Cell Measurements Using Configured Reference Signals while in RRC Inactive Mode

• US 20200137602A1
• Filed: 08/28/2019
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Zhang, Wei, Sun, Haitong, Xu, Fangli, Zhao, Pengkai, Lim, Junsung, Zeng, Wei, Hu, Haijing, Almalfouh, Sami M., Zhang, Dawei, Sebeni, Johnson O.
• Granted Patent: US 11,096,079 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

This disclosure relates to performing cell measurements using configured reference signals while in an inactive state in a cellular communication system. A wireless device may receive an indication of reference signal resources configured for use by the wireless device in the inactive state from a cellular base station that provides a serving cell to the wireless device. The reference signal resources may include channel state information reference signal resources that are aligned in time and/or frequency with a control resource set provided for a wakeup occasion of the wireless device while in the inactive state. The wireless device may perform cell measurements using the indicated reference signal resources while in the inactive state.

Claims

1. An apparatus, comprising:

a processor configured to cause a wireless device to;

receive an indication of reference signal resources configured for use by the wireless device in a radio resource control (RRC) inactive mode from a cellular base station that provides a serving cell to the wireless device; and

perform cell measurements for the serving cell using the indicated reference signal resources while in the RRC inactive mode.

2. The apparatus of claim 1,

wherein the reference signal resources comprise channel state information reference signal (CSI-RS) resources.

3. The apparatus of claim 1,

wherein the reference signal resources comprise reference signal resources that are aligned in one or more of time or frequency with a control resource set provided for a wakeup occasion of the wireless device while in the RRC inactive mode.

4. The apparatus of claim 1, wherein the processor is further configured to cause the wireless device to:

receive the indication of the reference signal resources from the cellular base station in downlink control information during a wakeup occasion of the wireless device while in the RRC inactive mode.

5. The apparatus of claim 1, wherein the processor is further configured to cause the wireless device to:

receive the indication of the reference signal resources from the cellular base station in an indication to transition from RRC connected mode to RRC inactive mode.

6. The apparatus of claim 1,

wherein the reference signal resources comprise a semi-persistent periodic set of reference signal resources.

7. The apparatus of claim 1, wherein the processor is further configured to cause the wireless device to, at a later time:

receive an indication of new reference signal resources for use by the wireless device in the RRC inactive mode; and

perform cell measurements using the new reference signal resources while in the RRC inactive mode.

8. The apparatus of claim 7,

wherein the new reference signal resources are received after a cell re-selection by the wireless device.

9. A wireless device, comprising:

a plurality of antennas;

a radio operably coupled to the plurality of antennas; and

a processor operably coupled to the radio;

wherein the wireless device is configured to;

receive an indication of reference signal resources configured for use by the wireless device in a radio resource control (RRC) inactive mode from a cellular base station that provides a serving cell to the wireless device,

wherein the reference signal resources comprise channel state information reference signal (CSI-RS) resources that are aligned in one or more of time or frequency with a control resource set provided for a wakeup occasion of the wireless device while in the RRC inactive mode; and

perform cell measurements using the indicated reference signal resources while in the RRC inactive mode.

10. The wireless device of claim 9,

wherein the reference signal resources are configured with a same beam configuration as used by the wireless device while in an RRC connected mode.

11. The wireless device of claim 9, wherein the wireless device is further configured to, while in the inactive mode:

receive an indication of an aperiodic reference signal resource assignment that supports a receiver beam sweep during a wakeup occasion of the wireless device while in the RRC inactive mode based at least in part on performing the cell measurements using the indicated reference signal resources while in the RRC inactive mode.

12. The wireless device of claim 9, wherein the wireless device is further configured to:

provide cell measurement reports to the serving cell while in the RRC inactive mode based at least in part on performing the cell measurements using the indicated reference signal resources while in the RRC inactive mode.

13. The wireless device of claim 9, wherein the wireless device is further configured to:

re-select to a new cell while in the RRC inactive mode, wherein the cell re-selection is within a Radio Access Network Notification Area (RNA); and

provide a RNA update based at least in part on the cell re-selection within the RNA.

14. The wireless device of claim 9,

wherein the reference signal resources further comprise resources configured for transmitting sounding reference signals in the RRC inactive mode.

15. The wireless device of claim 9, wherein the wireless device is further configured to:

determine that an RRC inactive mode inactivity timer has expired; and

perform cell measurements using synchronization signal block transmissions after the RRC inactive mode inactivity timer has expired.

16. The wireless device of claim 15, wherein the wireless device is further configured to:

transition to RRC idle mode after the RRC inactive mode inactivity timer has expired based at least in part on determining that the RRC inactive mode inactivity timer has expired.

17. A cellular base station, comprising:

a plurality of antennas;

a radio operably coupled to the plurality of antennas; and

a processor operably coupled to the radio;

wherein the cellular base station is configured to;

provide an indication of reference signal resources configured for use by a wireless device in a radio resource control (RRC) inactive mode; and

provide the reference signal resources configured for use by the wireless device while the wireless device is in the RRC inactive mode.

18. The cellular base station of claim 17, wherein the cellular base station is further configured to:

provide a control resource set during a wakeup occasion of the wireless device while in the RRC inactive mode, wherein the reference signal resources are aligned in one or more of time or frequency with the control resource set.

19. The cellular base station of claim 17, wherein the cellular base station is further configured to provide the indication of the reference signal resources in one of:

downlink control information provided during a wakeup occasion of the wireless device while the wireless device is in the RRC inactive mode;

or

an indication to transition from RRC connected mode to RRC inactive mode.

20. The cellular base station of claim 17, wherein the reference signal resources comprise resources configured for transmitting sounding reference signals in the RRC inactive mode, wherein the cellular base station is further configured to:

receive the sounding reference signals from the wireless device in the RRC inactive mode.