USER EQUIPMENT (UE) DOWNLINK TRANSMISSION CONFIGURATION INDICATION (TCI)-STATE SELECTION

• US 20190281587A1
• Filed: 05/08/2019
• Published: 09/12/2019
• Est. Priority Date: 05/10/2018
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Zhang, Yushu, Wang, Guotong, Xiong, Gang, Mondal, Bishwarup, Davydov, Alexei
• Granted Patent: US 10,986,622 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/088 using beam selection
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/56 based on priority criteria

Abstract

Systems, apparatuses, methods, and computer-readable media are provided for selecting a TCI-State for receiving downlink transmissions. In one example a processor/UE is configured to determine one or more candidate TCIs for a downlink slot; determine a scheduling offset between a physical downlink shared channel (PDSCH) and a physical downlink control channel (PDCCH); prioritize the candidate TCIs based on the scheduling offset; identify a highest priority candidate TCI; and select the highest priority candidate TCI for receiving the PDSCH.

Claims

1. An apparatus for a user equipment (UE) device, comprising baseband circuitry having:

a radio frequency (RF) interface configured to receive downlink signals during a plurality of downlink slots, wherein signals in each downlink slot are received according to a transmission configuration indication (TCI) that is mapped to a unique TCI-State in a set of preconfigured TCI-States assigned to the downlink slot; and

one or more processors configured to;

determine one or more candidate TCIs for a downlink slot;

determine a scheduling offset between a physical downlink shared channel (PDSCH) and a physical downlink control channel (PDCCH);

prioritize the candidate TCIs based on the scheduling offset;

identify a highest priority candidate TCI; and

select the highest priority candidate TCI for receiving the PDSCH.

2. The apparatus of claim 1, wherein the one or more processors are configured to:

identify a first TCI associated with the PDSCH as a first candidate TCI;

identify a second TCI associated with a downlink reference signal multiplexed with the PDSCH as a second candidate TCI; and

when the scheduling offset is below a threshold, assign a lowest priority to the first candidate TCI.

3. The apparatus of claim 1, wherein the one or more processors are configured to:

identify a first TCI associated with the PDSCH as a first candidate TCI;

identify a second TCI associated with a first downlink reference signal multiplexed with the PDSCH as a second candidate TCI; and

when the scheduling offset is above a threshold, assign a higher priority to the first candidate TCI than the second candidate TCI.

4. The apparatus of claim 3, wherein the first downlink reference signal comprises a periodic channel state information (CSI)-reference signal (RS) or a synchronization signal block (SSB) or a physical downlink control channel (PDCCH).

5. The apparatus of claim 3, wherein the one or more processors are configured to:

identify a third TCI associated with a second downlink reference signal multiplexed with the PDSCH as a third candidate TCI; and

when the scheduling offset is above a threshold, assign a higher priority to the first candidate TCI than the second candidate TCI and assign a lower priority to the first candidate TCI than the third candidate TCI.

6. The apparatus of claim 5, wherein the second downlink reference signal comprises an aperiodic CSI-RS.

7. The apparatus of claim 5, wherein the second downlink reference signal comprises a PDSCH scheduled by a PDCCH scrambled by system information (SI)-radio network transmission indicator (RNTI) or a PDSCH scheduled by a PDCCH scrambled by paging (P)-RNTI.

8. The apparatus of claim 1, wherein the one or more processors are configured to:

identify a first transmission configuration indicator (TCI) associated with the PDSCH as a first candidate TCI; and

identify a second TCI associated with a first downlink reference signal multiplexed with the PDSCH as a second candidate TCI, wherein the first downlink reference signal comprises a signal multiplexed with the PDSCH in a frequency division multiplexing or time division multiplexing manner.

9. The apparatus of claim 1, wherein the one or more processors are configured to, when the scheduling offset is above a threshold and when a media access control (MAC) control element (CE) reconfiguration of the set of preconfigured TCIs is acknowledged prior to when the PDCCH is transmitted and a period to apply new TCI-States expires after the PDCCH is transmitted but prior to when the PDSCH is transmitted:

select the TCI from the set of preconfigured TCI-States as defined when the PDCCH is transmitted.

10. The apparatus of claim 1, wherein the one or more processors are configured to, when the scheduling offset is above a threshold and when a media access control (MAC) control element (CE) reconfiguration of the set of preconfigured TCIs was acknowledged prior to the PDCCH and a period to apply new TCI-States expires after the PDCCH is transmitted but prior to when the PDSCH is transmitted:

select the TCI from the set of preconfigured TCI-States as defined when the PDSCH is transmitted.

11. The apparatus of claim 1, wherein the one or more processors are configured to, when the scheduling offset is above a threshold and when a media access control (MAC) control element (CE) reconfiguration of control resource set (CORESET) of TCIs associated with the PDCCH was acknowledged prior to the PDCCH and a period to apply new TCI-States expires after the PDCCH is transmitted but prior to when the PDSCH is transmitted:

determine that no TCI is present in the PDCCH; and

identify a CORESET TCI associated with the PDCCH as the highest priority candidate, wherein the identified CORESET TCI is selected from the CORESET as defined prior to the MAC CE reconfiguration.

12. The apparatus of claim 1, wherein the one or more processors are configured to, when the scheduling offset is above a threshold and when a media access control (MAC) control element (CE) reconfiguration of control resource set (CORESET) of TCIs associated with the PDCCH was acknowledged prior to the PDCCH and a period to apply new TCI-States expires after the PDCCH is transmitted but prior to when the PDSCH is transmitted:

determine that no TCI is present in the PDCCH; and

identify a CORESET TCI associated with the PDCCH as the highest priority candidate, wherein the identified CORESET TCI is selected from the CORESET as defined after to the MAC CE reconfiguration.

13. The apparatus of claim 1, wherein the one or more processors are configured to, when the scheduling offset is above a threshold and when a multi-slot PDSCH is being received:

select a TCI from the set of preconfigured TCI-States as defined when the PDCCH is transmitted.

14. The apparatus of claim 1, wherein the one or more processors are configured to, when the scheduling offset is above a threshold and when a multi-slot PDSCH is being received:

select a TCI from a set of predetermined TCI-States associated with a starting slot of the PDSCH.

15. The apparatus of claim 1, wherein the one or more processors are configured to, when the scheduling offset is above a threshold and when a multi-slot PDSCH is being received:

select a TCI from respective sets of predetermined TCI-States associated with each respective slot of the multi-slot PDSCH.

16. An apparatus for a gNB device, comprising baseband circuitry having:

a radio frequency (RF) interface configured to transmit PDSCH during a plurality of N downlink slots, wherein N is greater than 1, further wherein signals in each downlink slot are transmitted according to a transmission configuration indication (TCI) that identifies a unique TCI-State in a set of predetermined TCI-States assigned to the downlink slots; and

one or more processors configured to configure a set of predetermined TCIs associated with a set of N downlink slots.

17. One or more computer-readable media having instructions that, when executed, cause a user equipment (UE) device to:

determine one or more candidate TCIs for a downlink slot;

determine a scheduling offset between a physical downlink shared channel (PDSCH) and a physical downlink control channel (PDCCH);

prioritize the candidate TCIs based on the scheduling offset;

identify a highest priority candidate TCI; and

select the highest priority candidate TCI for receiving the PDSCH.

18. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to:

identify a first TCI associated with the PDSCH as a first candidate TCI;

identify a second TCI associated with a downlink reference signal multiplexed with the PDSCH as a second candidate TCI; and

when the scheduling offset is below a threshold, assign a lowest priority to the first candidate TCI.

19. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to:

identify a first TCI associated with the PDSCH as a first candidate TCI;

identify a second TCI associated with a first downlink reference signal multiplexed with the PDSCH as a second candidate TCI; and

when the scheduling offset is above a threshold, assign a higher priority to the first candidate TCI than the second candidate TCI.

20. The computer-readable media of claim 19, wherein the first downlink reference signal comprises a periodic channel state information (CSI)-reference signal (RS) or a synchronization signal block (SSB) or a physical downlink control channel (PDCCH).

21. The computer-readable media of claim 19, wherein the instructions, when executed, cause the UE device to:

identify a third TCI associated with a second downlink reference signal multiplexed with the PDSCH as a third candidate TCI; and

when the scheduling offset is above a threshold, assign a higher priority to the first candidate TCI than the second candidate TCI and assign a lower priority to the first candidate TCI than the third candidate TCI.

22. The computer-readable media of claim 21, wherein the second downlink reference signal comprises an aperiodic CSI-RS.

23. The computer-readable media of claim 21, wherein the second downlink reference signal comprises a PDSCH scheduled by a PDCCH scrambled by system information (SI)-radio network transmission indicator (RNTI) or a PDSCH scheduled by a PDCCH scrambled by paging (P)-RNTI.

24. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to:

identify a first transmission configuration indicator (TCI) associated with the PDSCH as a first candidate TCI; and

identify a second TCI associated with a first downlink reference signal multiplexed with the PDSCH as a second candidate TCI, wherein the first downlink reference signal comprises a signal multiplexed with the PDSCH in a frequency division multiplexing or time division multiplexing manner.

25. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to, when the scheduling offset is above a threshold and when a media access control (MAC) control element (CE) reconfiguration of the set of preconfigured TCIs is acknowledged prior to when the PDCCH is transmitted and a period to apply new TCI-States expires after the PDCCH is transmitted but prior to when the PDSCH is transmitted:

select the TCI from the set of preconfigured TCI-States as defined when the PDCCH is transmitted.

26. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to, when the scheduling offset is above a threshold and when a media access control (MAC) control element (CE) reconfiguration of the set of preconfigured TCIs was acknowledged prior to the PDCCH and a period to apply new TCI-States expires after the PDCCH is transmitted but prior to when the PDSCH is transmitted:

select the TCI from the set of preconfigured TCI-States as defined when the PDSCH is transmitted.

27. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to, when the scheduling offset is above a threshold and when a media access control (MAC) control element (CE) reconfiguration of control resource set (CORESET) of TCIs associated with the PDCCH was acknowledged prior to the PDCCH and a period to apply new TCI-States expires after the PDCCH is transmitted but prior to when the PDSCH is transmitted:

determine that no TCI is present in the PDCCH; and

identify a CORESET TCI associated with the PDCCH as the highest priority candidate, wherein the identified CORESET TCI is selected from the CORESET as defined prior to the MAC CE configuration.

28. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to, when the scheduling offset is above a threshold and when a media access control (MAC) control element (CE) reconfiguration of control resource set (CORESET) of TCIs associated with the PDCCH was acknowledged prior to the PDCCH and a period to apply new TCI-States expires after the PDCCH is transmitted but prior to when the PDSCH is transmitted:

determine that no TCI is present in the PDCCH; and

identify a CORESET TCI associated with the PDCCH as the highest priority candidate, wherein the identified CORESET TCI is selected from the CORESET as defined after to the MAC CE reconfiguration.

29. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to, when the scheduling offset is above a threshold and when a multi-slot PDSCH is being received:

select a TCI from the set of preconfigured TCI-States as defined when the PDCCH is transmitted.

30. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to, when the scheduling offset is above a threshold and when a multi-slot PDSCH is being received:

select a TCI from a set of predetermined TCI-States associated with a starting slot of the PDSCH.

31. The computer-readable media of claim 17, wherein the instructions, when executed, cause the UE device to, when the scheduling offset is above a threshold and when a multi-slot PDSCH is being received:

select a TCI from respective sets of predetermined TCI-States associated with each respective slot of the multi-slot PDSCH.