User Equipment and a Method for Power Control of Uplink Transmissions

• US 20150358915A1
• Filed: 07/15/2013
• Published: 12/10/2015
• Est. Priority Date: 01/10/2013
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Semaan, Eliane, DAHLMAN, Erik, HAMMARWALL, David, LI, Shaohua, RAHMAN, Imadur, SONG, Xinghua
• Granted Patent: US 9,872,256 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 52/146 Uplink power control
• 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 52/365 Power headroom reporting
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

A UE and a method performed by the UE for power control of uplink transmissions, when the UE is connected in dual connectivity mode to at least a first network node and a second network node are provided. The method comprises determining (210) to perform a first uplink transmission to the first network node and a second uplink transmission to the second network node, the uplink transmissions to be performed simultaneously. The method also comprises determining (220) a respective first and second uplink transmission power for the first and the second uplink transmission; and transmitting (240) the first and the second uplink transmissions at the first and the second uplink transmission power respectively when the sum of the first and second uplink transmission power is below a maximum transmission power.

Claims

1. A method performed by a User Equipment, UE, for power control of uplink transmissions, the UE being connected in dual connectivity mode to at least a first network node and a second network node, the method comprising:

determining to perform a first uplink transmission to the first network node and a second uplink transmission to the second network node, the uplink transmissions to be performed simultaneously,

determining a respective first and second uplink transmission power for the first and the second uplink transmission, and

transmitting the first and the second uplink transmissions at the first and the second uplink transmission power respectively when the sum of the first and second uplink transmission power is below a maximum transmission power.

2. A method according to claim 1, wherein if the sum of the first and the second uplink transmission power exceeds the maximum transmission power, the method comprising prioritising between the first and the second uplink transmission according to a predetermined rule.

3. A method according to claim 2, wherein the predetermined rule indicates to the UE to prioritise the first or the second uplink transmission based on a link quality between the UE and the first and the second network node respectively.

4. A method according to claim 2, wherein the first uplink transmission comprises control information and the second uplink transmission comprises data, wherein the predetermined rule indicates to the UE to prioritise the uplink transmission comprising control information by transmitting the first uplink transmission at the first uplink transmission power.

5. A method according to claim 4, further comprising transmitting the second uplink transmission at a transmission power of the maximum transmission power minus the first uplink transmission power.

6. A method according to claim 4, further comprising refraining from transmitting the second uplink transmission if the transmission power of the maximum transmission power minus the first uplink transmission power is below a first predefined threshold.

7. A method according to claim 2, wherein the predetermined rule indicates to the UE to scale at least the first second uplink transmission power based on a first scaling factor and then transmitting the first and the second uplink transmission at the scaled transmission power.

8. A method according to claim 7 wherein the predetermined rule indicates to the UE to scale the second uplink transmission power based on a second scaling factor and then transmitting the first uplink transmission at the scaled first uplink transmission power and transmitting the second uplink transmission at the scaled second uplink transmission power.

9. A method according to claim 7, further comprising receiving, from the first and the second network node, a respective first and second maximum tolerance value indicating a respective maximum difference between an expected transmission power and an actual transmission power.

10. A method according to claim 9, further comprising determining if the first and the second uplink transmission can be performed without exceeding the first or second maximum tolerance value and the maximum transmission power, and if not, transmitting the transmission having the highest priority at a transmission power indicated by the maximum tolerance value for that transmission.

11. A method according to claim 2, wherein the predetermined rule indicates to the UE to adapt modulation and/or coding of at least one of the first and the second uplink transmission due to reduced uplink transmission power, the method further comprising the UE signalling to the first and/or second network node the modulation and/or coding to be used and transmitting the first and/or the second uplink transmissions at the adapted modulation and/or coding.

12. A method according to claim 1, further comprising calculating a Power Headroom Reporting, PHR, based on whether simultaneous transmission of the first uplink transmission to the first network node and the second uplink transmission to the second network node is required or not.

13. A method according to claim 12, further comprising calculating a first PHR for the first uplink transmission to the first network node and a second PHR for the second uplink transmission to the second network node and reporting the first PHR to the first network node and the second PHR to the second network node.

14. A method according to claim 12, further comprising calculating one PHR for both the first uplink transmission and the second uplink transmission and reporting the one calculated PHR to both the first network node and the second network node.

29. A Computer program, comprising computer readable code means, which when run in a processor causes a User Equipment to perform the method according to claim 1.

15. A User Equipment, UE, adapted for power control of uplink transmissions, the UE being connected in dual connectivity mode to at least a first network node and a second network node, the UE comprising:

a determining unit adapted for determining to perform a first uplink transmission to the first network node and a second uplink transmission to the second network node, the uplink transmissions to be performed simultaneously, and for determining a respective first and second uplink transmission power for the first and the second uplink transmission, and

a transmitting unit adapted for transmitting the first and the second uplink transmissions at the first and the second uplink transmission power respectively when the sum of the first and second uplink transmission power is below a maximum transmission power.

16. A UE according to claim 15, further comprising a prioritisation unit, wherein if the sum of the first and the second uplink transmission power exceeds the maximum transmission power, the prioritising unit is adapted to prioritise between the first and the second uplink transmission according to a predetermined rule.

17. A UE according to claim 16, wherein the predetermined rule indicates to the UE to prioritise the first or the second uplink transmission based on a link quality between the UE and the first and the second network node respectively.

18. A UE according to claim 16, wherein the first uplink transmission comprises control information and the second uplink transmission comprises data, wherein the predetermined rule indicates to the UE to prioritise the uplink transmission comprising control information by transmitting the first uplink transmission at the first uplink transmission power.

19. A UE according to claim 18, wherein the transmitting unit further is adapted for transmitting the second uplink transmission at a transmission power of the maximum transmission power minus the first uplink transmission power.

20. A UE according to claim 18, wherein the transmitting unit further is adapted for refraining from transmitting the second uplink transmission if the transmission power of the maximum transmission power minus the first uplink transmission power is below a first predefined threshold.

21. A UE according to claim 16, wherein the predetermined rule indicates to the UE to scale at least the first uplink transmission power based on a first scaling factor and then transmitting the first and the second uplink transmission at the scaled transmission power.

22. A UE according to claim 21 wherein the predetermined rule indicates to the UE to scale the second uplink transmission power based on a second scaling factor, wherein the transmitting unit (303) is adapted for transmitting the first uplink transmission at the scaled first uplink transmission power and transmitting the second uplink transmission at the scaled second uplink transmission power.

23. A UE according to claim 21, further comprising a receiving unit adapted for receiving, from the first and the second network node, a respective first and second maximum tolerance value indicating a respective maximum difference between an expected transmission power and an actual transmission power.

24. A UE according to claim 23, wherein the determining unit further is adapted for determining if the first and the second uplink transmission can be performed without exceeding the first or second maximum tolerance value and the maximum transmission power, and if not, the transmitting unit is adapted for transmitting the transmission having the highest priority at a transmission power indicated by the maximum tolerance value for that transmission.

25. A UE according to claim 26, wherein the predetermined rule indicates to the UE to adapt modulation and/or coding of at least one of the first and the second uplink transmission due to reduced uplink transmission power, wherein the transmitting unit (303) further is adapted for signalling to the first and/or second network node the modulation and/or coding to be used and transmitting the first and/or the second uplink transmissions at the adapted modulation and/or coding.

26. A UE according to claim 15, further comprising a calculating unit adapted for calculating a Power Headroom Reporting, PHR, based on whether simultaneous transmission of the first uplink transmission to the first network node and the second uplink transmission to the second network node is required or not.

27. A UE according to claim 26, wherein the calculating unit (305) further is adapted for calculating a first PHR for the first uplink transmission to the first network node and a second PHR for the second uplink transmission to the second network node and the transmitting unit (303) is adapted for reporting the first PHR to the first network node and the second PHR to the second network node.

28. A UE according to claim 26, wherein the calculating unit further is adapted for calculating one PHR for both the first uplink transmission and the second uplink transmission and transmitting unit is adapted for reporting the one calculated PHR to both the first network node and the second network node.

30. (canceled)