Simultaneous Transmission in Multiple Timing Advance Groups

• US 20130195048A1
• Filed: 01/29/2013
• Published: 08/01/2013
• Est. Priority Date: 01/30/2012
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Ekpenyong, Anthony Edet, Bendlin, Ralf Matthias, Bertrand, Pierre
• Granted Patent: US 10,206,181 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 52/281 taking into account user or data type priority
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

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.

Claims

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 first serving cell;

identifying a Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), or Sounding Reference Symbol (SRS) transmission for a second serving cell other than the first serving cell;

transmitting a PRACH transmission to the first serving cell in a subframe; and

transmitting the PUCCH, PUSCH, or SRS transmission to the second serving cell in the same subframe.

2. The method of claim 1, further comprising:

scaling a transmission power level during the subframe so that a combined transmission power level for the PRACH transmission and the PUCCH, PUSCH, or SRS transmission does not exceed a maximum transmission power for the user equipment.

3. The method of claim 1, further comprising:

scaling down a PUCCH, PUSCH, or SRS transmission power level during the subframe so that a combined transmission power level for the PRACH transmission and the PUCCH, PUSCH, or SRS transmission does not exceed a maximum transmission power for the user equipment.

4. The method of claim 3, wherein:

said scaling down results in a PRACH transmission and no transmission of PUSCH, PUSCH, or SRS.

5. The method of claim 1, further comprising:

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.

6. The method of claim 1, further comprising:

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.

7. The method of claim 1, further comprising:

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 power level of the PRACH transmission during the second subframe.

8. The method of claim 1, further comprising:

determining that the PRACH transmission will be retransmitted in a second subframe;

identifying one or more other uplink transmissions during the second subframe;

increasing a transmission priority value for the PRACH transmission during the second subframe; and

increasing a power level of the PRACH transmission during the second subframe.

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), Physical Uplink Shared Channel (PUSCH), or Sounding Reference Symbol (SRS) transmission for a second serving cell other than the first serving cell;

generate a PRACH transmission for the first serving cell in a subframe; and

generate the PUCCH, PUSCH, or SRS transmission for the second serving cell in the same subframe; and

a modem configured to transmit the PUCCH, PUSCH, or SRS transmission to one or more base stations.

10. The user equipment device of claim 9, the processor further configured to:

scale a transmission power level during the subframe so that a combined transmission power level for the PRACH transmission and the PUCCH or PUSCH or SRS transmission does not exceed a maximum transmission power for the user equipment.

11. The user equipment device of claim 9, the processor further configured to:

scale down a PUCCH, PUSCH, or SRS transmission power level during the subframe so that a combined transmission power level for the PRACH transmission and the PUCCH, PUSCH, or SRS transmission does not exceed a maximum transmission power for the user equipment.

12. The user equipment device of claim 11, wherein:

the scaling down results in no transmission of PUSCH, PUSCH, or SRS when a combined transmission of PRACH and PUCCH, PUSCH, or SRS would exceed a maximum transmission power for the user equipment.

13. The user equipment device of claim 9, the processor further configured to:

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.

14. The user equipment device of claim 9, the processor further configured to:

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.

15. The user equipment device of claim 9, the processor further configured to:

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 power level of the PRACH transmission during the second subframe.

16. The user equipment device of claim 9, the processor further configured to:

determine that the PRACH transmission will be retransmitted in a second subframe;

identify one or more other uplink transmissions during the second subframe;

increase a transmission priority value for the PRACH transmission during the second subframe; and

increase a power level of the PRACH transmission during the second subframe.

17. A method comprising:

performing by one or more processors in 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;

identifying a transmission time difference between the first transmission and the second transmission within the subframe; and

scaling 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.

18. The method of claim 17, wherein a constant transmission power is assigned to all symbols in the first and second transmissions.

19. The method of claim 17, wherein the first and second transmissions are selected from one or more of:

a Physical Uplink Control Channel (PUCCH) transmission;

a Physical Uplink Shared Channel (PUSCH) transmission;

a Physical Random Access Channel (PRACH) transmission; and

a Sounding Reference Symbol (SRS) transmission.

20. 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;

identify a transmission time difference between the first transmission and the second transmission within the subframe; and

scale 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; and

a modem configured to transmit the first and second transmissions to one or more base stations.

21. The user equipment device of claim 20, wherein a constant transmission power is assigned to all symbols in the first and second transmissions.

22. The user equipment device of claim 20, wherein the first and second transmissions are selected from one or more of:

a Physical Uplink Control Channel (PUCCH) transmission;

a Physical Uplink Shared Channel (PUSCH) transmission;

a Physical Random Access Channel (PRACH) transmission; and

a Sounding Reference Symbol (SRS) transmission.