JP2016195413A - User terminal, radio base station, and radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in uplink throughput when a user terminal connects with a plurality of radio base stations.SOLUTION: A user terminal 20 includes: a transmission unit that communicates using a first cell group (CG) and a second CG, and transmits a plurality of types of uplink signals by each CG; and a control unit that performs control so that power is allocated to a prescribed type of uplink signal transmitted by the first CG preferentially to the prescribed type of uplink signal transmitted by the second CG. The transmission unit transmits user terminal capability information representing whether to support asynchronous dual connectivity or not to a radio base station. When the user terminal supports asynchronous dual connectivity and receives prescribed signaling from the radio base station, the control unit performs control so as not to change power of a signal in transmission in the middle of a sub-frame at the sub-frame of each CG, and controls transmission power in consideration of uplink signal transmission power of a sub-frame of the other CG overlapping with the sub-frame.SELECTED DRAWING: Figure 15

Description

  The present invention relates to a user terminal, a radio base station, and a radio communication method in a next generation mobile communication system.

  In the UMTS (Universal Mobile Telecommunications System) network, Long Term Evolution (LTE) has been specified for the purpose of higher data rate and low delay (Non-patent Document 1).

  LTE uses a multi-access scheme based on OFDMA (Orthogonal Frequency Division Multiple Access) for the downlink (downlink) and SC-FDMA (single carrier frequency division multiple access) for the uplink (uplink). Is used.

  For the purpose of further broadbanding and speeding up from LTE, for example, a successor system of LTE called LTE Advanced or LTE enhancement has been studied, and LTE Rel. It is specified as 10/11. LTE Rel. The 10/11 system band includes at least one component carrier (CC) having the system band of the LTE system as one unit. In this manner, collecting a plurality of CCs to increase the bandwidth is referred to as carrier aggregation (CA).

  LTE Rel., A further successor system of LTE. 12, various scenarios in which a plurality of cells are used in different frequency bands (carriers) are being studied. When the radio base stations forming a plurality of cells are substantially the same, the above-described CA can be applied. On the other hand, when radio base stations forming each cell are completely different, it is conceivable to apply dual connectivity (DC).

3GPP TS 36.300 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2”

  As described above, when radio base stations forming a plurality of cells are substantially the same (for example, when CA is applied), the radio base station comprehensively determines the uplink transmission power of the user terminal in each cell. The uplink transmission power can be controlled in consideration. However, when a plurality of radio base stations independently control the uplink transmission power of a user terminal as in dual connectivity, there is a risk of lowering throughput and communication quality in the uplink.

  The present invention has been made in view of the above points, and provides a user terminal, a radio base station, and a radio communication method capable of suppressing a decrease in uplink throughput when a user terminal is connected to a plurality of radio base stations. One of the purposes is to provide it.

  The user terminal which concerns on 1 aspect of this invention is a user terminal which communicates using a 1st cell group (CG) and 2nd CG, Comprising: The transmission part which each transmits multiple types of uplink signal by each CG, A control unit that controls to allocate power to a predetermined type of uplink signal transmitted by the first CG more preferentially than the predetermined type of uplink signal transmitted by the second CG, and The transmission unit transmits user terminal capability information indicating whether or not asynchronous dual connectivity is supported to the radio base station, and the control unit supports the asynchronous dual connectivity and performs predetermined signaling from the radio base station. In the subframe of each CG, control is performed so that the power of the signal being transmitted is not changed in the middle of the subframe, and overlaps with the subframe. And performing transmission power control in consideration of the transmission power of the uplink signals of all the subframes of different CG that.

  ADVANTAGE OF THE INVENTION According to this invention, when a user terminal connects with a some radio base station, the fall of an uplink throughput can be suppressed.

It is a schematic diagram of a carrier aggregation and dual connectivity. It is a figure which shows an example of the cell structure in a carrier aggregation and dual connectivity. In dual connectivity, it is a figure which shows an example in the case of connecting to each wireless base station by UL-CA. LTE Rel. It is a figure which shows the priority of the upstream signal in 11 UL-CA. It is a figure which shows an example of the priority of the uplink signal in each eNB / CG. It is a figure which shows an example of the priority of an upstream signal in the dual connectivity which concerns on 1st Embodiment. It is a figure which shows an example of the priority of an upstream signal in the dual connectivity which concerns on 1st Embodiment. It is a figure which shows an example in the case of becoming power limited in the middle of a sub-frame. It is a conceptual diagram explaining the transmission power control of 2nd Embodiment. It is a figure which shows an example of the flowchart of the electric power allocation determination based on the difference of the priority of the signal used as simultaneous transmission. It is a figure which shows an example of the electric power allocation determination based on the difference of the priority of the signal used as simultaneous transmission. It is a figure which shows an example of schematic structure of the radio | wireless communications system which concerns on one embodiment of this invention. It is a figure which shows an example of the whole structure of the wireless base station which concerns on one embodiment of this invention. It is a figure which shows an example of a function structure of the wireless base station which concerns on one embodiment of this invention. It is a figure which shows an example of the whole structure of the user terminal which concerns on one embodiment of this invention. It is a figure which shows an example of a function structure of the user terminal which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  Carrier aggregation and dual connectivity are both technologies in which user terminals connect and communicate simultaneously with a plurality of cells, and are applied to, for example, HetNet (Heterogeneous Network). Here, HetNet has been studied in the LTE-A system, and a small cell having a local coverage area of about several tens of meters is formed in a macro cell having a wide coverage area of about several kilometers in radius. It is a configuration. Note that carrier aggregation may be referred to as Intra-eNB CA, and dual connectivity may be referred to as Inter-eNB CA.

  FIG. 1 is a schematic diagram of carrier aggregation and dual connectivity. In the example illustrated in FIG. 1, the user terminal UE communicates with the radio base stations eNB1 and eNB2.

  FIG. 1 shows control signals transmitted and received via a physical downlink control channel (PDCCH) and a physical uplink control channel (PUCCH). For example, downlink control information (DCI: Downlink Control Information) is transmitted via PDCCH, and uplink control information (UCI: Uplink Control Information) is transmitted via PUCCH. Note that an enhanced physical downlink control channel (EPDCCH) may be used instead of PDCCH.

  FIG. 1A illustrates communication between the radio base stations eNB1 and eNB2 and the user terminal UE related to carrier aggregation. In the example shown in FIG. 1A, eNB1 is a radio base station (hereinafter referred to as a macro base station) that forms a macro cell, and eNB 2 is a radio base station (hereinafter referred to as a small base station) that forms a small cell.

  For example, the small base station may have a configuration such as an RRH (Remote Radio Head) connected to the macro base station. When carrier aggregation is applied, one scheduler (for example, a scheduler included in the macro base station eNB1) controls scheduling of a plurality of cells.

  In a configuration in which a scheduler of a macro base station controls scheduling of a plurality of cells, it is assumed that the base stations are connected by an ideal backhaul that is a high-speed line such as an optical fiber. .

  FIG. 1B shows communication between the radio base stations eNB1 and eNB2 and the user terminal UE related to dual connectivity. In the example shown in FIG. 1B, both eNB1 and eNB2 are macro base stations.

  When dual connectivity is applied, a plurality of schedulers are provided independently, and the plurality of schedulers (for example, the scheduler that the macro base station eNB1 has and the scheduler that the macro base station eNB2 has) have one or more jurisdictions. Control cell scheduling.

  In a configuration in which the scheduler of the macro base station eNB1 and the scheduler of the macro base station eNB2 control the scheduling of one or more cells under their jurisdiction, the delay between each base station cannot be ignored, for example, an X2 interface It is assumed that they are connected by a non-ideal backhaul.

  For this reason, in dual connectivity, it is assumed that cooperative control between dense eNBs equivalent to carrier aggregation cannot be performed. Therefore, downlink L1 / L2 control (PDCCH / EPDCCH) and uplink L1 / L2 control (UCI feedback by PUCCH / PUSCH) must be performed independently at each eNB.

  FIG. 2 is a diagram illustrating an example of a cell configuration in carrier aggregation and dual connectivity. In FIG. 2, the UE is connected to five cells (C1-C5). C1 is a PCell (Primary Cell), and C2-C5 is an SCell (Secondary Cell).

  As shown in FIG. 2A, in the carrier aggregation, the uplink control signal is transmitted via the PCell, so the SCell does not need to have the PCell function.

  On the other hand, as shown in FIG. 2B, in dual connectivity, each radio base station sets a cell group (CG: Cell Group) composed of one or a plurality of cells. Each cell group includes one or more cells formed by the same radio base station, or one or more cells formed by the same transmission point such as a transmission antenna device or a transmission station.

  Here, a cell group including PCell is called a master cell group (MCG: Master CG), and a cell group other than the MCG is called a secondary cell group (SCG: Secondary CG). In each cell group, carrier aggregation of two or more cells can be performed.

  A radio base station in which MCG is set is called a master base station (MeNB: Master eNB), and a radio base station in which SCG is set is called a secondary base station (SeNB: Secondary eNB).

  Note that the total number of cells constituting the MCG and SCG is set to be a predetermined value (for example, 5 cells) or less. The predetermined value may be determined in advance or may be dynamically set between the radio base station eNB and the user terminal UE. Also, depending on the implementation of the user terminal UE, the total value of the cells constituting the configurable MCG and SCG and the combination of the cells may be notified to the radio base station eNB as user terminal capability information (UE capability information). .

  In dual connectivity, it is assumed that the backhaul delay between eNBs is large as described above. Therefore, since each eNB independently transmits and receives control information with the UE, the SeNB is also referred to as a special cell (special cell, PUCCH setting cell, or the like) having functions equivalent to PCell (common search space, PUCCH, etc.) )Is required. In the example of FIG. 2B, the cell C3 is set as such a special cell.

  As described above, in dual connectivity, a user terminal needs to connect to a plurality of radio base stations using at least one uplink serving cell. Furthermore, it has been studied to perform UL-CA (uplink carrier aggregation) using two or more uplink serving cells for each radio base station. FIG. 3 is a diagram illustrating an example of a case where each radio base station is connected by UL-CA in dual connectivity. In FIG. 3, the user terminal is connected to each of MeNB and SeNB by UL-CA.

  Here, the transmission timing of the uplink signal is independently controlled by the MeNB and SeNB. Further, uplink signal transmission power control is also performed independently at the MeNB and SeNB. Therefore, at the timing when the transmission of the uplink signal to the MeNB and SeNB overlaps, the transmission of the uplink signal exceeding the allowable maximum power (Pcmax) of the user terminal may be requested. In the following, the fact that transmission power is limited as a result of a request for transmission of an uplink signal exceeding the allowable maximum power of the user terminal is also referred to as “Power-limited”.

  At this time, the user terminal has to reduce the transmission power until it becomes the allowable maximum power or less by reducing the transmission power or dropping the transmission signal based on some rule. Here, LTE Rel. In 11 UL-CA, priorities are set for a plurality of types of uplink signals to be transmitted to one radio base station, and according to the priorities, the total transmission power of each CC is equal to or lower than the allowable maximum power. It is stipulated that the transmission power be adjusted.

  FIG. 4 shows LTE Rel. It is a figure which shows the priority of the upstream signal in 11 UL-CA. As shown in FIG. 11, PRACH has the highest priority, followed by PUCCH, PUSCH w / UCI (PUSCH including UCI), PUSCH w / o UCI (PUSCH not including UCI), and SRS in that order. Each channel in FIG. 4 represents a signal transmitted through each channel, and is expressed in the same manner below.

  LTE Rel. 11 UL-CA, when the transmission periods of signals with different priorities overlap and become a power limited state, control is performed so that the signal with the lower priority is power-scaled or not transmitted (dropped). carry out. In addition, when signals having the same priority are overlapped and enter a power limited state, control is performed so that power scaling is applied to both signals at the same ratio.

  However, LTE Rel. In 12 dual connectivity, the priority between CG / eNB is not specified at all. For this reason, when the user terminal operates the transmission power of the uplink signal to each CG / eNB, the quality of the uplink signal that is not intended by the radio base station may be deteriorated, resulting in an increase in retransmission and a decrease in throughput.

  In order to solve this problem, the present inventors have studied to appropriately set the transmission priority of the uplink signal for the MeNB and SeNB when applying dual connectivity. As a result, the present inventors have conceived that transmission of a predetermined uplink signal of the MeNB is set to have priority over transmission of the same predetermined uplink signal of the SeNB. According to this configuration, the user terminal can reduce the influence of the limitation due to the maximum allowable power by increasing the priority of important control signals.

  In addition, the present inventors have conceived that power control is appropriately performed in consideration of the above priorities when uplink signal transmission timings are not synchronized in a plurality of radio base stations.

  Hereinafter, embodiments according to the present invention will be described in detail. In the following, for the sake of simplicity, an example in which a user terminal is connected to two radio base stations (MeNB, SeNB) with dual connectivity will be described, but the present invention is not limited to this. For example, the present invention can also be applied when a user terminal is connected to and communicates with three or more radio base stations controlled by independent schedulers. Moreover, the structure connected with a cell group instead of a wireless base station may be sufficient, and a wireless base station or a cell group is described also as eNB / CG below.

  In the following description, the priority in each eNB / CG is set to maintain the priority order (priority rule) shown in FIG. FIG. 5 is a diagram illustrating an example of priorities of uplink signals in each eNB / CG. FIG. 5A shows an example of priority in the MeNB / MCG, and FIG. 5B shows an example of priority in the SeNB / SCG. These priorities are assigned to Rel. 11 in the same order of priority as UL-CA (PRACH, PUCCH, PUSCH w / UCI, PUSCH w / o UCI, SRS). With this configuration, Rel. The processing of the user terminal can be performed in a unified manner as in the case of 11, and the mounting cost can be reduced. In addition, the priority in each eNB / CG is not restricted to the priority order of FIG. 5, You may use another priority order.

(First embodiment)
In the first embodiment of the present invention, a higher priority is set for each uplink signal to the MCG / MeNB than an uplink signal to the same type of SCG / SeNB as the uplink signal.

  In an example of the first embodiment, the priority rule is set so that all uplink signals of MeNB / MCG have priority over all uplink signals of SeNB / SCG. FIG. 6 is a diagram illustrating an example of priorities of uplink signals in the dual connectivity according to the first embodiment. As shown in FIG. 6, this priority rule is one in which the UL-CA priority in the MeNB / MCG (FIG. 5A) is set higher than the UL-CA priority in the SeNB / SCG (FIG. 5B). .

  By following this priority rule, it is possible to prevent the degradation of MCG / MeNB due to power limited, and it is possible to apply dual connectivity without degrading the macro cell coverage.

  In the above-described embodiment, SRS and PUSCH w / o UCI are exceptionally not based on the priority rule described above, and the priority may be greatly reduced in both MeNB / SeNB. For example, in FIG. 6, the PUSCH w / o UCI and SRS of the MeNB may have a lower priority than the PUSCH w / UCI of the SeNB. As a result, the channel of the MeNB with low priority consumes power, and the adverse effect due to the fact that signals related to SeNB connectivity / delay such as PRACH and PUCCH of the SeNB cannot obtain power can be further reduced. it can.

  Moreover, in the said Example, about PRACH and PUCCH, you may raise a priority greatly not only based on said priority rule exceptionally in both MeNB / SeNB. For example, in FIG. 6, the PRACH and PUCCH of the SeNB may have higher priority than the PUSCH w / UCI of the MeNB. Thereby, the channel of the MeNB having a low priority consumes power, and the adverse effect caused by the fact that signals that greatly affect the connectivity and delay of the SeNB such as PRACH and PUCCH of the SeNB cannot be obtained can be further reduced. .

  Further, in another example of the first embodiment, for each uplink signal of the same type, the MeNB / MCG is set to have a priority equal to or higher than the SeNB / SCG, and the priorities are set adjacent to each other. . Here, “adjacent” means, in other words, that priorities of other types of signals are not set between priorities of the same type of signals.

  FIG. 7 is a diagram illustrating an example of priorities of uplink signals in the dual connectivity according to the first embodiment. In FIG. 7, the priority in each eNB / CG is set to Rel. The priority rule is set to be the same as 11 UL-CA. This priority rule sets MeNB / MCG to a higher priority than SeNB / SCG for each signal. That is, in the present embodiment, when the priorities of the same type of uplink signals are considered together, they are set to be the same as the priority rules in each eNB / CG.

  By following this priority rule, power can be preferentially allocated to signals with high priority regardless of eNB / CG. In particular, since the priority of PUSCH, which is likely to cause a bandwidth limitation and is likely to cause power limitation, can be made relatively low, the influence on important control signals such as PRACH and PUCCH can be reduced.

  The predetermined signal may be configured to have the same priority in the MeNB / MCG and the SeNB / SCG. That is, it is good also as a structure which sets the priority to MeNB / MCG equivalent to the priority to SeNB / SCG for every uplink signal of the same kind. In this case, the signals having the same priority may be scaled at equal power or equal ratio when they become power limited, or may be dropped at the same time.

  As described above, according to the first embodiment, it is possible to secure transmission power of a signal with high priority even in dual connectivity, and it is possible to suppress a decrease in uplink throughput.

  When the user terminal holds a plurality of priority rules, downlink control information (DCI) from the radio base station, higher layer signaling (for example, RRC signaling), broadcast signal (for example, SIB), etc. The priority rule to be applied may be determined on the basis of the information on the priority rule notified by. For example, the priority rules of FIGS. 6 and 7 can be switched and applied based on the notified information.

(Second Embodiment)
When the uplink signal transmission timing is not synchronized (hereinafter also referred to as asynchronous dual connectivity) among a plurality of eNBs / CGs connected by dual connectivity, the priority of the uplink signal as described in the first embodiment It may be difficult to comply with the rules.

  This problem will be specifically described with reference to FIG. FIG. 8 is a diagram illustrating an example of a case where power is limited in the middle of a subframe. The horizontal axis in FIG. 8 indicates time, and the vertical direction indicates power allocated to the transmission signal. Further, the allowable maximum power of the user terminal is Pcmax, which is constant during the illustrated period.

  In the example of FIG. 8, first, the user terminal starts a PUSCH w / o UCI transmission process using SeNB / SCG. At this time, since no uplink signal is transmitted in the MeNB / MCG, the user terminal can transmit a signal with transmission power required by the SeNB.

  Next, during transmission of PUSCH w / o UCI by SeNB / SCG, transmission of PUSCH w / UCI by MeNB / MCG is started. At this time, there is a risk of becoming power limited. According to the priority rule of FIG. 6 or FIG. 7, since the priority of PUSCH w / UCI in MeNB / MCG is higher than PUSCH w / o UCI in SeNB / SCG, the latter transmission power is lowered in the middle of the subframe, It is required to control the total transmission power so that it falls within Pcmax.

  Moreover, after the transmission of PUSCH w / o UCI is completed in SeNB / SCG, transmission of PUCCH is started. At this time, there is a risk of becoming power limited. For example, when the priority rule of FIG. 7 is followed, since the priority of PUCCH in SeNB / SCG is higher than PUSCH w / UCI in MeNB / MCG, the latter transmission power is reduced in the middle of the subframe, and the total transmission power is Pcmax. It is required to control so as to be within the range.

  However, an operation of changing the power of a signal being transmitted in the middle of a subframe is not preferable. If such an operation is allowed, for example, there is a difference between the power of the reference signal for channel estimation and the data signal, which makes it difficult to demodulate based on the channel estimation. There is a risk that problems such as a change in orthogonality and difficulty in separation will occur when multiplexing with other UEs.

  Therefore, when the priority rule shown in FIG. 6 is adopted, when MeNB / MCG transmission occurs in the middle of a subframe, it is not preferable to change the power of a signal being transmitted by SeNB / SCG. Further, when the priority rule shown in FIG. 7 is adopted, it is not preferable to change the power of the signal currently being transmitted when a higher priority signal is generated in the middle of a subframe. Thus, in asynchronous dual connectivity, the priority of power distribution cannot always be observed, and it may be unclear how transmission power is determined.

  Therefore, in the second embodiment of the present invention, in the asynchronous dual connectivity, the priority as described in the first embodiment without changing the signal transmission power in the middle of the uplink subframe (UL subframe). Control to protect. Specifically, in the dual connectivity according to the present embodiment, detection of power limited and power scaling / dropping at the time of detection are performed in consideration of future uplink transmission signals regardless of synchronization or asynchronous between eNB / CG. Apply.

  First, before determining the transmission power of a predetermined UL subframe for a certain eNB / CG, all UL subframes of another eNB / CG having a simultaneous transmission section partially or entirely with the UL subframe. Check the transmission power. At this time, the UL grant / DL assignment indicating transmission of the UL subframe and the UL subframe overlapping before and after the UL subframe are detected and demodulated, and the UL transmission status (bandwidth, modulation scheme, and so on) is detected. Based on the required UL transmission power).

  Next, based on the UL transmission status investigation result, it is calculated whether there is a part that is power limited at the transmission timing of the UL subframe. Here, if there is a part that is power limited, the signal priority of the part is compared. For example, the priorities shown in FIGS. 6 and 7 can be used.

  As a result of comparing the priorities, the power allocation of the low-priority (non-priority) UL subframes to such a value that the power required for the high-priority (priority) UL subframes can be appropriately distributed (Scaling or dropping).

  FIG. 9 is a conceptual diagram illustrating transmission power control according to the second embodiment. In FIG. 9, one UL subframe that transmits a signal in the MeNB partially has a simultaneous transmission section with two UL subframes that transmit a signal in the SeNB.

  Before the user terminal determines the transmission power of the UL subframe of the MeNB, the UL in the UL subframes of two SeNBs that overlap with the UL subframe is determined based on the received UL grant / DL assignment information. Investigate the transmission power and recognize that there is a part that is power limited. Then, the priority of each signal is compared in this part, and the transmission power of the UL subframe that transmits the low priority signal is adjusted to allocate sufficient power to the priority signal.

  The case of applying the transmission power control according to the second embodiment will be described as an example in the example of FIG. Here, FIG. 7 is applied as the priority rule. First, before transmitting the SeNB / SCG PUSCH w / o UCI, the user terminal investigates the UL transmission status of the MeNB / MCG PUSCH w / UCI in a subframe overlapping with the subframe. According to FIG. 7, since PUSCH w / o UCI of SeNB / SCG has a lower priority than other signals, transmission is performed with reduced transmission power.

  Next, before transmitting the MeNB / MCG PUSCH w / UCI, the UL transmission status of the SeNB / SCG PUSCH w / o UCI and the PUCCH in the overlapping subframe is investigated. According to FIG. 7, the PUSCH w / UCI of the MeNB / MCG has a higher priority than the PUSCH w / o UCI of the SeNB / SCG, but has lower priority than the PUCCH of the SeNB / SCG. Send.

  Next, before transmitting the PUCCH of the SeNB / SCG, the UL transmission status of the PUSCH w / UCI of the MeNB / MCG in the overlapping subframe is investigated. According to FIG. 7, the PUCCH of the SeNB / SCG has higher priority than the PUSCH w / UCI of the MeNB / MCG, and therefore transmits with the transmission power requested by the SeNB.

  As described above, according to the second embodiment, transmission power control is performed in consideration of not only an uplink signal currently being transmitted but also an uplink signal scheduled to be transmitted in the future, so that even in dual connectivity, The transmission power of a high priority signal can be ensured without changing the transmission power in the middle, and a decrease in uplink / downlink throughput can be suppressed.

(Modification 1)
In the example of the second embodiment, the transmission power of a predetermined UL subframe for a certain eNB / CG is set to be equal to that of another eNB / CG having a simultaneous transmission section partially or entirely with the UL subframe. Although it was determined in consideration of the transmission power of the UL subframe, further UL subframes may be considered. Specifically, transmission power of a UL subframe that does not have a simultaneous transmission section with the UL subframe may be considered. For example, a UL subframe subsequent to the UL subframe may be considered. Moreover, you may consider the UL sub-frame further succeeding the UL sub-frame of another eNB / CG which has a simultaneous transmission area partially or entirely with the said UL sub-frame. For example, in the example of FIG. 8, when determining the transmission power of the PUSCH w / o UCI in the SeNB / SCG, in addition to the PUSCH w / UCI of the MeNB / MCG, consider the UL transmission status of the PUCCH of the SeNB / SCG. May be. As a result, power control can be suitably performed in consideration of the priority of the future signal and the power limited state.

(Modification 2)
In addition, in the asynchronous dual connectivity, in order to protect the transmission priority of the uplink signal while keeping the transmission power constant in the subframe, the user terminal can perform future transmission as shown in the second embodiment. It is necessary to read the UL grant / DL assignment for the signal and calculate the transmit power to know if it is power limited and if so, how much excess power is required. Such a process requires a new operation from the user terminal, which means that there is a possibility of increasing the burden of terminal implementation.

  Therefore, in a system using dual connectivity, user terminal capability information (UE capability information) may be defined as follows. For example, user terminal capability information indicating whether asynchronous dual connectivity can be supported may be defined. Moreover, you may prescribe | regulate the user terminal capability information which shows whether the transmission power of a future transmission signal can be calculated in advance. Moreover, you may prescribe | regulate the user terminal capability information showing whether transmission power can be shared dynamically between eNB / CG. These are notified from the user terminal to the radio base station before the dual connectivity is set. Based on the user terminal capability information, the radio base station performs communication so that the user terminal can perform appropriate transmission power control.

  Here, the radio base station may determine that the transmission power control according to the second embodiment can be applied to any user terminal having any of these capabilities. In addition, when the user terminal determines that the transmission power control according to the second embodiment cannot be applied, it is desirable to allocate power in a semi-static manner in advance for each eNB / CG. You may comprise.

(Modification 3)
In the above-described embodiment according to the present invention, the power distribution may be determined based on the difference in the priority of signals to be simultaneously transmitted. For example, in FIG. 7, when the priority of the PRACH of the MeNB / MCG is set to 1 and the priority in increments of 10 is set to the priority of the SRS of the SeNB / SCG, the priority between transmission signals (between subframes) is set. The difference can be calculated in the range of −9 to +9.

  FIG. 10 is a diagram illustrating an example of a flowchart of power distribution determination based on the priority difference of signals to be simultaneously transmitted. In the process of performing power scaling, power dropping may be performed instead.

First, the user terminal before transmitting the uplink signal at a given eNB / CG at a predetermined sub-frame, and calculates the difference delta ₁ and delta ₂ priority among subframes (step S10). Here, delta ₁ is obtained by subtracting the priority of sub-frame i-1 from the priority of the subframe i, delta ₂ is obtained by subtracting the priority of sub-frame i from the priority sub-frame i + 1 . The predetermined subframe is defined as subframe i, and a subframe of another eNB / CG that is transmitted earlier than subframe i that overlaps with subframe i overlaps with subframe i-1 and subframe i. A subframe of another eNB / CG that is transmitted later is a subframe i + 1.

Then, delta ₁ of the absolute value (| Δ ₁ |) is delta ₂ of the absolute value (| Δ ₂ |) it determines larger or not (step S20). When | Δ ₁ | is larger than | Δ ₂ | (step S20—YES), power scaling is performed on the subframe i (step S21).

On the other hand, if | Δ ₁ | is not greater than | Δ ₂ | (step S20—NO), it is further determined whether or not | Δ ₁ | is equal to | Δ ₂ | (step S22). When | Δ ₁ | is equal to | Δ ₂ | (YES in step S22), power scaling is performed on the subframe of SeNB (step S23). If | Δ ₁ | and | Δ ₂ | are not equal (step S22—NO), power scaling is performed on the subframe i + 1 and the subframe i−1 (step S24).

FIG. 11 is a diagram illustrating an example of power distribution determination based on a difference in priority of signals that are simultaneously transmitted. The upper part of FIG. 11 shows before power distribution according to the present embodiment, and the lower part shows after power distribution. In FIG. 11, the priorities of subframes i-1, i, i + 1 are 1, 2, and 7, respectively. Therefore, Δ ₁ = 1 and Δ ₂ = 5.

  Before the power distribution in FIG. 11, the transmission period of subframe i is power limited. If the flowchart of FIG. 10 is followed, the process of step S24 will be implemented and sub-frame i-1 and i + 1 will be power-scaled. As a result, the power of MeNB / MCG is maintained as in the lower part of FIG.

The case where | Δ ₁ | is larger than | Δ ₂ | corresponds to the case where the priority of the subframe i−1 is relatively higher than the subframe i and the subframe i + 1. In such a case, by performing power scaling on the subframe i, the transmission power of the subframe i-1 having a relatively high priority can be secured and the quality can be maintained. Also, when | Δ ₁ | is equal to | Δ ₂ |, power scaling of the SeNB subframe does not change the transmission power of the MeNB subframe, which is important for securing the connection between the user terminal and the network. Can be controlled. Further, when | Δ ₁ | is smaller than | Δ ₂ |, it means that the priorities of the subframe i-1 and the subframe i are relatively equal, and the priority of the subframe i + 1 is low. . Under such conditions, by performing power scaling on the subframe i−1 and the subframe i + 1, it is possible to provide an opportunity for the subframe i to secure power.

Note that FIG. 10 is an example of a power distribution determination method, and is not limited to this. For example, when Δ ₁ <0 and Δ ₂ <0 (for example, when the priority of subframes i-1, i, i + 1 is 7, 2, 1, respectively), steps S21 and S24 in FIG. 10 are performed. You may use the replaced flowchart. In addition, in the case of Δ ₁ Δ ₂ <0 (e.g., sub-frame i-1, i, the priority of the i + 1, respectively, when the 5,7,4), the the delta ₁ instead at step S20 in FIG. 10 it may be used flowchart to determine whether delta ₂ is greater than or not.

(Modification 4)
In the above-described embodiment, power scaling / dropping is appropriately performed. Specifically, the following two implementation methods can be selected. The first realization method is a method of performing power scaling / dropping in one step. In this case, the user terminal determines whether or not the total transmission power of all CCs of both CGs exceeds Pcmax when transmitting a certain UL subframe. As a result, if it is determined that it exceeds, power scaling / dropping is applied according to the priority rule in the second embodiment. According to this configuration, overall optimum power scaling / dropping can be performed according to the overall priority without considering the difference in CG.

  Another implementation method is a method of performing power scaling / dropping in two steps. When transmitting a certain UL subframe, the user terminal first determines whether or not the total transmission power per eNB / CG exceeds a predetermined value (for example, maximum transmission power per CG). As a result, when the total transmission power exceeds a predetermined value in any eNB / CG, power scaling / dropping is applied within the corresponding CG, and the transmission power is kept within a predetermined value for each eNB / CG. Note that this UE operation and priority rule is described in Rel. It is the same as 11 UL-CA. Thereafter, it is determined whether or not the total transmission power of each eNB / CG exceeds Pcmax. If it is determined that the total transmission power exceeds, power scaling is performed according to the priority rule between eNB / CG as described in the second embodiment. / Apply dropping. According to this configuration, power scaling to some extent can be performed by the existing process in the first step (determination per eNB / CG). Since processing for comparing priorities between CGs can be reduced, simplification of terminal processing and cost reduction of circuit configuration can be realized.

(Modification 5)
In the above-described embodiment, the transmission power of each channel (signal) is power scaled / dropped in each CC according to the determination result of whether or not the power is limited. Power scaling / dropping occurs as a result of power limited, and may not be able to report the “difference between maximum transmission power of UE and requested transmission power by eNB” that should be reported in PHR (Power Headroom Report). .

  Therefore, the calculation of PHR for each eNB / CG in dual connectivity is performed using values before applying power scaling / dropping performed as a result of power limited. That is, first, the difference between the value of the transmission power requested by each eNB and the maximum transmission power of each eNB / CG is calculated as PH, and the PHR is reported. In addition, when the maximum transmission power of each eNB / CG is not set, PH may be calculated using the maximum transmission power for each CC or the maximum transmission power for each user terminal. According to this configuration, it is possible to appropriately report how much surplus power is present with respect to the transmission power instructed by the eNB.

(Configuration of wireless communication system)
Hereinafter, a configuration of a wireless communication system according to an embodiment of the present invention will be described. In this wireless communication system, the wireless communication method according to each of the above embodiments or modifications is applied.

  FIG. 12 is a schematic configuration diagram showing an example of a radio communication system according to an embodiment of the present invention. As shown in FIG. 12, the radio communication system 1 is in a cell formed by a plurality of radio base stations 10 (11 and 12) and each radio base station 10, and is configured to be able to communicate with each radio base station 10. A plurality of user terminals 20. Each of the radio base stations 10 is connected to the higher station apparatus 30 and connected to the core network 40 via the higher station apparatus 30.

  In FIG. 12, the radio base station 11 is composed of, for example, a macro base station having a relatively wide coverage, and forms a macro cell C1. The radio base station 12 is configured by a small base station having local coverage, and forms a small cell C2. The number of radio base stations 11 and 12 is not limited to the number shown in FIG.

  In the macro cell C1 and the small cell C2, the same frequency band may be used, or different frequency bands may be used. The radio base stations 11 and 12 are connected to each other via an inter-base station interface (for example, optical fiber, X2 interface).

  Note that the macro base station 11 may be referred to as a radio base station, an eNodeB (eNB), a transmission point, or the like. The small base station 12 may be called a pico base station, a femto base station, a Home eNodeB (HeNB), a transmission point, an RRH (Remote Radio Head), or the like.

  The user terminal 20 is a terminal that supports various communication schemes such as LTE and LTE-A, and may include not only a mobile communication terminal but also a fixed communication terminal. The user terminal 20 can execute communication with other user terminals 20 via the radio base station 10.

  The upper station apparatus 30 includes, for example, an access gateway apparatus, a radio network controller (RNC), a mobility management entity (MME), and the like, but is not limited thereto.

  In the radio communication system 1, OFDMA (Orthogonal Frequency Division Multiple Access) is applied to the downlink and SC-FDMA (Single Carrier Frequency Division Multiple Access) is applied to the uplink as the radio access scheme. The uplink and downlink radio access methods are not limited to these combinations.

  In the wireless communication system 1, as a downlink channel, a downlink shared channel (PDSCH: Physical Downlink Shared Channel) shared by each user terminal 20, a downlink control channel (PDCCH: Physical Downlink Control Channel, EPDCCH: Enhanced Physical Downlink Control Channel). ), A broadcast channel (PBCH: Physical Broadcast Channel) and the like are used. User data, higher layer control information, and predetermined SIB (System Information Block) are transmitted by the PDSCH. Downlink control information (DCI) is transmitted by PDCCH and EPDCCH. A synchronization signal, MIB (Master Information Block), and the like are transmitted by the PBCH.

  In the radio communication system 1, an uplink shared channel (PUSCH) shared by each user terminal 20 and an uplink control channel (PUCCH) are used as uplink channels. User data and higher layer control information are transmitted by PUSCH.

  FIG. 13 is an overall configuration diagram of the radio base station 10 according to the present embodiment. The radio base station 10 includes a plurality of transmission / reception antennas 101 for MIMO transmission, an amplifier unit 102, a transmission / reception unit (reception unit) 103, a baseband signal processing unit 104, a call processing unit 105, and a transmission path interface 106. And. The transmission / reception unit 103 includes a transmission unit and a reception unit.

  User data transmitted from the radio base station 10 to the user terminal 20 via the downlink is input from the higher station apparatus 30 to the baseband signal processing unit 104 via the transmission path interface 106.

  The baseband signal processing unit 104 processes PDCP (Packet Data Convergence Protocol) layer processing, user data division / combination, RLC (Radio Link Control) retransmission control and other RLC layer transmission processing, MAC (Medium Access) for user data. Control) Retransmission control (for example, transmission processing of HARQ (Hybrid Automatic Repeat reQuest)), scheduling, transmission format selection, channel coding, inverse fast Fourier transform (IFFT) processing, precoding processing, etc. Is transferred to each transceiver 103. The downlink control signal is also subjected to transmission processing such as channel coding and inverse fast Fourier transform, and transferred to each transmitting / receiving unit 103.

  Each transmitting / receiving unit 103 converts the downlink signal output by precoding from the baseband signal processing unit 104 for each antenna into a radio frequency band and transmits the converted signal. The radio frequency signal frequency-converted by the transmission / reception unit 103 is amplified by the amplifier unit 102 and transmitted from the transmission / reception antenna 101.

  On the other hand, for the uplink signal, the radio frequency signal received by each transmission / reception antenna 101 is amplified by the amplifier unit 102. Each transmitting / receiving unit 103 receives the upstream signal amplified by the amplifier unit 102. The transmission / reception unit 103 converts the frequency of the received signal into a baseband signal and outputs it to the baseband signal processing unit 104.

  The baseband signal processing unit 104 performs Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing, and error correction on user data included in the input upstream signal. Decoding, MAC retransmission control reception processing, RLC layer, and PDCP layer reception processing are performed and transferred to the upper station apparatus 30 via the transmission path interface 106. The call processing unit 105 performs call processing such as communication channel setting and release, state management of the radio base station 10, and radio resource management.

  The transmission path interface 106 transmits and receives signals to and from the higher station apparatus 30 via a predetermined interface. Further, the transmission path interface 106 may transmit / receive a signal (backhaul signaling) to / from an adjacent radio base station via an interface between base stations (for example, an optical fiber or an X2 interface).

  FIG. 14 is a main functional configuration diagram of the baseband signal processing unit 104 included in the radio base station 10 according to the present embodiment. As illustrated in FIG. 14, the baseband signal processing unit 104 included in the radio base station 10 includes a control unit 301, a transmission signal generation unit 302, a mapping unit 303, a demapping unit 304, and a received signal decoding unit 305. , At least.

  The control unit 301 performs radio resource scheduling control (allocation control) for downlink signals and uplink signals based on instruction information from the higher station apparatus 30 and feedback information from each user terminal 20. That is, the control unit 301 has a function as a scheduler. In addition, when the other radio base station 10 and the higher station apparatus 30 function as a scheduler of the radio base station 10, the control unit 301 does not need to function as a scheduler.

  Specifically, the control unit 301 controls scheduling of a downlink reference signal, a downlink data signal transmitted by PDSCH, a downlink control signal transmitted by PDCCH and / or EPDCCH, and the like. In addition, the control unit 301 controls scheduling such as an uplink reference signal, an uplink data signal transmitted by PUSCH, an uplink control signal transmitted by PUCCH and / or PUSCH, and an RA preamble transmitted by PRACH. Information regarding these allocation controls is notified to the user terminal 20 using downlink control information (DCI).

  The control unit 301 controls the transmission signal generation unit 302 and the mapping unit 303 in order to adjust the uplink signal transmission power of the user terminal 20 connected to the radio base station 10.

  Specifically, the control unit 301 controls transmission power of the uplink signal based on PHR and channel state information (CSI) reported from the user terminal 20, an uplink data error rate, the number of HARQ retransmissions, and the like. The transmission signal generation unit 302 is instructed to generate a transmission power control (TPC) command, and the mapping unit 303 is controlled to include the TPC command in downlink control information (DCI) and to notify the user terminal 20. . As a result, the radio base station 10 can specify the transmission power of the uplink signal requested from the user terminal 20. The PHR may be notified by being included in a MAC CE (Control Element).

  Here, based on the PHR reported from the user terminal 20, the control unit 301 acquires information regarding uplink transmission power to each radio base station 10 to which the user terminal 20 is connected. Specifically, the control unit 301 acquires information on the transmission power of the cells belonging to the own station based on the PHR notified from the user terminal 20. Note that the control unit 301 uses the PUSCH bandwidth, channel state (path loss, etc.), transmission power density (PSD), MCS of cells formed by other radio base stations 10 for information related to transmission power of cells that do not belong to its own station. Levels, channel quality, etc. may be estimated. Further, the control unit 301 may calculate (estimate) the total surplus transmission power of the user terminal 20 from these pieces of information.

  The transmission signal generation unit 302 generates a downlink control signal, a downlink data signal, a downlink reference signal, and the like whose assignment is determined by the control unit 301, and outputs the generated signal to the mapping unit 303. Specifically, based on an instruction from the control unit 301, the transmission control signal generation unit 302 generates a DL assignment that notifies downlink signal allocation information and a UL grant that notifies uplink signal allocation information. Also, the downlink data signal is subjected to encoding processing and modulation processing according to the coding rate and modulation scheme determined based on CSI from each user terminal 20 and the like.

  Based on an instruction from the control unit 301, the mapping unit 303 maps the downlink signal generated by the transmission signal generation unit 302 to a radio resource and outputs it to the transmission / reception unit 103.

  Demapping section 304 demaps the signal received by transmission / reception section 103 and outputs the separated signal to received signal decoding section 305. Specifically, the demapping unit 304 demaps the uplink signal transmitted from the user terminal 20.

  The reception signal decoding unit 305 decodes a signal transmitted from the user terminal 20 through the uplink control channel (PRACH, PUCCH) (for example, a delivery confirmation signal (HARQ-ACK)), a data signal transmitted through the PUSCH, and the like. Output to the unit 301. Information included in the MAC CE notified from the user terminal 20 is also output to the control unit 301.

  FIG. 15 is an overall configuration diagram of the user terminal 20 according to the present embodiment. As shown in FIG. 15, the user terminal 20 includes a plurality of transmission / reception antennas 201 for MIMO transmission, an amplifier unit 202, a transmission / reception unit 203, a baseband signal processing unit 204, and an application unit 205. Yes. Note that the transmission / reception unit 203 may include a transmission unit and a reception unit.

  For downlink data, radio frequency signals received by a plurality of transmission / reception antennas 201 are each amplified by an amplifier unit 202. Each transmitting / receiving unit 203 receives the downlink signal amplified by the amplifier unit 202. The transmission / reception unit 203 converts the frequency of the received signal into a baseband signal and outputs it to the baseband signal processing unit 204.

  The baseband signal processing unit 204 performs FFT processing, error correction decoding, retransmission control reception processing, and the like on the input baseband signal. The downlink user data is transferred to the application unit 205. The application unit 205 performs processing related to layers higher than the physical layer and the MAC layer. In addition, broadcast information in the downlink data is also transferred to the application unit 205.

  On the other hand, uplink user data is input from the application unit 205 to the baseband signal processing unit 204. The baseband signal processing unit 204 performs retransmission control transmission processing (for example, HARQ transmission processing), channel coding, precoding, discrete Fourier transform (DFT) processing, IFFT processing, and the like. The data is transferred to the transmission / reception unit 203. The transmission / reception unit 203 converts the baseband signal output from the baseband signal processing unit 204 into a radio frequency band and transmits it. The radio frequency signal frequency-converted by the transmission / reception unit 203 is amplified by the amplifier unit 202 and transmitted from the transmission / reception antenna 201.

  FIG. 16 is a main functional configuration diagram of the baseband signal processing unit 204 included in the user terminal 20. As illustrated in FIG. 16, the baseband signal processing unit 204 included in the user terminal 20 includes a control unit 401, a transmission signal generation unit 402, a mapping unit 403, a demapping unit 404, a received signal decoding unit 405, The power limit detection unit 406 and the PH report generation unit 411 are included at least.

  The control unit 401 obtains, from the received signal decoding unit 405, the downlink control signal (signal transmitted by PDCCH) and the downlink data signal (signal transmitted by PDSCH) transmitted from the radio base station 10. The control unit 401 generates an uplink control signal (for example, an acknowledgment signal (HARQ-ACK)) or an uplink data signal based on a downlink control signal, a result of determining whether retransmission control is possible for the downlink data signal, or the like. Control. Specifically, the transmission signal generation unit 402 and the mapping unit 403 are controlled.

  Based on an instruction from the control unit 401, the transmission signal generation unit 402 generates an uplink control signal such as a delivery confirmation signal (HARQ-ACK) and channel state information (CSI). In addition, the transmission signal generation unit 402 generates an uplink data signal based on an instruction from the control unit 401. Note that the control unit 401 instructs the transmission signal generation unit 402 to generate an uplink data signal when the UL grant is included in the downlink control signal notified from the radio base station.

  Based on an instruction from control section 401, mapping section 403 maps the uplink signal generated by transmission signal generation section 402 to a radio resource and outputs the radio signal to transmission / reception section 203.

  Further, the control unit 401 controls the uplink transmission power of the user terminal 20. Specifically, the control unit 401 controls the transmission power of each cell (CC) based on signaling (for example, a TPC command) from each radio base station 20. Here, the control unit 401 holds the priority rule of the uplink signal to each radio base station 10, and when transmitting a plurality of uplink signals at the same timing, each control unit 401 refers to the priority and transmits each uplink signal. Controls signal transmission power.

  As the priority rule, the control unit 401 sets the priority to the first radio base station (for example, MeNB) and the priority to the second radio base station (for example, SeNB) for each uplink signal of the same type. Set higher. For example, the priority of all UL signals to the MeNB may be set higher than the priority of all UL signals to the SeNB (an example of the first embodiment). In addition, for each uplink signal of the same type, the priority to the first radio base station and the priority to the second radio base station may be set adjacently. Furthermore, the priority relationship between the signals is Rel. You may set so that the same order as 11 UL-CA may be maintained (another example of the first embodiment). The priority between signals in the eNB / CG is Rel. It is preferable to include the same order as that of 11 UL-CAs, that is, from the higher order, it is preferable to set the priority order of PUSCH including PRACH, PUCCH, UCI, PUSCH not including UCI, and SRS.

  In addition, when a plurality of priority rules are defined, the control unit 401 uses downlink control information (DCI) by downlink control channels (PDCCH, EPDCCH) from the radio base station 10 and higher layer signaling (for example, RRC). The priority rule to be applied may be determined on the basis of the information regarding the priority rule notified by signaling or a notification signal (for example, SIB).

  In addition, the control unit 401 transmits in cooperation with the power limit detection unit 406 so as to keep the above priority while ensuring that the transmission power of the signal is not changed in the middle of the uplink subframe (UL subframe). Perform power control. For this reason, the control unit 401 outputs the UL transmission status (bandwidth, modulation scheme, UL transmission power required based on these, etc.) to the power limit detection unit 406 from the received UL grant / DL assignment.

  Based on the information on the UL transmission status input from the control unit 401, the power limit detection unit 406 is configured to transmit the predetermined UL subframe to a certain eNB / CG (scheduled transmission period). The transmission power of all UL subframes of another eNB / CG having a simultaneous transmission section partially or entirely with the UL subframe is checked, and the total transmission power of the uplink signal to each eNB / CG is the allowable maximum power (Pcmax) Is determined, and the determination result is output to the control unit 401 (second embodiment).

  The control unit 401 compares the signal priority of the part that exceeds the allowable maximum power determined by the power limit detection unit 406 (becomes power limited). The control unit 401 reduces the power allocation of the low-priority (non-priority) UL subframe to a value that can appropriately distribute the power required for the high-priority (priority) UL subframe. (Scaling or dropping).

  Further, before making the above determination, the power limit detection unit 406 has a predetermined value (for example, maximum transmission power per eNB / CG) of the transmission power of each UL subframe for each eNB / CG in the scheduled transmission period. May be determined, and the determination result may be output to the control unit 401 (Modification 4).

  From the determination result of the power limit detection unit 406, the control unit 401 applies power scaling / dropping in the eNB / CG when the total transmission power exceeds the predetermined value in any eNB / CG, and the eNB / CG Transmission power is kept below a predetermined value for each CG.

  In addition, it is preferable that the transmission signal generation unit 402 generates user terminal capability information (UE capability information) for notifying the radio base station 10 that the configuration is as described above. For example, user terminal capability information indicating whether or not asynchronous dual connectivity can be supported, whether or not transmission power of a future transmission signal can be calculated, whether or not dynamic sharing of transmission power between eNBs / CGs, and the like may be generated (deformation) Example 2).

  Based on the instruction from the control unit 401, the PH report generation unit 411 sets the PH (Power Headroom) for each eNB / CG, the maximum transmission power of the uplink signal to the eNB / CG, and the eNB / CG first. It calculates from the difference between the requested transmission power of the uplink signal, generates a PHR, and outputs it to the transmission signal generator 402 (Modification 5).

  Demapping section 404 demaps the signal received by transmission / reception section 203 and outputs the separated signal to received signal decoding section 405. Specifically, the demapping unit 404 demaps the downlink signal transmitted from the radio base station 10.

  Received signal decoding section 405 decodes a downlink control signal (PDCCH signal) transmitted on the downlink control channel (PDCCH), and feeds back a delivery confirmation signal for scheduling information (assignment information to uplink resources) and the downlink control signal. The information regarding the cell to be processed, the TPC command, etc. are output to the control unit 401.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. For example, the above-described embodiments may be used alone or in combination. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Radio | wireless communications system 10, 11, 12 ... Wireless base station 20 ... User terminal 30 ... Host station apparatus 40 ... Core network 101 ... Transmission / reception antenna 102 ... Amplifier part 103 ... Transmission / reception part 104 ... Baseband signal processing part 105 ... Call processing Unit 106 ... Transmission path interface 201 ... Transmission / reception antenna 202 ... Amplifier unit 203 ... Transmission / reception unit 204 ... Baseband signal processing unit 205 ... Application unit 301 ... Control unit 302 ... Transmission signal generation unit 303 ... Mapping unit 304 ... Demapping unit 305 ... Received signal decoding unit 401 ... Control unit 402 ... Transmission signal generating unit 403 ... Mapping unit 404 ... Demapping unit 405 ... Received signal decoding unit 406 ... Power limit detection unit 411 ... PH report generating unit

Claims (6)

A user terminal that communicates using a first cell group (CG) and a second CG,
A transmission unit for transmitting a plurality of types of uplink signals in each CG;
A control unit that controls to allocate power to a predetermined type of uplink signal transmitted by the first CG more preferentially than the predetermined type of uplink signal transmitted by the second CG;
The transmitting unit transmits user terminal capability information indicating whether or not asynchronous dual connectivity is supported to the radio base station,
When the user terminal supports asynchronous dual connectivity and receives predetermined signaling from the radio base station, the control unit determines the power of a signal being transmitted in the subframe of each CG in the middle of the subframe. A user terminal that performs transmission power control in consideration of transmission power of uplink signals of all subframes of another CG that overlap with the subframe.   The control unit, when the user terminal supports asynchronous dual connectivity, and receives the predetermined signaling notified from the radio base station according to the user terminal capability information indicating that asynchronous dual connectivity is supported, The user terminal according to claim 1, wherein the transmission power control is performed.   The control unit controls the uplink signal transmitted by each CG so that power is preferentially allocated in the order of PRACH, a channel including UCI, a PUSCH not including UCI, and SRS. The user terminal according to claim 2.   A PH report generation unit that generates a PH report by calculating a PH (Power Headroom) for each CG based on the maximum transmission power of the uplink signal and the transmission power of the uplink signal requested by the CG. The user terminal according to claim 1 or 2. A radio base station that communicates with a user terminal that communicates using a first cell group (CG) and a second CG using a predetermined cell group,
A transmission unit for transmitting a control signal for transmission power of the uplink signal;
A reception unit for receiving an uplink signal whose transmission power is controlled based on the control signal,
The uplink signal is controlled to preferentially allocate power to a predetermined type of uplink signal transmitted by the first CG over the predetermined type of uplink signal transmitted by the second CG,
The receiving unit receives user terminal capability information indicating whether asynchronous dual connectivity is supported,
In the uplink signal, when the user terminal supports asynchronous dual connectivity and receives predetermined signaling from the radio base station, power is not changed in the middle of the subframe in each CG subframe. A radio base station characterized in that transmission power control is performed in consideration of transmission power of uplink signals of all subframes of another CG that are controlled and overlap with the subframe. A wireless communication method according to a user terminal that communicates using a first cell group (CG) and a second CG,
A step of transmitting a plurality of types of upstream signals in each CG;
Controlling to allocate power to a predetermined type of uplink signal transmitted by the first CG with priority over the predetermined type of uplink signal transmitted by the second CG;
Transmitting user terminal capability information indicating whether or not asynchronous dual connectivity is supported to the radio base station;
When the user terminal supports asynchronous dual connectivity and receives predetermined signaling from the radio base station, the power of a signal being transmitted is not changed in the middle of each subframe in each CG subframe. And a step of performing transmission power control in consideration of transmission power of uplink signals of all subframes of another CG overlapping with the subframe.

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