Sidelink synchronization priority rules

Patent metadata

Field	Value
Publication number	US-11375464-B2
Application number	US-201916542285-A
Country	US
Kind code	B2
Filing date	Aug 15, 2019
Priority date	Aug 15, 2019
Publication date	Jun 28, 2022
Grant date	Jun 28, 2022

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive a first kind of synchronization signals from a first synchronization source and may receive a second kind of synchronization signals from a second synchronization source. Additionally, the UE may determine a first priority for the first synchronization source and a second priority for the second synchronization source based on whether each synchronization source is connected to a global navigation satellite system from information in the synchronization signals. Accordingly, the UE may then select the synchronization source with the higher priority and communicate with one or more additional UEs based on synchronizing with the selected synchronization source. In some cases, the first kind of synchronization signals may include sidelink synchronization signals, and the second kind of synchronization signals may include data-based synchronization signals (e.g., demodulation reference signals).

First claim

What is claimed is:

1. A method for wireless communications at a user equipment (UE), comprising:
transmitting, to one or more synchronization sources comprising at least a first synchronization source and a second synchronization source, an indication of a UE capability for the UE to support one or more synchronization signals of a first kind and one or more synchronization signals of a second kind;
receiving, from the first synchronization source, one or more synchronization signals of the first kind;
receiving, from the second synchronization source, one or more synchronization signals of the second kind, the one or more synchronization sources comprising the first synchronization source and the second synchronization source;
determining a first priority for the first synchronization source based at least in part on the one or more synchronization signals of the first kind and a second priority for the second synchronization source based at least in part on the one or more synchronization signals of the second kind;
selecting the first synchronization source or the second synchronization source as a synchronization source for the UE based at least in part on the determined first priority and the determined second priority, wherein selecting the first synchronization source or the second synchronization source comprises determining whether the first synchronization source or the second synchronization source is directly or indirectly connected to a global navigation satellite system based at least in part on a sidelink synchronization signal identifier, or a media access control control element, or both; and
communicating with one or more UEs based at least in part on synchronizing with the selected synchronization source.

2. The method of claim 1 , wherein selecting the first synchronization source or the second synchronization source for the UE comprises:
determining, for the first synchronization source, a first value of a power parameter;
determining, for the second synchronization source, a second value of the power parameter; and
selecting the first synchronization source or the second synchronization source as the synchronization source for the UE based at least in part on the determined first priority, the determined second priority, the determined first value, and the determined second value.

3. The method of claim 2 , wherein the power parameter comprises a reference signal received power, a reference signal received quality, a signal-to-noise ratio, a signal-to-interference-plus-noise ratio, or a combination thereof.

4. The method of claim 1 , further comprising:
receiving, from the first synchronization source, synchronization information associated with the one or more synchronization signals of the first kind; and
determining whether the first synchronization source is connected to the global navigation satellite system based at least in part on the received synchronization information, wherein the first priority for the first synchronization source is determined based at least in part on whether the first synchronization source is connected to the global navigation satellite system.

5. The method of claim 4 , wherein the synchronization information of the one or more synchronization signals of the first kind comprises a primary synchronization signal identification, a secondary synchronization signal identification, in-coverage information in a physical sidelink broadcast channel signal, resources on which the one or more synchronization signals of the first kind are received, or a combination thereof.

6. The method of claim 4 , wherein the first priority is a first level if the first synchronization source is connected to the global navigation satellite system and a second level that is lower than the first level if the first synchronization source is not connected to the global navigation satellite system.

7. The method of claim 1 , further comprising:
receiving, from the second synchronization source, a synchronization state indication associated with the one or more synchronization signals of the second kind; and
determining whether the second synchronization source is connected to the global navigation satellite system based at least in part on the received synchronization state indication, wherein the second priority for the second synchronization source is based at least in part on whether the second synchronization source is connected to the global navigation satellite system.

8. The method of claim 7 , wherein the second priority is a first level if the second synchronization source is connected to the global navigation satellite system and a second level that is lower than the first level if the second synchronization source is not connected to the global navigation satellite system.

9. The method of claim 1 , wherein selecting the first synchronization source or the second synchronization source further comprises:
identifying that the determined first priority is a same priority as the determined second priority; and
selecting the first synchronization source or the second synchronization source based at least in part on a tie-breaking rule.

10. The method of claim 1 , wherein the determined second priority is higher than the determined first priority, the method further comprising:
determining a value of a power parameter for the second synchronization source; and
comparing the determined value of the power parameter to a threshold value.

11. The method of claim 10 , wherein selecting the first synchronization source or the second synchronization source comprises:
selecting the second synchronization source based at least in part on the determined second priority being higher than the determined first priority, and the determined value of the power parameter satisfying the threshold value.

12. The method of claim 10 , wherein selecting the first synchronization source or the second synchronization source comprises:
selecting the first synchronization source based at least in part on the second priority being higher than the first priority, and the determined value of the power parameter failing to satisfy the threshold value.

13. The method of claim 10 , further comprising:
receiving an indication of the threshold value.

14. The method of claim 1 , wherein:
the one or more synchronization signals of the first kind comprise a sidelink synchronization signal or a demodulation reference signal; and
the one or more synchronization signals of the second kind comprise a different one of the sidelink synchronization signal or the demodulation reference signal.

15. The method of claim 14 , wherein the sidelink synchronization signal comprises a primary synchronization signal, a secondary synchronization signal, and a physical sidelink broadcast channel signal.

16. The method of claim 1 , wherein:
the first synchronization source comprises a first UE; and
the second synchronization source comprises a second UE.

17. The method of claim 1 , wherein:
the first synchronization source is connected indirectly to the global navigation satellite system and uses a sidelink synchronization signal block synchronization procedure; and
the second synchronization source is connected directly to the global navigation satellite system and uses a non-sidelink synchronization signal block synchronization procedure.

18. An apparatus for wireless communications at a user equipment (UE), comprising: a processor, memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause

Assignees

• Qualcomm Inc

Inventors

• Gulati Kapil
• Bharadwaj Arjun
• Wu Shuanshuan
• Nguyen Tien Viet
• Baghel Sudhir Kumar

Classifications

• H04W56/0025

  synchronizing potentially movable access points · CPC title

• H04W56/0005 Primary

  synchronizing of arrival of multiple uplinks · CPC title

• H04W56/0015 Primary

  one node acting as a reference for the others · CPC title