Techniques for selecting subcarrier spacing for signal detection

Patent metadata

Field	Value
Publication number	US-10985964-B2
Application number	US-201816126832-A
Country	US
Kind code	B2
Filing date	Sep 10, 2018
Priority date	Sep 11, 2017
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

Techniques are described herein that allow a user equipment (UE) to configure a subcarrier spacing value while monitoring synchronization signals of neighboring cells. In some wireless communication systems, synchronization signals in given radio frequency spectrum band may be transmitted using one of a plurality of different subcarrier spacings. In some cases, a network entity, such as a base station, may transmit an indication to the UE that indicates the subcarrier spacing used by a cell to transmit a specific set of synchronization signals. In some cases, the UE may select a subcarrier spacing based on a database of subcarrier spacings stored locally by the UE. In some cases, the UE may select the subcarrier spacing based on a predetermined configuration.

First claim

What is claimed is:

1. A method for wireless communication at a base station, comprising:
initiating an intra-frequency and inter-frequency search and measurement procedure for a user equipment (UE) connected to the base station;
identifying which one or more radio frequency spectrum band resources of a plurality of radio frequency spectrum band resources are to be monitored by the UE during the intra-frequency and inter-frequency search and measurement procedure;
identifying a subcarrier spacing of a synchronization signal transmitted by a neighboring cell based at least in part on identifying which one or more radio frequency spectrum band resources are to be monitored; and
transmitting an indication of the subcarrier spacing of the synchronization signal to the UE.

2. The method of claim 1 , further comprising:
identifying the neighboring cell to be monitored by the UE during the intra-frequency and inter-frequency search and measurement procedure, wherein identifying the subcarrier spacing is based at least in part on identifying the neighboring cell.

3. The method of claim 1 , wherein:
the identified subcarrier spacing is selected from a set of two possible subcarrier spacings for a given set of radio frequency spectrum band resources.

4. The method of claim 3 , wherein in sub-six radio frequency spectrum bands the subcarrier spacing for the synchronization signal is 15 kilohertz or 30 kilohertz.

5. The method of claim 3 , wherein in millimeter wave (mmW) radio frequency spectrum bands the subcarrier spacing for the synchronization signal is 120 kilohertz or 240 kilohertz.

6. The method of claim 1 , further comprising:
identifying a plurality of subcarrier spacings of synchronization signals transmitted by a plurality of cells that neighbor the base station; and
storing the plurality of subcarrier spacings, wherein identifying the subcarrier spacing of the neighboring cell is based at least in part on storing the plurality of subcarrier spacings.

7. The method of claim 1 , further comprising:
receiving a measurement report from the UE based at least in part on transmitting the indication.

8. The method of claim 1 , wherein:
the indication is part of a measurement configuration message transmitted by the base station to the UE.

9. The method of claim 1 , wherein:
the indication is a one-bit field.

10. The method of claim 1 , wherein:
the indication is part of a radio resource control (RRC) message.

11. A method for wireless communication at a user equipment (UE), comprising:
receiving an indication, from a base station, indicating one or more radio frequency spectrum band resources to be monitored by the UE during an intra-frequency and inter-frequency search and measurement procedure;
identifying the one or more radio frequency spectrum band resources to be monitored by the UE during the intra-frequency and inter-frequency search and measurement procedure based on the received indication;
identifying a plurality of subcarrier spacings of a synchronization signal transmitted by a neighboring cell, the plurality of subcarrier spacings being associated with the one or more radio frequency spectrum band resources identified to be monitored; and
performing the search and measurement procedure by monitoring the synchronization signal of the neighboring cell using one or more of the plurality of subcarrier spacings.

12. The method of claim 11 , further comprising:
determining a search order for the plurality of subcarrier spacings, wherein monitoring the synchronization signal comprises monitoring the synchronization signal using a first subcarrier spacing in the search order and monitoring the synchronization signal using a second subcarrier spacing in the search order after using the first subcarrier spacing.

13. The method of claim 12 :
the indication from a base station further indicates a subcarrier spacing associated with a specific synchronization signal, wherein determining the search order is based at least in part on receiving the indication.

14. The method of claim 12 , further comprising:
identifying the first subcarrier spacing from the plurality of subcarrier spacings using a database of subcarrier spacings stored by the UE, wherein determining the search order is based at least in part on using the database of subcarrier spacings stored by the UE.

15. The method of claim 12 , further comprising:
identifying the first subcarrier spacing from the plurality of subcarrier spacings based on a preconfigured order, wherein determining the search order is based at least in part on using the preconfigured order.

16. The method of claim 11 , further comprising:
transmitting a measurement report to a base station based at least in part on monitoring the synchronization signal using the one or more of the plurality of subcarrier spacings.

17. The method of claim 11 , further comprising:
identifying a subcarrier spacing of a specific synchronization signal transmitted by a cell connected to the UE; and
storing the subcarrier spacing of the cell, wherein identifying the plurality of subcarrier spacings of the neighboring cell is based at least in part on storing the subcarrier spacing.

18. The method of claim 11 , wherein:
the plurality of subcarrier spacings includes a set of two possible subcarrier spacings for a given set of radio frequency spectrum band resources.

19. The method of claim 18 , wherein in sub-six radio frequency spectrum bands the plurality of subcarrier spacings for the synchronization signal is 15 kilohertz or 30 kilohertz.

20. The method of claim 18 , wherein in millimeter wave (mmW) radio frequency spectrum bands the plurality of subcarrier spacings for the synchronization signal is 120 kilohertz or 240 kilohertz.

21. The method of claim 11 , further comprising:
monitoring each of the plurality of subcarrier spacings based at least in part on failing to receive an indication from a base station about a subcarrier spacing associated with a specific synchronization signal.

22. The method of claim 11 , wherein monitoring the synchronization signal of the neighboring cell is performed using the one or more of the plurality of subcarrier spacings after the synchronization signal is detected using one of the plurality of subcarrier spacings.

23. A method for wireless communication at a user equipment (UE), comprising:
initiating an intra-frequency and inter-frequency search and measurement procedure;
receiving an indication, from a base station, indicating one or more radio frequency spectrum band resources to be monitored by the UE during the intra-frequency and inter-frequency search and measurement procedure;
identifying the one or more radio frequency spectrum band resources of a plurality of radio frequency spectrum band resources are to be monitored during the intra-frequency and inter-frequency search and measurement procedure based on the received indication;
identifying a subcarrier spacing of a synchronization signal transmitted by a neighboring cell from a plurality of possible subcarrier spacings of the synchronization signal based at least in part on identifying which one or more radio frequency spectrum band resources are to be monitored, the plurality of subcarrier spacings being associated with which one or more radio frequency spectrum band resources are to be monitored; and
monitoring the synchronization signal of the neighboring cell using the identified subcarrier spacing.

Assignees

• Qualcomm Inc

Inventors

• Vaze Chinmay Shankar
• Ly Hung Dinh
• Gorokhov Alexei Yurievitch
• Yee Nathan
• Sankar Hari
• Challa Raghu Narayan

Classifications

• H04L27/2613

  Structure of the reference signals · CPC title

• H04L27/26025 Primary

  Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking (allocating sub-channels of the transmission path H04L5/003) · CPC title

• H04L27/2692

  with preamble design, i.e. with negotiation of the synchronisation sequence with transmitter or sequence linked to the algorithm used at the receiver · CPC title

• H04L27/2666 Primary

  Acquisition of further OFDM parameters, e.g. bandwidth, subcarrier spacing, or guard interval length · CPC title

• H04L5/0092

  Indication of how the channel is divided · CPC title