Transmission configuration indication based beam switching

Patent metadata

Field	Value
Publication number	US-10651917-B2
Application number	US-201916244306-A
Country	US
Kind code	B2
Filing date	Jan 10, 2019
Priority date	Jan 12, 2018
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

Transmission configuration indication (TCI) states may be used to indicate beam switching for data beams and/or control beams. A total set of TCI states may be divided into subsets of TCI states. TCI states conveyed via downlink control information (DCI) may thus act as beam switching indications depending on which subset a conveyed TCI state resides. A base station may transmit an indication that such DCI based control beam switching is enabled. Based on whether TCI state (e.g., included in DCI) belongs to a first subset of TCI states or a second subset of TCI states, a wireless device (e.g., that receives the DCI) may trigger a beam switching operation. Beam switching operations may include data beam switching or both data beam switching and control beam switching. The UE may then receive a downlink control channel and a downlink data channel based on the triggered beam switching operation.

First claim

What is claimed is:

1. A method for wireless communication at a user equipment (UE), comprising:
receiving, from a base station, a first indication that downlink control information (DCI)-based control beam switching is enabled;
receiving, from the base station, downlink control information (DCI) indicating a transmission configuration indication (TCI) state, wherein the indicated TCI state is associated with a data beam switch or both a control beam switch and the data beam switch;
triggering, based at least in part on the first indication and the TCI state, a first beam switching operation or a second beam switching operation, wherein the first beam switching operation comprises data beam switching and the second beam switching operation comprises data beam switching and control beam switching; and
receiving a downlink control channel and a downlink data channel based at least in part on the triggered beam switching operation.

2. The method of claim 1 , wherein the control beam switching of the second beam switching operation comprises:
identifying a quasi-collocation (QCL) relationship between reference signals of the downlink control channel and a reference signal set corresponding to the indicated TCI state.

3. The method of claim 1 , further comprising:
determining whether the indicated TCI state belongs to a first subset of TCI states or a second subset of TCI states based at least in part on a most significant bit (MSB) of the indicated TCI state, wherein the first subset of TCI states are associated with the data beam switch and the second subset of TCI states are associated with both the control beam switch and the data beam switch.

4. The method of claim 1 , further comprising:
receiving, from the base station, a second indication that TCI state information in DCI is enabled; and
triggering the first beam switching operation or the second beam switching operation is further based at least in part on the second indication.

5. The method of claim 4 , wherein at least one of the first indication or the second indication is received in radio resource control (RRC) signaling or in a media access control (MAC) control element (MAC-CE).

6. The method of claim 1 , further comprising:
refraining from performing the second beam switching operation for a period of time defined by a threshold control offset parameter.

7. The method of claim 6 , further comprising:
receiving the threshold control offset parameter from the base station.

8. The method of claim 6 , further comprising:
transmitting an acknowledgment (ACK) or negative acknowledgment (NACK) message for the received DCI, wherein a beginning of the period of time is defined by a transmission time of the ACK or NACK message for the received DCI.

9. The method of claim 1 , wherein the control beam switching of the second beam switching operation comprises:
identifying a quasi-collocation (QCL) relationship between an aperiodic channel state information reference signal (CSI-RS) and a reference signal set corresponding to the indicated TCI state.

10. A method for wireless communication at a base station, comprising:
transmitting to a user equipment (UE) a first indication that downlink control information (DCI)-based control beam switching is enabled;
transmitting to the UE downlink control information (DCI) indicating a transmission configuration indication (TCI) state, wherein the indicated TCI state is associated with a data beam switch or both a control beam switch and the data beam switch;
triggering, based at least in part on the first indication and the TCI state, a first beam switching operation or a second beam switching operation, wherein the first beam switching operation comprises data beam switching and the second beam switching operation comprises data beam switching and control beam switching; and
transmitting a downlink control channel and a downlink data channel based at least in part on the triggered beam switching operation.

11. The method of claim 10 , wherein the control beam switching of the second beam switching operation comprises:
setting a quasi-collocation (QCL) relationship between reference signals of the downlink control channel and a reference signal set corresponding to the indicated TCI state.

12. The method of claim 10 , wherein a most significant bit (MSB) of the indicated TCI state indicates whether the indicated TCI state belongs to a first subset of TCI states or a second subset of TCI states, wherein the first subset of TCI states are associated with the data beam switch and the second subset of TCI states are associated with both the control beam switch and the data beam switch.

13. The method of claim 10 , further comprising:
transmitting to the UE a second indication that TCI state information in DCI is enabled, wherein triggering the first beam switching operation or the second beam switching operation is further based at least in part on the second indication.

14. The method of claim 13 , wherein at least one of the first indication or the second indication is transmitted using radio resource control (RRC) signaling or a media access control (MAC) control element (MAC-CE).

15. The method of claim 10 , wherein the control beam switching of the second beam switching operation comprises:
setting a quasi-collocation (QCL) relationship between an aperiodic channel state information reference signal (CSI-RS) and a reference signal set corresponding to the indicated TCI state.

16. An apparatus for wireless communication at a user equipment (UE), comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory and executable by the processor to cause the apparatus to:
receive, from a base station, a first indication that downlink control information (DCI)-based control beam switching is enabled;
receive, from the base station, downlink control information (DCI) indicating a transmission configuration indication (TCI) state, wherein the indicated TCI state is associated with a data beam switch or both a control beam switch and the data beam switch;
trigger, based at least in part on the first indication and the TCI state, a first beam switching operation or a second beam switching operation, wherein the first beam switching operation comprises data beam switching and the second beam switching operation comprises data beam switching and control beam switching; and
receive a downlink control channel and a downlink data channel based at least in part on the triggered beam switching operation.

17. The apparatus of claim 16 , wherein the instructions to the control beam switching of the second beam switching operation are executable by the processor to cause the apparatus to:
identify a quasi-collocation (QCL) relationship between reference signals of the downlink control channel and a reference signal set corresponding to the indicated TCI state.

18. The apparatus of claim 16 , wherein the instructions are further executable by the processor to cause the apparatus to:
determine whether the indicated TCI state belongs to a first subset of TCI states or a second subset of TCI states based at least in part on a most significant bit (MSB) of the indicated TCI state, wherein the first subset of TCI states are associated with the data beam switch and the second subset of TCI states are associated with both the control beam switch and the data beam switch.

19. The apparatus of claim 16 , wherein the instructions are further executable by the processor to cause the ap

Assignees

• Qualcomm Inc

Inventors

• John Wilson Makesh Pravin
• Luo Tao
• Lee Heechoon

Classifications

• H04L5/0091

  Signalling for the administration of the divided path, e.g. signalling of configuration information · CPC title

• H04L5/0053

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title

• H04L1/1607

  Details of the supervisory signal · CPC title

• H04L5/0094

  Indication of how sub-channels of the path are allocated · CPC title

• H04L5/0073

  Allocation arrangements that take into account other cell interferences · CPC title