Method and apparatus for PUSCH/PUCCH power scaling considering dual connectivity in power limited state

1. A system comprising:

a Master evolved NodeB (MeNB) to establish a Radio Resource Control (RRC) connection with a User Equipment (UE), the MeNB being associated with a Master Cell Group (MCG) including one or more serving cells configurable for the UE; and

a Secondary eNB (SeNB) to establish a connection with the UE, the SeNB being associated with a Secondary Cell Group (SCG) including one or more serving cells configurable for the UE,

wherein:

the MeNB is configured to determine an uplink channel to be received from the UE through a serving cell of the MCG in subframe i, and the SeNB is configured to determine an uplink channel to be received from the UE through a serving cell of the SCG in the subframe i;

the MeNB is configured to determine an output power threshold in the subframe i; which is associated with a transmit power reduction for at least one of:

the uplink channel determined to be received through the serving cell of the MCG in the subframe i; and

the uplink channel determined to be received through the serving cell of the SCG in the subframe i;

the MeNB is configured to receive the uplink channel from the UE through the serving cell of the MCG in subframe i; and

the SeNB is configured to receive the uplink channel from the UE through the serving cell of the SCG in subframe i.

2. The system of claim 1 , wherein a priority between the uplink channel determined to be received through the serving cell of the MCG and the uplink channel determined to be received through the serving cell of the SCG is based on Uplink Control Information (UCI) included in at least one of the uplink channels and based on a type of a cell group, and

wherein the transmit power reduction is applied for a lower-prioritized uplink channel from among the uplink channels.

3. The system of claim 1 , further comprising:

when total transmit power for uplink transmissions from the UE in the subframe i exceeds the output power threshold in the subframe i, the system is configured to receive at least one uplink channel from the UE in the subframe i with reduced transmit power.

4. The system of claim 3 , wherein the output power threshold in the subframe i corresponds to {circumflex over (P)} CMAX (i), a linear value of a total configured maximum output power P CMAX configured for the UE in the subframe i.

5. The system of claim 2 , wherein an uplink channel transmitted through the MCG has a higher priority than an uplink channel transmitted through the SCG if the lower-prioritized uplink channel is not determined based on the UCI.

6. The system of claim 1 , wherein the uplink channels each comprise at least one of a Physical Uplink Control Channel (PUCCH) and a Physical Uplink Shared Channel (PUSCH).

7. The system of claim 2 , wherein an uplink channel including a Scheduling Request (SR) or a Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) has a higher priority than an uplink channel including Channel State Information (CSI).

8. A method comprising:

establishing, by a Master evolved NodeB (MeNB), a Radio Resource Control (RRC) connection with a User Equipment (UE), the MeNB being associated with a Master Cell Group (MCG) including one or more serving cells configurable for the UE;

establishing, by a Secondary eNB (SeNB), a connection with the UE, the SeNB being associated with a Secondary Cell Group (SCG) including one or more serving cells configurable for the UE;

determining an uplink channel to be received from the UE through a serving cell of the MCG in subframe i, and determining an uplink channel to be received from the UE through a serving cell of the SCG in the subframe i;

determining an output power threshold in the subframe i, which is associated with a transmit power reduction for at least one of:

the uplink channel determined to be received through the serving cell of the MCG in the subframe i; and

the uplink channel determined to be received through the serving cell of the SCG in the subframe i; and

receiving the uplink channel from the UE through the serving cell of the MCG in subframe i, and receiving the uplink channel from the UE through the serving cell of the SCG in subframe i.

9. The method of claim 8 , wherein a priority between the uplink channel determined to be received through the serving cell of the MCG and the uplink channel determined to be received through the serving cell of the SCG is based on Uplink Control Information (UCI) included in at least one of the uplink channels and based on a type of a cell group, and

wherein the transmit power reduction is applied for a lower-prioritized uplink channel from among the uplink channels.

10. The method of claim 8 , further comprising:

when total transmit power for uplink transmissions from the UE in the subframe i exceeds the output power threshold in the subframe i, receiving at least one uplink channel from the UE in the subframe i with reduced transmit power.

11. The method of claim 9 , wherein an uplink channel transmitted through the MCG has a higher priority than an uplink channel transmitted through the SCG if the lower-prioritized uplink channel is not determined based on the UCI.

12. The method of claim 9 , wherein an uplink channel including a Scheduling Request (SR) or a Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) has a higher priority than an uplink channel including Channel State Information (CSI).

13. A User Equipment (UE) comprising:

a transceiver to establish a Radio Resource Control (RRC) connection with a Master evolved NodeB (MeNB), and to establish a connection with a Secondary eNB (SeNB), the MeNB being associated with a Master Cell Group (MCG) including one or more serving cells configurable for the UE, and the SeNB being associated with a Secondary Cell Group (SCG) including one or more serving cells configurable for the UE; and

a processor configured to determine to transmit a first uplink channel through a serving cell of the MCG in subframe i and to determine to transmit a second uplink channel through a serving cell of the SCG in the subframe i,

wherein the processor determines whether to control a transmit power reduction for at least one of:

the first uplink channel determined to be transmitted through the serving cell of the MCG in the subframe i; and

the second uplink channel determined to be transmitted through the serving cell of the SCG in the subframe i,

wherein the processor controls the transmit power reduction for a lower-prioritized uplink channel from among the first and second uplink channels, and

wherein the transceiver, after the control of the transmit power reduction, transmits the first uplink channel through the serving cell of the MCG in the subframe i and the second uplink channel through the serving cell of the SCG in the subframe i.

14. The UE of claim 13 , wherein the processor determines, based on a type of a cell group and based on Uplink Control Information (UCI) included in at least one of the first and second uplink channels, a priority between the first uplink channel and the second uplink channel.

15. The UE of claim 14 , wherein the priority is determined primarily based on the UCI and determined secondarily based on the type of a cell group, the type of a cell group comprising the MCG and the SCG, and

wherein an uplink channel transmitted through the MCG has a higher priority than an uplink channel transmitted through the SCG if the lower-prioritized uplink channel is not determined based on the UCI.

16. The UE of claim 14 , wherein:

the processor determines that an uplink channel including a Scheduling Request (SR) or a Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) has a higher priority than an uplink channel including Channel State Information (CSI).

17. A method comprising:

establishing a Radio Resource Control (RRC) connection with a Master evolved NodeB (MeNB), the MeNB being associated with a Master Cell Group (MCG) including one or more serving cells configurable for a User Equipment (UE);

establishing a connection with a Secondary eNB (SeNB), the SeNB being associated with a Secondary Cell Group (SCG) including one or more serving cells configurable for the UE;

determining to transmit a first uplink channel through a serving cell of the MCG in subframe i and determining to transmit a second uplink channel through a serving cell of the SCG in the subframe i;

determining whether to control a transmit power reduction for at least one of:

the first uplink channel determined to be transmitted through the serving cell of the MCG in the subframe i; and

the second uplink channel determined to be transmitted through the serving cell of the SCG in the subframe i;

controlling the transmit power reduction for a lower-prioritized uplink channel from among the first and second uplink channels; and

transmitting, from the UE and after the control of the transmit power reduction, the first uplink channel through the serving cell of the MCG in the subframe i and the second uplink channel through the serving cell of the SCG in the subframe i.

18. The method of claim 17 , further comprising determining, based on a type of a cell group and based on Uplink Control Information (UCI) included in at least one of the first and second uplink channels, a priority between the first uplink channel and the second uplink channel.

19. The method of claim 18 , wherein the priority is determined primarily based on the UCI and determined secondarily based on the type of a cell group, the type of a cell group comprising the MCG and the SCG, and

wherein an uplink channel transmitted through the MCG has a higher priority than an uplink channel transmitted through the SCG if the lower-prioritized uplink channel is not determined based on the UCI.

20. The method of claim 18 , further comprising:

determining that an uplink channel including a Scheduling Request (SR) or a Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) has a higher priority than an uplink channel including Channel State Information (CSI).