Multiplexing solutions in dual connectivity

1. 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 the apparatus to:

determine a first transmission power for first uplink communications between the UE and a first cell group associated with a first radio access technology (RAT);

determine a second transmission power for second uplink communications between the UE and a second cell group associated with a second RAT, wherein the first uplink communications overlap in time with the second uplink communications;

reduce the second transmission power of the second uplink communications to a third transmission power when a summation of the first transmission power and the second transmission power is greater than a power threshold, wherein reducing the second transmission power is based at least in part on the overlap in time and on a capability of the UE to perform dynamic power sharing between the first RAT and the second RAT, and wherein a summation of the first transmission power and the third transmission power is less than or equal to the power threshold; and

perform one or both of the first uplink communications or the second uplink communications based at least in part on reducing the second transmission power, wherein performing one or both of the first uplink communications or the second uplink communications comprises dropping the second uplink communications when a difference between the second transmission power and the third transmission power is greater than a threshold value.

2. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:

determine an asymmetric power reduction factor for the second uplink communications with the second cell group, wherein the third transmission power for the second uplink communications between the UE and the second cell group is based at least in part on the asymmetric power reduction factor.

3. The apparatus of claim 1 , wherein, to perform one or both of the first uplink communications or the second uplink communications, the instructions are further executable by the processor to cause the apparatus to:

perform the second uplink communications with the second cell group when the difference between the second transmission power and the third transmission power is less than the threshold value.

4. The apparatus of claim 1 , wherein the third transmission power for the second uplink communications with the second cell group is based at least in part on the first transmission power for the first uplink communications with the first cell group.

5. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:

determine that a first frequency band of the first uplink communications with the first cell group at least partially overlaps with a second frequency band of the second uplink communications with the second cell group, wherein the third transmission power for the second uplink communications with the second cell group is based at least in part on the first frequency band overlapping with the second frequency band.

6. The apparatus of claim 1 , wherein, to determine the third transmission power, the instructions are executable by the processor to cause the apparatus to:

calculate the third transmission power for the second uplink communications with the second cell group based at least in part on a power sharing type of the UE and a capability of the UE to support intra-band Evolved Universal Terrestrial Access Network (E-UTRAN) New Radio (NR) Dual Connectivity (EN-DC) between the first RAT and the second RAT.

7. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:

determine whether to perform the second uplink communications with the second cell group based at least in part on a symbol alignment between the first uplink communications with the first cell group and the second uplink communications with the second cell group.

8. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:

receive a first grant for the first uplink communications with the first cell group and a second grant for the second uplink communications with the second cell group; and

perform dynamic power sharing between the first cell group and the second cell group when the first grant and the second grant are received within a time window.

9. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:

determine whether to perform the second uplink communications with the second cell group based at least in part on a hop boundary alignment between the first uplink communications with the first cell group and the second uplink communications with the second cell group.

10. The apparatus of claim 1 , wherein the first RAT comprises a Long Term Evolution (LTE) RAT and the second RAT comprises a New Radio (NR) RAT.

11. The apparatus of claim 1 , wherein the capability of the UE to perform dynamic power sharing between the first RAT and the second RAT is associated with an Evolved Universal Terrestrial Access Network (E-UTRAN) New Radio (NR) Dual Connectivity (EN-DC) mode of the UE.

12. A method for wireless communications at a user equipment (UE), comprising:

determining a first transmission power for first uplink communications between the UE and a first cell group associated with a first radio access technology (RAT);

determining a second transmission power for second uplink communications between the UE and a second cell group associated with a second RAT, wherein the first uplink communications overlap in time with the second uplink communications;

reduce the second transmission power of the second uplink communications to a third transmission power when a summation of the first transmission power and the second transmission power is greater than a power threshold, wherein reducing the second transmission power is based at least in part on the overlap in time and on a capability of the UE to perform dynamic power sharing between the first RAT and the second RAT, and wherein a summation of the first transmission power and the third transmission power is less than or equal to the power threshold; and

performing one or both of the first uplink communications or the second uplink communications based at least in part on reducing the second transmission power, wherein performing one or both of the first uplink communications or the second uplink communications comprises dropping the second uplink communications when a difference between the second transmission power and the third transmission power is greater than a threshold value.

13. The method of claim 12 , further comprising:

determining an asymmetric power reduction factor for the second uplink communications with the second cell group, wherein determining the third transmission power for the second uplink communications between the UE and the second cell group is based at least in part on the asymmetric power reduction factor.

14. The method of claim 12 , wherein performing one or both of the first uplink communications or the second uplink communications comprises:

performing the second uplink communications with the second cell group when the difference between the second transmission power and the third transmission power is less than the threshold value.

15. The method of claim 12 , wherein the third transmission power for the second uplink communications with the second cell group is based at least in part on the first transmission power for the first uplink communications with the first cell group.

16. The method of claim 12 , further comprising:

determining that a first frequency band of the first uplink communications with the first cell group at least partially overlaps with a second frequency band of the second uplink communications with the second cell group, wherein determining the third transmission power for the second uplink communications with the second cell group is based at least in part on the first frequency band overlapping with the second frequency band.

17. The method of claim 12 , wherein determining the third transmission power comprises:

calculating the third transmission power for the second uplink communications with the second cell group based at least in part on a power sharing type of the UE and a capability of the UE to support intra-band Evolved Universal Terrestrial Access Network (E-UTRAN) New Radio (NR) Dual Connectivity (EN-DC) between the first RAT and the second RAT.

18. The method of claim 12 , further comprising:

determining whether to perform the second uplink communications with the second cell group based at least in part on a symbol alignment between the first uplink communications with the first cell group and the second uplink communications with the second cell group.

19. The method of claim 12 , further comprising:

receiving a first grant for the first uplink communications with the first cell group and a second grant for the second uplink communications with the second cell group; and

performing dynamic power sharing between the first cell group and the second cell group when the first grant and the second grant are received within a time window.

20. The method of claim 12 , further comprising:

determining whether to perform the second uplink communications with the second cell group based at least in part on a hop boundary alignment between the first uplink communications with the first cell group and the second uplink communications with the second cell group.

21. The method of claim 12 , wherein the first RAT comprises a Long Term Evolution (LTE) RAT and the second RAT comprises a New Radio (NR) RAT.

22. The method of claim 12 , wherein the capability of the UE to perform dynamic power sharing between the first RAT and the second RAT is associated with an Evolved Universal Terrestrial Access Network (E-UTRAN) New Radio (NR) Dual Connectivity (EN-DC) mode of the UE.

23. An apparatus for wireless communications at a user equipment (UE), comprising:

means for determining a first transmission power for first uplink communications between the UE and a first cell group associated with a first radio access technology (RAT);

means for determining a second transmission power for second uplink communications between the UE and a second cell group associated with a second RAT, wherein the first uplink communications overlap in time with the second uplink communications;

means for reducing the second transmission power of the second uplink communications to a third transmission power when a summation of the first transmission power and the second transmission power is greater than a power threshold, wherein reducing the second transmission power is based at least in part on the overlap in time and on a capability of the UE to perform dynamic power sharing between the first RAT and the second RAT, and wherein a summation of the first transmission power and the third transmission power is less than or equal to the power threshold; and

means for performing one or both of the first uplink communications or the second uplink communications based at least in part on reducing the second transmission power, wherein performing one or both of the first uplink communications or the second uplink communications comprises dropping the second uplink communications when a difference between the second transmission power and the third transmission power is greater than a threshold value.

24. The apparatus of claim 23 , further comprising:

means for determining an asymmetric power reduction factor for the second uplink communications with the second cell group, wherein determining the third transmission power for the second uplink communications between the UE and the second cell group is based at least in part on the asymmetric power reduction factor.

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

determine a first transmission power for first uplink communications between the UE and a first cell group associated with a first radio access technology (RAT);

determine a second transmission power for second uplink communications between the UE and a second cell group associated with a second RAT, wherein the first uplink communications overlap in time with the second uplink communications;

reduce the second transmission power of the second uplink communications to a third transmission power when a summation of the first transmission power and the second transmission power is greater than a power threshold, wherein reducing the second transmission power is based at least in part on the overlap in time and on a capability of the UE to perform dynamic power sharing between the first RAT and the second RAT, and wherein a summation of the first transmission power and the third transmission power is less than or equal to the power threshold; and

perform one or both of the first uplink communications or the second uplink communications based at least in part on reducing the second transmission power, wherein performing one or both of the first uplink communications or the second uplink communications comprises dropping the second uplink communications when a difference between the second transmission power and the third transmission power is greater than a threshold value.