Simultaneous transmission in multiple timing advance groups
Systems and methods for specifying UE power control allocation for simultaneous transmission of PRACH in a secondary serving cell and PUCCH/PUSCH/SRS in a different serving cell in another timing advance group are disclosed. Rules are provided for prioritizing transmission of PRACH and/or other UL channels/signals. Additionally, UE power allocation is controlled for misaligned subframes across different timing advance groups. Latency of UL synchronization for a secondary serving cell is reduced by prioritizing PRACH retransmission.
1. A method comprising:
performing by one or more processors in a user equipment device,
receiving a Physical Downlink Control Channel (PDCCH) order to initiate a random access procedure on a serving cell;
identifying a Physical Uplink Control Channel (PUCCH) transmission for a different serving cell other than the serving cell;
transmitting a Physical Random Access Channel (PRACH) transmission to the serving cell in a subframe;
transmitting the PUCCH transmission to the different serving cell in the subframe; and
scaling down the PUCCH transmission power level during a portion of the subframe having overlapping PRACH and PUCCH transmissions so that a combined transmission power level for the PRACH transmission and the PUCCH transmission during the overlapping portion does not exceed a maximum transmission power for the user equipment device.
2. The method of claim 1 , wherein:
said scaling down results in a PRACH transmission and no transmission of PUCCH.
3. A method comprising:
performing by one or more processors in a user equipment device:
receiving a Physical Downlink Control Channel (PDCCH) order to initiate a random access procedure on a first serving cell;
identifying a Physical Uplink Control Channel (PUCCH) transmission for a second serving cell other than the first serving cell;
transmitting a Physical Random Access Channel (PRACH) transmission to the first serving cell in a subframe;
transmitting the PUCCH transmission to the second serving cell in the subframe;
determining that the PRACH transmission will be retransmitted in a second subframe; and
increasing a power level of the PRACH transmission during the second subframe.
4. The method of claim 3 , further comprising:
identifying one or more other uplink transmissions during the second subframe.
5. A method comprising:
performing by one or more processors in a user equipment device:
receiving a Physical Downlink Control Channel (PDCCH) order to initiate a random access procedure on a first serving cell;
identifying a Physical Uplink Control Channel (PUCCH) or Sounding Reference Symbol (SRS) transmission for a second serving cell other than the first serving cell;
transmitting a Physical Random Access Channel (PRACH) transmission to the first serving cell in a subframe;
transmitting the PUCCH or SRS transmission to the second serving cell in the subframe;
determining that the PRACH transmission will be retransmitted in a second subframe;
identifying one or more other uplink transmissions during the second subframe; and
increasing a transmission priority value for the PRACH transmission during the second subframe.
6. The method of claim 5 , further comprising:
increasing a power level of the PRACH transmission during the second subframe.
7. A user equipment device, comprising:
a processor configured to:
identify a Physical Downlink Control Channel (PDCCH) order to initiate a random access procedure on a serving cell;
identify a Physical Uplink Control Channel (PUCCH) transmission for a different serving cell other than the serving cell;
generate a Physical Random Access Channel (PRACH) transmission for the first serving cell in a subframe;
generate the PUCCH transmission for the different serving cell in the subframe;
scale down a PUCCH transmission power level during a portion of the subframe having overlapping PRACH and PUCCH transmissions so that a combined transmission power level for the PRACH transmission and the PUCCH transmission during the overlapping portion does not exceed a maximum transmission power for the user equipment device; and
a modem configured to transmit the PUCCH transmission to one or more base stations.
8. The user equipment device of claim 7 , wherein:
the scaling down results in no transmission of PUCCH when a combined transmission of PRACH and PUCCH would exceed a maximum transmission power for the user equipment device.
9. A user equipment device, comprising:
a processor configured to:
identify a Physical Downlink Control Channel (PDCCH) order to initiate a random access procedure on a first serving cell;
identify a Physical Uplink Control Channel (PUCCH) transmission for a second serving cell other than the first serving cell;
generate a Physical Random Access Channel (PRACH) transmission for the first serving cell in a subframe;
generate the PUCCH transmission for the second serving cell in the subframe;
determine that the PRACH transmission will be retransmitted in a second subframe; and
increase a power level of the PRACH transmission during the second subframe; and
a modem configured to transmit the PUCCH or PRACH transmission to one or more base stations.
10. The user equipment device of claim 9 , the processor further configured to:
identify one or more other uplink transmissions during the second subframe.
11. A user equipment device, comprising:
a processor configured to:
identify a Physical Downlink Control Channel (PDCCH) order to initiate a random access procedure on a first serving cell;
identify a Physical Uplink Control Channel (PUCCH) or Sounding Reference Symbol (SRS) transmission for a second serving cell other than the first serving cell;
generate a Physical Random Access Channel (PRACH) transmission for the first serving cell in a subframe;
generate the PUCCH or SRS transmission for the second serving cell in the subframe;
determine that the PRACH transmission will be retransmitted in a second subframe;
identify one or more other uplink transmissions during the second subframe; and
increase a transmission priority value for the PRACH transmission during the second subframe; and
a modem configured to transmit the PUCCH or SRS transmission to one or more base stations.
12. The user equipment device of claim 11 , the processor further configured to:
increase a power level of the PRACH transmission during the second subframe.
13. A method comprising:
performing by one or more processors in a user equipment:
identifying a first transmission for a first serving cell during a subframe;
identifying a second transmission for a second serving cell during the subframe; and
scaling transmission power levels for only one of the first transmission or the second transmission only during such time that the first transmission and the second transmission overlap so that a combined transmission power level for the first transmission and the second transmission does not exceed a maximum transmission power for the user equipment, wherein the first transmission is a Physical Uplink Control Channel (PUCCH) transmission, and the second transmission is a Physical Random Access Channel (PRACH) transmission.
14. A method comprising:
performing by one or more processors in a user equipment:
identifying a first transmission for a first serving cell during a subframe, wherein a constant transmission power is assigned to all symbols in the first transmission;
identifying a second transmission for a second serving cell during the subframe, wherein a constant transmission power is assigned to all symbols in the second transmission;
identifying a transmission time difference between the first transmission and the second transmission within the subframe; and
scaling, responsive to the transmission time difference, transmission power levels for the first transmission or the second transmission or both prior to a start of the subframe so that a combined transmission power level for the first transmission and the second transmission does not exceed a maximum transmission power for the user equipment, wherein the first transmission is a Physical Uplink Control Channel (PUCCH) transmission, and the second transmission is a Physical Random Access Channel (PRACH) transmission.
15. A user equipment device, comprising:
a processor configured to:
identify a first transmission for a first serving cell during a subframe;
identify a second transmission for a second serving cell during the subframe; and
scale transmission power levels for only one of the first transmission or the second transmission and only during such time that the first transmission and the second transmission overlap so that a combined transmission power level for the first transmission and the second transmission does not exceed a maximum transmission power for the user equipment device; and
a modem configured to transmit the first and second transmissions to one or more base stations, wherein the first transmission is a Physical Uplink Control Channel (PUCCH) transmission, and the second transmission is a Physical Random Access Channel (PRACH) transmission.
16. A user equipment device, comprising:
a processor configured to:
identify a first transmission for a first serving cell during a subframe, wherein a constant transmission power is assigned to all symbols in the first transmission;
identify a second transmission for a second serving cell during the subframe, wherein a constant transmission power is assigned to all symbols in the second transmission;
identify a transmission time difference between the first transmission and the second transmission within the subframe; and
scale, responsive to the transmission time difference, transmission power levels for the first transmission or the second transmission or both prior to a start of the subframe so that a combined transmission power level for the first transmission and the second transmission does not exceed a maximum transmission power for the user equipment device; and
a modem configured to transmit the first and second transmissions to one or more base stations, wherein the first transmission is a Physical Uplink Control Channel (PUCCH) transmission, and the second transmission is a Physical Random Access Channel (PRACH) transmission.