Power control based on semi-static direction for dual connectivity
Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify a maximum transmission power for an uplink transmission on a first cell of a first cell group (CG) based on a direction of communications (e.g., uplink, downlink, or flexible) with a separate cell of a second CG during a same duration of the uplink transmission and within a same first frequency range, where the direction of communications is either an actual direction or an assumed direction. The UE may receive an uplink grant scheduling the uplink transmission during a symbol and within the first frequency range, determine the maximum transmission power for the UE based on the direction of communications for the separate cell during the symbol and within the first frequency range, and subsequently transmit the uplink transmission in accordance with the maximum transmission power.
1. A method for wireless communications at a user equipment (UE), comprising:
receiving an uplink grant scheduling an uplink transmission on a first cell group during a symbol and within a first frequency range;
determining a maximum transmission power for the uplink transmission based at least in part on a direction of communications with a second cell group during a duration of the symbol; and
transmitting the uplink transmission on the first cell group within the first frequency range in accordance with the maximum transmission power.
2. The method of claim 1 , wherein determining the maximum transmission power for the uplink transmission comprises:
determining to use a first maximum transmission power when an actual direction of communications with the second cell group within the first frequency range is downlink; and
determining to use a second maximum transmission power when the actual direction of communications with the second cell group within the first frequency range is uplink or flexible, wherein the second maximum transmission power is different from the first maximum transmission power.
3. The method of claim 2 , wherein the second maximum transmission power is less than the first maximum transmission power.
4. The method of claim 1 , wherein determining the maximum transmission power for the uplink transmission comprises:
assuming that the direction of communications with the second cell group within the first frequency range is either uplink or flexible; and
determining to use, as the maximum transmission power, a lesser of two selectable maximum transmission power values, based at least in part on the assumption.
5. The method of claim 1 , further comprising:
determining whether to use an actual direction or an assumed direction of communications with the second cell group within the first frequency range in determining the maximum transmission power for the uplink transmission.
6. 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:
receive an uplink grant scheduling an uplink transmission on a first cell group during a symbol and within a first frequency range;
determine a maximum transmission power for the uplink transmission based at least in part on a direction of communications with a second cell group during a duration of the symbol; and
transmit the uplink transmission on the first cell group within the first frequency range in accordance with the maximum transmission power.
7. The apparatus of claim 6 , wherein the instructions to determine the maximum transmission power for the uplink transmission are executable by the processor to cause the apparatus to:
determine to use a first maximum transmission power when an actual direction of communications with the second cell group within the first frequency range is downlink; and
determine to use a second maximum transmission power when the actual direction of communications with the second cell group within the first frequency range is uplink or flexible, wherein the second maximum transmission power is different from the first maximum transmission power.
8. The apparatus of claim 7 , wherein the second maximum transmission power is less than the first maximum transmission power.
9. The apparatus of claim 6 , wherein the instructions to determine the maximum transmission power for the uplink transmission are executable by the processor to cause the apparatus to:
assume that the direction of communications with the second cell group within the first frequency range is either uplink or flexible; and
determine to use, as the maximum transmission power, a lesser of two selectable maximum transmission power values, based at least in part on the assumption.
10. The apparatus of claim 6 , wherein the instructions are further executable by the processor to cause the apparatus to:
determine whether to use an actual direction or an assumed direction of communications with the second cell group within the first frequency range in determining the maximum transmission power for the uplink transmission.
11. The apparatus of claim 6 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive an additional uplink grant scheduling an additional uplink transmission; and
determine an additional transmission power for the additional uplink transmission based at least in part on a direction of communications with a third entity not within the first frequency range.
12. The apparatus of claim 11 , wherein the maximum transmission power and the additional transmission power are each determined based at least in part on the direction of communications within respective frequency ranges.
13. The apparatus of claim 11 , wherein the uplink grant and the additional uplink grant are received jointly on the first cell group and with a carrier indication field to indicate which component carrier each of the uplink grant and the additional uplink grant pertain, and wherein the maximum transmission power and the additional transmission power are each determined based at least in part on the direction of communications within respective frequency ranges.
14. The apparatus of claim 6 , wherein the instructions are further executable by the processor to cause the apparatus to:
identify that cross-carrier scheduling across different frequency ranges is configured, such that the uplink grant is received on a component carrier within a second frequency range, while the uplink transmission is scheduled within the first frequency range; and
determine to use, as the maximum transmission power, a lesser of two selectable maximum transmission power values, based at least in part on cross-carrier scheduling across different frequency ranges being configured.
15. The apparatus of claim 14 , wherein the determination to use the lesser of the two selectable maximum transmission power values is based on an assumed direction of communications with the second cell group within the first frequency range.
16. The apparatus of claim 14 , wherein the instructions to determine to use, as the maximum transmission power, the lesser of the two selectable maximum transmission power values further are executable by the processor to cause the apparatus to:
identify that the uplink grant is received via a downlink control information message; and
determine to use the lesser of the two selectable maximum transmission power values as the maximum transmission power based on both the uplink grant being received via the downlink control information message and on cross-carrier scheduling across different frequency ranges being configured.
17. The apparatus of claim 14 , wherein the instructions to determine to use, as the maximum transmission power, the lesser of the two selectable maximum transmission power values further are executable by the processor to cause the apparatus to:
identify that the uplink grant is received via a downlink control information message of format 0_1 with a carrier indication field; and
determine to use the lesser of the two selectable maximum transmission power values as the maximum transmission power based on both the uplink grant being received via the downlink control information message having format 0_1 and the carrier indication field and on cross-carrier scheduling across different frequency ranges being configured.
18. The apparatus of claim 6 , wherein the instructions are further executable by the processor to cause the apparatus to:
determine an actual direction based at least in part on a semi-static time domain duplexing configuration, a synchronization signal/physical broadcast channel block measurement time configuration window, a downlink channel monitoring occasion configuration, a downlink semi-persistent scheduling configuration, medium access control information, or a combination thereof.
19. The apparatus of claim 6 , wherein the direction comprises an uplink, downlink, or flexible transmission direction.
20. An apparatus for wireless communications at a user equipment (UE), comprising:
means for receiving an uplink grant scheduling an uplink transmission on a first cell group during a symbol and within a first frequency range;
means for determining a maximum transmission power for the uplink transmission based at least in part on a direction of communications with a second cell group during a duration of the symbol; and
means for transmitting the uplink transmission on the first cell group within the first frequency range in accordance with the maximum transmission power.