KR20120048449A - Apparatus and method for transmitting power information of component carrier in multiple component carrier system - Google Patents

Abstract

PURPOSE: A power information transmission method of a component carrier and an apparatus thereof are provided to increase the reliability of a MAC message and to remove the waste of a resource within a MAC control component. CONSTITUTION: A terminal calculates maximum transmission power about component carriers(S2600). The terminal sets up a cell indicator field for indicating component carriers having the maximum transmission power(S2625). If a cell indicator field about a CC(Component Carrier) of a main serving cell indicates zero, the terminal configures a MAC(Medium Access Control) CC of a first format(S2645). The terminal transmits the MAC CC to a base station(S2650).

Description

Apparatus and method for transmitting power information of a component carrier in a multi-component carrier system {APPARATUS AND METHOD FOR TRANSMITTING POWER INFORMATION OF COMPONENT CARRIER IN MULTIPLE COMPONENT CARRIER SYSTEM}

The present invention relates to wireless communication, and more particularly, to an apparatus and method for transmitting power information of a component carrier in a multi-component carrier system.

3rd Generation Partnership Project (3GPP) long term evolution (LTE) and Institute of Electrical and Electronics Engineers (IEEE) 802.16m are being developed as candidates for the next generation wireless communication system. The 802.16m specification implies two aspects: past continuity, a modification to the existing 802.16e specification, and future continuity, a specification for the next generation of IMT-Advanced systems. Accordingly, the 802.16m standard requires all the advanced requirements for the IMT-Advanced system to be maintained while maintaining compatibility with the Mobile WiMAX system based on the 802.16e standard.

Wireless communication systems generally use one bandwidth for data transmission. For example, the second generation wireless communication system uses a bandwidth of 200KHz ~ 1.25MHz, the third generation wireless communication system uses a bandwidth of 5MHz ~ 10MHz. In order to support increasing transmission capacity, recent 3GPP LTE or 802.16m continues to expand its bandwidth to 20 MHz or more. In order to increase the transmission capacity, it is necessary to increase the bandwidth. However, even when the level of service required is low, supporting a large bandwidth can cause a large power consumption.

Accordingly, a multiple component carrier system has emerged, which defines a carrier having one bandwidth and a center frequency and enables transmission and / or reception of data over a wide band through a plurality of carriers. By using one or more carriers, it is possible to support narrowband and broadband at the same time. For example, if one carrier corresponds to a bandwidth of 5 MHz, it can support a maximum bandwidth of 20 MHz by using four carriers.

One way for the base station to efficiently utilize the resources of the terminal is to use the power information of the terminal. Power control technology is an essential core technology for minimizing interference factors and reducing battery consumption of a terminal for efficient allocation of resources in wireless communication. The terminal may determine the uplink transmission power according to scheduling information such as a transmission power control (TPC), a modulation and coding scheme (MCS), and a bandwidth allocated by the base station.

However, as the multi-component carrier system is introduced, the uplink transmission power of the component carrier must be taken into consideration comprehensively, so that power control of the terminal becomes more complicated. This complexity may cause problems in terms of maximum transmission power of the terminal. In general, the terminal should be operated by a power lower than the maximum transmission power that is the transmission power of the allowable range. If the base station schedules the transmission power more than the maximum transmission power, it may cause a problem that the actual uplink transmission power exceeds the maximum transmission power. This is because power control of a multi-element carrier is not clearly defined, or information on uplink transmission power is not sufficiently shared between the terminal and the base station.

An object of the present invention is to provide an apparatus for transmitting and receiving power information on a component carrier in a multi-component carrier system.

Another technical problem of the present invention is to provide a transmission method and a reception method of power information on a component carrier in a multi-component carrier system.

Another technical problem of the present invention is to provide a method for configuring power information on a component carrier in a multi-component carrier system.

Another technical problem of the present invention is to provide a structure of a MAC control element for a component carrier in a multi-component carrier system.

Another technical problem of the present invention is to provide a method for analyzing a MAC control element for a component carrier in a multi-component carrier system.

Another technical problem of the present invention is to provide a method for analyzing a MAC control element for a component carrier in a multi-component carrier system.

Another technical problem of the present invention is to provide a method for grouping and indicating a component carrier having the same maximum transmit power in a multi-component carrier system.

Another technical problem of the present invention is to provide a method for indicating a maximum transmission power for each transmission type in a multi-element carrier system.

According to an aspect of the present invention, a method of transmitting power information by a terminal in a multi-component carrier system is provided. The transmission method may include calculating a maximum transmit power that can be output for a plurality of component carriers, setting a cell indicator field indicating component carriers having the same maximum transmit power, and displaying the same maximum transmit power. Setting a power field, generating a medium access control (MAC) message including the cell indicator field and the first power field, and transmitting the MAC message to a base station; do.

According to another aspect of the present invention, a terminal for transmitting power information in a multi-element carrier system is provided. The terminal includes a power calculation unit for calculating a maximum transmit power that can be output for each of a plurality of component carriers, the same power cell group determination unit for determining a group consisting of the component carriers having the same maximum transmit power, included in the group Generating a MAC message including a cell indicator field indicating a component carrier, a first power field indicating the same maximum transmission power, and a second power field indicating a maximum transmission power different from the same maximum transmission power; A power information generator, and an uplink information transmitter for transmitting the MAC message to the base station.

According to the present invention, a P _cmax value transmitted for efficient uplink power control in a wireless system using carrier aggregation may be configured without resource waste on a MAC control element. Since there is no resource waste in the MAC control element, it is possible to increase the reliability of the MAC message and to reduce the waste of uplink resources used for control.

1 shows a wireless communication system.
2 is an explanatory diagram illustrating the same intra-band contiguous carrier aggregation.
3 is an explanatory diagram illustrating the same in-band non-contiguous carrier aggregation.
4 is an explanatory diagram illustrating the same inter-band carrier aggregation.
5 shows linkage between a downlink component carrier and an uplink component carrier in a multi-carrier system.
6 is an example of a graph showing surplus power on the time-frequency axis to which the present invention is applied.
7 is another example of a graph showing surplus power on the time-frequency axis to which the present invention is applied.
8 is a conceptual diagram illustrating an effect of uplink scheduling of a base station on transmission power of a terminal in a wireless communication system.
9 is an explanatory diagram illustrating a power adjustment amount and a maximum transmission power in a multi-element carrier system according to an embodiment of the present invention.
10 is a block diagram illustrating a structure of a MAC protocol data unit (MAC PDU) for power reporting according to an embodiment of the present invention.
11 is a block diagram illustrating a structure of a MAC PDU for power reporting according to another embodiment of the present invention.
12 is an explanatory diagram illustrating an example of a method of selecting a power report cell group.
13 is an explanatory diagram for explaining another example of the method for selecting a power report cell group.
14 is an explanatory diagram illustrating another example of a method of selecting a power report cell group.
15 is a structure of a MAC control element for power reporting according to an embodiment of the present invention.
16 is a structure of a MAC control element for power reporting according to another embodiment of the present invention.
17 is a structure of a MAC control element for power reporting according to another embodiment of the present invention.
18 is a structure of a MAC control element for power reporting according to another embodiment of the present invention.
19 is an example of utilization of a MAC control element for power reporting according to FIG. 18.
20 is another example of utilization of the MAC control element for power reporting according to FIG.
21 shows a structure of a MAC control element for power reporting according to another embodiment of the present invention.
22 is an example of utilization of a MAC control element for power reporting according to FIG. 21.
FIG. 23 is another example of utilization of a MAC control element for power reporting according to FIG.
24 is an explanatory diagram illustrating a method of interpreting a MAC control element for power reporting according to an embodiment of the present invention.
25 is a flowchart illustrating a method of transmitting power information according to an embodiment of the present invention.
26 is a flowchart illustrating a method of transmitting power information by a terminal according to an embodiment of the present invention.
27 is a flowchart illustrating a method of receiving power information by a base station according to an embodiment of the present invention.
28 is a block diagram illustrating a terminal transmitting power information and a base station receiving power information according to an embodiment of the present invention.
29 is a flowchart illustrating a format for transmitting power information in consideration of simultaneous PUCCH / PUSCH transmission according to an embodiment of the present invention.
30 is a flowchart illustrating a method of transmitting power information by a terminal according to another embodiment of the present invention.
31 is a flowchart illustrating a method of receiving power information by a base station according to another embodiment of the present invention.

Hereinafter, some embodiments will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure rather unclear.

In addition, in describing the component of this specification, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but between components It will be understood that may be "connected", "coupled" or "connected".

In addition, the present invention will be described with respect to a wireless communication network. The work performed in the wireless communication network may be performed in a process of controlling a network and transmitting data by a system (e.g., a base station) Work can be done at a terminal connected to the network.

1 shows a wireless communication system.

Referring to FIG. 1, the wireless communication system 10 is widely deployed to provide various communication services such as voice and packet data.

The wireless communication system 10 includes at least one base station (BS) 11. Each base station 11 provides a communication service for a specific geographic area (generally called a cell) 15a, 15b, 15c. The cell may again be divided into multiple regions (referred to as sectors).

The mobile station (MS) 12 may be fixed or mobile, and may include a user equipment (UE), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, and a PDA. (personal digital assistant), wireless modem (wireless modem), a handheld device (handheld device) may be called other terms.

The base station 11 generally refers to a fixed station communicating with the terminal 12, and may be referred to as other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, and the like. have. The cell should be interpreted in a comprehensive sense of a part of the area covered by the base station 11 and encompasses various coverage areas such as megacells, macrocells, microcells, picocells and femtocells.

In the following, downlink means communication from the base station 11 to the terminal 12, and uplink means communication from the terminal 12 to the base station 11. In downlink, the transmitter may be part of the base station 11 and the receiver may be part of the terminal 12.

In uplink, the transmitter may be part of the terminal 12 and the receiver may be part of the base station 11.

There are no restrictions on multiple access schemes applied to wireless communication systems. (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA , OFDM-CDMA, and the like. A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

Layers of the radio interface protocol between the terminal and the network are based on the lower three layers of the Open System Interconnection (OSI) model, which is well known in communication systems. (Second layer) and L3 (third layer).

The physical layer, which is the first layer, is connected to the upper medium access control (MAC) layer through a transport channel, and data between the MAC and the physical layer moves through the transport channel. . In addition, data is moved between different physical layers, that is, between physical layers of a transmitting side and a receiving side through a physical channel. There are several physical control channels used in the physical layer. A physical downlink control channel (PDCCH) for transmitting physical control information is a HARQ (hybrid automatic repeat) associated with a resource allocation of a paging channel (PCH) and a downlink shared channel (DL-SCH) and DL-SCH to a UE. request) Provides information. The PDCCH may carry an uplink grant informing the UE of resource allocation of uplink transmission. The physical control format indicator channel (PCFICH) informs the UE of the number of OFDM symbols used for PDCCHs and is transmitted every subframe. PHICH (physical Hybrid ARQ Indicator Channel) carries a HARQ ACK / NAK signal in response to uplink transmission. Physical uplink control channel (PUCCH) carries uplink control information such as HARQ ACK / NAK, scheduling request, and CQI for downlink transmission. Physical uplink shared channel (PUSCH) carries an uplink shared channel (UL-SCH).

The situation in which the UE transmits a PUCCH or a PUSCH is as follows.

The terminal configures a PUCCH for at least one or more of information on channel quality information (CQI), or information on a precoding matrix index (PMI) or rank indicator (RI) selected based on measured spatial channel information. Send periodically. In addition, the terminal should transmit information on ACK / NACK (Acknowledgement / non-Acknowledgement) for the downlink data received from the base station to the base station after a predetermined number of subframes after receiving the downlink data. For example, when downlink data is received in the nth subframe, the PUCCH configured with ACK / NACK information for the downlink data is transmitted in the n + 4 subframe. If all of the ACK / NACK information cannot be transmitted on the PUCCH allocated from the base station, or if the PUCCH capable of transmitting ACK / NACK is not allocated from the base station, the ACK / NACK information may be carried on the PUSCH.

The second data layer, the radio data link layer, is composed of a MAC layer, an RLC layer, and a PDCP layer. The MAC layer is a layer responsible for mapping between logical channels and transport channels. The MAC layer selects an appropriate transport channel for transmitting data transmitted from the RLC layer, and supplies necessary control information to a header of a MAC protocol data unit (PDU). Add to The RLC layer is located on top of the MAC to support reliable transmission of data. In addition, the RLC layer segments and concatenates RLC Service Data Units (SDUs) delivered from a higher layer to configure data of an appropriate size for a wireless section. The RLC layer of the receiver supports a reassemble function of data to recover the original RLC SDU from the received RLC PDUs. The PDCP layer is used only in the packet switched area, and may compress and transmit the header of the IP packet to increase the transmission efficiency of packet data in the wireless channel.

The third layer, the RRC layer, controls the lower layer and exchanges radio resource control information between the terminal and the network. Various RRC states such as an idle mode and an RRC connected mode are defined according to the communication state of the UE, and transition between RRC states is possible as needed. The RRC layer defines various procedures related to radio resource management such as system information broadcasting, RRC connection management procedure, multi-element carrier setup procedure, radio bearer control procedure, security procedure, measurement procedure, mobility management procedure (handover), etc. do.

Carrier aggregation (CA) supports a plurality of carriers, also referred to as spectrum aggregation or bandwidth aggregation. Individual unit carriers bound by carrier aggregation are called component carriers (CC). Each CC is defined by a bandwidth and a center frequency. Carrier aggregation is introduced to support increased throughput, prevent cost increases due to the introduction of wideband radio frequency (RF) devices, and ensure compatibility with existing systems. For example, if five CCs are allocated as granularity in a carrier unit having a 5 MHz bandwidth, a bandwidth of up to 20 MHz may be supported.

CCs may be divided into primary CCs (hereinafter referred to as PCCs) and secondary CCs (hereinafter referred to as SCCs) according to activation. PCC is always active carrier, SCC is a carrier that is activated / deactivated according to a specific condition. Activation refers to the transmission or reception of traffic data being made or in a ready state. Deactivation means that transmission or reception of traffic data is impossible, and measurement or transmission of minimum information is possible. The terminal may use only one PCC, or may use one or more SCCs together with the PCC. The terminal may be assigned a PCC and / or SCC from the base station.

Carrier aggregation includes intra-band contiguous carrier aggregation as shown in FIG. 2, intra-band non-contiguous carrier aggregation as shown in FIG. 3, and inter-band carrier as shown in FIG. Can be divided into aggregates.

First, referring to FIG. 2, in-band adjacent carrier aggregation is performed between consecutive CCs in the same band. For example, the aggregated CCs CC # 1, CC # 2, CC # 3, ..., CCN are all adjacent.

Referring to FIG. 3, in-band non-adjacent carrier aggregation is achieved between discrete CCs. For example, the aggregated CCs CC # 1 and CC # 2 are spaced apart from each other by a specific frequency.

Referring to FIG. 4, when a plurality of CCs exist, one or more CCs are aggregated on different frequency bands. For example, CC1, which are aggregated CCs, exist in band # 1, and CC2 exists in band # 2.

The number of carriers aggregated between the downlink and the uplink may be set differently. The case where the number of downlink CCs and the number of uplink CCs are the same is called symmetric aggregation, and when the number is different, it is called asymmetric aggregation.

In addition, the size (ie bandwidth) of the CCs may be different. For example, assuming that 5 CCs are used for a 70 MHz band configuration, 5 MHz CC (carrier # 0) + 20 MHz CC (carrier # 1) + 20 MHz CC (carrier # 2) + 20 MHz CC (carrier # 3) It may be configured as + 5MHz CC (carrier # 4).

Hereinafter, a multiple carrier system refers to a system supporting carrier aggregation. Adjacent carrier aggregation and / or non-adjacent carrier aggregation may be used in a multi-carrier system, and either symmetric aggregation or asymmetric aggregation may be used.

5 shows linkage between a downlink component carrier and an uplink component carrier in a multi-carrier system.

Referring to FIG. 5, in downlink, downlink component carriers (hereinafter, referred to as DL CCs) D1, D2, and D3 are aggregated, and in uplink, uplink component carriers (hereinafter, referred to as UL CCs) U1, U2, and U3 are represented. Are concentrated. Where Di is an index of DL CC and Ui is an index of UL CC (i = 1, 2, 3). At least one DL CC is a PCC and the rest is an SCC. Similarly, at least one UL CC is a PCC and the rest are SCCs. For example, D1 and U1 are PCCs, and D2, U2, D3, and U3 are SCCs.

In the FDD system, the DL CC and the UL CC are configured to be connected 1: 1, D1 is connected to U1, D2 is set to U2, and D3 is set to 1: 1 to U3. The UE establishes a connection between the DL CCs and the UL CCs through system information transmitted through a logical channel BCCH or a UE-specific RRC message transmitted by a DCCH. Each connection configuration may be set cell specific or UE specific.

5 illustrates only a 1: 1 connection between a DL CC and a UL CC as an example, but may also establish a connection configuration of 1: n or n: 1. In addition, the index of the component carrier does not correspond to the order of the component carrier or the position of the frequency band of the component carrier.

Hereinafter, a description will be given of the power headroom (PH).

The surplus power means extra power that can be used in addition to the power currently used by the UE for uplink transmission. For example, suppose a terminal having a maximum transmission power of 10W, which is an allowable transmission power. And suppose that the current terminal uses a power of 9W in the frequency band of 10Mhz. Since the terminal can additionally use 1W, surplus power becomes 1W.

Here, if the base station allocates a frequency band of 20Mhz to the terminal, power of 9W × 2 = 18W is required. However, since the maximum power of the terminal is 10W, if 20Mhz is allocated to the terminal, the terminal may not use all of the frequency band, or the base station may not properly receive the signal of the terminal because of insufficient power. In order to solve this problem, the terminal reports that the surplus power is 1W to the base station, so that the base station can schedule within the surplus power range. This report is called a Power Headroom Report (PHR).

Since surplus power changes from time to time, a periodic surplus power reporting method may be used. According to the periodic surplus power reporting method, when the periodic timer expires, the terminal triggers the surplus power report, and when the surplus power is reported, the terminal restarts the periodic timer.

In addition, the surplus power report may be triggered when the Path Loss (PL) estimate measured by the UE changes to a predetermined reference value or more. The path loss estimate is measured by the terminal based on a reference symbol received power (RSRP).

The surplus power P _PH is defined as a difference between the maximum transmit power P _cmax configured in the terminal and the estimated power P _{estimated for} uplink transmission as expressed by Equation 1, and is expressed in dB.

Surplus power P _PH may also be referred to as power headroom PH, remaining power, or surplus power. That is, the remaining value excluding the P _estimated which is the sum of the transmit powers used in each CC from the maximum transmit power of the terminal set by the base station becomes the P _PH value.

As an example, P _estimated is equal to an estimated power P _{PUSCH for} transmission of a Physical Uplink Shared CHannel (PUSCH). Therefore, in this case, P _PH can be obtained by Equation 2. Equation 2 is a case where only the PUSCH is transmitted in the uplink, and this is called Type 1. Surplus power according to type 1 is referred to as type 1 surplus power.

As another example, P _estimated is equal to the sum of the power P _PUSCH estimated for the transmission of the _PUSCH and the power P _PUCCH estimated for the transmission of the Physical Uplink Control Channel (PUCCH). Therefore, in this case, the surplus power can be obtained by the equation (3). Equation 2 is a case where a PUSCH and a PUCCH are simultaneously transmitted in uplink, and this is called type 2. Surplus power according to type 2 is referred to as type 2 surplus power.

The surplus power according to Equation 3 is represented as a graph in the time-frequency axis as shown in FIG. This shows the surplus power for one CC.

Referring to FIG. 6, the set maximum transmission power P _cmax of the terminal is composed of P _PH 605, P _PUSCH 610, and P _PUCCH 615. In other words, this is the exception of the P _PUSCH (610) and P _PUCCH (615) in the P _cmax power is defined as P _PH (605). Each power is calculated in units of a transmission time interval (TTI).

The primary serving cell is the only serving cell having a UL PCC capable of transmitting PUCCH. Therefore, since the PUCCH cannot be transmitted in the secondary serving cell, surplus power is determined as in Equation 2, and a parameter and an operation for the method for reporting surplus power determined by Equation 3 are not defined.

On the other hand, in the main serving cell, the operation and parameters for the method of reporting surplus power determined by Equation 3 may be defined. If the terminal receives the uplink grant from the base station to transmit the PUSCH in the main serving cell and simultaneously transmits the PUCCH in the same subframe according to a predetermined rule, the terminal at the time when the surplus power report is triggered And all surplus power according to Equation 3 are transmitted to the base station.

In a multi-component carrier system, surplus power may be individually defined for a plurality of configured CCs, which is represented as a graph in the time-frequency axis as shown in FIG. 7. Hereinafter, the maximum transmit power set in the terminal is referred to as P _cmax , the maximum transmit power for each CC is referred to as P _{cmax, c} , and the maximum transmit power of CCi is referred to as P _{cmax and ci} .

7, the maximum transmit power is set for each terminal P _cmax is CC1, CC2, ..., the sum of the maximum transmit power for the P _{cmax CCn, c1,} P _{cmax, c2,} ..., P _{cmax, cn} Is the same as Generalizing the maximum transmit power for each CC is as follows.

P _PH (705) of CC1 is _{P cmax, c1 -P PUSCH (710} ) the same as _{-P PUCCH (715), P PH} (720) of CCn is _{P cmax, cn -P PUSCH (725} ) -P PUCCH (730 ) As such, the maximum transmit power set in the terminal in the multi-component carrier system should take into account the maximum transmit power of each component carrier. Therefore, it is defined differently from the maximum transmit power in a single component carrier system.

8 is a conceptual diagram illustrating an effect of uplink scheduling of a base station on transmission power of a terminal in a wireless communication system.

Referring to FIG. 8, the terminal receives an uplink grant through the PDCCH that allows uplink data transmission from the base station at time (or subframe) t0. Therefore, the terminal should calculate the amount of transmission power according to the uplink grant at t0.

First, at time t0, the UE weights a PUSCH power offset (800) value and a transmission power control (TPC) 805 value received from the base station and a path loss (PL) 810 between the base station and the UE. The primary transmit power 825 is calculated in consideration of the value a (received from the base station). The first transmission power (1st Tx Power, 825) is mainly based on a parameter that is influenced by the path environment between the base station and the terminal and a parameter that is determined by the policy of the network. In addition, the UE considers a second transmission power (2nd Tx Power) 830 in consideration of the QPSK modulation included in the uplink grant and the scheduling parameter 815 indicating the allocation of 10 resource blocks (RBs). Calculate The secondary transmission power 830 is a transmission power changed through uplink scheduling of the base station.

Accordingly, the terminal may calculate the final uplink transmission power by adding both the primary transmission power 825 and the secondary transmission power 830. Here, the final uplink transmission power may not exceed the configured maximum UE transmit power (P _cmax ) of the configured UE. In the example of FIG. 8, since the final transmission power is smaller than the value of P _cmax at the time t0, uplink information transmission according to the set parameter is possible. In addition, there is a surplus power (power headroom) 820, which is a margin for additional transmission power. The surplus power 820 is transmitted by the terminal to the base station according to a rule determined by the wireless communication system.

At time t1, the base station changes to the scheduling parameter 850 indicating the 16QAM modulation scheme and the allocation of 50 resource blocks in consideration of the transmission power that can be additionally set to the terminal through the information of the surplus power 820. The terminal resets the secondary transmit power 865 according to the scheduling parameter 850. The primary transmit power 860 at t1 is a PUSCH power offset (835) value and a transmit power control (TPC) 840 value and a value weighted to PL 845 between the base station and the terminal (received from the base station). Is determined in consideration of, and assumes the same as the primary transmit power 825 at t0.

At time t1, P _cmax is changed to a value close to P _{cmax _L} , whereas the sum of the secondary transmit power 865 and the primary transmit power 860 required by the scheduling parameter 850 exceeds P _cmax . . That is, P _{cmax _H} -P there occurs a surplus power estimation error 855 as the _cmax. As described above, when the scheduling for the uplink resource is performed based only on the surplus power information, the terminal cannot set uplink transmission power expected by the base station, and thus performance degradation occurs. When using the component carrier aggregation scheme, the surplus power estimation error 855 becomes larger.

Whether a single component carrier system or a multi-component carrier system, the maximum transmission power set in the terminal is affected by the power adjustment of the terminal. Power adjustment means to reduce the maximum transmission power set in the terminal within a certain allowable range, it may be referred to as Maximum Power Reduction (MPR). The amount of power reduced by the power adjustment is referred to as the power adjustment amount. The reason for reducing the maximum transmission power set in the terminal is as follows. There is a case where the maximum transmission power has to be limited by the type of signal to be transmitted currently based on the hardware configuration in the terminal (particularly, RF (Radio Frequency)).

The maximum transmission power in consideration of power adjustment is expressed by the following equation.

Here, P _cmax is the maximum transmission power set for the UE, P _{cmax -L} is the minimum value, P _cmax-H of P _cmax is the maximum value of P _cmax. More specifically, P _{cmax -L} and P _{cmax -H} are each calculated by the following equation.

Here, MIN [a, b] is the smaller of a and b, P _Emax is the maximum power determined by the RRC signaling of the base station, and ΔT _C is applied when there is uplink transmission at the edge of the band. The amount of power to be made, which is 1.5 dB or 0 dB depending on the bandwidth. P _powerclass is a power value according to several power classes defined to support various terminal specifications in the system. In general, LTE system supports power class 3, P _powerclass by power class 3 is 23dBm. PC is the amount of power adjustment, and APC (Additional Power Coordination) is an additional amount of power signaled by the base station.

The power regulation may be set to a specific range or to a certain constant. The power adjustment may be defined in terminal units, may be defined in each CC unit, or may be set to a predetermined range or constant in each CC unit. In addition, the power adjustment may be set to a range or a constant depending on whether the PUSCH resource allocation of each CC is continuous or discontinuous. The power adjustment may be set to a range or a constant according to the presence or absence of the PUCCH.

9 is an explanatory diagram illustrating a power adjustment amount and a maximum transmission power in a multi-element carrier system according to an embodiment of the present invention. For convenience of explanation, it is assumed that only one UL CC is allocated to the terminal.

Referring to FIG. 9, assuming that ΔT _C = 0, the maximum value P _cmax−H of the maximum transmit power P _cmax may be 23 dB corresponding to the power class 3. The minimum value P _cmax-L of the maximum transmit power P _cmax is the maximum value P _{cmax -H} minus the power adjustment amount (PC, 900) and the additional power adjustment amount (APC, 905). That is, the terminal reduces the minimum value P _cmax-L of the maximum transmission power P _cmax by using the power adjustment amount PC 900 and the additional power adjustment amount APC 905. The maximum transmit power P _cmax is determined between the maximum value P _cmax-H and the minimum value P _cmax-L .

Meanwhile, the uplink transmission power 930 is represented by the sum of the bandwidth (BW), the power 915 determined by the MCS and the RB, the path loss (PL, 920), and the PUSCH transmission power control (PUSCH TPCs, 925). . Surplus power (PH, 910) is the maximum transmission power (P _max ) minus the uplink transmission power (930).

In FIG. 9, only one UL CC is described. However, when a plurality of UL CCs are allocated, the maximum transmit power will be given in units of terminals rather than in units of UL CCs. It can be given as the sum of the maximum transmit powers.

In calculating the maximum transmit power, P _Emax , ΔT _C , P _powerclass , and additional power adjustment amount (APC) are information known or known by the base station. However, since the power adjustment amount PC may be variable, the maximum transmission power of the terminal also varies accordingly. When the terminal reports the surplus power to the base station, the base station can only estimate the extent of the maximum transmission power through the surplus power. Since the base station performs an uncertain uplink scheduling within the estimated maximum transmit power, the base station may schedule the modulation / channel bandwidth / RB requiring a transmit power of the maximum transmit power or more for the terminal. This problem may occur more prominently in a multi-component carrier system. Therefore, the terminal needs to inform the base station of the amount or range of the maximum transmission power for each CC. Hereinafter, the maximum transmit power for each CC is referred to as a carrier maximum transmit power (P _{cmax, c} ).

Meanwhile, scheduling cases of various CCs may exist in a multi-component carrier environment. For each case, the transmission of P _{cmax and c} information is required. However _, if the amount of P _{cmax , c} information is too large, it may be a problem under limited uplink resources. It may occur that P _{cmax , c} is the same for several CCs.

As an example, P _{cmax and c} may be the same among a plurality of CCs according to a scheduling configuration. Since the P _{cmax and c} information is a value related to the characteristics of the radio frequency (RF), it is highly likely to have the same value for each CC for the same scheduling configuration. Herein, the scheduling setting refers to a setting including a CC configuration, a RB (Resource Block) configuration, a Modulation and Coding Scheme (MCS) configuration, and the like scheduled to the UE.

As another example, when all set CCs are configured with one RF, the values of P _{cmax and c} may have the same value over a plurality of CCs.

As another example, one type of P _cmax, and _c of type 2 P _{cmax, c} can be identical in value in accordance with an aspect of resource allocation.

In all these cases, it is a waste of resources to send the same P _{cmax , c} values repeatedly for multiple CCs.

This problem can be solved by two methods. The first method is to present a triggering condition such that the same P _{cmax , c} is not continuously transmitted for the same scheduling setup. The second method is to create one field representing the same values when the P _{cmax , c} values transmitted by triggering are the same, and construct a MAC control element comprising the one field. According to these two methods, it is possible to prevent the waste of uplink resources and further increase the efficiency of the uplink grant in consideration of uplink control. Hereinafter, first, a definition and expression method of the maximum carrier power of the carrier will be described. The structure of the MAC control element according to the second method will be described in detail.

1. Definition and Expression Method of Carrier Maximum Transmitting Power (P _{cmax .c} )

Carrier maximum transmit power (P _{cmax .c} ) is expressed in dB as the maximum transmit power that can be output per one UL CC. Carrier maximum transmit power may be given to the threshold value as 20dB≤P _{cmax .c} <22dB, it may be given as a constant, such as P _{cmax .c} = 20dB. The maximum transmission power of the carrier may be expressed by quantizing a predetermined size in dB units, for example, in 1 dB units. That is, P _cmax.c may be expressed as 1 dB, 2 dB, 3 dB, or the like. The maximum carrier power may be set differently for each UL CC or may be set to the same value. For example, UL CC1 is set to P _cmax.c1 , and UL CC2 and UL CC3 are both P _{cmax .} can be set to _c2 .

The maximum carrier power is divided into at least one level having a predetermined range. Between each step there is a dB difference of constant or variable magnitude. The terminal and the base station operate a range mapping table in which an index is assigned to each step. By using the range mapping table, it is effective because the size of the maximum transmit power of a carrier can be expressed by only an index. The size of the range mapping table is determined according to the amount of information (for example, the number of bits) used for reporting the carrier maximum transmission power. The report on the range of the maximum transmission power of the carrier and the report of the maximum transmission power of the carrier are used in the same sense, and hereinafter, the report of the maximum transmission power of the carrier will be referred to for the unification of the term.

The number of bits representing the maximum carrier power depends on what the system defines. More bits may allow for a wider or more granular range of power reporting. However, if the UE consumes a lot of uplink resources to report the maximum carrier power to the base station, it may cause a significant degradation of system performance. Therefore, there is a need for a method of minimizing the amount of information required for reporting the maximum transmit power of the carrier. Hereinafter, a method of expressing a carrier maximum transmission power in 3 bits and 5 bits will be described. However, this is merely an example and the number of bits does not limit the present invention.

Table 1 is a range mapping table according to an embodiment of the present invention. This is a case where 3 bits are used for reporting the maximum transmission power of the carrier.

Index P _{cmax .c} (dB) Range Report 0 P _{cmax .c} ≥22 (or 22≤P _{cmax .c} ≤23) One 20≤P _{cmax .c} <22 2 18≤P _{cmax .c} <20 3 16≤P _{cmax .c} <18 4 14≤P _{cmax .c} <16 5 12≤P _{cmax .c} <14 6 10≤P _{cmax .c} <12 7 P _{cmax .c} <10

Referring to Table 1, the range of carrier maximum transmit power is divided into eight levels. The index is 3 bits and indicates the range of the maximum carrier power of the eight steps. For example, index 3 indicates that the range of the carrier maximum transmit power 16≤P _{cmax .c} <18. As such, one index is mapped to a range of one carrier maximum transmit power. After determining the range to which the maximum carrier power belongs, the terminal may report the maximum carrier power as an index mapped to the determined range. For example, assuming that UL CC1 and UL CC2 are configured in the terminal, the terminal may report index 2 to the base station for UL CC1 and index 5 to the base station for UL CC2. Each step in the range of carrier maximum transmit power differs by a certain amount, that is, by 2 dB intervals.

The range of the maximum transmission power in the carrier range of the mapping table may vary according to the power class (P _powerclass) of the terminal. The power class of the terminal is the maximum output power for any transmission bandwidth within the channel bandwidth. As an example, a total of four power classes of the terminal defined in the LTE system, among which the maximum transmission power is defined in the power class 3 is 23dB. The power class is measured at least one subframe period, and the range of maximum power reduction (MPR) is set depending on the power class.

Table 2 is a range mapping table according to another example of the present invention. This is a case where 4 bits are used to report the maximum transmission power of the carrier, and there is a 1 dB difference between steps in the maximum transmission power range of the carrier.

Index P _{cmax .c} (dB) Range Report 0 P _{cmax .c} ≥22 (or 22≤P _{cmax .c} ≤23) One 21≤P _{cmax .c} <22 2 20≤P _{cmax .c} <21 3 19≤P _{cmax .c} <20 4 18≤P _{cmax .c} <19 5 17≤P _{cmax .c} <18 6 16≤P _{cmax .c} <17 7 15≤P _{cmax .c} <16 8 14≤P _{cmax .c} <15 9 13≤P _{cmax .c} <14 10 12≤P _{cmax .c} <13 11 11≤P _{cmax .c} <12 12 10≤P _{cmax .c} <11 13 9≤P _{cmax .c} <10 14 8≤P _{cmax .c} <9 15 P _{cmax .c} <8

Referring to Table 3, the maximum carrier power range is divided into 16 levels. The index is 4 bits and indicates the range of the maximum carrier power in step 16 above. For example, index 3 indicates that the range of the carrier maximum transmit power 19≤P _{cmax .c} <20.

The table can also be constructed by setting the dB difference at each step of the lower index based on the power class. This is shown in Table 3.

Index P _{cmax .c} (dB) Range Report 0 P _powerclass One P _powerclass -1≤P _{cmax .c} <P _powerclass 2 _{P powerclass -2≤P cmax .c <P powerclass} -1 3 _{P powerclass -3≤P cmax .c <P powerclass} -2 4 _{P powerclass -4≤P cmax .c <P powerclass} -3 5 _{P powerclass -5≤P cmax .c <P powerclass} -4 6 _{P powerclass -6≤P cmax .c <P powerclass} -5 7 _{P powerclass -7≤P cmax .c <P powerclass} -6 8 _{P powerclass -8≤P cmax .c <P powerclass} -7 9 _{P powerclass -9≤P cmax .c <P powerclass} -8 10 _{P powerclass -10≤P cmax .c <P powerclass} -9 11 _{P powerclass -11≤P cmax .c <P powerclass} -10 12 _{P powerclass -12≤P cmax .c <P powerclass} -11 13 _{P powerclass -13≤P cmax .c <P powerclass} -12 14 _{P powerclass -14≤P cmax .c <P powerclass} -13 15 _{P powerclass -15≤P cmax .c <P powerclass} -14

Referring to Table 3, there is a 1dB difference between each step in all indexes.

Table 4 is a range mapping table according to another example of the present invention. This is a case where 5 bits are used for reporting the maximum transmission power of the carrier, and there is a constant 1 dB difference between steps in the range of the maximum transmission power of the carrier.

Index P _{cmax .c} (dB) Range Report 0 P _{cmax .c} ≥22 (or 22≤P _{cmax .c} ≤23) One 21≤P _{cmax .c} <22 2 20≤P _{cmax .c} <21 3 19≤P _{cmax .c} <20 4 18≤P _{cmax .c} <19 5 17≤P _{cmax .c} <18 6 16≤P _{cmax .c} <17 7 15≤P _{cmax .c} <16 8 14≤P _{cmax .c} <15 9 13≤P _{cmax .c} <14 10 12≤P _{cmax .c} <13 11 11≤P _{cmax .c} <12 12 10≤P _{cmax .c} <11 13 9≤P _{cmax .c} <10 14 8≤P _{cmax .c} <9 15 7≤P _{cmax .c} <8 16 6≤P _{cmax .c} <7 17 5≤P _{cmax .c} <6 18 4≤P _{cmax .c} <5 19 3≤P _{cmax .c} <4 20 2≤P _{cmax .c} <3 21 1≤P _{cmax .c} <2 22 0≤P _{cmax .c} <1 23 Reserved 24 Reserved 25 Reserved 26 Reserved 27 Reserved 28 Reserved 29 Reserved 30 Reserved 31 Reserved

Referring to Table 4, the maximum carrier power range is divided into a total of 32 levels. The index is 5 bits, which indicates the range of the maximum carrier power in 32 steps. For example, the index 19 indicates that the range of the carrier maximum transmit power 3≤P _{cmax .c} <4. Since the maximum transmit power should be greater than zero, there is no range of the maximum transmit power mapped to the remaining indexes 23 to 31. Therefore, indexes 23 to 31 remain as reserved code points.

 Tables 1 to 4 show differences of 1 dB between steps. Of course, the range mapping table may be configured to have an ndB difference between steps, or the range mapping table may be configured to have a variable size difference for each step.

2. Structure of Information for Power Reporting

10 is a block diagram illustrating a structure of a MAC protocol data unit (MAC PDU) for power reporting according to an embodiment of the present invention. MAC PDUs are also called Transport Blocks (TBs).

Referring to FIG. 10, the MAC PDU 1000 includes a MAC header 1010, at least one MAC control element 1020, 1025, at least one MAC Service Data Unit 1030-1, 1030-m) and padding 1040.

MAC control elements 1020 and 1025 are control messages generated by the MAC layer.

The MAC SDUs 1030-1,... 1030-m are the same as the RLC PDUs delivered in the Radko Link Control (RLC) layer. Padding 1040 is a predetermined number of bits added to make the size of the MAC PDU constant. The MAC control elements 1020,..., 1025, MAC SDUs 1030-1,... 100-m, and padding 1040 together are also referred to as MAC payloads.

MAC header 1010 includes at least one sub-header (1010-1, 1010-2, ..., 1010-k), each subheader (1010-1, 1010-2, ... .1010-k) corresponds to one MAC SDU or one MAC control element or padding. The order of the subheaders 1010-1, 1010-2,..., 1010-k is arranged in the same order as the corresponding MAC SDUs, MAC control elements or paddings within the MAC PDU 1000.

Each subheader 1010-1, 1010-2, ..., 1010-k contains four fields: R, R, E, LCID, or R, R, E, LCID, F, L Field may be included. A subheader containing four fields is a subheader corresponding to a MAC control element or padding, and a subheader containing six fields is a subheader corresponding to a MAC SDU.

The logical channel identification information (LCID) field is an identification field for identifying a logical channel corresponding to a MAC SDU or for identifying a type of a MAC control element or padding and may be 5 bits.

For example, the LCID field indicates whether the corresponding MAC control element is a surplus power MAC control element for transmission of surplus power, a feedback request MAC control element for requesting feedback information from the terminal, and discontinuous reception. DRX (Discontinuous Reception) command for the command Identifies whether it is a MAC control element or a Contention Resolution Identity (MAC) control element for contention resolution between terminals.

In addition, according to the present invention, the LCID field may identify whether the corresponding MAC control element is a MAC control element for power reporting. There is one LCID field for each MAC SDU, MAC control element or padding. Table 5 is an example of an LCID field.

Index LCID values 00000 CCCH 00001-01010 Identity of the logical channel 01011-10111 Reserved 11000 Scell activation / deactivation 11001 Reference CC Indicator 11010 Power Report (CA) 11011 C-RNTI 11100 Truncated BSR 11101 Short bsr 11110 Long bsr 11111 Padding

Referring to Table 5, the LCID field value of 11010 may indicate that the corresponding MAC control element is a MAC control element for power reporting of at least one component carrier according to the present invention. The MAC control element for power reporting includes at least one of power headroom information and carrier maximum transmit power information P _{cmax and c} information. The surplus power information is information including at least one surplus power field (PHF) and an additional field related thereto. The carrier maximum transmit power information is information including at least one carrier maximum transmit power field and additional fields related thereto. Here, a field is at least one bit representing meaningful information. For example, the surplus power field is a field indicating surplus power, and the carrier maximum transmit power field is a field indicating carrier maximum transmit power. The number of bits in these fields is determined by the system.

11 is a block diagram illustrating a structure of a MAC PDU for power reporting according to another embodiment of the present invention.

Referring to FIG. 11, the MAC PDU 1100 includes a MAC header 1110, a MAC control element 1120 for power reporting, a MAC SDU 1130, and a padding 1140.

The MAC header 1110 includes at least one MAC subheader (not shown). The MAC subheader and the MAC control element 1120 for power reporting are configured in octets. An octet refers to 8 bits of information. For example, the MAC subheader is composed of an R field 1111, an E field 1112, an LCID field 1113, an F field 1114, and an L field 1115.

The L field 1115 indicates the length of the MAC control element 1120 for the corresponding power report in bytes. The MAC control element 1120 for power reporting includes at least one octet, and each octet includes any one of surplus power information and carrier maximum transmit power. Accordingly, the MAC control element 1120 for power reporting may include both surplus power information and carrier maximum transmit power, or may include only one of them.

3. Power report cell group and same power cell group

(1) Power Report Cell Group (PRCG)

In order to report the power of the CC, the terminal and the base station must first discuss about which CC the power is reported. The UE reports the first carrier maximum transmit power for CC1 because the base station cannot determine whether the first carrier maximum transmit power is for CC1 or CC2. Therefore, the CC to be reported should be specified, and the set of CCs to be reported is called a Power Report Cell Group (PRCG). Therefore, the carrier maximum transmit power is reported only for CCs belonging to the power report cell group, and the carrier maximum transmit power is not reported for CCs that are not.

In more detail, there may be a first mode in which the UE dynamically informs the base station as bitmap information and a second mode in which the UE belongs to the power report cell group in advance. In the case of the first mode, bitmap information may be included in the MAC control element. In this case, the bitmap information may be disposed at the front end of the MAC control element, may be included in the MAC control element for surplus power reporting, or may be included in the MAC control element for maximum transmission power reporting.

Regarding the criteria for selecting a power report cell group, there may be various cases.

As an example, all cells configured in the terminal are selected as the power report cell group.

12 is an explanatory diagram illustrating an example of a method of selecting a power report cell group.

Referring to FIG. 12, three CCs CC1, CC2, and CC3 are set in the terminal. RF1 includes CC1 and CC2, and RF2 includes CC3.

As another example, only activated cells are selected as the power reporting cell group.

13 is an explanatory diagram for explaining another example of the method for selecting a power report cell group.

Referring to FIG. 13, when three CCs CC1, CC2, and CC3 are configured in a terminal, only CC1 and CC2 are activated, and CC3 is in a deactivated state. In this case, the deactivation state means a state in which data and control information transmission is not performed until the activation command falls through the corresponding CC. In the situation of FIG. 13, the number of CCs available for transmission is three, but the CCs used for actual transmission are CC1 and CC2.

As another example, only scheduled cells are selected as the power report cell group.

14 is an explanatory diagram illustrating another example of a method of selecting a power report cell group.

Referring to FIG. 14, in a situation in which three CCs CC1, CC2, and CC3 are configured in a terminal, only CC1 and CC2 are currently scheduled. Here, CC3 is not actually scheduled, but calculates surplus power (PH) based on virtual resource allocation and MCS level. This virtual CC surplus power is required because the base station must detect a change in pathloss for the CC if it is not scheduled in the current frame but is scheduled later. In general, when calculating surplus power for a scheduled CC, it should proceed regardless of the virtual surplus power.

The algorithm for the selection of power reporting cell groups is an issue of implementation. One possible example is a case in which the transmission of P _{cmax , c} does not occur from the terminal to the base station when the same P _{cmax , c} value exists for the same scheduling configuration. At this time, the base station would be replaced with P _cmax, the value of _c that was the value of P _{cmax, c} has an existing for the scheduling set.

(2) Identical Power Cell Group (IPCG)

The problem of resource waste caused by overlapping transmission of the same carrier maximum transmit power field for different CCs should be solved. To this end, the terminal selects a plurality of CCs having the same carrier maximum transmit power among a plurality of CCs belonging to the power report cell group. The terminal configures one representative carrier maximum transmit power field for the selected plurality of CCs as a MAC control element. The selected plurality of CCs is called an Identical Power Cell Group (IPCG). An equal power cell group is a subset of a power reporting cell group. The terminal may include a separate cell indicator (CI) indicating a CC belonging to the same power cell group in the MAC control element.

The MAC control element for power reporting includes at least one of a cell indicator field (CI field: CIF), an R field, and a P field.

The cell indicator field is a field indicating a CC (or cell) belonging to the same power cell group. The cell indicator field may be in a bitmap format. That is, one bit is mapped 1: 1 with one cell of the power report cell group, and the value of the bit indicates whether the cell belongs to the same power cell group. That is, if the bit value is '1', the cell belongs to the same power cell group, and if the bit value is '0', the cell does not. For example, suppose the cell indicator field is an 8-bit bitmap and hgfedcba. Assume that eight CCs (CC0, CC1, CC2, ..., CC7) belonging to the power report cell group are mapped to each bit. That is, CC0 is mapped to a, CC1 to b, CC2 to c, CC3 to d, CC4 to e, CC5 to f, CC6 to g, and CC7 to h. If CC0, CC2, CC7 belong to the same power cell group, a = 1, c = 1, h = 1, and the remaining b = d = e = f = g = 0. Thus, the cell indicator field is 10000101. This indicates that the maximum carrier power of CC0, the maximum carrier power of CC2, and the maximum carrier power of CC7 are all the same.

The example assumes that all CCs belong to a power reporting cell group. However, there may be cases where some CCs do not belong to the power reporting cell group. Among the bits of the cell indicator field, a bit corresponding to a CC that does not belong to the power report cell group has no meaning. This bit is called a D field. The D field represents a field that is not considered by the protocol between the terminal and the base station (Don't care). The cell indicator field may or may not include a D field. In the above example, five CCs (CC0, CC2, CC3, CC6, CC7) of the eight CCs belong to the power report cell group, and the remaining three CCs (CC1, CC4, CC5) do not belong. The bits corresponding to the remaining three CCs are represented by a D field. That is, 10DD01D1.

The R field indicates a reserved bit that does not contain meaningful information.

The P field means padding bit. Padding is a bit added to match the MAC control element to a multiple of octets and does not contain meaningful information.

There are four types of maximum carrier power fields as shown in Table 6.

Carrier maximum transmit power field
(P _{cmax, c} FIeld) Description P _{cmax, c} -T2 FIeld Indicates carrier maximum transmit power for type 2 UL PCC P _{cmax, c} -T1 FIeld Indicates carrier maximum transmit power for type 1 UL PCC P _{cmax, c} -G FIeld Displays the maximum transmit power of carrier that represents CC belonging to IPCG P _{cmax, c} -P FIeld Displays the maximum carrier power for each CC that does not belong to IPCG

Referring to Table 6, all four types of carrier maximum transmit power fields have the same number of bits and indicate homogeneous information (carrier maximum transmit power). These may be included in a MAC control element for one power report.

If there is no separate identifier to distinguish them in the MAC control element, the type of carrier maximum transmission power field can be distinguished in the arrangement order. The ordering rules of each field are as follows. For example, in the MAC control element for power reporting, it may be arranged in the order of P _{cmax , c} -T2 field, P _{cmax, c} -T1 field, P _{cmax , c} -G field, P _{cmax , c} -P field. have. Or, it may be arranged in the order of P _{cmax, c} -T1 field, P _{cmax , c} -T2 field, P _{cmax , c} -G field, P _{cmax , c} -P field. A plurality of P _{cmax , c} -P fields may be arranged according to a rule previously promised between the terminal and the base station. For example, they may be arranged in cell index order. Ascending or descending arrays will follow the rules set by the system. For _example, P _{cmax, c} -P1 = cell index _2, P _{cmax, c} -P2 = cell index _3, P _{cmax, c} -P3 = Assuming a cell index 1, if the rules are promised high P _{cmax, c} -P3, is arranged in the order of _{P cmax, c -P1, P cmax} , c -P2.

Hereinafter, the structure of the MAC control element for power reporting according to each field combination will be described in detail.

4. Structure of MAC Control Element for Power Reporting

The structure of the MAC control element for power reporting can be divided into two types. One is an octet structure, and the other is a continuous structure. The octet structure is a structure that separates meaningful information into a certain number of bits, for example, 8 bits. A field exceeding one octet is included in the next octet. For example, suppose you have a 3-bit long field a. Even if there are two bits in the first octet, all three bits of the field a are included in the new second octet. That is, only two bits of the field a are included in the first octet and the remaining one bit is not included in the second octet.

On the other hand, the continuous structure is a structure in which each field is arranged continuously. Therefore, no separate R field is included between the fields.

(1) octet structure

15 is a structure of a MAC control element for power reporting according to an embodiment of the present invention. This is the case where each P _{cmax , c} field is 3 bits.

Referring to FIG. 15, the MAC control element 1500 for power reporting includes a plurality of R fields, a cell indicator field in a bitmap format, a P _{cmax , c} -T 2 field, P _{cmax , c} -T 1 field, P _{cmax, c} -G fields, P _{cmax , c} -P1 fields, ..., P _{cmax , c} -Pn fields, and at least one padding bit P.

The MAC control element 1500 for power reporting is configured in octets of 8 bits. The first octet Oct 1 includes an 8-bit cell indicator field. Since the P _{cmax and c} fields are 3 bits, one octet may include up to two P _{cmax and c} fields. Within one octet is filled with the P _{cmax, c} field and the remaining bits are set to the R field. On the other hand, the arrangement order of the P _{cmax , c} field may be determined as follows according to the type.

The second octet Oct 2 includes two R fields, a P _{cmax , c} -T 2 field, and a P _{cmax , c} -T 1 field.

The third octet Oct 3 includes two R fields, a P _{cmax , c} -G field, and a P _{cmax , c} -P 1 field. The k-th octet Oct k includes two R fields, a P _{cmax , a c} -P n field, and a padding bit. In FIG. 15, the arrangement order of the P _{cmax and c} fields is not limited to the present invention, and other arrangement orders will also correspond to the technical scope of the present invention.

The cell indicator field of CCs included in the same power cell group is indicated by 1, and their representative carrier maximum transmit power values are input to the values of P _{cmax and c} -G fields. Further, the indicator field of the CC-cell is not included in the same power group of cells is indicated by 0, the individual carrier maximum transmission power value of these is inputted to the respective P _{cmax, c} -P1 field to P _{cmax, c} field -Pn .

16 is a structure of a MAC control element for power reporting according to another embodiment of the present invention. This is the case where each P _{cmax , c} field is 4 bits.

Referring to FIG. 16, the MAC control element 1600 for power reporting includes a cell indicator field, a P _{cmax , c-} T2 field, a P _{cmax , c-} T1 field, P _{cmax , c} -G field, P in a bitmap format. _{cmax , c} -P1 fields, ..., P _{cmax , c} -Pn fields, and at least one padding bit P.

The first octet Oct 1 includes an 8-bit cell indicator field. Since the P _{cmax and c} fields are 4 bits, one octet may include at most two P _{cmax and c} fields. Since one octet is filled with the P _{cmax and c} fields, there are no bits left, so there is no R field. On the other hand, the arrangement order of the P _{cmax, c} field may be determined as follows according to the type.

The second octet Oct 2 includes a P _{cmax , c} -T2 field and a P _{cmax , c} -T1 field. The third octet Oct 3 includes a P _{cmax , c} -G field and a P _{cmax , c} -P1 field. The k-th octet Oct k includes a P _{cmax , c} -P n field and a padding bit. In FIG. 16, the arrangement order of the P _{cmax and c} fields is not limited to the present invention, and other arrangement orders will also correspond to the technical scope of the present invention.

17 is a structure of a MAC control element for power reporting according to another embodiment of the present invention. This is the case where each P _{cmax , c} field is 5 bits.

Referring to FIG. 17, a MAC control element 1700 for power reporting includes a plurality of R fields, a cell indicator field in a bitmap format, a P _{cmax , c} -T 2 field, P _{cmax , c} -T 1 field, P _{cmax , c} -G field, P _{cmax , c} -P1 field, ..., P _{cmax , c} -Pn field, and at least one padding bit P.

The first octet Oct 1 includes an 8-bit cell indicator field. Since the P _{cmax , c} field is 5 bits, one octet may include at most one P _{cmax , c} field. One octet is filled with one P _{cmax , c} field and the remaining three bits are set to the R field. On the other hand, the arrangement order of the P _{cmax, c} field may be determined as follows according to the type.

The second octet (Oct 2) is divided into three fields and P R _{cmax, c} -T2 the field, the third octet (Oct3) includes three fields R and P _{cmax, c} -T1 field. The fourth octet Oct 4 includes three R fields and P _{cmax , c} -G fields, and the fifth octet Oct 5 includes three R fields and P _{cmax , c} -P 1 fields. The kth octet (Oct k) includes three R fields and a P _{cmax , c} -P n field. In FIG. 17, the arrangement order of the P _{cmax and c} fields is not limited to the present invention, and other arrangement orders will also correspond to the technical scope of the present invention.

18 is a structure of a MAC control element for power reporting according to another embodiment of the present invention. This is the case where each P _{cmax , c} field is 6 bits.

Referring to FIG. 18, the MAC control element 1800 for power reporting includes a plurality of R fields, a cell indicator field in a bitmap format, a P _{cmax , c} -T 2 field, P _{cmax , c} -T 1 field, P _{cmax , c} -G field, P _{cmax , c} -P1 field, ..., P _{cmax , c} -Pn field, and at least one padding bit P.

The first octet Oct 1 includes an 8-bit cell indicator field. Since the P _{cmax , c} field is 6 bits, one octet may include at most one P _{cmax , c} field. One octet is filled with one P _{cmax , c} field and the remaining two bits are set to the R field. On the other hand, the arrangement order of the P _{cmax, c} field may be determined as follows according to the type.

The second octet (Oct 2) is two R fields and P _{cmax, c} -T2 the field, the third octet (Oct3) comprises two R fields and P _{cmax, c} -T1 field. The fourth octet Oct 4 includes two R fields and a P _{cmax , c} -G field, and the fifth octet Oct 5 includes two R fields and a P _{cmax , c} -P 1 field. The k-th octet Oct oc includes two R fields and a P _{cmax and c} -P n fields. In FIG. 18, the arrangement order of the P _{cmax and c} fields is not limited to the present invention, and other arrangement orders will also correspond to the technical scope of the present invention.

19 is an example of utilization of a MAC control element for power reporting according to FIG. 18.

Referring to FIG. 19, the MAC control element 1900 for power reporting includes a plurality of R fields, a bit indicator format cell indicator field, a P _{cmax , c} -G field, and a P _{cmax , c} field.

The cell indicator field is DDD0111D. The D field indicates which CC does not belong to the power report cell group. Suppose that in order from the rightmost bit to the leftmost bit, they are mapped to CC0, CC1, CC2, ..., CC7. Since CC0, CC5, CC6, and CC7 are D fields, they do not belong to the power report cell group. The power report cell group includes only CC1, CC2, CC3, and CC4. Since the main serving cell CC0 is set to the D field, the P _{cmax , c} -T2 and P _{cmax , c} -T1 fields _{, which} are the P _{cmax and c} fields of the main serving cell, are assigned to the MAC control element 1900 for power reporting. not included.

The bits corresponding to CC1, CC2, and CC3 are all 1. Therefore, CC1, CC2, and CC3 belong to the same power cell group. The carrier maximum transmit power values for CC1, CC2, and CC3 are all the same as the maximum transmit power values indicated by the P _{cmax, c} -G fields. And CC4 has individual P _{cmax and c} fields.

20 is another example of utilization of the MAC control element for power reporting according to FIG.

Referring to FIG. 20, the first embodiment is a case where a bit value corresponding to CC0 of the main serving cell is 0 in the cell indicator field, and the second embodiment is a bit value corresponding to CC0 of the main serving cell is 1 in the cell indicator field. If

Referring to Embodiment 1, the MAC control element 2000 for power reporting includes a plurality of R fields, bitmap format cell indicator fields, P _{cmax , c} -T2 fields, P _{cmax , c} -T1 fields, P _{cmax , c} -G field, P _{cmax, c} -P1 field, ..., P _{cmax , c} -Pn field. A cell indicator field corresponding to CC0 of 0 means that CC0 does not belong to the same power cell group. This also means that the individual P _{cmax, c} field, P _{cmax, c} -T2 field and P _{cmax, c} -T1 field for CC0 present. The number of remaining P _{cmax , c} -P1 fields, ..., P _{cmax , c} -Pn fields is determined depending on whether they belong to the same power cell group.

Referring to Embodiment 2, the MAC control element 2010 for power reporting includes a plurality of R fields, bitmap format cell indicator fields, P _{cmax , c} -G fields, P _{cmax , c} -P1 fields, ... , P _{cmax and c} -Pn fields. Exemplary MAC control element for, when compared with Example 1, Example 2 of the power report (2010) does not include the P _{cmax, c} -T2 field, P _{cmax, c} -T1 field. This is because CC0 belongs to the same power cell group. That is, since the carrier maximum transmit power value for CC0 is represented by the P _{cmax , c} -G fields, no separate P _{cmax , c} field is required.

(2) continuous structure

21 shows a structure of a MAC control element for power reporting according to another embodiment of the present invention.

Referring to FIG. 21, the MAC control element 2100 for power reporting includes a cell indicator field, P _{cmax, c} -T2 field, P _{cmax , c} -T1 field, P _{cmax , c} -G field, P _{cmax , c-} P1 field,..., P _{cmax , c} -Pn field and padding bit P. Unlike the octet structure, the continuous structure is characterized by no R field because there is no space between the fields.

22 is an example of utilization of a MAC control element for power reporting according to FIG. 21. This is the case where the P _{cmax and c} fields are 6 bits.

Referring to FIG. 22, the MAC control element 2200 for power reporting includes a cell indicator field, a P _{cmax, c} -G field, a P _{cmax , c} -P field. Since the bit of the main serving cell CC0 in the cell indicator field is set to the D field, the P _{cmax , c} -T2 and P _{cmax, c} -T1 fields _{, which} are the P _{cmax and c} fields of the main serving cell, are MAC for power reporting. It is not included in the control element 1900.

The bits corresponding to CC1, CC2, and CC3 are all 1. Therefore, CC1, CC2, and CC3 belong to the same power cell group. The carrier maximum transmit power values for CC1, CC2, and CC3 are all the same as the maximum transmit power values indicated by the P _{cmax, c} -G fields. And CC4 has individual P _{cmax and c} fields.

FIG. 23 is another example of utilization of a MAC control element for power reporting according to FIG. This is the case where the P _{cmax and c} fields are 6 bits.

Referring to FIG. 23, the first embodiment is a case where a bit value corresponding to CC0 of the main serving cell is 0 in the cell indicator field, and the second embodiment is a bit value corresponding to CC0 of the main serving cell is 1 in the cell indicator field. If

Referring to Embodiment 1, the MAC control element 2300 for power reporting includes a plurality of R fields, bitmap format cell indicator fields, P _{cmax , c} -T2 fields, P _{cmax , c} -T1 fields, P _{cmax , c} -G field, P _{cmax, c} -P1 field, ..., P _{cmax , c} -Pn field. A cell indicator field corresponding to CC0 of 0 means that CC0 does not belong to the same power cell group. This also means that the individual P _{cmax, c} field, P _{cmax, c} -T2 field and P _{cmax, c} -T1 field for CC0 present. The number of remaining P _{cmax , c} -P1 fields, ..., P _{cmax , c} -Pn fields is determined depending on whether they belong to the same power cell group.

Referring to Embodiment 2, the MAC control element 2310 for power reporting includes a plurality of R fields, a cell indicator field in a bitmap format, a P _{cmax , c} -G field, a P _{cmax , c} -P 1 field, ... , P _{cmax and c} -Pn fields. Exemplary MAC control element for, when compared with Example 1, Example 2 of the power report (2010) does not include the P _{cmax, c} -T2 field, P _{cmax, c} -T1 field. This is because CC0 belongs to the same power cell group. That is, since the carrier maximum transmit power value for CC0 is represented by the P _{cmax , c} -G fields, no separate P _{cmax , c} field is required.

5. Procedure of Power Report

Hereinafter, MAC control elements for power reporting are divided into four formats. As an example, the MAC control element including all kinds of P _{cmax and c} fields is called a first format MAC control element. That is, the first format MAC control element includes all of the cell indicator field, P _{cmax , c} -T2 field, P _{cmax , c} -T1 field, P _{cmax , c} -G field, P _{cmax , c} -P field. This is a case where CC0 does not belong to the same power cell group, at least two CCs belonging to the same power cell group exist, and at least one CC does not belong to the same power cell group. Of course, if the carrier maximum transmit power of all CCs belonging to the power report cell group is the same, the P _{cmax and c} -P fields may be excluded.

As another example, a MAC control element including only a cell indicator field, a P _{cmax , c} -G field, and a P _{cmax , c} -P field is called a second format MAC control element. This is a case where CC0 belongs to the same power cell group, at least two CCs belonging to the same power cell group, and at least one CC does not belong to the same power cell group. Of course, if the carrier maximum transmit power of all CCs belonging to the power report cell group is the same, the P _{cmax and c} -P fields may be excluded. Here, the case where the primary serving cell (Pcell) belongs to the power report cell group (PRCG) and the primary serving cell belongs to the same power cell group (IPCG) corresponds to P _{CMAX , C} -T1, P _{CMAX , C} -T2. This is the case that the value to be substituted is the value of the P _{CMAX , C} -G field. That is, when P _{CMAX , C} -T1 = P _{CMAX , C} -T2 = P _{CMAX , C} -G. On the other hand, if the main serving cell does not belong to the power report cell group, the values of P _{CMAX , C} -T1 and P _{CMAX, C} -T2 do not exist.

As another example, a MAC control element including a P _{cmax , c} -T2 field, a P _{cmax , c} -T1 field, and a P _{cmax , c} -P field is called a third format MAC control element. The third format MAC control element does not include the P _{cmax , c} -G fields. This is the case that the same power cell group is Null, that is, there is no CC belonging to the same power cell group because the maximum carrier power for each CC is different. The terminal may exclude the cell indicator field from the third format MAC control element. This is because the transmission of the cell indicator field is rather unnecessary redundancy in this case, since none of the CCs have the same maximum transmit power value. Thus, the third format MAC control element does not include a cell indicator field.

Both the first format MAC control element and the second format MAC control element include a cell indicator field, while the third format MAC control element does not include a cell indicator field. At the first of the third format MAC control element, a P _{cmax , c} -T2 field or P _{cmax, c} -T1 field _{, which} is not a cell indicator field _, is located. Due to this difference, the base station must have a special algorithm to interpret the first field. Through this algorithm, the base station can distinguish whether the MAC control element is a first or second format MAC control element or a third format MAC control element. This would also be unnecessary waste if separate control information indicating whether the first field is a cell indicator field.

As another example, the MAC control element including the P _{cmax and c} -P fields is called a fourth format MAC control element. The fourth format MAC control element does not include a P _{cmax , c} -T2 field, a P _{cmax , c} -T1 field, and a P _{cmax , c} -G field. This is the case that the same power cell group is Null, that is, there is no CC belonging to the same power cell group because the maximum carrier power for each CC is different. The terminal may exclude the cell indicator field from the fourth format MAC control element. This is because the transmission of the cell indicator field is rather unnecessary redundancy in this case, since none of the CCs have the same maximum transmit power value. Thus, the fourth format MAC control element does not include a cell indicator field. In addition, since the main serving cell is not included in the power report cell group, it does not include the P _{cmax , c} -T2 field, and the P _{cmax , c} -T1 field.

Hereinafter, a description will be given of a method for a base station to interpret a format of a MAC control element by itself using a value of an L field in a MAC subheader. The method of analysis depends on whether the MAC control element includes both the surplus power field and the carrier maximum transmit power field or only the carrier maximum transmit power field.

24 is an explanatory diagram illustrating a method of interpreting a MAC control element for power reporting according to an embodiment of the present invention. This is the structure of the MAC control element of format 3, which represents an octet structure or a continuous structure.

Referring to FIG. 24, the first embodiment includes a case where a MAC control element 2400 for power reporting includes a MAC control element 2410 for surplus power reporting and a MAC control element 2420 for reporting maximum carrier power. to be. Surplus power and carrier maximum transmit power are related to each other in that they are used to grant an appropriate uplink scheduling to the terminal. Therefore, when reporting power of the terminal, the maximum carrier power may be reported together with the surplus power. On the other hand, the second embodiment is a case in which the MAC control element 2450 for power reporting includes only the MAC control element for reporting the maximum carrier power.

Referring to Embodiment 1, the length of the MAC control element 2410 for surplus power reporting is M. And, the length of the MAC control element 2420 for reporting the maximum carrier power of the carrier is N. Thus, the total length L = M + N of the MAC control element 2400 for power reporting. Where L, M, and N are integer multiples of the byte. The MAC control element 2420 for reporting the maximum transmit power of the carrier includes P _{cmax , c} -T2 field 2421, P _{cmax , c} -T1 field 2422, P _{cmax , c} -P1 field 2423, ... , P _{cmax, c-} Pn fields 2424 and padding bits 2425. Here, the CI field or the P _{cmax, c} -G field is included, or the CI field or the P _{cmax , c} -G field is included, and the P _{cmax , c} -T2 field 2421, P _{cmax , c} -T1 field 2422 may be removed.

Referring to Embodiment 2, the MAC control element 2450 for reporting the maximum carrier power of the carrier includes a P _{cmax , c} -T2 field 2245, P _{cmax , c} -T1 field 2452, P _{cmax , c} -P1 field 2453,..., P _{cmax , c} -Pn field 2454, and padding bit 2455. Here, a CI field or a P _{cmax , c} -G field is included, or the CI field or a P _{cmax , c} -G field is included, and the P _{cmax , c} -T2 field 2421, P _{cmax, c} -T1 field are included. 2422 may be removed. The total length L = N of MAC control element 2450 for power reporting.

The lengths of the P _{cmax , c} -T2 fields, P _{cmax , c} -T1 fields, P _{cmax , c} -P fields are S _T2 , S _T1 , S _P , respectively, and the total number of P _{cmax , c} fields (= power report Let the number of CC) belong to the group of cells N _P.

(1) First, it is assumed that the main serving cell belongs to the power report cell group. If the MAC control element is a continuous structure, the base station interprets the MAC control element as format 3 if the following equation is established, and if it is not, it interprets it as format 1 or format 2.

On the other hand, when the MAC control element has an octet structure, the analysis method is divided into two cases according to the number of bits of the P _{cmax and c} fields.

First, when the P _{cmax , c} field is 3 bits or 4 bits, two P _{cmax , c} fields may exist in one octet. Therefore, in this case, if the following equation is established, the base station interprets the MAC control element as format 3, and if not, interprets it as format 1 or format 2.

Next, when the P _{cmax , c} field is 5 bits or 6 bits, one P _{cmax, c} field may exist in one octet. Therefore, in this case, if the following equation is established, the base station interprets the MAC control element as format 3, and if not, interprets it as format 1 or format 2.

The base station already knows the value of N _{P, and} the values of S _T2 , S _T1 and S _P have already been determined. If Equation 8 to Equation 10 holds for N obtained from L, this indicates that the MAC control element does not include a cell indicator field and a P _{cmax , c} -G field. Thus, it can be seen that the third format.

(2) Next, it is assumed that the main serving cell does not belong to the power report cell group. If the MAC control element has a continuous structure, the base station interprets the MAC control element as format 4 if the following equation is established, and if it is not, it interprets it as format 1 or format 2.

On the other hand, when the MAC control element has an octet structure, the analysis method is divided into two cases according to the number of bits of the P _{cmax and c} fields.

First, when the P _{cmax , c} field is 3 bits or 4 bits, two P _{cmax , c} fields may exist in one octet. Therefore, in this case, if the following equation is established, the base station interprets the MAC control element for power reporting as format 4, and if not, it interprets as format 1 or format 2.

Next, when the P _{cmax , c} field is 5 bits or 6 bits, one P _{cmax, c} field may exist in one octet. Therefore, in this case, if the following equation is established, the base station interprets the MAC control element for power reporting as format 4, and if not, it interprets as format 1 or format 2.

The base station already knows the value of N _{P, and} the value of S _P has already been determined. Equations 11 through 13 hold for N obtained from L, indicating that the MAC control element does not include a cell indicator field and a P _{cmax , c} -G field. Therefore, it can be seen that the third format or the fourth format.

25 is a flowchart illustrating a method of transmitting power information according to an embodiment of the present invention.

Referring to FIG. 25, the terminal calculates respective carrier maximum transmit powers P _{cmax and c} for CCs of the power report cell group PRCG (S2500). As an example of a method for obtaining a carrier maximum transmission power, Equation 1 to Equation 7 may be used. The information on the power report cell group may be already known between the terminal and the base station, or may be information transmitted separately by the terminal to the base station or informed by the base station to the terminal in advance. The maximum carrier power may be expressed based on the range mapping table shown in Tables 1 to 4.

The terminal determines the same power cell group (IPCG) (S2505). In this step, the UE may determine CCs of the CCs belonging to the power report cell group having the same carrier maximum transmit power or a difference less than or equal to the threshold as the same power cell group.

The terminal generates power information (S2510). The power information may be higher layer signaling such as a MAC message or an RRC message or may be physical layer signaling. The power information may refer to a MAC control element for power reporting. Alternatively, the power information may specifically refer to a MAC control element for reporting the maximum transmission power of the carrier. Alternatively, the power information may refer to both the MAC control element for surplus power reporting and the MAC control element for maximum carrier power reporting. Alternatively, the power information may mean a carrier maximum transmission power field. The power information may include a cell index indicator indicating a CC belonging to the same power cell group.

The terminal transmits power information to the base station (S2515).

The base station obtains the carrier maximum transmit power information for the CC of the power report cell group from the power information (S2520). In order to obtain the maximum carrier power value of each CC from the power information, the power information may be analyzed, which may be determined by the above-described analysis method.

The base station performs uplink scheduling for each CC based on the obtained carrier maximum transmit power value (S2525). In addition, an uplink grant as shown in Table 7 may be generated and informed to the terminal.

The uplink grant is information corresponding to format 0 of downlink control information (DCI) transmitted on the PDCCH and includes information such as RB, modulation and coding scheme (MCS), and TPC.

26 is a flowchart illustrating a method of transmitting power information by a terminal according to an embodiment of the present invention.

Referring to Figure 26, the terminal calculates the respective carrier maximum transmit power (P _{cmax, c)} of the CC of the power report cell group (PRCG) (S2600). As an example of a method for obtaining a carrier maximum transmission power, Equation 1 to Equation 7 may be used. The information on the power report cell group may be already known between the terminal and the base station, or may be information transmitted separately by the terminal to the base station or informed by the base station to the terminal in advance. The maximum carrier power may be expressed based on the range mapping table shown in Tables 1 to 4.

The terminal determines whether the same power cell group (IPCG) exists (S2605). If there is no CC belonging to the same power cell group, the terminal determines whether the main serving cell is included in the power report cell group (S2610). In this case, when the main serving cell is included in the power report cell group, a MAC control element of a third format is configured (S2615). On the other hand, if the main serving cell is not included in the power report cell group, a MAC control element of a fourth format is configured (S2620). Here, the fourth format MAC control element does not include a P _{cmax , c} -T2 field, a P _{cmax , c} -T1 field, and a P _{cmax , c} -G field.

In step S2605, if there are two or more CCs belonging to the same power cell group, the terminal configures a cell indicator field (S2625). The cell indicator field is in a bitmap format, and the terminal may configure the cell indicator field by setting a bit value mapped to each CC to 1 or 0.

The terminal determines whether the CC of the main serving cell belongs to the power report cell group (S2630). This may be determined by whether the bit corresponding to the CC of the main serving cell is set to the D field in the cell indicator field. If the CC of the main serving cell does not belong to the power report cell group, the terminal configures the MAC control element of the second format (S2635). That is, it configures the MAC control element excluding the P _{cmax and c} -G fields.

If the CC of the primary serving cell belongs to the power report cell group, the terminal determines whether the cell indicator field for the CC of the primary serving cell indicates 1 (S2640). If the cell indicator field for the CC of the primary serving cell indicates 1, the terminal again configures the MAC control element of the second format (S2635).

On the other hand, if the cell indicator field for the CC of the main serving cell indicates 0, the terminal configures the MAC control element of the first format (S2645). Thereafter, the terminal transmits the MAC control element to the base station (S2650).

27 is a flowchart illustrating a method of receiving power information by a base station according to an embodiment of the present invention.

Referring to Figure 27, the base station receives the MAC control element (CE) from the terminal (S2700). The base station determines whether the CC exists in the same power cell group (S2705).

If the CC does not exist in the same power cell group, the base station determines whether the main serving cell is included in the power report cell group (S2710). At this time, if the main serving cell is included in the power report cell group, it is determined as a MAC control element of a third format (S2715). On the other hand, if the main serving cell is not included in the power report cell group, it is determined as a MAC control element of a fourth format (S2720). Here, the fourth format MAC control element does not include a P _{cmax , c} -T2 field, a P _{cmax , c} -T1 field, and a P _{cmax, c} -G field.

On the other hand, if there is at least one CC in the same power cell group, the base station determines whether the cell indicator field for the CC of the main serving cell is set to the D field (S2725).

If the cell indicator field for the CC of the main serving cell is set to the D field, the base station determines the MAC control element as the MAC control element of the second format (S2730). If the cell indicator field for the CC of the main serving cell is not set to the D field, the base station determines whether the cell indicator field for the CC of the main serving cell is 1 (S2735).

If the cell indicator field for the CC of the primary serving cell is 1, the base station determines the MAC control element as the second format (S2730). If the cell indicator field for the CC of the primary serving cell is 0, the base station determines the MAC control element as the first format (S2740).

The method of interpreting whether the MAC control element is in the first and second formats or the third format may follow the example described in FIG. 24.

The base station successfully interprets the MAC control element to obtain a carrier maximum transmit power value for the CC belonging to the power report cell group (S2745).

28 is a block diagram illustrating a terminal transmitting power information and a base station receiving power information according to an embodiment of the present invention.

Referring to FIG. 28, the terminal 2800 includes a power calculator 2805, an identical power cell group determiner 2810, a power information generator 2815, and an uplink information transmitter 2820.

The power calculator 2805 calculates surplus power or maximum carrier power for the CC.

The same power cell group determiner 2810 may compare the magnitudes of the carrier maximum transmit power of each CC and determine CCs having the same or less than a threshold as the same power cell group.

The power information generator 2815 expresses the maximum carrier power of each CC or the representative maximum transmit power of the same power cell group based on Tables 1 to 4 above. Then, power information is generated in the manner described with reference to FIGS. 10 to 24. The power information may be higher layer signaling such as a MAC message or an RRC message or may be physical layer signaling. The power information may refer to a MAC control element for power reporting. Alternatively, the power information may specifically refer to a MAC control element for reporting the maximum transmission power of the carrier. Alternatively, the power information may refer to both the MAC control element for surplus power reporting and the MAC control element for maximum carrier power reporting. Alternatively, the power information may mean a carrier maximum transmission power field. The power information may include a cell index indicator indicating a CC belonging to the same power cell group.

The uplink information transmitter 2820 transmits power information to the base station 2850.

The base station 2850 includes an uplink information receiver 2855, a power information analyzer 2860, a power acquirer 2865, and a scheduling unit 2870.

The uplink information receiver 2855 receives power information from the terminal 2800.

The power information analyzer 2860 analyzes the power information based on the example described with reference to FIGS. 24 to 27. Thus, it is determined whether the format of the power information is the first format, the second format, the third format, or the fourth format.

The power acquisition unit 2865 extracts a carrier maximum transmit power field based on the analyzed power information format, and calculates a carrier maximum transmit power value for each CC from this.

The scheduling unit 2870 performs uplink scheduling based on a carrier maximum transmit power value for each CC and generates an uplink grant.

29 is a flowchart illustrating a format for transmitting power information in consideration of simultaneous PUCCH / PUSCH transmission according to an embodiment of the present invention. 29 shows selection according to PUCCH / PUSCH simultaneous transmission mode setting.

Referring to FIG. 29, there may be a transmission mode in which PUSCH and PUCCH transmission may occur simultaneously in uplink transmission, and a transmission mode in which PUSCH and PUCCH transmission cannot occur simultaneously. The uplink transmission mode may be determined differently by higher signaling (RRC signaling).

The terminal determines whether the PUSCH and the PUCCH can be transmitted simultaneously (S2900). If PUSCH and PUCCH transmission can occur simultaneously, a P _{CMAX , C} -T1 field or a P _{CMAX, C} -T2 field may appear. However, when it is impossible to simultaneously perform PUSCH and PUCCH transmission, the P _{CMAX and C-} T2 fields may not appear. That is, the values of P _{CMAX and C} -T2 are not transmitted.

Hereinafter, MAC control elements for power reporting for a case in which a mode in which PUSCH and PUCCH transmission cannot occur at the same time are set are further divided into four formats.

As an example, the MAC control element including the P _{cmax and c} fields excluding all kinds of P _{CMAX and C} -T2 is called a fifth format MAC control element. That is, the fifth format MAC control element includes all of the cell indicator field, the P _{cmax , c} -T1 field, the P _{cmax , c} -G field, and the P _{cmax , c} -P field. This is a case where CC0 does not belong to the same power cell group, at least two CCs belonging to the same power cell group exist, and at least one CC does not belong to the same power cell group. Of course, if the carrier maximum transmit power of all CCs belonging to the power report cell group is the same, the P _{cmax and c} -P fields may be excluded.

As another example, a MAC control element including only a cell indicator field, a P _{cmax , c} -G field, and a P _{cmax , c} -P field is called a sixth format MAC control element. This is a case where CC0 belongs to the same power cell group, at least two CCs belonging to the same power cell group, and at least one CC does not belong to the same power cell group. Of course, if the carrier maximum transmit power of all CCs belonging to the power report cell group is the same, the P _{cmax and c} -P fields may be excluded. Here, the case where Pcell belongs to PRCG and Pcell belongs to IPCG is a case where a value corresponding to P _{CMAX , C} -T1 is substituted as a value of P _{CMAX , C} -G field. In contrast, Pcell is not part of a PRCG is when the value of P _{CMAX, C} -T1 exists.

As another example, a MAC control element including a P _{cmax , c} -T1 field, and a P _{cmax , c} -P field is called a seventh format MAC control element. The seventh format MAC control element does not include the P _{cmax , c} -G fields. This is the case that the same power cell group is Null, that is, there is no CC belonging to the same power cell group because the maximum carrier power for each CC is different. The terminal may exclude the cell indicator field from the third format MAC control element. This is because the transmission of the cell indicator field is rather unnecessary redundancy in this case, since none of the CCs have the same maximum transmit power value. Therefore, the seventh format MAC control element does not include a cell indicator field.

Both the fifth format MAC control element and the sixth format MAC control element include a cell indicator field, while the seventh format MAC control element does not include a cell indicator field. The first field of the seventh format MAC control element is not a cell indicator field but a P _{cmax , c} -T 1 field. Due to this difference, the base station must have a special algorithm to interpret the first field. Through this algorithm, the base station can distinguish whether the MAC control element is the fifth or sixth format MAC control element or the seventh format MAC control element. This would also be unnecessary waste if separate control information indicating whether the first field is a cell indicator field.

As another example, the MAC control element including the P _{cmax and c} -P fields is called an eighth format MAC control element. The eighth format MAC control element does not include a P _{cmax , c} -T2 field, a P _{cmax , c} -T1 field, and a P _{cmax , c} -G field. This is the case that the same power cell group is Null, that is, there is no CC belonging to the same power cell group because the maximum carrier power for each CC is different. The terminal may exclude the cell indicator field from the eighth format MAC control element. This is because the transmission of the cell indicator field is rather unnecessary redundancy in this case, since none of the CCs have the same maximum transmit power value. Thus, the eighth format MAC control element does not include a cell indicator field. Also, since the main serving cell is not included in the power report cell group, it does not include the P _{cmax and c} -T1 fields.

In addition, in determining the P _{CMAX , C} value, even if the PUSCH and the PUCCH are transmitted simultaneously _, it may have one P _{CMAX , C} value for the main serving cell. This is because P _{CMAX , C} -T1 and P _{CMAX , C} -T2 for the primary serving cell calculated in the actual transmission can be calculated equally. At this time, P _{CMAX , C} -T1 and P _{CMAX , C} -T2 may be configured with one P _{CMAX , C} field.

In addition, P _CMAX, in determining the value _C, for a virtual resource P _CMAX, assuming that _C value is not be transferred, from the primary serving cell, when the PUSCH to be transmitted alone P _{CMAX, C} -T2 value not it is transferred Only the P _{CMAX , C} -T1 field may exist. Therefore, one P _{CMAX , C} field may be configured for the primary serving cell.

In addition, P _CMAX, in determining the value _C, assuming that they not a P _{CMAX, C} value transmitted for a virtual resource, the PUCCH transmission when being alone in the primary serving cell P _{CMAX, C} -T1 values not it is transferred Only the P _{CMAX , C} -T2 field may exist. Therefore, one P _{CMAX , C} field may be configured for the primary serving cell.

In step S2900, if the PUSCH and PUCCH transmission can occur at the same time, the terminal configures any one of the MAC control elements of the first, second, third, and fourth formats (S2905). On the other hand, if the PUSCH and PUCCH transmission is not possible to occur at the same time, the terminal configures any one of the MAC control elements of the fifth, sixth, seventh, and eighth format (S2910).

30 is a flowchart illustrating a method of transmitting power information by a terminal according to another embodiment of the present invention.

Referring to FIG. 30, the terminal calculates each carrier maximum transmit power P _{cmax , c} for the CC of the power report cell group PRCG (S3000). As an example of a method for obtaining a carrier maximum transmission power, Equation 1 to Equation 7 may be used. The information on the power report cell group may be already known between the terminal and the base station, or may be information transmitted separately by the terminal to the base station or informed by the base station to the terminal in advance. The maximum carrier power may be expressed based on the range mapping table shown in Tables 1 to 4.

The terminal determines whether the same power cell group (IPCG) exists (S3005). If there is no CC belonging to the same power cell group, the terminal determines whether the main serving cell is included in the power report cell group (S3010). At this time, if the main serving cell is included in the power report cell group, a MAC control element of a seventh format is configured (S3015). On the other hand, if the main serving cell is not included in the power report cell group, the MAC control element of the eighth format is configured (S3020).

In step S3005, if two or more CCs belonging to the same power cell group exist, the terminal configures a cell indicator field (S3025). The cell indicator field is in a bitmap format, and the terminal may configure the cell indicator field by setting a bit value mapped to each CC to 1 or 0.

The terminal determines whether the CC of the main serving cell belongs to the power report cell group (S3030). This may be determined by whether the bit corresponding to the CC of the main serving cell is set to the D field in the cell indicator field. If the CC of the main serving cell does not belong to the power report cell group, the terminal configures the MAC control element of the sixth format (S3035).

If the CC of the primary serving cell belongs to the power report cell group, the terminal determines whether the cell indicator field for the CC of the primary serving cell indicates 1 (S3040). If the cell indicator field for the CC of the primary serving cell indicates 1, the terminal again configures a MAC control element of the sixth format (S3035).

On the other hand, if the cell indicator field for the CC of the main serving cell indicates 0, the terminal configures the MAC control element of the fifth format (S3045). Thereafter, the terminal transmits the MAC control element to the base station (S3050).

31 is a flowchart illustrating a method of receiving power information by a base station according to another embodiment of the present invention.

Referring to Figure 31, the base station receives the MAC control element (CE) from the terminal (S3100). The base station determines whether the CC exists in the same power cell group (S3105).

If the CC does not exist in the same power cell group, the base station determines whether the main serving cell is included in the power report cell group (S3110). At this time, if the main serving cell is included in the power report cell group, it is determined as a MAC control element of a third format (S3115). On the other hand, if the main serving cell is not included in the power report cell group, it is determined as the MAC control element of the eighth format (S3120).

On the other hand, if there is at least one CC in the same power cell group, the base station determines whether the cell indicator field for the CC of the main serving cell is set to the D field (S3125).

If the cell indicator field for the CC of the main serving cell is set to the D field, the base station determines the MAC control element as the MAC control element of the sixth format (S3130). If the cell indicator field for the CC of the main serving cell is not set to the D field, the base station determines whether the cell indicator field for the CC of the main serving cell is 1 (S3135).

If the cell indicator field for the CC of the primary serving cell is 1, the base station determines the MAC control element as a sixth format (S3130). If the cell indicator field for the CC of the primary serving cell is 0, the base station determines the MAC control element as a fifth format (S3140).

The base station successfully analyzes the MAC control element to obtain a carrier maximum transmit power value for the CC belonging to the power report cell group (S3145).

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (8)

In the multi-component carrier system in the power information transmission method by the terminal,
Calculating a maximum transmit power output for each of the plurality of component carriers;
Setting a cell indicator field indicating component carriers having the same maximum transmit power;
Setting a first power field indicating the same maximum transmit power;
Generating a medium access control (MAC) message including the cell indicator field and the first power field; And
Transmitting the MAC message to a base station. The method of claim 1,
The MAC message includes a MAC subheader and a MAC control element, wherein the MAC subheader is a logical channel identifier identifying the MAC control element as a MAC control element for power reporting. And LCID). The method of claim 2,
And the MAC control element includes the cell indicator field and the first power field. The method of claim 2,
And the MAC control element is an integer multiple of an octet of 8 bits in length. The method of claim 1,
The MAC message includes a maximum transmission power of a first type and a PUSCH and a physical uplink control channel (PUCCH) when only a physical uplink shared channel (PUSCH) is transmitted. And a second power field indicating any one of the maximum transmission powers of the second type when all the transmissions are performed. The method of claim 1,
The MAC message further includes a third power field indicating a maximum transmit power for the component carrier having a maximum transmit power different from the same maximum transmit power. A terminal for transmitting power information in a multi-component carrier system,
A power calculator for calculating a maximum transmit power that can be output for each of the plurality of CCs;
An equal power cell group determiner configured to determine a group consisting of component carriers having the same maximum transmit power;
MAC including a cell indicator field indicating a component carrier included in the group, a first power field indicating the same maximum transmit power, and a second power field indicating a maximum transmit power different from the same maximum transmit power A power information generator for generating a message; And
And an uplink information transmitter for transmitting the MAC message to the base station. The method of claim 7, wherein
The power information generator generates the MAC message including a MAC subheader and a MAC control element, wherein the MAC subheader identifies that the MAC control element is a MAC control element for power reporting. Terminal characterized in that it comprises a Logical Channel Identifier (LCID).

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