measurement associated with the at least one first beam and at least one second beam quality measurement associated with the at least one second beam; and wherein the detecting the at least one beam switching event comprises at least one of: determining that a difference between the at least one first beam quality measurement and the at least one second beam quality measurement exceeds a first threshold difference; or determining that the at least one first beam quality measurement is below a second threshold.
  5. The method of claim 4, wherein the at least one first beam quality measurement and the at least one second beam quality measurement comprises one or more of: a layer 1 reference signal received power (L1-RSRP) ; a layer 1 signal-to-interference plus noise ratio (L1-SINR) ; a channel quality indicator (CQI) ; a hypothetical block error rate (BLER) ; or a spectrum efficiency (SE) .
  6. The method of claim 4, wherein the calculating the one or more beam quality measurements comprises one or more of: calculating the one or more beam quality measurements based on the one or more RSs; calculating the one or more beam quality measurements based on downlink reference signals configured in one or more TCI states; calculating the one or more beam quality measurements based on a TRS used for QCL indication; calculating the one or more beam quality measurements based on a first SSB that is quasi-co-located with a CSI-RS used for QCL indication in a first TCI state; or calculating the one or more beam quality measurements based on a second SSB that is used for QCL indication in a second TCI state.
  7. The method of any of claims 1-6, further comprising transmitting, to the network entity, UE capability information indicating whether the UE supports UE initiated beam switching.
  8. The method of any of claims 1-7, further comprising one or more of: identifying, in the indication to switch, a best UE beam for each SSBRI, CRI, or TCI index; identifying, in the indication to switch, QCL parameters for each SSBRI, CRI, or TCI index; or identifying, in the indication to switch, a layer 3 reference signal received power (L3-RSRP) for each SSBRI, CRI, or TCI index.
  9. The method of any of claims 1-8, further comprising detecting a predetermined or configurable number of beam switching events within a predetermined or configurable detection interval.
  10. The method of any of claims 1-9, wherein the RSs comprise at least one of synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RSs) .
  11. The method of any of claims 1-10, wherein the indication to switch comprises at least one of a SSB resource indicator (SSBRI) associated with the at least one second beam, a CSI-RS resource indicator (CRI) associated with the at least one second beam, or a transmission configuration indicator (TCI) index associated with the at least one second beam.
  12. The method of claim 11, further comprising: determining quasi-co-location (QCL) parameters based on one or more of: a tracking reference signal (TRS) indicated by the SSBRI, the CRI, or the TCI index, or a configured TRS; and applying the QCL parameters for the communicating with the network entity via the at least one second beam.
  13. The method of any of claims 1-12, wherein the transmitting the indication to switch comprises transmitting, to the network entity, the indication in a beam report.
  14. The method of any of claims 1-12, wherein the transmitting the indication to switch comprises transmitting, to the network entity, the indication in a request to switch from the at least one first beam to the at least one second beam.
  15. A method for wireless communications by a network entity (120) , comprising: transmitting (304) , to a user equipment (UE) (110) , a UE initiated beam switching configuration indicating a plurality of reference signals (RSs) associated with a plurality of beams; transmitting (308) , to the UE, one or more RSs associated with one or more beams; receiving (312) , from the UE, an indication to switch from communicating via at least one first beam to communicating via at least one second beam; and communicating (318) with the UE via the at least one second beam.
  16. The method of claim 15, further comprising transmitting, to the UE, a response to the receiving the indication to switch, the response including one or more of: an action delay or an action time for the switching to communicating via the at least one second beam; one or more synchronization signal block (SSB) resource indicators (SSBRIs) , channel state information reference signal (CSI-RS) resource indicators (CRIs) , or one or more transmission configuration indicator (TCI) indexes received from the UE in the indication to switch; or another indication of target uplink or downlink channels associated with the at least one second beam.
  17. The method of claims 15 or 16, wherein the UE initiated beam switching configuration includes one of more of: an indicator indicating whether a beam report is for beam switching; a number of reported synchronization signal block (SSB) resource indicators (SSBRIs) , channel state information reference signal (CSI-RS) resource indicators (CRIs) , or transmission configuration indicator (TCI) indexes; a first uplink resource for a beam report for beam switching; a report quantity for the beam report for beam switching; target uplink channels or downlink channels for beam switching; a first set of one or more SSBs or CSI-RSs for beam measurement; a second set of CSI-RSs for tracking reference signals (TRSs) for quasi-colocation (QCL) TypeA parameter identification; an action delay for the beam switching; a set of uplink power control parameters for uplink power control after the beam switching; a number of requested SSBRIs, CRIs, or TCI indexes; a first threshold to identify the at least one second beam; a second threshold to determine a beam quality for the at least one first beam; a number of beam switching request events to trigger a beam switching request; a detection interval for beam switching event detection; an indicator indicating whether to include a beam quality indicator with a SSBRI, CRI, or TCI index associated with a beam; a second uplink resource to transmit a beam switching request; a scheduling request (SR) to request an uplink grant for a beam switching request transmission; a maximum number of retransmissions of beam switching request; or a monitoring window for a response to the beam switching request.
  18. An apparatus, comprising: a communication unit; and a processing system configured to control the communication unit to implement any one of the methods of claims 1-17.

Description

UE INITIATED BEAM SWITCHING TECHNICAL FIELD Aspects of the present disclosure relate generally to wireless communication and techniques for UE initiated beam switching. BACKGROUND Beamforming is a technique that can enhance the signal quality between a network entity and a UE thereby improving data rates, reducing latency, and increasing overall network performance. In beamforming, the transmitter directs radio frequency (RF) transmission towards a specific direction (e.g., towards an intended receiver) , creating a "beam" of focused energy, rather than radiating the signal in all directions equally. BRIEF SUMMARY The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein. One innovative aspect of the subject matter described in this disclosure can be implemented as a method for wireless communications by a user equipment. The method may include receiving, from a network entity, a UE initiated beam switching configuration indicating a plurality of reference signals (RSs) associated with a plurality of beams. The method may further include receiving, from the network entity, one or more RSs associated with one or more beams. The method may further include transmitting, to the network entity, an indication to switch from communicating via at least one first beam to communicating via at least one second beam based on the one or more RSs. The method may further include communicating with the network entity via the at least one second beam. Another innovative aspect of the subject matter described in this disclosure can be implemented as a method for wireless communications by a network entity. The method may include transmitting, to a user equipment (UE) , a UE initiated beam switching configuration indicating a plurality of reference signals (RSs) associated with a plurality of beams. The method may further include transmitting, to the UE, one or more RSs associated with one or more beams. The method may further include receiving, from the UE, an indication to switch from communicating via at least one first beam to communicating via at least one second beam. The method may further include communicating with the UE via the at least one second beam. Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS Note that the relative dimensions of the following figures may not be drawn to scale. Like reference numbers and designations in the various drawings indicate like elements. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced. Figure 1 is a conceptual diagram illustrating an example wireless system including a user equipment communicating with a network entity. Figure 2 is a block diagram illustrating example configurations of a network entity and a user equipment. Figure 3 is a sequence diagram illustrating example operations of a communications process for UE initiated beam switching. Figure 4 is a flow chart diagram illustrating example UE operations of a method for UE initiated beam switching. Figure 5 is a flow chart diagram illustrating example network entity operations of a method for UE initiated beam switching. Figure 6 is a flow chart diagram illustrating example network entity operations of a method for detecting a beam switching request event. Figure 7A is a diagram illustrating an example of beam switching based on an indicated TCI state. Figure 7B is a diagram illustrating an example of beam switching based on multiple indicated TCI states. Figure 7C is a diagram illustrating an example of UE initiated joint uplink and downlink beam switching. Figure 7D is a diagram illustrating an example of UE initiated separate uplink and downlink beam switching. Figure 8A is a diagram illustrating an example of joint uplink and downlink beam switching in a response to a UE initiated beam switch. Figure 8B is a diagram illustrating an example of separate uplink and downlink beam switching in a response to a UE initiated beam switch. Figure 9 is a diagram illustrating an example timeline for additional TRS sets based on QCL parameter identification. Figure 10 is a diagram illustrating an example timeline for an additional TRS with dynamic QCL update based QCL parameter identification. Figure 11 is a diagram illustrating an example timeline including a scheduling restriction after beam switching. DETAILED DESCRIPTION The following description is directed to certain implementations for the purpose of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art wi