Uplink power sharing in dual connectivity

Abstract

Systems and methods enabling uplink power sharing for dual connectivity are disclosed. Embodiments are described herein in which a maximum Uplink (UL) power on each link is configured statically, semi-statically, or dynamically. In general, regardless of the embodiment, uplink power for uplink transmissions from a wireless device on two simultaneous links is controlled such that the total uplink power does not exceeds a maximum UL transmission power level while, in some embodiments, taking into account priorities of the two links and/or priorities of various uplink channels transmitted by the wireless device on the two links. Notably, while the embodiments described herein focus on dual connectivity, the embodiments described herein can easily be extended to any number of two or more simultaneous links.

Claims

1. A method of operating a wireless device having a first link to a first wireless network node in a wireless communications network and a second link to a second wireless network node in the wireless communications network, the method comprising: receiving, via Radio Resource Control (RRC) signaling, a configured maximum transmit power level for the first link; determining a maximum transmit power level for the second link from the wireless device to the second wireless network node, where the maximum transmit power level for the second link is a function of a maximum allowable transmit power level and a transmission power of at least one of subframe (i1) and subframe i of the first link, the transmission power of the at least one of subframe (i1) and subframe i of the first link being limited by the configured maximum transmit power level for the first link; and transmitting on the second link in subframe j according to the maximum transmit power level for the second link; wherein the first link and the second link are simultaneous dual-connectivity links, each link being configured to support a plurality of aggregated carriers and a plurality of uplink channel types including a control channel and/or a random access channel, and wherein subframe (i1) and subframe i of the first link overlap with subframe j of the second link.

2. The method of claim 1 wherein a sum of a maximum transmit power level for the first link from the wireless device to the first wireless network node and the maximum transmit power level for the second link is less than or equal to the maximum allowable transmit power level.

3. The method of claim 1 wherein the maximum allowable transmit power level varies from one subframe to another subframe.

4. The method of claim 1 wherein the first and second links have asynchronous overlapping transmissions, further comprising: determining whether a total transmit power across a subframe of the first link and an overlapping subframe of the second link exceeds the maximum allowable transmit power level for the subframe of the first link; and if the total transmit power across the subframe of the first link and the overlapping subframe of the second link exceeds the maximum allowable transmit power level for the subframe of the first link, scaling a transmit power level for an uplink channel or signal in the subframe of the first link such that, after scaling, the total transmit power across the subframe of the first link and the overlapping subframe of the second link does not exceed the maximum allowable transmit power level for the subframe of the first link.

5. The method of claim 1 wherein the maximum transmit power level for the second link is the function of the maximum allowable transmit power level and the transmission power of subframe (i1) of the first link.

6. The method of claim 5 further comprising: determining a maximum transmit power level for subframe i of the first link from the wireless device to the first wireless network node as the function of the maximum allowable transmit power level and the transmission power of subframe j of the second link; and transmitting on the first link in subframe i according to the maximum transmit power level for subframe i.

7. The method of claim 1 wherein the maximum transmit power level for the second link is the function of the maximum allowable transmit power level and the transmission power of subframe i of the first link.

8. The method of claim 1 wherein the maximum transmit power level for the second link is the function of the maximum allowable transmit power level, the transmission power of subframe (i1) of the first link, and the transmission power of subframe i of the first link.

9. The method of claim 1, further comprising: determining a type of uplink channel to be transmitted in a first cell of the second link using subframe (j) and a type of uplink channel to be transmitted in a second cell of the second link using subframe (j); and assigning transmission priorities to the uplink channels to be transmitted over the second link based on the determined uplink channel types.

10. The method of claim 9, further comprising: determining a type of uplink channel to be transmitted in a first cell of the first link using subframes (i) and (i1) and a type of uplink channel to be transmitted in a second cell of the first link using subframes (i) and (i1); and assigning transmission priorities to the uplink channels to be transmitted over the first link based on the determined uplink channel types.

11. A method of operating a wireless device having a first link to a first wireless network node in a wireless communications network and a second link to a second wireless network node in the wireless communications network, the method comprising: determining a first maximum transmit power level for the first link from the wireless device to the first wireless network node and a second maximum transmit power level for the second link from the wireless device to the second wireless network node, where each of the first maximum transmit power level and the second maximum transmit power level is a function of a maximum allowable transmit power level and the first maximum transmit power level and the second maximum transmit power level are semi-statically defined, and a sum of the first maximum transmit power level and the second maximum transmit power level is greater than the maximum allowable power; and transmitting on the first link and the second link in subframe j according to the first maximum transmit power level and the second maximum transmit power level, respectively; wherein the first link and the second link are simultaneous dual-connectivity links, each link being configured to support a plurality of aggregated carriers and a plurality of uplink channel types including a control channel and/or a random access channel, and wherein subframe (i1) and subframe i of the first link overlap with subframe j of the second link.

12. The method of claim 11 wherein determining the first maximum transmit power level and the second maximum transmit power level comprises: for a particular subframe of the first link, determining the first maximum transmit power level for the particular subframe of the first link according to a semi-static definition of the first maximum transmit power level as a first fraction of the maximum allowable transmit power for the particular subframe of the first link; and for a particular subframe of the second link that is either synchronous transmission with the particular subframe of the first link or asynchronous partially overlapping transmission with the particular subframe of the first link, determining the second maximum transmit power level for the particular subframe of the second link according to a semi-static definition of the second maximum transmit power level as a second fraction of the maximum allowable transmit power for the particular subframe of the second link.

13. The method of claim 12 wherein the sum of the first fraction and the second fraction is greater than 1.

14. The method of claim 11 wherein transmitting on the first link and the second link according to the first maximum transmit power level and the second maximum transmit power level, respectively, comprises transmitting on the first link according to the first maximum transmit power level, if the calculated transmit power level for the first link is greater than the first maximum transmit power level.

15. A wireless device having a first link to a first wireless network node in a wireless communications network and a second link to a second wireless network node in the wireless communications network, comprising: a transmitter; at least one processor; and memory containing software instructions executable by the at least one processor whereby the wireless device is operative to: receive, via Radio Resource Control (RRC) signaling, a configured maximum transmit power level for the first link; determine a maximum transmit power level for the second link from the wireless device to the second wireless network node where the maximum transmit power level is a function of a maximum allowable transmit power level and a transmission power of at least one of subframe (i1) and subframe i of the first link, the transmission power of the at least one of subframe (i1) and subframe i of the first link being limited by the configured maximum transmit power level for the first link; and transmit, via the transmitter, on the second link according to the maximum transmit power level; wherein the first link and the second link are simultaneous dual-connectivity links, each link being configured to support a plurality of aggregated carriers and a plurality of uplink channel types including a control channel and/or a random access channel; and wherein subframe (i1) and subframe i of the first link overlap with subframe j of the second link.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

(2) FIG. 1 illustrates a basic Long Term Evolution (LTE) downlink physical resource;

(3) FIG. 2 is a schematic diagram of an LTE time domain structure;

(4) FIG. 3 illustrates a LTE downlink subframe with a control region of three Orthogonal Frequency Division Multiplexing (OFDM) symbols;

(5) FIG. 4 illustrates processing of Layer 1 (L1)/Layer 2 (L2) control signaling LTE where, for each Physical Downlink Control Channel (PDCCH), a Cyclic Redundancy Check (CRC) is attached to each Downlink Control Information (DCI) message;

(6) FIG. 5 is a schematic diagram illustrating common and User Equipment device (UE) specific search spaces for two UEs;

(7) FIG. 6 is a schematic diagram illustrating resources specifically assigned for uplink L1/L2 control on LTE Release 8 Physical Uplink Control Channel (PUCCH);

(8) FIG. 7 illustrates Carrier Aggregation (CA);

(9) FIG. 8 illustrates Frequency Division Duplex (FDD) and Time Division Duplex (TDD) in a cellular communications network;

(10) FIG. 9 illustrate LTE frame structures for FDD and TDD;

(11) FIG. 10 illustrates seven different TDD configurations allowed in LTE;

(12) FIG. 11 illustrates a scenario where an uplink transmission in one cell interferes with downlink transmission in a neighboring cell;

(13) FIG. 12 is a schematic diagram illustrating uplink power for a Master evolved or enhanced Node B (MeNB) and a Secondary evolved or enhanced Node B (SeNB) when a wireless device is operating in a dual-connectivity mode of operation;

(14) FIG. 13 illustrates a cellular communications network enabling uplink power control for dual connectivity according to some embodiments of the present disclosure;

(15) FIG. 14 is a schematic diagram illustrating static maximum power levels defined for the MeNB link and the SeNB link according to some embodiments of the present disclosure;

(16) FIG. 15 is a flow chart that illustrates the operation of a wireless device to operate according to a static configuration of maximum transmit power levels for the MeNB link and the SeNB link according to some embodiments of the present disclosure;

(17) FIG. 16 illustrates one of the steps of FIG. 15 in more detail according to some embodiments of the present disclosure;

(18) FIG. 17 illustrates the process of FIG. 15 in which the wireless device determines the maximum transmit power levels for the MeNB and SeNB links by assigning values to the maximum transmit power levels based on a defined criterion;

(19) FIG. 18 illustrates semi-static configuration of the maximum transmit power levels for the MeNB and SeNB links according to some embodiments of the present disclosure;

(20) FIG. 19 illustrates one example in which semi-statically defined maximum transmit power levels for the MeNB and SeNB links can take two or more levels with a known pattern according to some embodiments of the present disclosure;

(21) FIG. 20 illustrates one example in which the maximum transmit power levels for the MeNB and SeNB links are applied only when a total calculated transmission power across the links exceeds a maximum allowable transmit power level;

(22) FIG. 21 is a flow chart that illustrates the operation of a wireless device to transit uplink transmissions on the MeNB and SeNB links according to a semi-static uplink power control scheme according to some embodiments of the present disclosure;

(23) FIG. 22 illustrates one of the steps of FIG. 21 in more detail according to some embodiments of the present disclosure;

(24) FIG. 23 illustrates the process of FIG. 21 in which the wireless device determines the maximum transmit power levels for the MeNB and SeNB links by semi-statically assigning values to the maximum transmit power levels based on a defined criterion according to some embodiments of the present disclosure;

(25) FIG. 24 illustrates one example of dynamic configuration of the maximum transmit power levels for the MeNB and SeNB links according to some embodiments of the present disclosure;

(26) FIG. 25 is a flow chart that illustrates the operation of the wireless device to dynamically determine the maximum transmit power levels for the MeNB and SeNB links and to transmit uplink transmissions on the link k according to the determined maximum transmit power levels according to some embodiments of the present disclosure;

(27) FIG. 26 is a flow chart illustrating the operation of the wireless device according to some dynamic power level configuration embodiments of the present disclosure;

(28) FIG. 27 is a flow chart that illustrates the operation of the wireless device according to some embodiments in which only the earlier of two overlapping subframes is considered;

(29) FIGS. 28A and 28B illustrate a process for determining PUCCH transmit power level according to some embodiments of the present disclosure;

(30) FIG. 29 illustrates a process for determining Physical Uplink Shared Channel (PUSCH) transmit power level according to some embodiments of the present disclosure;

(31) FIG. 30 illustrates a process for determining PUSCH transmit power level according to some other embodiments of the present disclosure;

(32) FIG. 31 illustrates a process for determining PUSCH transmit power level by power scaling across all carriers and links according to some embodiments of the present disclosure;

(33) FIG. 32 is a flow chart that illustrates a procedure that utilizes a power scaling scheme according to some embodiments of the present disclosure;

(34) FIG. 33 is a flow chart that illustrates one embodiment of using the this prioritization of uplink channels to assign the maximum transmit power levels for the MeNB and SeNB links according to some embodiments of the present disclosure;

(35) FIG. 34 is a block diagram of a base station according to some embodiments of the present disclosure;

(36) FIG. 35 is a block diagram of a wireless device according to some embodiments of the present disclosure; and

(37) FIG. 36 is a block diagram of a wireless device according to some other embodiments of the present disclosure.

DETAILED DESCRIPTION

(38) The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.

(39) Systems and methods enabling uplink power sharing for dual connectivity are disclosed. Embodiments are described herein in which a maximum uplink (UL) power on each link is configured statically, semi-statically, or dynamically. In general, regardless of the embodiment, uplink power for uplink transmissions from a wireless device on two simultaneous links is controlled such that the total uplink power does not exceeds a maximum UL transmission power level while, in some embodiments, taking into account priorities of the two links and/or priorities of various uplink channels transmitted by the wireless device on the two links. Notably, while the embodiments described herein focus on dual connectivity, the embodiments described herein can easily be extended to any number of two or more simultaneous links.

(40) FIG. 13 illustrates a cellular communications network 10 enabling uplink power control for dual connectivity according to some embodiments of the present disclosure. In the description provided herein, the cellular communications network 10 is a Long Term Evolution (LTE) network and, as such, LTE terminology is oftentimes used. However, the present disclosure is not limited to LTE. Rather, the embodiments disclosed herein can be implemented in any suitable wireless system that supports dual connectivity. As such, a more general term wireless network node is used herein to refer to any wireless node in any type of wireless network (e.g., a radio access node such as a base station or an enhanced or evolved Node B (eNB) in a cellular communications network such as an LTE network, a wireless access node in a local wireless network such as a WiFi network, or the like).

(41) As illustrated, the cellular communications network 10 includes a wireless (e.g., a User Equipment device (UE)) having two simultaneous links to a Master eNB (MeNB) 14 and a Secondary eNB (SeNB) 16 for uplink transmissions according to a dual connectivity scheme. The MeNB 14 may also be referred to herein as an anchor eNB, and the SeNB 16 may also be referred to herein as a booster eNB.

(42) As discussed above, one problem with conventional dual connectivity schemes is that the maximum UL transmission power levels for the two links are independent from one another. As a result, the total uplink transmit power of the wireless device 12 may exceed a maximum allowable transmit power level. The maximum allowable transmit power level is some predefined power level that is, for example, defined to take into account the maximum UL power allowed in the given cell, the UE power class of the wireless device 12, the modulation and transmit bandwidth, compliance with applicable electromagnetic energy absorption requirements, and other requirements. As discussed below, systems and methods are described herein that ensure that the total transmit power of the wireless device 12 across the two links does not exceed the maximum allowable transmit power level.

(43) In some embodiments, the maximum allowable transmit power level is enforced by defining two static, fixed maximum transmit power levels, P.sub.MeNB,max and P.sub.SeNB,max, for the link to the MeNB 14 and the link to the SeNB 16, respectively, where
{circumflex over (P)}.sub.MeNB,max+{circumflex over (P)}.sub.SeNB,max={circumflex over (P)}.sub.CMAX(i)(1)
Here {circumflex over (P)}.sub.MeNB,max is the linear value of a maximum output power of the wireless device 12 on the MeNB link, {circumflex over (P)}.sub.SeNB,max is the linear value of a maximum output power of the wireless device 12 on the SeNB link, and {circumflex over (P)}.sub.CMAX(i) is the linear value of a configured total maximum output power P.sub.CMAX of the wireless device 12 for subframe i. The total maximum output power {circumflex over (P)}.sub.CMAX(i) of the wireless device 12 may be fixed (i.e., the same for all subframes) or may be variable (e.g., vary between at least some subframes over time).

(44) The static maximum power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are known to both the MeNB 14 and the SeNB 16 as well as the wireless device 12. The static maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max do not vary with time. In particular, in some embodiments, the static maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are defined as static fractions, or static percentages, of the total maximum output power {circumflex over (P)}.sub.CMAX(i) of the wireless device 12. Note, however, that while the static fractions do not change over time, the total maximum output power {circumflex over (P)}.sub.CMAX(i) may, in some embodiments, change over time. As a result, the static maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max may actually vary over time, but the proportions of the total maximum output power {circumflex over (P)}.sub.CMAX(i) that correspond to the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max do not change. One benefit of using the static maximum power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max is that no explicit signaling is necessary.

(45) FIG. 14 is a schematic diagram illustrating static maximum power levels defined for MeNB and SeNB links according to one example. As illustrated, in this example, {circumflex over (P)}.sub.MeNB,max={circumflex over (P)}.sub.SeNB,max=0.5{circumflex over (P)}.sub.CMAX(i). However, this is only an example. As will be appreciated by one of ordinary skill in the art upon reading this disclosure, this static scenario may more generally be expressed as:
{circumflex over (P)}.sub.MeNB,max=.sub.MeNB{circumflex over (P)}.sub.CMAX(i) and
{circumflex over (P)}.sub.SeNB,max=.sub.SeNB{circumflex over (P)}.sub.CMAX(i), where
.sub.MeNB+.sub.SeNB=1.

(46) The maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max may be allocated in any suitable manner. As a first example, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max may be allocated as {circumflex over (P)}.sub.MeNB,max={circumflex over (P)}.sub.SeNB,max=5{circumflex over (P)}.sub.CMAX(i). This allocation treats the MeNB link and the SeNB link equally in terms of uplink power. As a second example, the MeNB link and the SeNB link may be assigned unequal maximum power levels (i.e., {circumflex over (P)}.sub.MeNB,max{circumflex over (P)}.sub.SeNB,max) according to, e.g., a number of uplink antenna ports that the wireless device 12 uses over the two links, the number of serving cells configured with uplink transmission on each of the two links, or an average number of Resource Blocks (RBs) that the wireless device 12 is expected to be assigned over the two links.

(47) FIG. 15 is a flow chart that illustrates the operation of the wireless device 12 to operate according to a static configuration of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max according to some embodiments of the present disclosure. This process simply illustrates some of the embodiments described above. As illustrated, the wireless device 12 determines the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max for the simultaneous links to the MeNB 14 and the SeNB 16 (step 100). As discussed above, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max may be defined as static fractions, or percentages, of the total maximum allowable output power {circumflex over (P)}.sub.CMAX(i) of the wireless device 12. These static fractions, which are denoted as .sub.MeNB and .sub.MeNB above, may be assigned in any suitable manner (e.g., defined by the wireless device 12 or configured by the MeNB 14). The wireless device 12 transmits uplink transmissions on the MeNB link and the SeNB link according to the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max, respectively (step 102).

(48) FIG. 16 illustrates step 100 of FIG. 15 in more detail according to some embodiments of the present disclosure. FIG. 16 illustrates the manner in which the maximum transmit power level {circumflex over (P)}.sub.MeNB,max is determined. The same process can be used to determine the maximum transmit power level {circumflex over (P)}.sub.SeNB,max. As illustrated, a subframe index is first initialized (e.g., to a value of 0) (step 200). The wireless device 12 then determines the maximum transmit power level {circumflex over (P)}.sub.MeNB,max for subframe i of the link to the MeNB 14, which is referred to herein as link k, according to a static definition of the maximum transmit power level {circumflex over (P)}.sub.MeNB,max as a fraction of the maximum allowable transmit power {circumflex over (P)}.sub.CMAX(i) of the wireless device 12 for subframe i (step 202). The index i is then incremented (step 204), and the process then returns to step 202. In this manner, the wireless device 12 determines the maximum transmit power level {circumflex over (P)}.sub.MeNB,max for each subframe i transmitted on link k (i.e., the link to the MeNB 14).

(49) Using the same process, the wireless device 12 determines the maximum transmit power level {circumflex over (P)}.sub.SeNB,max for each subframe i transmitted on link k (i.e., the link to the SeNB 16) according to a static definition of the maximum transmit power level {circumflex over (P)}.sub.SeNB,max as a fraction of the maximum allowable transmit power level for the subframe i transmitted on link k. Notably, for this discussion, it is assumed that the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) is determined by taking into account the requirements of subframe i to be transmitted on link k and the requirements of subframe i to be transmitted on link k.

(50) As discussed above, in some embodiments, the wireless device 12 assigns the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max based on a criterion such as, for example, a number of uplink antenna ports that the wireless device 12 uses over the two links, the number of serving cells configured with uplink transmission on each of the two links, or an average number of RBs that the wireless device 12 is expected to be assigned over the two links. In this regard, FIG. 17 illustrates the process of FIG. 15 in which the wireless device 12 determines the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max by assigning (potentially unequal) values to the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max based on a defined criterion according to some embodiments of the present disclosure.

(51) More specifically, as illustrated, the wireless device 12 determines the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max (step 100) by assigning (potentially unequal) values as the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max based on a predefined criterion (step 300). As discussed above, the predefined criterion may be, for example, a number of uplink antenna ports that the wireless device 12 uses over the two links, the number of serving cells configured with uplink transmission on each of the two links, or an average number of RBs that the wireless device 12 is expected to be assigned over the two links. In some embodiments, more than one of these criteria may be considered. As discussed above, the wireless device 12 transmits uplink transmissions on the MeNB link and the SeNB link according to the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max, respectively (step 102).

(52) The embodiments of FIGS. 14 through 17 relate to a static configuration of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max for the simultaneous uplink transmissions to the MeNB 14 and the SeNB 16 according to the dual connectivity scheme. The discussion will now turn to embodiments in which the configuration of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max is semi-static.

(53) In some embodiments, instead of assigning static or fixed maximum transmit power levels, adjustment may be made in a semi-static manner over time. In some embodiments, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are fixed over a period T (e.g., fractions or percentages of the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) over a period T are fixed), while the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max may vary from one time period T to another (e.g., fractions or percentages of the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) may vary from one time period T to another).

(54) Semi-static configuration of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max is illustrated in FIG. 18. In this example, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are defined as semi-static fractions, or percentages, .sub.MeNB and .sub.MeNB, of the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i). In particular, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max during a first time period (T.sub.1), which are denoted as {circumflex over (P)}.sub.MeNB,max(T.sub.1) and {circumflex over (P)}.sub.SeNB,max(T.sub.1), are:
{circumflex over (P)}.sub.MeNB,max(T.sub.1)=.sub.MeNB(T.sub.1){circumflex over (P)}.sub.CMAX(i), and
{circumflex over (P)}.sub.SeNB,max(T.sub.1)=.sub.SeNB(T.sub.1){circumflex over (P)}.sub.CMAX(i),
where .sub.MeNB(T.sub.1) and .sub.SeNB(T.sub.1) are the semi-statically defined fractions defined for the first time period T.sub.1 and .sub.MeNB(T.sub.1)+.sub.SeNB(T.sub.1)=1. Notably, in this example, it is assumed that the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) is constant during the first time period T.sub.1, but the present disclosure is not limited thereto. Similarly, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max during a second time period (T.sub.2), which are denoted as {circumflex over (P)}.sub.MeNB,max(T.sub.2) and {circumflex over (P)}.sub.SeNB,max(T.sub.2), are:
{circumflex over (P)}.sub.MeNB,max(T.sub.2)=.sub.MeNB(T.sub.2){circumflex over (P)}.sub.CMAX(i), and
{circumflex over (P)}.sub.SeNB,max(T.sub.2)=.sub.SeNB(T.sub.2){circumflex over (P)}.sub.CMAX(i),
where .sub.MeNB(T.sub.2) and .sub.SeNB(T.sub.2) are the semi-statically defined fractions defined for the second time period T.sub.2 and .sub.MeNB(T.sub.2)+.sub.SeNB(T.sub.2)=1. Notably, in this example, it is assumed that the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) is also constant during the second time period T.sub.2, but the present disclosure is not limited thereto.

(55) The adjustment of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max is expected to be slow (i.e., long T) (e.g., the adjustments may be made semi-statically via some semi-statically signaling such as, for example, Radio Resource Control (RRC) signaling). For example, adjustments may be desired when the wireless device 12 moves from an outdoor environment to an indoor environment, or vice versa. The benefit is that the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max can be adjusted over time to match the varying conditions that the wireless device 12 experiences. In some embodiments, the wireless device 12 performs the semi-static adjustment of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max and signals the resulting values for the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max to the MeNB 14 and the SeNB 16.

(56) In one example embodiment, for a given time period T, the wireless device 12 tracks an average path loss on the MeNB link (i.e., link k) and the SeNB link (link k). The wireless device 12 then selects {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max in proportion to the path loss on MeNB link and the SeNB link in the next time period T. This approach attempts to maintain the same data rate over the two links by allocating proportionally higher power to poorer links to compensate for the path loss.

(57) As another example, for a given time period T, the wireless device 12 tracks the average path loss on the MeNB link and the SeNB link and selects {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max reversely in proportion to the path loss on the MeNB link and the SeNB link in the next time period T. This approach attempts to maximize the aggregate data rate over the two links by allocating more power to the link with better channel condition.

(58) In other examples, the wireless device 12 may vary the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max in time according to other factors such as, for example: (a) uplink interference the wireless device 12 causes, (b) a number of uplink antenna ports that the wireless device 12 uses over the two links, (c) an average number of RBs that the wireless device 12 is assigned, (d) a Quality of Service Class Indicator (QCI) of the bearers on the two links, and/or (e) the number of serving cells configured with uplink transmission on each link.

(59) A variation of the semi-static power allocation is that within the period T, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max can take two or more levels with a known pattern. One example is illustrated in FIG. 19. This can be useful for handling Discontinuous Transmission (DTX) of the MeNB 14 or the SeNB 16. For example, the higher level is for the subframes that the wireless device 12 may have uplink transmission, and the lower level is for the periods where it is known that there is no uplink transmission. Note that FIG. 19 is only an example. The pattern may have any number of two or more maximum transmit power levels within the time period T.

(60) In one alternative embodiment, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max for the links are applied only when a total calculated transmission power across the uplinks to the MeNB 14 and the SeNB 16 exceeds the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i). The semi-static maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are not applied when the total calculated transmission power for the MeNB 14 and the SeNB 16 does not exceed the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i). One example is given in FIG. 20.

(61) FIG. 21 is a flow chart that illustrates the operation of the wireless device 12 to transmit uplink transmissions on the links to the MeNB 14 and the SeNB 16 according to a semi-static uplink power control scheme according to some embodiments of the present disclosure. This process corresponds to at least some of the semi-static embodiments described above. As illustrated, optionally (as indicated by dashed lines), the wireless device 12 determines whether a total calculated transmit power for the wireless device 12 for the MeNB link and the SeNB link is greater than the predefined maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) (step 400). If not, the wireless device 12 transmits the uplink transmissions to the MeNB 14 and the SeNB 14 over the respective links using the calculated transmit power levels (step 402), and the process then returns to step 400 if there is scheduled UL transmission to MeNB and/or SeNB. The calculated transmit power levels may be, for example, the transmit power levels calculated (e.g., in the conventional manner) without taking the uplink transmit power level of one link into consideration when calculating the uplink transmit power level of the other link (i.e., when calculating the transmit power levels for the two links separately).

(62) Conversely, if the total calculated transmit power for the wireless device 12 for the MeNB link and the SeNB link is greater than the predefined maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i), the wireless device 12 determines semi-static maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max for the MeNB link and the SeNB link, respectively (step 404). As discussed above, in some embodiments, the semi-static maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are semi-static in that they are defined according to semi-static fractions .sub.MeNB and .sub.SeNB of the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i), where the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) may be static or variable. Notably, in this embodiment, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max (or equivalently the fractions .sub.MeNB and .sub.SeNB) are updated for each time period T. The wireless device 12 then transmits uplink transmissions to the MeNB 14 and the SeNB 16 over the corresponding links according to the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max determined in step 404 (step 406). The process then returns to step 400 and is repeated. In some embodiments, the process is repeated for each subframe of each of the two links.

(63) FIG. 22 illustrates step 404 of FIG. 21 in more detail according to some embodiments of the present disclosure. FIG. 22 illustrates the manner in which the maximum transmit power level {circumflex over (P)}.sub.MeNB,max is determined according to a semi-static definition of the maximum transmit power level {circumflex over (P)}.sub.MeNB,max as a fraction of the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i). The same process can be used to determine the maximum transmit power level {circumflex over (P)}.sub.SeNB,max. As illustrated, a subframe index is first initialized (e.g., to a value of 0) (step 500). The wireless device 12 then determines the maximum transmit power level {circumflex over (P)}.sub.MeNB,max for subframe i of the link to the MeNB 14, which is referred to herein as link k, according to a semi-static definition of the maximum transmit power level {circumflex over (P)}.sub.MeNB,max as a fraction of the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) of the wireless device 12 for subframe i (step 502). The index i is then incremented (step 504), and the process then returns to step 502. In this manner, the wireless device 12 determines the maximum transmit power level {circumflex over (P)}.sub.MeNB,max for each subframe i transmitted on link k (i.e., the link to the MeNB 14).

(64) Using the same process, the wireless device 12 determines the maximum transmit power level {circumflex over (P)}.sub.SeNB,max for each subframe i transmitted on link k (i.e., the link to the SeNB 16) according to a semi-static definition of the maximum transmit power level {circumflex over (P)}.sub.SeNB,max as a fraction of the maximum allowable transmit power level for the subframe i transmitted on link k. Notably, for this discussion, it is assumed that the maximum allowable transmit power level is determined by taking into account the requirements of subframe i to be transmitted on link k and the requirements of subframe i transmitted on link k.

(65) As discussed above, in some embodiments, the wireless device 12 semi-statically assigns the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max based on a criterion such as, for example, (a) uplink interference the wireless device 12 causes, (b) a number of uplink antenna ports that the wireless device 12 uses over the two links, (c) an average number of RBs that the wireless device 12 is assigned, (d) a QCI of the bearers on the two links, and/or (e) the number of serving cells configured with uplink transmission on each link. In this regard, FIG. 23 illustrates the process of FIG. 21 in which the wireless device 12 determines the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max by semi-statically assigning (potentially unequal) values to the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max based on a defined criterion according to some embodiments of the present disclosure.

(66) More specifically, as illustrated, the wireless device 12 determines the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max (step 404) by assigning (potentially unequal) semi-static values as the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max based on a predefined criterion (step 600). As discussed above, the predefined criterion may be, for example, (a) uplink interference the wireless device 12 causes, (b) a number of uplink antenna ports that the wireless device 12 uses over the two links, (c) an average number of RBs that the wireless device 12 is assigned, (d) a QCI of the bearers on the two links, and/or (e) the number of serving cells configured with uplink transmission on each link. In some embodiments, more than one of these criteria may be considered.

(67) Thus far, the discussion has focused on static and semi-static configuration of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max. The discussion will now turn to embodiments in which the configuration of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max is dynamic. Like in the embodiments discussed above, uplink power control is provided for the scenario where the wireless device 12 has two connections, or links, to two network nodes, respectively. Each connection, or link, may be further composed of one or more serving cells associated with the wireless device 12. In particular, a Master Cell Group (MCG) is a group of serving cells associated with the MeNB 14, and a Secondary Cell Group (SCG) is a group of serving cells associated with the SeNB 16.

(68) One example of dynamic configuration of the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max is illustrated in FIG. 24. As illustrated, for the asynchronous case where the subframe boundaries on the two links are not aligned, the wireless device 12 determines the maximum transmission power {circumflex over (P)}.sub.MeNB,max for each subframe i on the MeNB link (link k) by taking into consideration the used transmission power in one or more overlapping subframes of the SeNB link (link k), and vice versa. As illustrated, each subframe on the MeNB link has two overlapping subframes on the SeNB link. Likewise, each subframe on the SeNB link has two overlapping subframes on the MeNB link. For example, subframe i on the SeNB link is partially overlapped by subframes i and i+1 on the MeNB link. It is important to note here that although for simplicity, MeNB and SeNB subframes indices are both denoted with variable i, i1, etc., in general MeNB and SeNB subframes may have substantially different subframe numbering and be denoted with two different variables. For example, in general subframes of MeNB is denoted with index E while subframes of SeNB is denoted with index F. As discussed below in detail, in some embodiments, the transmission power on both overlapping subframes is taken into consideration. In other embodiments, the transmission power of only the earlier (in time) of the two overlapping subframes is taken into consideration. Further, in some embodiments, the dynamic transmit power control for a particular subframe of a link k, k is performed only if the total calculated transmit power for the subframe and its overlapping subframe(s) on the other link exceeds the maximum allowable transmit power for the wireless device 12.

(69) More specifically, in some embodiments, the wireless device 12 follows the procedure outline below to determine the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max that the wireless device 12 uses for uplink transmission on the MeNB link (denoted as link k) and the SeNB link (denoted as link k), respectively. For brevity, it is assumed in the procedure below that only one cell in each link has configured uplink, and only one uplink channel is sent in an uplink subframe (e.g., Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH)).

(70) Step 1: For a subframe i of the link k, the wireless device 12 calculates a value {circumflex over (P)}.sup.k(i1) which takes into account the transmission power limits according to the first slot of subframe i on link k. Notably, while the term slot is used, it is important to point out that, as would be understood by one of ordinary skill in the art, the value {circumflex over (P)}.sup.k(i1) is more precisely a maximum transmit power for subframe i of the link k when taking into account the transmission power of the overlapping subframe i on link k (i.e., the earlier of the two subframes on link k that partially overlap the subframe i on link k). This overlap may be any amount of overlap depending on the time offset between the subframe boundaries of the two links k and k. In one specific case or example, the timing offset is such that the overlap between subframe i on link k and the overlapping subframe i on link k is equal to a slot. However, the overlap is not limited thereto. As such, in the discussion below, the subframe on the link k that is said to overlap the first slot of subframe i on link k is to be understood as the subframe on the link k having: (a) a starting subframe boundary that is before (in time) the starting subframe boundary of the subframe i on link k and (b) an ending subframe boundary that is after the starting subframe boundary of subframe i on link k but before the ending subframe boundary of subframe i on link k. Conversely the subframe on link k that is said to overlap the second slot of subframe i on link k is to understood as the subframe on link k having: (a) a starting subframe boundary that is after the starting subframe boundary of subframe i on link k but before the ending subframe boundary of subframe i on link k and (b) and ending subframe boundary that is after the ending subframe boundary of subframe i on link k.

(71) If there is an uplink transmission on the other link k overlapping the first slot of subframe i on link k, calculate
{circumflex over (P)}.sup.k(i1)=min({circumflex over (P)}.sub.SL.sup.k(i),{circumflex over (P)}.sub.CMAX(i){circumflex over (P)}.sub.used.sup.k(i1)),
where {circumflex over (P)}.sub.CMAX(i) refers to the linear value of the total configured maximum output power {circumflex over (P)}.sub.CMAX, {circumflex over (P)}.sub.used.sup.k(i1) refers to the power level used by the other link k on the subframe that overlaps the first slot of the subframe i on link k, {circumflex over (P)}.sub.SL.sup.k(i) is the calculated linear power value for the link k assuming link k is the single link on which the wireless device 12 has uplink transmission in the entire duration of subframe i of link k (i.e., assuming non-overlap with link k). Thus, {circumflex over (P)}.sup.k(i1) is the lesser of the calculated linear power value for the link k assuming link k is the single link on which the wireless device 12 has uplink transmission in the entire duration of subframe i of link k and unused portion of the maximum output power {circumflex over (P)}.sub.CMAX(i) for subframe i of link k when considering the used power in the other link k on the subframe that overlaps the first slot of the subframe i on link k. If there is no transmission on the other link (link k) overlapping the first slot of subframe i of link k, {circumflex over (P)}.sub.used.sup.k(i1)=0 and {circumflex over (P)}.sup.k(i1)={circumflex over (P)}.sub.SL.sup.k(i).

(72) Step 2: For the subframe i of link k, the wireless device 12 calculates value {circumflex over (P)}.sup.k(i) which takes into account the transmission power limits according to the second slot of subframe i on link k. If there is an uplink transmission on the other link k overlapping the second slot of subframe i on link k, {circumflex over (P)}.sup.k(i) is calculated as if subframe i of the link k is aligned in subframe boundary with the overlapping subframe of link k. In this step, priority of the uplink channel types between the two links is taken into account. If there is no uplink transmission on the other link k overlapping the second slot of subframe i on link k, {circumflex over (P)}.sup.k(i)={circumflex over (P)}.sub.SL.sup.k(i).

(73) Step 3: The final power level (i.e., {circumflex over (P)}.sub.MeNB,max or {circumflex over (P)}.sub.SeNB,max) that the wireless device 12 selects for subframe i of link k is {circumflex over (P)}.sub.*.sup.k(i)=min({circumflex over (P)}.sup.k(i1), {circumflex over (P)}.sup.k(i)). This power level represents the total available power for the given link, i.e. in the example of one MeNB and SeNB. It represents the total available power for all carriers on either of these links. For example, if link k is configured with two uplink component carriers, then the total available power of link k is further shared by the transmission over the two uplink carriers. Note that if subframe boundary of the two links are aligned (synchronized network with one Timing Advance Group (TAG)), then the calculation degenerates into {circumflex over (P)}.sub.*.sup.k(i)={circumflex over (P)}.sub.SL.sup.k(i). This same process is repeated for each subframe of the link k. Likewise, this process is performed to determine P.sub.SeNB,max for link k.

(74) As one simplification, step 2 and step 3 can be omitted. The possible overlapping between the second slot of subframe i for link k and the first slot of subframe i+1 for link k is not considered at all, then the final power level degenerates into {circumflex over (P)}.sub.*.sup.k(i)={circumflex over (P)}.sup.k(i1).

(75) Note also that if Sounding Reference Signal (SRS) on one link overlaps with a higher-priority transmission on the other link, SRS may be dropped rather than being power scaled.

(76) The steps above can be modified to account for the variation where two uplink channels (e.g., PUCCH and PUSCH) are allowed in a same uplink subframe for a given link. If there is only one uplink channel on link k (i.e., no simultaneous PUSCH and PUCCH), {circumflex over (P)}.sub.SL.sup.k(i) is the calculated linear power value for the uplink channel (PUSCH or PUCCH) on link k assuming non-overlap with link k. {circumflex over (P)}.sub.*.sup.k(i) is the final power level of the uplink channel on link k. This is the scenario assumed in description of steps 1 and 2. Conversely, if there are two simultaneous uplink channels on link k (e.g., simultaneous PUSCH and PUCCH in a subframe), {circumflex over (P)}.sub.SL.sup.k(i) is the sum of the calculated linear power value for the uplink channels (PUSCH and PUCCH) on link k assuming non-overlap with link k. In most cases, {circumflex over (P)}.sub.SL.sup.k(i)={circumflex over (P)}.sub.CMAX(i). {circumflex over (P)}.sup.k(i) obtained in step 2 is the maximum power for both uplink channels on link k. To further allocate {circumflex over (P)}.sub.*.sup.k(i) between two simultaneous uplink channels, the final power level of each individual uplink channel is calculated with the existing formulae taking {circumflex over (P)}.sub.*.sup.k(i) as {circumflex over (P)}.sub.CMAX(i).

(77) In the description above, it is assumed that each link has only one serving cell configured with uplink transmission (LTE Release 12). Further details for scenarios where each link configures multiple cells with uplink transmission (LTE Release 13 and later) are desirable. Steps 1-3 above can be modified to account for such case.

(78) In the description above, it is assumed that each link has only one serving cell configured with uplink transmission. However, steps 1-3 above can be extended to the case where each link configures multiple cells with uplink transmissions.

(79) Step 1: For a subframe i of a link k, the wireless device 12 calculates value {circumflex over (P)}.sub.c.sup.k(i1) for serving cell c which takes into account the transmission power limits according to the first slot of subframe i on link k. If there is an uplink transmission on the other link k overlapping the first slot of subframe i on link k, calculate

(80) ${\hat{P}}_{\mathrm{sum}}^k\left(i-1\right)=\min \left(\underset{c}{.Math.}{\hat{P}}_c^k\left(i-1\right),{\hat{P}}_{\mathrm{CMAX}}\left(i\right)-\underset{c^{}}{.Math.}{\hat{P}}_{c^{}}^{k^{}}\left(i-1\right)\right),$
where {circumflex over (P)}.sub.CMAX(i) refers to the linear value of the total configured maximum output power P.sub.CMAX of the wireless device 12, P.sub.c.sup.k(i1) refers to the power level used by serving cell c in the other link k that overlaps the first slot of the subframe i, {circumflex over (P)}.sub.c.sup.k(i1) is the calculated linear power value for serving cell c in the link k assuming link k is the single link on which the wireless device 12 has uplink transmission in the entire duration of subframe i (i.e., assuming non-overlap with link k). If there is no transmission on the other link (link k) overlapping the first slot of subframe i of link k,

(81) $\underset{c^{}}{.Math.}{\hat{P}}_{c^{}}^{k^{}}\left(i-1\right)=0\mathrm{and}{\hat{P}}_{\mathrm{sum}}^k\left(i-1\right)=\underset{c}{.Math.}{\hat{P}}_c^k\left(i-1\right).$

(82) Step 2: For subframe i of link k, the wireless device 12 calculates a value {circumflex over (P)}.sub.sum.sup.k(i) which takes into account the transmission power limits according to the second slot of subframe i on link k. If there is an uplink transmission on the other link k overlapping the second slot of subframe i on link k, {circumflex over (P)}.sub.sum.sup.k(i) is calculated as if subframe i of the link k is aligned in subframe boundary with the overlapping subframe of link k. In this step, priority of uplink channel types between the two links is taken into account. If there is no uplink transmission on the other link k overlapping the second slot of subframe i on link k,

(83) ${\hat{P}}_{\mathrm{sum}}^k\left(i\right)=\underset{c}{.Math.}{\hat{P}}_c^k\left(i\right).$

(84) Step 3: The final total power level that the wireless device 12 uses for subframe i of link k is {circumflex over (P)}.sub.*.sup.k(i)=min({circumflex over (P)}.sub.sum.sup.k(i1), {circumflex over (P)}.sub.sum.sup.k(i)). If {circumflex over (P)}.sub.*.sup.k(i)={circumflex over (P)}.sub.sum.sup.k(i1), the final power level for serving cell c in subframe i of link k is {circumflex over (P)}.sub.c.sup.k(i1) as determined in step 1; else if {circumflex over (P)}.sub.*.sup.k(i)={circumflex over (P)}.sub.sum.sup.k(i), the final power level serving cell c in subframe i of link k is {circumflex over (P)}.sub.c.sup.k(i) as determined in step 2.

(85) The following is one example of the process described above. For SeNB subframe i: Step 1. {circumflex over (P)}.sup.SeNB(i1)={circumflex over (P)}.sub.SL.sup.SeNB(i), where {circumflex over (P)}.sub.SL.sup.seNB(i) is the calculated power value of subframe i of SeNB link assuming non-overlap with MeNB; Step 2. {circumflex over (P)}.sup.SeNB(i) is calculated assuming SeNB subframe i is aligned with MeNB subframe i. In this step, priority of uplink channel types between MeNB and SeNB links is considered. Step 3. Final power of SeNB subframe i is:
{circumflex over (P)}.sub.*.sup.SeNB(i)=min({circumflex over (P)}.sup.SeNB(i1),{circumflex over (P)}.sup.SeNB(i)).

(86) For MeNB subframe i: Step 1. {circumflex over (P)}.sup.MeNB(i1)=min ({circumflex over (P)}.sub.SL.sup.MeNB(i),{circumflex over (P)}.sub.CMAX(i){circumflex over (P)}.sub.*.sup.SeNB(i)), where {circumflex over (P)}.sub.SL.sup.MeNB(i) is the calculated power value of subframe i of MeNB link assuming non-overlap with SeNB. Step 2. {circumflex over (P)}.sup.MeNB(i) is calculated assuming MeNB subframe i is aligned with SeNB subframe (i+1). In this step, priority of uplink channel types between MeNB and SeNB links is considered. Step 3. Final power of MeNB subframe i is
{circumflex over (P)}.sub.*.sup.MeNB(i)=min({circumflex over (P)}.sup.MeNB(i1),{circumflex over (P)}.sup.MeNB(i)).

(87) FIGS. 25 and 26 are flow charts that illustrate some embodiments of the dynamic transmit power configuration schemes described above. More specifically, FIG. 25 is a flow chart that illustrates the operation of the wireless device 12 to dynamically determine the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and to transmit uplink transmissions on the link k according to the determined maximum transmit power level {circumflex over (P)}.sub.MeNB,max according to some embodiments of the present disclosure. As illustrated, the wireless device 12 determines the maximum transmit power level {circumflex over (P)}.sub.MeNB,max for subframe i of link k taking into consideration the overlap between subframe i of link k and subframes i and i+1 of link k using, e.g., any one of the dynamic processes described above (step 700). The wireless device 12 transmits an uplink transmission on subframe i of link k according to the determined maximum transmit power level {circumflex over (P)}.sub.MeNB,max (step 702). The wireless device 12 then increments the subframe index i (step 704), and the process is then repeated for the next subframe on link k. This same process may also be used in the same manner for the subframes of the link k.

(88) FIG. 26 is a flow chart illustrating the operation of the wireless device 12 according to some embodiments of steps 1-3 of the dynamic process described above. As illustrated, the wireless device 12 calculates (or otherwise determines) a first transmit power level for subframe i of link k considering the overlap between subframe i of link k and subframe i of link k (step 800). The wireless device 12 also calculates (or otherwise determines) a second transmit power level for subframe i of link k considering the overlap between subframe i of link k and subframe i+1 of link k (step 802). The wireless device 12 then determines the maximum transmit power level {circumflex over (P)}.sub.MeNB,max for subframe i of link k as the minimum of the first and second power levels calculated in steps 800 and 802 (step 804). This process is repeated for each subframe of link k. In the same manner, this process can be used to determine the maximum transmit power level {circumflex over (P)}.sub.SeNB,max for each subframe of link k.

(89) In the embodiments of the dynamic scheme described above, the wireless device 12 takes into consideration the overlap between the subframe i of one link with both overlapping subframes of the other link. In other embodiments, only the overlap with the earliest (in time) of the two overlapping subframes is considered. The other overlapping subframe is not considered.

(90) In this regard, FIG. 27 is a flow chart that illustrates the operation of the wireless device 12 according to some embodiments in which only the earlier of the two overlapping subframes is considered. More specifically, FIG. 27 is a flow chart that illustrates the operation of the wireless device 12 to dynamically determine the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and to transmit uplink transmissions on the link k according to the determined maximum transmit power level {circumflex over (P)}.sub.MeNB,max according to some embodiments of the present disclosure. As illustrated, the wireless device 12 determines the maximum transmit power level {circumflex over (P)}.sub.MeNB,max for subframe i of link k taking into consideration only the overlap between subframe i of link k and subframe i of link k (i.e., the earlier of the two overlapping subframes of link k) using, e.g., any one of the dynamic processes described above (step 900). The wireless device 12 transmits an uplink transmission on subframe i of link k according to the determined maximum transmit power level {circumflex over (P)}.sub.MeNB,max (step 902). The wireless device 12 then increments the subframe index i (step 904), and the process is then repeated for the next subframe on link k. This same process may also be used in the same manner for the subframes of the link k.

(91) The discussion will now turn to some other dynamic uplink power control schemes according to some other embodiments of the present disclosure. In general, in these embodiments, PUCCH power control and PUSCH power control are provided. The PUSCH transmit power level is scaled if the total combined transmit power across both links for all channels is greater than the maximum allowable transmit power.

(92) PUCCH power control: The transmission power of PUCCH on either the MeNB link or the SeNB link are, in some embodiments, determined as illustrated in FIGS. 28A and 28B and described as follows. If serving cell c is the primary cell (i.e., the cell of the primary component carrier when using carrier aggregation) on the MeNB 14 (step 1000) and if there will be an overlapping transmission in time from the subframe i1 on the SeNB link (i.e., link k) (step 1002), the P.sub.PUCCH transmit power (i.e., transmit power for PUCCH) for subframe i on the MeNB link is determined taking into consideration used transmit power in the overlapping subframe i1 on link k (step 1004). In particular, in some embodiments, the PUCCH transmit power for subframe i on the MeNB link is determined according to:

(93) $P_{\mathrm{PUCCH},\mathrm{MeNB}}\left(i\right)=\min \left\{\begin{array}{c}\min \left(\begin{array}{c}{P}_{\mathrm{CMAX},c}\left(i\right),P_{\mathrm{CMAX}}\left(i\right)-\underset{c}{.Math.}{P}_{\mathrm{PUSCH},c,\mathrm{SeNB}}\left(i-1\right)-\\ P_{\mathrm{PUCCH},\mathrm{SeNB}}\left(i-1\right)\end{array}\right),\\ \begin{array}{c}{P}_{0\mathrm{\_PUCCH},\mathrm{MeNB}}+{\mathrm{PL}}_c+h\left(n_{\mathrm{CQI}},n_{\mathrm{HARQ}},n_{\mathrm{SR}}\right)+\\ {}_{\mathrm{F\_PUCCH},\mathrm{MeNB}}\left(F\right)+{}_{\mathrm{TxD},\mathrm{MeNB}}\left(F^{}\right)+g\left(i\right)\end{array}\end{array}\right\}\left[\mathrm{dBm}\right]$
In this equation, the top term in the outermost minimization function is to consider the used transmit power in the overlapping subframe i1 of link k (i.e., the SeNB link). In this example, the used transmit power is the PUSCH transmit power and the PUCCH transmit power used for the SeNB link. Thus, the top term (which is itself a minimization function) returns the minimum of: (a) the maximum allowable transmit power for the subframe i and (b) a difference between the maximum allowable transmit power and the total transmit power already used (both PUSCH and PUCCH) in the overlapping subframe i1 of the SeNB link. The bottom term in the equation above is the conventional PUCCH transmit power. Thus, the PUCCH transmit power for subframe i on the MeNB link is the minimum of: (a) P.sub.CMAX,c(i), (b) the unused amount of P.sub.CMAX(i) when taking into consideration the total transmit power already used in the overlapping subframe i1 of the SeNB link, and (c) the conventional PUCCH transit power, which does not take into consideration any overlapping subframes of the SeNB link.

(94) If there is no overlap between subframe i on the MeNB link and subframe i1 on the SeNB link, the wireless device 12 determines the PUCCH transmit power for subframe i of the MeNB link in a normal or conventional manner (step 1006). In one particular example, the wireless device 12 determines the PUCCH transmit power for subframe i of the MeNB link as:

(95) $P_{\mathrm{PUCCH},\mathrm{MeNB}}\left(i\right)=\min \left\{\begin{array}{c}{P}_{\mathrm{CMAX},c}\left(i\right),\\ \begin{array}{c}{P}_{0\mathrm{\_PUCCH},\mathrm{MeNB}}+{\mathrm{PL}}_c+h\left(n_{\mathrm{CQI}},n_{\mathrm{HARQ}},n_{\mathrm{SR}}\right)+\\ {}_{\mathrm{F\_PUCCH},\mathrm{MeNB}}\left(F\right)+{}_{\mathrm{TxD},\mathrm{MeNB}}\left(F^{}\right)+g\left(i\right)\end{array}\end{array}\right\}\left[\mathrm{dBm}\right]$

(96) Returning to step 1000, if serving cell c is not the primary cell on the MeNB 14 but is the primary cell on the SeNB 16 (step 1008) and if the there is an overlap with subframe i1 on the MeNB link (link k) (step 1010), the wireless device 12 determines the P.sub.PUCCH transmit power (i.e., transmit power for PUCCH) for subframe i on the SeNB link taking into consideration used transmit power in the overlapping subframe i1 on link k (step 1012). In particular, in some embodiments, the PUCCH transmit power for subframe i on the SeNB link is determined according to:

(97) $P_{\mathrm{PUCCH},\mathrm{SeNB}}\left(i\right)=\min \left\{\begin{array}{c}\min \left(\begin{array}{c}{P}_{\mathrm{CMAX},c}\left(i\right),P_{\mathrm{CMAX}}\left(i\right)-\underset{c}{.Math.}{P}_{\mathrm{PUSCH},c,\mathrm{MeNB}}\left(i-1\right)-\\ P_{\mathrm{PUCCH},\mathrm{MeNB}}\left(i-1\right)\end{array}\right),\\ \begin{array}{c}{P}_{0\mathrm{\_PUCCH},\mathrm{SeNB}}+{\mathrm{PL}}_c+h\left(n_{\mathrm{CQI}},n_{\mathrm{HARQ}},n_{\mathrm{SR}}\right)+\\ {}_{\mathrm{F\_PUCCH},\mathrm{SeNB}}\left(F\right)+{}_{\mathrm{TxD},\mathrm{SeNB}}\left(F^{}\right)+g\left(i\right)\end{array}\end{array}\right\}\left[\mathrm{dBm}\right]$
In this equation, the top term in the outermost minimization function is to consider the used transmit power in the overlapping subframe i1 of link k (i.e., the MeNB link). In this example, the used transmit power is the PUSCH transmit power and the PUCCH transmit power used for the MeNB link. Thus, the top term (which is itself a minimization function) returns the minimum of: (a) the maximum allowable transmit power for the subframe i and (b) a difference between the maximum allowable transmit power and the total transmit power already used (both PUSCH and PUCCH) in the overlapping subframe i1 of the MeNB link. The bottom term in the equation above is the conventional PUCCH transmit power. Thus, the PUCCH transmit power for subframe i on the SeNB link is the minimum of: (a) P.sub.CMAX,c(i), (b) the unused amount of P.sub.CMAX(i) when taking into consideration the total transmit power already used in the overlapping subframe i1 of the MeNB link, and (c) the conventional PUCCH transit power, which does not take into consideration any overlapping subframes of the MeNB link.

(98) If there is no overlap between subframe i on the SeNB link and subframe i1 on the MeNB link, the wireless device 12 determines the PUCCH transmit power for subframe i of the SeNB link in a normal or conventional manner (step 1014). In one particular example, the wireless device 12 determines the PUCCH transmit power for subframe i of the SeNB link as:

(99) $P_{\mathrm{PUCCH},\mathrm{SeNB}}\left(i\right)=\min \left\{\begin{array}{c}{P}_{\mathrm{CMAX},c}\left(i\right),\\ \begin{array}{c}{P}_{0\mathrm{\_PUCCH},\mathrm{SeNB}}+{\mathrm{PL}}_c+h\left(n_{\mathrm{CQI}},n_{\mathrm{HARQ}},n_{\mathrm{SR}}\right)+\\ {}_{\mathrm{F\_PUCCH},\mathrm{SeNB}}\left(F\right)+{}_{\mathrm{TxD},\mathrm{SeNB}}\left(F^{}\right)+g\left(i\right)\end{array}\end{array}\right\}\left[\mathrm{dBm}\right]$
This process can be repeated by the wireless device 12 for each subframe of both the MeNB link and the SeNB link.

(100) PUSCH power control: The transmission power of PUSCH on either the MeNB link or the SeNB link are, in some embodiments, determined as illustrated in FIG. 29 and described as follows. In general, FIG. 29 illustrates a process in which the PUSCH transmit power of one link is scaled by taking into consideration transmit power in an earlier overlapping subframe of the other link. If the total transmit power of the wireless device 12 for subframe i (the MeNB link or the SeNB link) would exceed the maximum allowable transmit power {circumflex over (P)}.sub.CMAX(i) (step 1100) and if there will be an overlapping transmission in time from subframe i1 on the SeNB link to subframe i on the MeNB link (step 1102), the wireless device 12 scales the PUSCH transmit power level {circumflex over (P)}.sub.PUSCH,c(i) for the serving cell c on the MeNB link in subframe i (step 1104). In some embodiments, the wireless device 12 scales the PUSCH transmit power level {circumflex over (P)}.sub.PUSCH,c(i) for the serving cell c on the MeNB link in subframe i such that the following condition is satisfied:

(101) 0$\underset{c}{.Math.}{w}_1\left(i\right).Math.{\hat{P}}_{\mathrm{PUSCH},c}\left(i\right)\left(\left({\hat{P}}_{\mathrm{CMAX}}\left(i\right)-\underset{c}{.Math.}{\hat{P}}_{\mathrm{PUSCH},c,\mathrm{SeNB}}\left(i-1\right)-{\hat{P}}_{\mathrm{PUCCH},\mathrm{SeNB}}\left(i-1\right)\right)\right)$
where w.sub.1(i) is the scaling factor.

(102) Otherwise, if there will be an overlapping transmission in time from subframe i1 on the MeNB link to subframe i on the SeNB link (step 1106), the wireless device 12 scales the PUSCH transmit power level {circumflex over (P)}.sub.PUSCH,c(i) for the serving cell c on the SeNB link in subframe i (step 1108). In some embodiments, the wireless device 12 scales the PUSCH transmit power level {circumflex over (P)}.sub.PUSCH,c(i) for the serving cell c on the SeNB link in subframe i such that the following condition is satisfied:

(103) $\underset{c}{.Math.}{w}_1\left(i\right).Math.{\hat{P}}_{\mathrm{PUSCH},c}\left(i\right)\left(\left({\hat{P}}_{\mathrm{CMAX}}\left(i\right)-\underset{c}{.Math.}{\hat{P}}_{\mathrm{PUSCH},c,\mathrm{MeNB}}\left(i-1\right)-{\hat{P}}_{\mathrm{PUCCH},\mathrm{MeNB}}\left(i-1\right)\right)\right)$

(104) This process of FIG. 29 illustrates that the PUSCH transmission of the later subframe i of one link takes at most the leftover power after subframe (i1) of the other link. This process may be useful by itself if there is no PUCCH in subframe i in parallel with PUSCH of subframe i. In that case, only the overlap needs to be addressed.

(105) The wireless device 12 may determine the PUSCH transmit power in other manners. For instance, FIG. 30 and the following text describe one example of a process by which the wireless device 12 determines the PUSCH transmit power. As illustrated in FIG. 30, if the wireless device 12 transmits PUSCH for the serving cell c on either MeNB link or the SeNB link (step 1200), then the PUSCH transmit power level P.sub.PUSCH,c(i) for the wireless device 12 for PUSCH transmission in subframe i for the serving cell c is determined (step 1202). In some embodiments, the PUSCH transmit power level P.sub.PUSCH,c(i) for the wireless device 12 for PUSCH transmission in subframe i for the serving cell c is given by:

(106) $P_{\mathrm{PUSCH},c}\left(i\right)=\min \left\{\begin{array}{c}{P}_{\mathrm{CMAX},c}\left(i\right)-\underset{c}{.Math.}.Math.{\hat{P}}_{\mathrm{PUCCH},c}\left(i\right),\\ \begin{array}{c}10{\log }_{10}\left(M_{\mathrm{PUSCH},c}\left(i\right)\right)+P_{\mathrm{O\_PUSCH},c}\left(j\right)+\\ {}_c\left(j\right).Math.{\mathrm{PL}}_c+{}_{\mathrm{TF},c}\left(i\right)+f_c\left(i\right)\end{array}\end{array}\right\}\left[\mathrm{dBm}\right]$
wherein {circumflex over (P)}.sub.PUCCH,c(i) could also be zero assuming that there are no ongoing PUCCH transmissions. Another alternative is that PUSCH transmission on the MeNB link (link k) only considers PUCCH transmission on the MeNB link, e.g. PUSCH transmissions on the MeNB link only consider PUCCH transmissions on the MeNB link. The same may be true for the SeNB link.

(107) The process of FIG. 30 and the equation above do not address overlap between subframe i of the one link with subframe (i1) of the other link. Rather, only the PUCCH and PUSCH in subframe i of the same link are considered. In the equation above, the first term in the minimization function indicates that the PUCCH has priority over PUSCH. The PUSCH transmit power is at most what is left over after PUCCH transmission. The second term is the calculated natural, or conventional, PUSCH transmit power level, which is calculated according to the needs of PUSCH itself. Taking the minimum of these terms says, in effect, that if the natural PUSCH power is low, then the natural PUSCH power will be used. Otherwise, if the natural PUSCH power is high, then the PUSCH transmit power will be capped at the amount of power remaining after allocating power to the PUCCH transmission. The process of FIG. 30 is particularly beneficial when there is no overlap with an earlier subframe (i1) of the other link.

(108) In some embodiments, power scaling across all carriers and links is provided for dynamic configuration. As illustrated in FIG. 31, in some embodiments, if the total transmit power of the wireless device 12 would exceed {circumflex over (P)}.sub.CMAX(i) and there will be an overlapping transmission in time from the subframe i1 on one link to subframe i of the other link (step 1300), the wireless device 12 scales the PUSCH transmit power level for subframe i of the other link (step 1302). More specifically, in some embodiments, if the total transmit power of the wireless device 12 would exceed {circumflex over (P)}.sub.CMAX(i) and there will be an overlapping transmission in time from the subframe i1 on the SeNB link to subframe i on the MeNB link, the wireless device 12 scales {circumflex over (P)}.sub.PUSCH,c(i) for the serving cell c on the MeNB link (link k) in subframe i such that the following condition is satisfied:

(109) $\underset{c}{.Math.}w\left(i\right).Math.{\hat{P}}_{\mathrm{PUSCH},c}\left(i\right)\left(\left({\hat{P}}_{\mathrm{CMAX}}\left(i\right)-\underset{c}{.Math.}{\hat{P}}_{\mathrm{PUSCH},c,\mathrm{SeNB}}\left(i-1\right)-{\hat{P}}_{\mathrm{PUCCH},\mathrm{SeNB}}\left(i-1\right)\right)-\underset{c}{.Math.}.Math.{\hat{P}}_{\mathrm{PUCCH},c}\left(i\right)\right)$
Otherwise, if there will be an overlapping transmission in time from the subframe i1 on the MeNB link to subframe i on the SeNB link, the wireless device 12 scales {circumflex over (P)}.sub.PUSCH,c,SeNB(i) for the serving cell c on the MeNB link (link k) in subframe i such that the following condition is satisfied:

(110) $\underset{c}{.Math.}w\left(i\right).Math.{\hat{P}}_{\mathrm{PUSCH},c}\left(i\right)\left(\left({\hat{P}}_{\mathrm{CMAX}}\left(i\right)-\underset{c}{.Math.}{\hat{P}}_{\mathrm{PUSCH},c,\mathrm{MeNB}}\left(i-1\right)-{\hat{P}}_{\mathrm{PUCCH},\mathrm{MeNB}}\left(i-1\right)\right)-\underset{c}{.Math.}.Math.{\hat{P}}_{\mathrm{PUCCH},c}\left(i\right)\right)$

(111) This scaling combines the two considerations from above, namely: (a) overlap between subframe i on one link with subframe (i1) on the other link and (b) need of PUCCH in subframe i. In these scaling embodiments, in the event of insufficient power, PUSCH has lower priority, and the PUSCH transmit power level is scaled so that both (a) and (b) are taken into consideration. Also, note that in the two equations above illustrating the scaling, the PUCCH power level is from earlier PUCCH power level calculations. Hence, if in PUCCH power calculation the UE determines that there is no more power left over after PUCCH power calculation, then the weights w(i) of PUSCH can be set to zero. In this case, PUSCH gets no power and is essentially dropped.

(112) The scaling equations can also be explained in the following manner. The right-hand side of the two preceding equations is a calculation of transmit power left over after subtracting the transmit power needs of subframe i1 of the other link and the PUCCH transmit power needs of subframe i of the link from the maximum allowable transmit power. On the left-hand sides of the equations, the natural power level of PUSCH (e.g., calculated as the 10 log 10( ) term in the PUSCH power control description above) is scaled down by applying weights w(i) so that it does not exceed the value calculated on the right-hand side of the equation.

(113) The above scaling embodiments can also be combined with a configurable maximum transmission power value per link, e.g., the power cannot exceed this power independent from if there is something transmitted or not on the other link. Alternatively, the scaling embodiments does consider if there is something transmitted or not on the other link, such that the maximum power limitation is only applied in case the UE may exceed the maximum transmission power shared by two links.

(114) In the embodiments above, it was assumed that for any given instant {circumflex over (P)}.sub.MeNB,max+{circumflex over (P)}.sub.SeNB,max={circumflex over (P)}.sub.CMAX(i). Alternatively, the maximum transmit power levels P.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are not defined such that the sum of maximum power must be equal to {circumflex over (P)}.sub.CMAX. For instance, the wireless device 12 could first determine the transmission power for the MeNB link and the SeNB link separately, assuming non-existence of the other link(s). Then, the wireless device 12 could perform power scaling over two (or more) simultaneous links if the total power for the two (or more) links determined in the previous step exceeds the maximum allowed power {circumflex over (P)}.sub.CMAX(i).

(115) FIG. 32 illustrates one embodiment of a procedure that utilizes such a scaling scheme. As illustrated, the wireless device 12 configures the maximum (allowable) transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max separately (step 1400). In this embodiment, the sum of the configured maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max could exceed the maximum allowable transmission power level {circumflex over (P)}.sub.CMAX for the wireless device 12. However, one special case is that both {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are equal to {circumflex over (P)}.sub.CMAX.

(116) Note that the relative priority between the PUCCH on the MeNB link and the PUCCH on the SeNB link can be set by the relative values of {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max. In one example, {circumflex over (P)}.sub.MeNB,max={circumflex over (P)}.sub.CMAX, {circumflex over (P)}.sub.SeNB,max={circumflex over (P)}.sub.CMAX. In this case, the wireless device 12 determines the power of the uplink channel(s) on the MeNB link (as discussed below in step 1402) without being limited by the SeNB link and determines the power of the uplink channel(s) on the SeNB link (as discussed below in step 1402) without being limited by the MeNB link. The wireless device 12 then scales the power of uplink channels on the MeNB link and the SeNB link equally in step 1404 (discussed below) if {circumflex over (P)}.sub.CMAX will be exceed by the sum without scaling.

(117) In another example, {circumflex over (P)}.sub.MeNB,max={circumflex over (P)}.sub.CMAX, {circumflex over (P)}.sub.SeNB,max=0.5{circumflex over (P)}.sub.CMAX. In this case, in step 1402 discussed below, the wireless device 12 determines the transmit power for the uplink channels on the MeNB link without being limited by the SeNB link, whereas the wireless device 12 determines the transmit power for the uplink channels on the SeNB link with the limitation that maximum total power across the SeNB channels cannot exceed 0.5{circumflex over (P)}.sub.CMAX. This biases power allocation in favor of the MeNB uplink channels if equal scaling is applied in step 1404 (i.e., w.sub.MeNB(i)=w.sub.SeNB(i)).

(118) After configuring the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max, the wireless device 12 calculates, or otherwise determines, the transmit power levels for the uplink channels to be transmitted on the MeNB link and the SeNB link (step 1402). In some embodiments, for each link, the calculation of the transmit power for the corresponding uplink channels could reuse the principles for LTE Release 11 Carrier Aggregation (CA) including channel prioritization as well as the power scaling. Notably, as discussed above, in some embodiments, the relative priority between the PUCCH on the MeNB link and the PUCCH on the SeNB link can be set by the relative values of {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max. This relative priority may be taken into consideration when calculating the transmit power for the uplink channels, as discussed above.

(119) The wireless device 12 performs scaling of the transmit power levels over all (active) channels for both of the links such that the total transmit power does not exceed the maximum allowable transmit power level {circumflex over (P)}.sub.CMAX(i) (step 1404). In some embodiments, the wireless device 12 performs scaling over all the active channels for both the MeNB link and the SeNB link so that the total power does not exceed {circumflex over (P)}.sub.CMAX according to:

(120) $\underset{c}{.Math.}{w}_{\mathrm{MeNB}}\left(i\right).Math.{\hat{P}}_{\mathrm{MeNB},c}\left(i\right)+.Math.\underset{c}{.Math.}{w}_{\mathrm{SeNB}}\left(i\right).Math.{\hat{P}}_{\mathrm{SeNB},c}\left(i\right){\hat{P}}_{\mathrm{CMAX}}\left(i\right)$
where w.sub.MeNB(i) and w.sub.SeNB(i) are the scaling factors for the MeNB link and the SeNB link, respectively, and 0w.sub.MeNB(i)1,0w.sub.SeNB(i)1. The power scaling for the MeNB link and the SeNB link could either be same or different. In some embodiments, the ratio of scaling factors for the MeNB link and the SeNB link are signalled to the wireless device 12. In other embodiments, the scaling factors are the same and determined by the wireless device 12. Lastly, the wireless device 12 transmits all channels for both the MeNB link and the SeNB link according to the scaled transmit power levels (step 1406).

(121) The process of FIG. 32 can be combined with either static or semi-statically defined {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max. Handling of unsynchronized subframes between the MeNB link and the SeNB link can be handled by considering overlapping in both slots or only considering overlapping in first slot.

(122) Thus far, the embodiments described have related to static, semi-static, and dynamic power level configuration when the wireless device 12 is operating with dual connectivity. In other embodiments, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max are assigned based on priorities assigned to the links or to the uplink channels transmitted on the links according to some embodiments of the present disclosure. In this regarding, in some embodiments, the following uplink transmission priorities, p, are assigned between the different types of uplink channels that can be transmitted on the MeNB link and the SeNB link: Physical Random Access Channel (PRACH) (p=1) PUCCH with Uplink Control Information (UCI) (p=2) PUSCH with UCI (p=3) PUSCH without UCI (p=4) SRS (p=5)
Based on these priorities, the maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max can be, for example, assigned according to the following: Share power equally if the transmissions over the two links have same priority level p; Give full power to a link with higher priority level p, then give the rest to transmission of next priority; Drop SRS if it overlaps the higher priority channels. Notably, SRS may not be dropped all the time. For example, if required SRS power is less than the guaranteed power level of the link, then SRS may not be dropped.

(123) For two transmissions with UCI, the prioritization can further separate out UCI elements. For example, Hybrid Automatic Repeat Request (HARQ) Acknowledgements/Non-Acknowledgements (ACKs/NACKs), or HARQ-ACK can be treated with higher priority than other UCI elements (Channel State Information (CSI)). In this case, the modified priority (high to low) can be defined as: PRACH (p=1) PUCCH with HARQ-ACK (p=2) PUSCH with HARQ-ACK (p=3) PUSCH with CSI only (i.e., without HARQ-ACK) (p=4) PUCCH with CSI only (i.e., without HARQ-ACK) (p=5) SRS (p=6) PUSCH with UCI carries aperiodic CSI reports triggered by eNB

(124) FIG. 33 is a flow chart that illustrates one embodiment of using the prioritization of uplink channels to assign the maximum transmit power levels P.sub.MeNB,max and P.sub.SeNB,max according to some embodiments of the present disclosure. As illustrated, the wireless device 12 assigns the maximum transmit power levels P.sub.MeNB,max and P.sub.SeNB,max for the links based on priorities associated with the links (step 1500). As discussed above, the priorities associated with the links is, at least in some embodiments, based on priorities assigned to, or otherwise associated with, the uplink channels to be transmitted on the links, which are referred to herein as active uplink channels for the links. The priorities may be assigned to the uplink channels based on the channel types or the information, or content, of the channels. The wireless device 12 transmits uplink transmissions, including the active uplink channels, on the links according to the assigned maximum transmit power levels {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max (step 1502).

(125) FIG. 34 is a block diagram of a base station 18 according to some embodiments of the present disclosure. As illustrated, the base station 18 includes a baseband unit 20 including one or more processors 22 (e.g., Central Processing Unit(s) (CPU(s)), Application Specific Integrated Circuit(s) (ASIC(s)), and/or Field Programmable Gate Array(s) (FPGA(s))), memory 24, and a network interface 26 and one or more radio units 28 including one or more transmitters 30 and one or more receivers 32 coupled to one or more antennas 34. In some embodiments, the functionality of the base station 18 described herein is implemented in software that is stored by the memory 24 and executed by the processor(s) 22, whereby the base station 18 operates according to any of the embodiments described herein.

(126) In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the base station 18 according to any of the embodiments described herein is provided. In one embodiment, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as the memory 24).

(127) FIG. 35 is a block diagram of a wireless device 36 according to some embodiments of the present disclosure. As illustrated, the wireless device 36 includes one or more processors 38 (e.g., CPU(s), ASIC(s), and/or FPGA(s)), memory 40, and one or more transceivers 42 including one or more transmitters 44 and one or more receivers 46 coupled to one or more antennas 48. In some embodiments, the functionality of the wireless device 36 described herein is implemented in software stored in the memory 40 and executed by the processor(s) 38, whereby the wireless device 36 operates according to any of the embodiments described herein.

(128) In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the wireless device 12 according to any of the embodiments described herein is provided. In one embodiment, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as the memory 40).

(129) FIG. 36 is a block diagram that illustrates the wireless device 36 according to some other embodiments of the present disclosure. As illustrated, the wireless device 36 includes a power level determination module 50 and a transmit module 52, each of which is implemented in software. The power level determination module 50 operates to determine {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max according to any of the embodiments described herein. The transmit module 52 operates to transmit on the links k and k (via an associated transmitter(s) of the wireless device 36, which are not shown in FIG. 36) in accordance with the determined values for {circumflex over (P)}.sub.MeNB,max and {circumflex over (P)}.sub.SeNB,max.

(130) In one example embodiment, a method is performed at a UE for calculating power for a first link for a first subframe. The method comprises determining whether there is an uplink transmission on a second link overlapping a first time slot of the first subframe; if a uplink transmission exists on the second link, calculating power {circumflex over (P)}.sup.k (i1)=min ({circumflex over (P)}.sub.SL.sup.k(i),{circumflex over (P)}.sub.CMAX(i){circumflex over (P)}.sub.used.sup.k(i1)), where {circumflex over (P)}.sub.CMAX(i) refers to the linear value of the UE total configured maximum output power level P.sub.CMAX, P.sub.used.sup.k(i1) refers to the power level used by the other link k that overlaps the first slot of the subframe i; {circumflex over (P)}.sub.SL.sup.k(i) is the calculated linear power value for the link k assuming link k is the single link that the UE has uplink transmission in the entire duration of subframe i (i.e., assuming non-overlap with link k). The method further comprises determining whether there is an uplink transmission on the second link overlapping a second slot of the first subframe. If so, the method comprises calculating a power {circumflex over (P)}.sup.k(i) for a second subframe subsequent to the first subframe as if subframe i of the link k is aligned in subframe boundary with the overlapping subframe of link k.

(131) The following acronyms are used throughout this disclosure. s Microsecond ACK Acknowledgement AL Aggregation Level ASIC Application Specific Integrated Circuit CA Carrier Aggregation CC Component Carrier CCE Control Channel Element CFI Control Format Indicator CIF Carrier Indicator Field CPU Central Processing Unit CRC Cyclic Redundancy Check C-RNTI Cell Radio Network Temporary Identifier CRS Common Reference Symbol CSI Channel State Information dB Decibel dBm Milli-Decibels DCI Downlink Control Information DFT Discrete Fourier Transform DL PCC Downlink Primary Component Carrier DTX Discontinuous Transmission eNB Enhanced or Evolved Node B ePDCCH Enhanced Physical Downlink Control Channel FDD Frequency Division Duplex FPGA Field Programmable Gate Array GNSS Global Navigation Satellite System HARQ Hybrid Automatic Repeat Request LTE Long Term Evolution MAC Medium Access Control MCG Master Cell Group MeNB Master Enhanced or Evolved Node B MHz Megahertz ms Millisecond NACK Non-Acknowledgement OFDM Orthogonal Frequency Division Multiplexing PCell Primary Cell PDCCH Physical Downlink Control Channel PDSCH Physical Downlink Shared Channel PRACH Physical Random Access Channel PRB Physical Resource Block PUCCH Physical Uplink Control Channel PUSCH Physical Uplink Shared Channel QCI Quality of Service Class Indicator QPSK Quadrature Phase Shift Keying RB Resource Block REG Resource Element Group RLC Radio Link Control RNTI Radio Network Temporary Identifier RRC Radio Resource Control RSRP Reference Signal Received Power SCC Secondary Component Carrier SCG Secondary Cell Group SeNB Secondary Enhanced or Evolved Node B SRS Sounding Reference Signal TAG Timing Advance Group TDD Time Division Duplex TP Transmission Point TPC Transmit Power Control TS Technical Specification UCI Uplink Control Information UE User Equipment UL Uplink UL PCC Uplink Primary Component Carrier VRB Virtual Resource Block

(132) Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.