Method and apparatus for power control for wireless transmissions on multiple component carriers associated with multiple timing advances
A method and apparatus for power control for wireless transmissions are disclosed. A wireless transmit/receive unit (WTRU) may determine a first transmit power for a first physical channel for a first serving cell in a first timing advanced group (TAG) and a second transmit power for a second physical channel for a second serving cell in a second TAG. The first TAG may be associated with a first timing advance value and the second TAG may be associated with a second timing advance value. The WTRU may determine a WTRU configured maximum output power (P C MAX ) for an overlapping portion, which may be a portion of a transmission of the first channel in a first slot that overlaps in time with a portion of a transmission of the second channel in a next slot. The WTRU may adjust at least one of the first physical channel and the second physical channel.
1. A method for power control by a wireless transmit/receive unit (WTRU), the method comprising:
determining a first transmit power for a first physical channel for a first serving cell in a first timing advance group (TAG) and a second transmit power for a second physical channel for a second serving cell in a second TAG, wherein the first TAG is associated with a first timing advance value and the second TAG is associated with a second timing advance value;
determining a WTRU configured maximum output power for an overlapping portion, wherein the overlapping portion is a portion of a transmission over the first physical channel in a first slot that overlaps in time with a portion of a transmission over the second physical channel in a next slot;
adjusting at least one of the first physical channel and the second physical channel, wherein a sum of transmit powers of the first physical channel and the second physical channel in the overlapping portion does not exceed the determined the WTRU configured maximum output power for the overlapping portion; and
transmitting data over at least one of the first physical channel and the second physical channel.
2. The method of claim 1 , wherein adjusting at least one of the first physical channel and the second physical channel includes adjusting at least one of the first transmit power and the second transmit power.
3. The method of claim 1 , wherein adjusting at least one of the first physical channel and the second physical channel includes dropping at least one of the first physical channel and the second physical channel.
4. The method of claim 1 , wherein adjusting at least one of the first physical channel and the second physical channel is performed on a condition that the sum of the transmit powers of the first physical channel and the second physical channel in the overlapping portion is to exceed the WTRU configured maximum output power for the overlapping portion.
5. The method of claim 1 , wherein at least one of the first physical channel and the second physical channel is a sounding reference signal (SRS).
6. The method of claim 1 , wherein the WTRU configured maximum output power is a P C MAX .
7. A wireless transmit/receive unit (WTRU) for power control, the WTRU comprising:
a processor; and
a transceiver operatively coupled to the processor; wherein:
the processor is configured to determine a first transmit power for a first physical channel for a first serving cell in a first timing advance group (TAG) and a second transmit power for a second physical channel for a second serving cell in a second TAG, wherein the first TAG is associated with a first timing advance value and the second TAG is associated with a second timing advance value;
the processor is configured to determine a WTRU configured maximum output power for an overlapping portion, wherein the overlapping portion is a portion of a transmission over the first physical channel in a first slot that overlaps in time with a portion of a transmission over the second physical channel in a next slot;
the processor and the transceiver are configured to adjust at least one of the first physical channel and the second physical channel, wherein a sum of transmit powers of the first physical channel and the second physical channel in the overlapping portion does not exceed the determined the WTRU configured maximum output power for the overlapping portion; and
the processor and the transceiver are configured to transmit data over at least one of the first physical channel and the second physical channel.
8. The WTRU of claim 7 , wherein to adjust at least one of the first physical channel and the second physical channel includes adjusting at least one of the first transmit power and the second transmit power.
9. The WTRU of claim 7 , wherein to adjust at least one of the first physical channel and the second physical channel includes dropping at least one of the first physical channel and the second physical channel.
10. The WTRU of claim 7 , wherein to adjust at least one of the first physical channel and the second physical channel is performed on a condition that the sum of the transmit powers of the first physical channel and the second physical channel in the overlapping portion is to exceed the WTRU configured maximum output power for the overlapping portion.
11. The WTRU of claim 7 , wherein at least one of the first physical channel and the second physical channel is a sounding reference signal (SRS).
12. The WTRU of claim 7 , wherein the WTRU configured maximum output power is a P C MAX .