Method and Arrangement for Uplink Power Control

• US 20130039286A1
• Filed: 01/27/2012
• Published: 02/14/2013
• Est. Priority Date: 08/09/2011
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Larsson, Daniel, Bachl, Rainer, Gerstenberger, Dirk, Tynderfeldt, Tobias
• Granted Patent: US 8,934,403 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/221 using past power control commands
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network

Abstract

The disclosure relates to methods and devices for performing uplink power control in a radio communication system. An example method comprises a step of receiving, at a user equipment (UE) a transmit power control (TPC) command. The method also comprises, if the UE does not have an uplink transmission scheduled for a subframe associated with the TPC command, a step of accumulating, by the UE, the TPC command with previously received TPC commands based on whether the UE has reached a maximum transmit power or a minimum transmit power in a reference format for a Physical Uplink Shared Channel (PUSCH), Sounding Reference Signal (SRS) or Physical Uplink Control Channel (PUCCH) transmission. Thus the UE is enabled to receive TPC commands while the UE is not transmitting anything in the uplink.

Claims

1. A method for performing uplink power control in a radio communication system, the method comprising:

receiving, at a user equipment, UE, a transmit power control, TPC command,

wherein if the UE does not have an uplink transmission scheduled for a subframe associated with said TPC command, accumulating, by the UE, said TPC command with previously received TPC commands based on whether the UE has reached a maximum transmit power or a minimum transmit power in a reference format for a Physical Uplink Shared Channel, PUSCH, Sounding Reference Signal, SRS, or Physical Uplink Control Channel, PUCCH, transmission.

2. The method according to claim 1, further comprising:

transmitting, by the UE, in the uplink at a power level which is based upon accumulated TPC commands.

3. The method according to claim 1, wherein, if the UE has reached said maximum transmit power in the reference format, said TPC command is not accumulated with previously received TPC commands when the TPC command is a positive TPC command.

4. The method according to claim 1, wherein, if the UE has reached said minimum transmit power in the reference format, said TPC command is not accumulated with previously received TPC commands when the TPC command is a negative TPC command.

5. The method according to claim 1, wherein said TPC command is received in a Downlink Control Information, DCI, format 3/3A message.

6. The method according to claim 1, wherein the reference format specifies fixed values for Maximum Power Reduction, MPR, Additional Maximum Power Reduction, A-MPR, and Power Management Maximum Power Reduction, P-MPR.

7. The method according to claim 6, wherein the reference format specifies MPR to 0 dB, A-MPR to 0 dB and P-MPR to 0 dB.

8. The method according to claim 1, wherein the reference format for a PUSCH transmission is based on fixed parameter value assumptions for M_PUSHc(i) and Δ

_TFc(i), wherein M_PUSHc(i) is the number of resource blocks assigned for a serving cell c and Δ

_TFc(i) is a transport format compensator for the serving cell c.

9. The method according to claim 1, wherein parameter values of said reference format are pre-configured in the UE.

10. The method according to claim 1, wherein parameter values of said reference format are received in the UE via signalling.

11. A user equipment, UE, configured for use in a radio communication system, the UE comprising:

a transceiver configured to receive a transmit power control, TPC command, and a processor,

wherein the processor is configured to, if the UE does not have an uplink transmission scheduled for a subframe associated with said TPC command, accumulate said TPC command with previously received TPC commands based on whether the UE has reached a maximum transmit power or a minimum transmit power in a reference format for a Physical Uplink Shared Channel, PUSCH, Sounding Reference Signal, SRS, or Physical Uplink Control Channel, PUCCH, transmission.

12. The UE according to claim 11, wherein the transceiver is further configured to transmit in an uplink at a power level which is based upon accumulated TPC commands.

13. The UE according to claim 11, wherein the processor is configured to, if the UE has reached said maximum transmit power in the reference format, not accumulate said TPC command with previously received TPC commands when the TPC command is a positive TPC command.

14. The UE according to claim 11, wherein, the processor is configured to, if the UE has reached said minimum transmit power in the reference format, not accumulate said TPC command with previously received TPC commands when the TPC command is a negative TPC command.

15. The UE according to claim 11, wherein the transceiver is configured to receive said TPC command in a Downlink Control Information, DCI, format 3/3A message.

16. The UE according to claim 11, wherein the reference format specifies fixed values for Maximum Power Reduction, MPR, Additional Maximum Power Reduction, A-MPR, and Power Management Maximum Power Reduction, P-MPR.

17. The UE according to claim 16, wherein the reference format specifies MPR to 0 dB, A-MPR to 0 dB and P-MPR to 0 dB.

18. The UE according to claim 11, wherein the reference format for a PUSCH transmission is based on fixed parameter value assumptions for M_PUSHc(i) and Δ

_TFc(i), wherein M_PUSHc(i) is the number of resource block assigned for a serving cell c and Δ

_TFc(i) is a transport format compensator for the serving cell c.

19. The UE according to claim 11, wherein the UE is pre-configured with parameter values of said reference format.

20. The UE according to claim 11, wherein the transceiver is configured to receive parameter values of said reference format via signalling.