Method and Apparatus for Managing Transmit Power for Device-To-Device Communication

• US 20130178221A1
• Filed: 03/01/2013
• Published: 07/11/2013
• Est. Priority Date: 07/31/2006
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Inventors: Jung, Hyejung, Nangia, Vijay
• Granted Patent: US 8,839,362 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04L 2209/122 Hardware reduction or efficient architectures
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/04 for providing a confidential data exchange among entities communicating through data packet networks
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/166 at the transport layer
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys
• CPC Class Codes: H04L 9/3271 using challenge-response
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• 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 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/383 power control in peer-to-peer links

Abstract

A method and apparatus for managing transmit power for device-to-device communication is provided. According to an embodiment of the invention, a UE uses a component carrier of one cell to engage in D2D communication. In parallel with its D2D communication, the UE uses one or more other component carriers of one or more other cells to engage in cellular communication. The UE configures its D2D transmit power as well as its cellular transmit power so that its total transmit power does not exceed the UEs maximum power limit, and so that the transmit power on a component carrier of a cell does not exceed the maximum power limit for the cell that provides the component carrier.

Claims

1. A method, on a first USE, for managing transmit power in device-to-device communication and cellular communication, the method comprising:

determining a first configured maximum output power, wherein the first configured maximum output power is based on a configuration of a first cell;

determining a second configured maximum output power, wherein the second configured maximum output power is based on the configuration of the first cell and a configuration of a second cell;

determining whether a total transmit power would exceed the second configured maximum output power;

if it is determined that the total transmit power would exceed the second configured maximum output power, performing steps comprising;

determining a cellular transmit power based on one or more of a plurality of factors, the plurality comprising

the first configured maximum output power,

the second configured maximum output power,

the relative priority of service of device-to-device communication and cellular communication;

transmitting a cellular signal on a carrier of the first cell at the determined cellular transmit power;

determining a device-to-device transmit power based one or more of a plurality of factors, the plurality comprising

the first configured maximum output power,

the second configured maxim t output power,

the relative priority of service of device-to-device communication and cellular communication;

transmitting a device-to-device signal to a second UE on a carrier of the second cell at the determined device-to-device transmit power.

2. The method of claim 1, wherein

the plurality of factors for determining cellular transmit power further comprises a transmit power of a cellular uplink control channel,

the step of determining a cellular transmit power comprises determining a cellular uplink data channel transmit power based on one or more of the plurality of factors,

the step of transmitting the cellular signal comprises:

transmitting a cellular data signal on the carrier of the first cell at the determined cellular uplink data channel transmit power, and

transmitting a cellular control signal on the carrier of the first cell at the cellular uplink control channel transmit power.

3. The method of claim 1, wherein the plurality of factors on which the cellular transmit power level is based further comprises a guaranteed transmit power for device-to-device communication up to a predetermined threshold.

4. The method of claim 1, wherein

the plurality of factors on which the device-to-device transmit power is based further comprises a maximum power reduction to the configured maximum output power for D2D transmission, and

the plurality of factors on which the cellular transmit power is based further comprises the maximum power reduction to the configured maximum output power for D2D transmission.

5. The method of claim 1, wherein the relative priority comprises the priority of one or more of a cellular uplink control channel and a cellular uplink data channel that carries uplink control information.

6. The method of claim 1, wherein

w₂(i)·

{circumflex over (P)}_D2D(i)+w₃(i)·

{circumflex over (P)}_PUSCH,k(i)+w₄(i)·

{circumflex over (P)}_PUCCH(i)≦

{circumflex over (P)}_CMAX(i)

wherein

{circumflex over (P)}_D2D(i) is the linear value of power setting of device-to-device signal transmission from the first UE to the second UE without power scaling,

{circumflex over (P)}_PUSCH,k(i) is the linear value of power setting of cellular uplink data channel signal transmission from the first UE to a primary cell k without power scaling,

{circumflex over (P)}_PUCCH(i) is the linear value of power setting of cellular uplink control channel signal transmission from the first UE without power scaling,

{circumflex over (P)}_CMAX,k(i) is the linear value of the first configured maximum output power level,

{circumflex over (P)}_CMAX(i) is the linear value of the second configured maximum output power level,

{circumflex over (P)}_PUSCH,k(i)+{circumflex over (P)}_PUCCH(i)≦

{circumflex over (P)}_CMAX,k(i)

w₂(i), w₃(i) and w₄(i) are power scaling factors,

the determined device-to-device transmit power and the determined cellular transmit power are

{tilde over (P)}_D2D(i)=w₂(i)·

{circumflex over (P)}_D2D(i),

{tilde over (P)}_PUSCH,k(i)=w₃(i)·

{circumflex over (P)}_PUSCH,k(i),

{tilde over (P)}_PUCCH(i)=w₄(i)·

{circumflex over (P)}_PUCCH(i), and

0≦

w₂(i),w₃(i),w₄(i)≦

1.

7. The method of claim 6, wherein when device-to-device communication has a lower priority than cellular communication,

{tilde over (P)}_D2D(i)=min({circumflex over (P)}_D2D(i),{circumflex over (P)}_CMAX(i)−

{circumflex over (P)}_PUCCH(i)−

{circumflex over (P)}_PUSCH,k(i))

8. The method of claim 6, wherein when device-to-device communication has a higher priority than cellular communication, and the device-to-device communication is guaranteed to have up to a particular amount of power {circumflex over (P)}_D2D,Limit in linear value,

{tilde over (P)}_PUCCH(i)=min ({circumflex over (P)}_PUCCH(i),{circumflex over (P)}_CMAX(i)−

{circumflex over (P)}_D2D,Limit(i))

{tilde over (P)}_PUSCH,k(i)=min({circumflex over (P)}_PUSCH,k(i),({circumflex over (P)}_CMAX(i)−

{circumflex over (P)}_D2D,Limit(i)−

{tilde over (P)}_PUCCH(i)))

{tilde over (P)}_D2D(i)=min({circumflex over (P)}_D2D(i),{circumflex over (P)}_CMAX(i)−

{tilde over (P)}_PUCCH(i)−

{tilde over (P)}_PUSCH,k(i)),

9. The method of claim 6, wherein when the device-to-device communication has the second highest priority following the cellular uplink control channel,

{tilde over (P)}_D2D(i)=min({circumflex over (P)}_D2D(i),{circumflex over (P)}_CMAX(i)−

{circumflex over (P)}_PUCCH(i))

{tilde over (P)}_PUSCH,k(i)=min({circumflex over (P)}_PUSCH,k(i),{circumflex over (P)}_CMAX(i)−

{circumflex over (P)}_D2D(i)−

{circumflex over (P)}_PUCCH(i))

10. The method of claim 6, further comprising determining the device-to-device transmit power and the transmit power for the cellular uplink shared channel on the cell k based on an additional power scaling coefficient or factor α

, wherein;

11. A method for transmitting over a plurality of uplink carriers, the method comprising:

receiving an indication, from a network entity, to perform device-to-device communication on a first uplink carrier of the plurality of uplink carriers;

determining a total configured maximum output power, the total configured maximum output power being based on maximum power requirements for a plurality of configured serving cells associated with the plurality of uplink carriers;

transmitting a device-to-device signal on the first uplink carrier at a first transmit power level if the total transmit power of the UE would exceed the total configured maximum output power, or at a second transmit power level if the total transmit power of the UE would not exceed the total configured maximum output power;

transmitting a set of cellular signals on one or more uplink carriers of the plurality of uplink carriers other than the first uplink carrier at a first set of transmit power levels if the total transmit power of the UE would exceed the total configured maximum output power, or at a second set of transmit power levels if the total transmit power of the UE would not exceed the total configured maximum output power.

12. The method of claim 11, wherein the total configured maximum output power is a first total configured maximum output power the method further comprising:

determining a second total configured maximum output power, the second total configured maximum output power being based on the maximum power requirements for the plurality of configured serving cells except a cell associated with the first uplink carrier,

wherein the first set of transmit power levels of the set of cellular signals is based on one or more of the first and second total configured maximum output powers.

13. The method of claim 11, wherein the first set of transmit power levels of the set of cellular signals is determined based on whether there is a guaranteed transmit power for device-to-device communication up to a predetermined threshold.

14. The method of claim 12, wherein the first transmit power level of the device-to-device signal and the first set of transmit power levels of the set of cellular signals are determined based on a maximum power reduction of a configured maximum output power for the D2D transmission.

15. The method of claim 11, wherein the first transmit power level of the device-to-device signal and the first set of transmit power levels of the set of cellular signals are determined based on the priority of service of device-to-device communication relative to that of cellular communication.

16. The method of claim 15, wherein the relative priority comprises priority of a control uplink channel and a data uplink Channel carrying uplink control information in cellular communication.

17. The method of claim 12, wherein the first transmit power level of the device-to-device signal, {tilde over (P)}_D2D(i), and the first set of transmit power levels of the set of cellular signals, {tilde over (P)}_PUCCH(i), {tilde over (P)}_PUSCH,k(i), and {tilde over (P)}_PUSCH,c(i), for subframe i satisfy inequalities comprising:

18. The method of claim 17, wherein when the device-to-device communication has a lower priority than the cellular communication, the first transmit power level of the device-to-device signal, {tilde over (P)}_D2D(i) and the first set of transmit power levels of the set of cellular signals, {tilde over (P)}_PUCCH(i), {tilde over (P)}_PUSCH,k(i), and {tilde over (P)}_PUSCH,c(i) are determined according to,

19. The method of claim 17, wherein when the device-to-device communication has a higher priority than the cellular communication, and the device-to-device communication is guaranteed to have up to a particular amount of power {circumflex over (P)}_D2D,Limit, the first transmit power level of the device-to-device signal, {tilde over (P)}_D2D(i), and the first set of transmit power levels of the set of cellular signals, {tilde over (P)}_PUCCH(i), {circumflex over (P)}_PUSCH,k(i), and {circumflex over (P)}_PUSCH,c(i) are determined according to,

20. The method of claim 19, further comprising using any remaining power for the device-to-device communication, when w₁(i)=0, and determining the first transmit power level of the device-to-device signal, {tilde over (P)}_D2D(i) according to, allowing {tilde over (P)}_D2D(i) to be larger than {circumflex over (P)}_D2D,Limit as follows:

{tilde over (P)}<sub>CMAX,−

j</sub>(i)=min({circumflex over (P)}<sub>CMAX,−

j</sub>(i),({circumflex over (P)}_CMAX(i)−

{circumflex over (P)}_D2D,Limit(i)))

{tilde over (P)}_PUCCH(i)=min({circumflex over (P)}_PUCCH(i),{tilde over (P)}<sub>CMAX,−

j</sub>(i))

{tilde over (P)}_PUSCH,k(i)=min({circumflex over (P)}_PUSCH,k(i),({tilde over (P)}<sub>CMAX,−

j</sub>(i)−

{tilde over (P)}_PUCCH(i)))

{tilde over (P)}_D2D(i)=min({circumflex over (P)}_D2D(i),{circumflex over (P)}_CMAX(i)−

{tilde over (P)}_PUCCH(i)−

{tilde over (P)}_PUSCH,k(i)).

21. The method of claim 17, the first transmit power level of the device-to-device signal, {tilde over (P)}_D2D(i), and the first set of transmit power levels of the set of cellular signals, {tilde over (P)}_PUCCH(i), {tilde over (P)}_PUSCH,k(i), and {tilde over (P)}_PUSCH,c(i) are determined according to,

22. The method of claim 17, the first transmit power level of the device-to-device signal, and {tilde over (P)}_D2D(i), the first set of transmit power levels of the set of cellular signals, {tilde over (P)}_PUCCH(i), {tilde over (P)}_PUSCH,k(i), and {tilde over (P)}_PUSCH,c(i) are determined according to,

23. The method of claim 17, further comprising determining the device-to-device signal transmit power and the transmit power for the uplink data channel that does not include uplink control information based on an additional power scaling coefficient or factor a resulting in reduction of the second total configured maximum output power of cellular communication to allow additional power for device-to-device transmission, wherein:

24. A UE comprising:

a processor;

a memory electrically coupled to the processor, the memory having stored therein executable instructions;

a transceiver electrically coupled to the processor;

wherein the processor is configured to execute the instructions to perform steps comprising;

determining a first configured maximum output power, wherein the first configured maximum output power is based on a configuration of a first cell;

determining a second configured maximum output power, wherein the second configured maximum output power is based on the configuration of the first cell and a configuration of a second cell;

determining whether a total transmit power would exceed the second configured maximum output power;

if it is determined that the total transmit power would exceed the second configured maximum output power, performing steps comprising;

determining a cellular transmit power based on one or more of a plurality of factors, the plurality comprising

the first configured maximum output power,

the second configured maximum output power,

the relative priority of service of device-to-device communication and cellular communication;

transmitting a cellular signal on a carrier of the first cell at the determined cellular transmit power;

determining a device-to-device transmit power based on one or more of a plurality of factors, the plurality comprising

the first configured maximum output power,

the second configured maximum output power,

the relative priority of service of device-to-communication and cellular communication;

causing the transceiver to transmit a device-to-device signal to a second UE on a carrier of the second cell at the determined device-to-device transmit power.

25. A UE comprising:

a processor;

a memory electrically coupled to the processor, the memory having stored therein executable instructions;

a transceiver electrically coupled to the processor;

wherein the processor is configured to execute the instructions to perform steps comprising;

receiving an indication, from a network entity, to perform device-to-device communication on a first uplink carrier of the plurality of uplink carriers;

determining a total configured maximum output power, the total configured maximum output power being based on maximum power requirements for a plurality of configured serving cells associated with the plurality of uplink carriers;

causing the transceiver to transmit a device-to-device signal on the first uplink carrier at a first transmit power level if the total transmit power of the UE would exceed the total configured maximum output power, or at a second transmit power level if the total transmit power of the UE would not exceed the total configured maximum output power;

causing the transceiver to transmit a set of cellular signals on one or more uplink carriers of the plurality of uplink carriers other than the first uplink carrier at a first set of transmit power levels if the total transmit power of the UE would exceed the total configured maximum output power, or at a second set of transmit power levels if the total transmit power of the UE would not exceed the total configured maximum output power.