Downlink pathloss determination for transmit power control for sidelink communications

1. A method of communications at a user equipment (UE), comprising:

receiving, by the UE and in a direction of a sidelink transmission beam, a plurality of synchronization reference signals from a base station, wherein the sidelink transmission beam is configured at the UE for transmitting sidelink communications to a second UE;

measuring a respective Reference Signal Received Power (RSRP) value of each of the plurality of synchronization reference signals;

determining a highest RSRP value from each of the respective RSRP values;

calculating a downlink pathloss associated with a sidelink open loop power control based on the highest RSRP value; and

determining a transmit power of communication with the second UE on a sidelink based on a minimum between a sum of a desired received signal power at the second UE and the downlink pathloss and a sum of the desired received signal power at the second UE and a pathloss between the UE and the second UE.

2. The method of claim 1 , wherein the plurality of synchronization reference signals correspond to a plurality of Synchronization Signal Block (SSB) transmission signals.

3. The method of claim 2 , wherein calculating the downlink pathloss further comprises calculating the downlink pathloss based on a difference between a transmit power value of the plurality of SSB transmission signals and the highest RSRP value.

4. The method of claim 1 , wherein receiving the plurality of synchronization reference signals further comprises receiving the plurality of synchronization reference signals on a receiving beam.

5. The method of claim 4 , wherein the receiving beam is used for communicating with the second UE on a sidelink.

6. The method of claim 1 , further comprising determining, by the UE, a transmit power of communications with the second UE on a sidelink based on the downlink pathloss.

7. The method of claim 6 , wherein determining the transmit power of communication with the second UE on the sidelink further comprises calculating a sidelink transmit power based on a target receive power value and the downlink pathloss.

8. The method of claim 7 , wherein the target receive power value corresponds to an open loop power control for the sidelink transmit power.

9. The method of claim 6 , further comprising transmitting, by the UE to the second UE via the sidelink, a sidelink transmission based on the transmit power.

10. The method of claim 9 , wherein the transmit power compensates for the downlink pathloss and limit interference caused by the sidelink transmission to a network entity.

11. The method of claim 1 , wherein the pathloss between the UE and the second UE is calculated based on a RSRP with a transmit power by the second UE.

12. An apparatus for communication at a user equipment (UE), comprising:

a memory configured to store instructions; and

one or more processors communicatively coupled with the memory, wherein the one or more processors are configured to execute the instructions to:

receive, in a direction of a sidelink transmission beam, a plurality of synchronization reference signals from a base station, wherein the sidelink transmission beam is configured at the UE for transmitting sidelink communications to a second UE;

measure a respective Reference Signal Received Power (RSRP) value of each of the plurality synchronization reference signals;

determine a highest RSRP value from each of the respective RSRP values;

calculate a downlink pathloss associated with a sidelink open loop power control based on the highest RSRP value; and

determining a transmit power of communications with the second UE on a sidelink based on a minimum between a sum of a desired received signal power at the second UE and the downlink pathloss and a sum of the desired received signal power at the second UE and a pathloss between the UE and the second UE.

13. The apparatus of claim 12 , wherein the plurality of synchronization reference signals correspond to a plurality of Synchronization Signal Block (SSB) transmission signals.

14. The apparatus of claim 13 , wherein the one or more processors configured to calculate the downlink pathloss are further configured to calculate the downlink pathloss based on a difference between a transmit power value of the plurality of SSB transmission signals and the highest RSRP value.

15. The apparatus of claim 12 , wherein the one or more processors configured to receive the plurality of synchronization reference signals are further configured to receive the plurality of synchronization reference signals on a receiving beam.

16. The apparatus of claim 15 , wherein the receiving beam is used for communicating with the second UE on a sidelink.

17. The apparatus of claim 12 , wherein the one or more processors are configured to determine, by the UE, a transmit power of communications with the second UE on the sidelink based on the downlink pathloss.

18. The apparatus of claim 17 , the one or more processors configured to determine the transmit power of communication with the second UE on the sidelink are further configured to calculate a sidelink transmit power based on a target receive power value and the downlink pathloss.

19. The apparatus of claim 18 , wherein the target receive power value corresponds to an open loop power control for the sidelink transmit power.

20. The apparatus of claim 17 , wherein the one or more processors are configured to transmit, by the UE to the second UE via the sidelink, a sidelink transmission based on the transmit power.

21. The apparatus of claim 20 , wherein the transmit power compensates for the downlink pathloss and limit interference caused by the sidelink transmission to a network entity.