Directional measurements for sidelink synchronization signal transmission

1. A method for wireless communication by a user equipment (UE), comprising:

measuring each beam of a plurality of beams associated with an access link between the UE and a network entity;

generating a signal metric that is a function of measurements of two or more beams of the plurality of beams associated with the access link based at least in part on the measuring of each beam of the plurality of beams associated with the access link;

identifying a sidelink configuration for synchronization signal transmission within a sidelink channel based at least in part on the signal metric; and

transmitting a synchronization signal via the sidelink channel based at least in part on the sidelink configuration.

2. The method of claim 1 , further comprising:

transmitting an indicator of the sidelink configuration to a second UE via the sidelink channel.

3. The method of claim 1 , further comprising:

transmitting, via the sidelink channel, an information block having a flag that indicates the synchronization signal is being transmitted in coverage or out of coverage.

4. The method of claim 1 , wherein the synchronization signal corresponds to a synchronization signal identifier selected from an in coverage set or an out of coverage set.

5. The method of claim 1 , wherein the synchronization signal is transmitted via the sidelink channel based at least in part on the signal metric satisfying a threshold specified in the sidelink configuration.

6. The method of claim 1 , further comprising:

skipping a subsequent transmission of the synchronization signal via the sidelink channel based at least in part on an update to the signal metric not satisfying a threshold specified in the sidelink configuration.

7. The method of claim 1 , wherein generating the signal metric comprises:

generating a reference signal measurement for each beam of the plurality of beams associated with the access link between the UE and the network entity;

selecting a defined number of the plurality of beams having a highest reference signal measurement based at least in part on the reference signal measurement for each beam; and

generating the signal metric as the function of the reference signal measurement for the defined number of the plurality of beams.

8. The method of claim 7 , wherein the function is an average function, a maximum function, a minimum function, an average function for reference signal measurements that satisfy a threshold, a number of reference signal measurements above or below a threshold for at least one cell, or any combination thereof.

9. The method of claim 7 , wherein the reference signal measurement is a reference signal receive power measurement, a signal to noise ratio, a signal to interference plus noise ratio, a reference signal receive quality measurement, a received signal strength indicator, or any combination thereof.

10. The method of claim 1 , wherein the sidelink configuration corresponds to a synchronization signal identifier selected from an in coverage set or an out of coverage set.

11. The method of claim 1 , wherein the sidelink configuration includes a flag in an information block that indicates an in coverage set or an out of coverage set.

12. The method of claim 1 , wherein the sidelink configuration comprises a sidelink synchronization signal configuration for synchronization signal transmission via the sidelink channel that is based at least in part on the signal metric.

13. The method of claim 1 , wherein the sidelink configuration comprises a resource pool configuration for data transmission via the sidelink channel that is based at least in part on the signal metric and one or more beam shapes used for measuring the plurality of beams.

14. The method of claim 13 , further comprising:

transmitting or receiving the data transmission via the sidelink channel based at least in part on the resource pool configuration.

15. The method of claim 1 , wherein the signal metric is based at least in part on measuring the plurality of beams associated with the access link between the UE and the network entity using a plurality of antenna panels of the UE.

16. The method of claim 1 , further comprising:

periodically generating an update to the signal metric based at least in part on measuring the plurality of beams associated with the access link between the UE and the network entity.

17. The method of claim 1 , further comprising:

establishing the access link with the network entity or a transmission/reception point.

18. An apparatus for wireless communication by 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 the apparatus to:

measure each beam of a plurality of beams associated with an access link between the UE and a network entity;

generate a signal metric that is a function of measurements of two or more beams of the plurality of beams associated with the access link based at least in part on the measuring of each beam of the plurality of beams associated with the access link;

identify a sidelink configuration for synchronization signal transmission within a sidelink channel based at least in part on the signal metric; and

transmit a synchronization signal via the sidelink channel based at least in part on the sidelink configuration.

19. The apparatus of claim 18 , wherein the instructions are further executable by the processor to cause the apparatus to:

transmit an indicator of the sidelink configuration to a second UE via the sidelink channel.

20. The apparatus of claim 18 , wherein the instructions are further executable by the processor to cause the apparatus to:

transmit, via the sidelink channel, an information block having a flag that indicates the synchronization signal is being transmitted in coverage or out of coverage.

21. The apparatus of claim 18 , wherein the synchronization signal corresponds to a synchronization signal identifier selected from an in coverage set or an out of coverage set.

22. The apparatus of claim 18 , wherein the synchronization signal is transmitted via the sidelink channel based at least in part on the signal metric satisfying a threshold specified in the sidelink configuration.

23. The apparatus of claim 18 , wherein the instructions are further executable by the processor to cause the apparatus to:

skip a subsequent transmission of the synchronization signal via the sidelink channel based at least in part on an update to the signal metric not satisfying a threshold specified in the sidelink configuration.

24. The apparatus of claim 18 , wherein the instructions to generate the signal metric are executable by the processor to cause the apparatus to:

generate a reference signal measurement for each beam of the plurality of beams associated with the access link between the UE and the network entity;

select a defined number of the plurality of beams associated with the access link between the UE and the network entity having a highest reference signal measurement based at least in part on the reference signal measurement for each beam; and

generate the signal metric as the function of the reference signal measurement for the defined number of the plurality of beams associated with the access link between the UE and the network entity.

25. The apparatus of claim 24 , wherein the function is an average function, a maximum function, a minimum function, an average function for reference signal measurements that satisfy a threshold, a number of reference signal measurements above or below a threshold for at least one cell, or any combination thereof.

26. The apparatus of claim 24 , wherein the reference signal measurement is a reference signal receive power measurement, a signal to noise ratio, a signal to interference plus noise ratio, a reference signal receive quality measurement, a received signal strength indicator, or any combination thereof.

27. The apparatus of claim 24 , wherein the sidelink configuration includes a synchronization signal identifier selected from an in coverage set or an out of coverage set.

28. The apparatus of claim 24 , wherein the sidelink configuration includes a flag in an information block that indicates an in coverage set or an out of coverage set.

29. An apparatus for wireless communication by a user equipment (UE), comprising:

means for measuring each beam of a plurality of beams associated with an access link between the UE and a network entity;

means for generating a signal metric that is a function of measurements of two or more beams of the plurality of beams associated with the access link based at least in part on the measuring of each beam of the plurality of beams associated with the access link;

means for identifying a sidelink configuration for synchronization signal transmission within a sidelink channel based at least in part on the signal metric; and

means for transmitting a synchronization signal via the sidelink channel based at least in part on the sidelink configuration.

30. A non-transitory computer-readable medium storing code for wireless communication by a user equipment (UE), the code comprising instructions executable by a processor to:

measure each beam of a plurality of beams associated with an access link between the UE and a network entity;

generate a signal metric that is a function of measurements of two or more beams of the plurality of beams associated with the access link based at least in part on the measuring of each beam of the plurality of beams associated with the access link;

identify a sidelink configuration for synchronization signal transmission within a sidelink channel based at least in part on the signal metric; and

transmit a synchronization signal via the sidelink channel based at least in part on the sidelink configuration.

31. The method of claim 1 , wherein:

the signal metric is an average of measurements of the plurality of beams associated with the access link between the UE and the network entity, and

the sidelink configuration is based at least in part on the average of the measurements of the plurality of beams associated with the access link between the UE and the network entity.