Design of uplink power control and time-division multiplexing patterns for dual active protocol stack based handover

Abstract

Aspects of the disclosure further provide various apparatuses and methods for wireless communications. One apparatus includes processing circuitry that when a first uplink transmission on a source cell and a second uplink transmission on a target cell overlap in a frequency domain, determines whether the first uplink transmission on the source cell and the second uplink transmission on the target cell are in overlapping time resources. When the first uplink transmission on the source cell and the second uplink transmission on the target cell are in the overlapping time resources, the processing circuitry cancels the first uplink transmission on the source cell and performs the second uplink transmission on the target cell.

What is claimed is: 
     
         1 . A method of wireless communication at a user equipment (UE) that connects to both a source cell and a target cell, the method comprising:
 when a first uplink transmission on the source cell and a second uplink transmission on the target cell overlap in a frequency domain,
 determining whether the first uplink transmission on the source cell and the second uplink transmission on the target cell are in overlapping time resources; 
 when the first uplink transmission on the source cell and the second uplink transmission on the target cell are in the overlapping time resources,
 cancelling the first uplink transmission on the source cell; and 
 performing the second uplink transmission on the target cell. 
 
   
     
     
         2 . The method of  claim 1 , further comprising:
 determining a first transmission power for the first uplink transmission on the source cell and a second transmission power for the second uplink transmission on the target cell;   when the first uplink transmission and the second uplink transmission are in the overlapping time resources and a total power of the first transmission power and the second transmission power is above a first threshold,
 reducing the first transmission power for the first uplink transmission to a third transmission power so that a total power of the second transmission power and the third transmission power is equal to or less than the first threshold; and 
 performing the first uplink transmission at the third transmission power and the second uplink transmission at the second transmission power. 
   
     
     
         3 . The method of  claim 2 , wherein the performing the first uplink transmission at the third transmission power and the second uplink transmission at the second transmission power further comprises:
 performing the first uplink transmission at the third transmission power and the second uplink transmission at the second transmission power when a difference between the second transmission power and the third transmission power is not above a second threshold; and   dropping the first uplink transmission on the source cell when the difference between the second transmission power and the third transmission power is above the second threshold.   
     
     
         4 . The method of  claim 2 , further comprising:
 performing the first uplink transmission at the first transmission power and the second uplink transmission at the second transmission power through non-overlapping time resources.   
     
     
         5 . The method of  claim 1 , wherein the source cell is in a source master cell group (MCG) and the target cell is in a target MCG. 
     
     
         6 . The method of  claim 1 , wherein the UE supports dual active protocol stack (DAPS) based handover (HO). 
     
     
         7 . The method of  claim 1 , further comprising:
 dropping the first uplink transmission on the source cell when the UE indicates that simultaneous uplink transmission to the source cell and the target cell is not supported.   
     
     
         8 . An apparatus that wireless connects to both a source cell and a target cell, the apparatus comprising:
 processing circuitry configured to:   when a first uplink transmission on the source cell and a second uplink transmission on the target cell overlap in a frequency domain,
 determine whether the first uplink transmission on the source cell and the second uplink transmission on the target cell are in overlapping time resources; 
 when the first uplink transmission on the source cell and the second uplink transmission on the target cell are in the overlapping time resources,
 cancel the first uplink transmission on the source cell; and 
 perform the second uplink transmission on the target cell. 
 
   
     
     
         9 . The apparatus of  claim 8 , wherein the processing circuitry is further configured to:
 determine a first transmission power for the first uplink transmission on the source cell and a second transmission power for the second uplink transmission on the target cell;   when the first uplink transmission and the second uplink transmission are in the overlapping time resources and a total power of the first transmission power and the second transmission power is above a first threshold,
 reduce the first transmission power for the first uplink transmission to a third transmission power so that a total power of the second transmission power and the third transmission power is equal to or less than the first threshold; 
 perform the first uplink transmission at the third transmission power and the second uplink transmission at the second transmission power. 
   
     
     
         10 . The apparatus of  claim 9 , wherein the processing circuitry is further configured to:
 perform the first uplink transmission at the third transmission power and the second uplink transmission at the second transmission power when a difference between the second transmission power and the third transmission power is not above a second threshold; and   drop the first uplink transmission on the source cell when the difference between the second transmission power and the third transmission power is above the second threshold.   
     
     
         11 . The apparatus of  claim 9 , wherein the processing circuitry is further configured to:
 perform the first uplink transmission at the first transmission power and the second uplink transmission at the second uplink transmission power through non-overlapping time resources.   
     
     
         12 . The apparatus of  claim 8 , wherein the source cell is in a source master cell group (MCG) and the target cell is in a target MCG. 
     
     
         13 . The apparatus of  claim 8 , wherein the processing circuitry is further configured to:
 perform dual active protocol stack (DAPS) based handover (HO).   
     
     
         14 . The apparatus of  claim 8 , wherein the processing circuitry is further configured to:
 drop the first uplink transmission on the source cell when simultaneous uplink transmission to the source cell and the target cell is not supported by the apparatus.   
     
     
         15 . A non-transitory computer-readable storage medium storing a program executable by at least one processor to perform:
 when a first uplink transmission on a source cell and a second uplink transmission on a target cell overlap in a frequency domain,
 determining whether the first uplink transmission on the source cell and the second uplink transmission on the target cell are in overlapping time resources; 
 when the first uplink transmission on the source cell and the second uplink transmission on the target cell are in the overlapping time resources,
 cancelling the first uplink transmission on the source cell; and 
 performing the second uplink transmission on the target cell. 
 
   
     
     
         16 . The non-transitory computer-readable storage medium of  claim 15 , wherein the stored program executable by the at least one processor is further to perform:
 determining a first transmission power for the first uplink transmission on the source cell and a second transmission power for the second uplink transmission on the target cell;   when the first uplink transmission and the second uplink transmission are in the overlapping time resources and a total power of the first transmission power and the second transmission power is above a first threshold,
 reducing the first transmission power for the first uplink transmission to a third transmission power so that a total power of the second transmission power and the third transmission power is equal to or less than the first threshold; 
 performing the first uplink transmission at the third transmission power and the second uplink transmission at the second transmission power. 
   
     
     
         17 . The non-transitory computer-readable storage medium of  claim 16 , wherein the stored program executable by the at least one processor is further to perform:
 performing the first uplink transmission at the third transmission power and the second uplink transmission at the second transmission power when a difference between the second transmission power and the third transmission power is not above a second threshold; and   dropping the first uplink transmission on the source cell when the difference between the second transmission power and the third transmission power is above the second threshold.   
     
     
         18 . The non-transitory computer-readable storage medium of  claim 16 , wherein the stored program executable by the at least one processor is further to perform:
 executing the first uplink transmission at the first transmission power and the second uplink transmission at the second uplink transmission power through non-overlapping time resources.   
     
     
         19 . The non-transitory computer-readable storage medium of  claim 15 , wherein the source cell is in a source master cell group (MCG) and the target cell is in a target MCG. 
     
     
         20 . The non-transitory computer-readable storage medium of  claim 15 , wherein the stored program executable by the at least one processor is further to perform:
 executing dual active protocol stack (DAPS) based handover (HO).