KR20120047123A - Apparatus and method of transmitting maximum transmission power information in multiple component carrier system - Google Patents

Abstract

PURPOSE: A transmission apparatus of maximum transmission power information in a multi-component carrier wave system is provided to prevent an over uplink scheduling by grasping maximum transmission power. CONSTITUTION: A base station transmits an uplink approval signal to a terminal(S1600). The terminal calculates carrier maximum transmission power for the established uplink component carrier(S1605). The terminal creates carrier wave maximum transmission power information including a carrier wave maximum transmission power field related to the uplink component carrier(S1610). The terminal transmits the carrier wave maximum transmission power information to the base station through uplink resources(S1615).

Description

Apparatus and method for transmitting maximum transmit power information in multi-element carrier system {APPARATUS AND METHOD OF TRANSMITTING MAXIMUM TRANSMISSION POWER INFORMATION IN MULTIPLE COMPONENT CARRIER SYSTEM}

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

Another object of the present invention is to provide an apparatus and a method for receiving maximum transmit power information in a multi-element carrier system.

Another technical problem of the present invention is to provide a method for triggering the calculation of the maximum transmit power in a multi-component carrier system.

Another technical problem of the present invention is to provide a method for indexing a range of maximum transmit power step by step in a multi-component carrier system.

Another technical problem of the present invention is to provide a method of updating a reference table regarding the maximum transmit power in a multi-component carrier system.

Another technical problem of the present invention is to provide a structure of maximum transmission power information in a multi-component carrier system.

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

According to an aspect of the present invention, there is provided a method of transmitting maximum transmit power information by a terminal in a multi-component carrier system. The transmission method may include calculating a maximum transmit power output from an uplink component carrier, generating a medium access control (MAC) message including a first field indicating a value of the maximum transmit power, And transmitting the MAC message to a base station. The MAC message includes a MAC control element, the MAC control element is configured in octets, and a single octet includes the first field.

According to another aspect of the present invention, there is provided a method of receiving maximum transmission power information by a base station in a multi-element carrier system. The receiving method includes transmitting an uplink grant indicating an uplink resource for transmission of new uplink data to the terminal, and receiving a MAC message from the terminal through the uplink resource. The MAC message includes a MAC control element, the MAC control element is configured in octets, one octet includes a first field, and the first field is the maximum output from an uplink component carrier configured in the terminal. Indicates the value of the transmit power.

According to another aspect of the present invention, a terminal for transmitting maximum transmission power information in a multi-component carrier system. The terminal receives from the base station an acknowledgment (ACK) indicating that the base station has successfully received the maximum transmit power information indicating the maximum transmit power output from the uplink grant and uplink component carrier for the transmission of new uplink data. A downlink information receiver, a maximum transmit power calculator for calculating the maximum transmit power, a maximum transmit power information generator for generating the maximum transmit power information in the form of a MAC message, and transmitting the maximum transmit power information to the base station It includes an uplink information transmitter. The MAC message includes a MAC control element, the MAC control element is configured in octet units, and one octet includes a first field indicating the maximum transmission power.

According to another aspect of the present invention, there is provided a base station for receiving maximum transmission power information in a multi-element carrier system. The base station is a scheduling unit for determining the uplink parameters required for the terminal to perform the uplink transmission, and configures an uplink grant with the determined uplink parameters, uplink information receiver for receiving the maximum transmission power information from the terminal, And a downlink information transmitter for transmitting an ACK indicating that the maximum transmission power information has been successfully received from the terminal and the uplink grant to the terminal. The maximum transmit power information indicates a maximum transmit power that can be output from an uplink component carrier configured in the terminal.

Since the base station knows the maximum transmit power for each uplink component carrier, interference can be reduced by preventing excessive uplink scheduling. In addition, the base station can clearly know which uplink component carrier the maximum transmit power relates to. Furthermore, by monitoring the amount of change in the maximum transmit power and triggering the report of the maximum transmit power at an appropriate point in time, it is possible to efficiently use the uplink resources by reducing the frequency of the maximum transmit power report.

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 coordination report according to an embodiment of the present invention.
11 is a block diagram illustrating a structure of a MAC control element for reporting a maximum carrier power according to an embodiment of the present invention.
12 is a block diagram illustrating a structure of a MAC control element for reporting a maximum carrier power according to another embodiment of the present invention.
13 is a block diagram illustrating a part of a structure of a MAC PDU for reporting a maximum carrier power according to another embodiment of the present invention.
14 is a block diagram illustrating a part of a structure of a MAC PDU for reporting a maximum carrier power according to another embodiment of the present invention.
15 is a block diagram illustrating a structure of a field mapping indicator according to an embodiment of the present invention.
16 is a flowchart illustrating a method of reporting a maximum carrier power according to an embodiment of the present invention.
17 is a flowchart illustrating a method of reporting a maximum transmission power of a carrier by a terminal according to an embodiment of the present invention.
18 is a flowchart illustrating a method of reporting a maximum carrier power by a terminal according to another embodiment of the present invention.
19 is a flowchart illustrating a method of receiving a report of a carrier maximum transmit power by a base station according to an embodiment of the present invention.
20 is a block diagram illustrating a terminal for reporting a maximum carrier power and a base station for receiving according to an 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 transmission power set in the terminal is referred to as P _cmax , the maximum transmission power for each CC set in the terminal is referred to as P _{cmax and c} , and the maximum transmission 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.

9, when assumed that △ T _C = 0, the maximum value (P _{cmax- H)} of the maximum transmission power (P _cmax) may be a 23dB corresponding to the power class 3. The minimum value (P _{cmax- L)} of the maximum transmission power (P _cmax) is a value obtained by subtracting the maximum value (P _{cmax -H)} power adjustment amount (PC, 900) and an additional power adjustment amount (APC, 905) in the. 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 uncertain uplink scheduling within the estimated maximum transmit power, the base station may schedule the modulation / channel bandwidth / RB that requires a transmit power of the maximum transmit power or more for the terminal in the worst case. 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.

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

Carrier maximum transmit power (P _{cmax .c)} are expressed in dB as a transmittable maximum transmission power per 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 carrier power may be set differently for each UL CC or may be set to the same value. For example, UL CC1 is P _{cmax . c1} and UL CC2 and UL CC3 are both P _{cmax .} can be set to _c2 .

A large amount of information is required to represent the maximum carrier power. If the UE consumes a large amount of uplink resources to report the maximum carrier power to the base station, it may cause significant deterioration 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.

In order to reduce the amount of information, the maximum transmission power of the carrier may be quantized in dB units, for example, 1 dB units. That is, P _{cmax .c} may be expressed as 1 dB, 2 dB, 3 dB, or the like. However, even if quantized, a large amount of information is still required to represent the maximum transmit power amount.

According to one aspect of the present invention, the carrier maximum transmit 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.

As an example, each step has a constant dB difference. 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.

In the range mapping table, the range of the maximum carrier power may vary according to a power class 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 2, 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.

Table 3 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 carrier power, and there is a constant 2 dB difference between steps in the range of the maximum carrier power.

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 8≤P _{cmax .c} <10 8 6≤P _{cmax .c} <8 9 4≤P _{cmax .c} <6 10 2≤P _{cmax .c} <4 11 0≤P _{cmax .c} <2 12 Reserved 13 Reserved 14 Reserved 15 Reserved

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. Since each step has a 2 dB difference, the maximum transmit power range is _{0≤P cmax.c} <2 in step 11. Since the maximum transmit power should be greater than zero, the remaining indexes 12 to 15 do not have a range of mapped maximum transmit powers. Thus, indices 12 through 15 remain as reserved code points.

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.

As another example, each step has a variable magnitude dB difference. Table 5 is a range mapping table according to another example of the present invention. This is a case where 4 bits are used for reporting the maximum transmit 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 8≤P _{cmax .c} <10 8 7≤P _{cmax .c} <8 9 6≤P _{cmax .c} <7 10 5≤P _{cmax .c} <6 11 4≤P _{cmax .c} <5 12 3≤P _{cmax .c} <4 13 2≤P _{cmax .c} <3 14 1≤P _{cmax .c} <2 15 0≤P _{cmax .c} <1

Referring to Table 5, 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. From step 0 (index 0) to step 7 (index 7) there is a 2 dB difference for each step, and from step 8 (index 8) to step 15 (index 15) there is a 1 dB difference for each step. That is, the difference in size of each step is variable.

In contrast to Table 5, there may be a 2 dB difference in each step of the lower index and a 1 dB difference in each step of the upper index. This is shown in Table 6.

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 12≤P _{cmax .c} <14 10 10≤P _{cmax .c} <12 11 8≤P _{cmax .c} <9 12 6≤P _{cmax .c} <8 13 4≤P _{cmax .c} <6 14 2≤P _{cmax .c} <4 15 0≤P _{cmax .c} <2

Referring to Table 6, there is a 1 dB difference between each step up to 0-8, the upper index, and a 2 dB difference between steps up to 9-15, the lower index.

In contrast to Tables 1 to 6, the table may be configured by setting the dB difference at each step of the lower index based on P _powerclass . This is shown in Table 7.

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 7, there is a 1dB difference between each step in all indexes.

Tables 1 to 7 above use a range mapping table as an example of the maximum carrier power. The number of steps, the size difference between the steps, and the size of the range of the maximum carrier power range are all examples, and do not limit the technical spirit of the present invention. Furthermore, the method of classifying the report of the maximum carrier power step by step and expressing as the size difference and the size of the range between each step will all be included in the technical idea of the present invention.

2. Structure of Information for Reporting Carrier Maximum Transmission Power (P _{cmax .c} )

The information used for reporting the maximum carrier power may be higher layer signaling, for example, a message of the RRC layer or a message of the MAC layer. Alternatively, it may be a lower layer signaling such as a physical layer. Hereinafter, a method of configuring information for reporting the maximum carrier power as a message of the MAC layer will be described in detail.

10 is a block diagram illustrating a structure of a MAC protocol data unit (MAC PDU) for reporting a maximum carrier power 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 P _{cmax .c} MAC control element for reporting the maximum carrier power. There is one LCID field for each MAC SDU, MAC control element or padding. Table 8 shows an example of an LCID field.

Index LCID values 00000 CCCH 00001-01010 Identity of the logical channel 01011-10110 Reserved 10111 P _{cmax .c} Report 11000 Scell activation / deactivation 11001 Reference CC Indicator 11010 Power Headroom Report 11011 C-RNTI 11100 Truncated BSR 11101 Short bsr 11110 Long bsr 11111 Padding

Referring to Table 8, the LCID field value of 10111 may indicate that the corresponding MAC control element is a P _{cmax .c} MAC control element according to the present invention.

The structure of the MAC control element for reporting the maximum carrier power may vary depending on the number of bits in the maximum carrier power field and the number of carriers to be reported.

11 is a block diagram illustrating a structure of a MAC control element for reporting a maximum carrier power according to an embodiment of the present invention.

Referring to FIG. 11, the MAC control element for reporting the maximum carrier power includes at least one carrier maximum transmit power field (P _cmax field). Alternatively, the MAC control element for reporting the maximum carrier power of the carrier includes at least one R field.

The first embodiment 1100 and the second embodiment 1105 are MAC control elements when the carrier maximum transmit power field is 3 bits. If one MAC control element is 8 bits having an octet structure, one MAC control element may include up to two carrier maximum transmit power fields. Embodiment 1 (1100) is a case where one MAC control element includes two carrier maximum transmit power fields 1102, and in Embodiment 2 (1105), one MAC control element includes one carrier maximum transmit power field ( 1107). The remaining bits used in the carrier maximum transmit power field become the R field. That is, in the first embodiment 1100, the MAC control element includes two R fields 1101, and in the second embodiment 1105, the MAC control element includes five R fields 1106. One carrier maximum transmit power field includes a maximum transmit power value for one CC.

The third embodiment 1110 to the fourth embodiment 1115 are MAC control elements when the carrier maximum transmit power field is 4 bits. Embodiment 3 (1110) is a case where one MAC control element includes two carrier maximum transmit power fields 1111, and Embodiment 4 (11115) one MAC control element includes one carrier maximum transmit power field ( 1117). The remaining bits used in the carrier maximum transmit power field become the R field. That is, in the third embodiment 1110, there are no R fields in the MAC control element. In the fourth embodiment 1115, the MAC control element includes four R fields 1116.

Embodiment 5 1120 is a MAC control element when the carrier maximum transmit power field is 5 bits. Thus, if the MAC control element is eight bits octet, the MAC control element includes one carrier maximum transmit power field 1122 and three R fields 1121.

12 is a block diagram illustrating a structure of a MAC control element for reporting a maximum carrier power according to another embodiment of the present invention.

Referring to FIG. 12, in Embodiment 1 1200, a MAC control element for reporting a maximum carrier power of a type includes a type indicator field (1201), a cell index field (1202), and a maximum carrier transmission. This is the case including the power fields P _{cmax and c} fields 1203. The type indication field 1201 distinguishes whether the surplus power of the UL CC of the serving cell corresponding to the carrier maximum transmit power field 1203 is type 1 or type 2. The carrier maximum transmit power field 1203 indicates a carrier maximum transmit power of a UL CC based on the power ranges as shown in Tables 1 to 7, and the cell index field 1202 indicates an index of a serving cell including the UL CC. Indicates.

In the second embodiment 1210, the MAC control element for reporting the maximum carrier power includes a cell index field 1211 and a maximum carrier power field 1212. That is, the MAC control element for reporting the maximum carrier power may include at least two of the maximum carrier power field, the cell index field and the type indication field.

In addition, the MAC control element for reporting the maximum carrier power may include at least one carrier maximum transmit power field. Alternatively, the MAC control element for reporting the maximum carrier power may include at least one cell index field. Alternatively, the MAC control element for reporting the maximum carrier power may include at least one type indication field.

13 is a block diagram illustrating a part of a structure of a MAC PDU for reporting a maximum carrier power according to another embodiment of the present invention. The MAC PDU of FIG. 13 is a structure for reporting a carrier maximum transmit power for all UL CCs belonging to an activated serving cell.

Referring to FIG. 13, the MAC PDU 1300 includes a MAC subheader 1305 and a MAC control element 1310.

The MAC control element 1310 includes at least one carrier maximum transmit power field. For example, the MAC control element 1310 includes a first carrier maximum transmit power field 1315 and / or a second carrier maximum transmit power field 1320. The first carrier maximum transmit power field 1315 is a field for indicating a carrier maximum transmit power value when considering type 1 for the UL PCC belonging to the primary serving cell. On the other hand, the second carrier maximum transmit power field 1320 is a field for indicating a carrier maximum transmit power value when considering type 2 for the UL PCC belonging to the main serving cell. As described above, only the PUSCH may be transmitted on the UL PCC of the primary serving cell (type 1), and the PUCCH and the PUSCH may be simultaneously transmitted (type 2). Therefore, the carrier maximum transmit power field exists in pairs for the UL PCC. The terminal may inform the base station of the maximum carrier power for the type 1 and the type 2 through the MAC PDU 1300 structure.

Next, since the UL SCC belonging to the secondary serving cell has only Type 1, the MAC control element 1310 includes one carrier maximum transmit power field 1325, ..., 1330 for each activated UL SCC.

The MAC control element 1310 includes a carrier maximum transmit power field for all activated UL CCs. If the arrangement order of the carrier maximum transmit power field is prescribed between the terminal and the base station, the base station may map the carrier maximum transmit power field of each order to the corresponding UL CC. Accordingly, there is no need for a separate indicator indicating which UL CC the carrier maximum transmit power field is for. In this case, the MAC control element 1310 may additionally include an R field in addition to the carrier maximum transmit power field as in various embodiments of FIG. 11.

14 is a block diagram illustrating a part of a structure of a MAC PDU for reporting a maximum carrier power according to another embodiment of the present invention. The MAC PDU of FIG. 14 is a structure for reporting only a carrier maximum transmit power for some selected UL CCs among all UL CCs belonging to an activated serving cell. Here, the selected partial UL CC refers to a UL CC having a certain criterion, for example, a change amount ΔP _{cmax , c} of the maximum carrier power of a carrier is greater than or equal to a threshold.

Referring to FIG. 14, the MAC PDU 1400 includes a MAC subheader 1405 and a MAC control element 1410.

The MAC control element 1410 includes a field mapping indicator 1415 and at least one carrier maximum transmit power field 1420, 1425. The field mapping indicator 1415 indicates to which UL CC each of the carrier maximum transmit power fields 1420 and 1425 in the MAC control element 1410 are mapped. The field mapping indicator 1415 has a bitmap format, and a UL CC to which each bit is mapped is fixed. For example, when the field mapping indicator 1415 is abc, a may be mapped to UL CC1, b may be mapped to UL CC2, and c may be mapped to UL CC3. Meanwhile, each bit may be 0 or 1 to indicate whether the carrier maximum transmit power fields 1420 and 1425 for a specific UL CC are included in the MAC control element 1410.

Since the MAC control element 1410 includes a field mapping indicator 1415, a cell index field indicating which carrier the carrier maximum transmit power fields 1420 and 1425 are about is not required. Accordingly, in this case, the MAC control element 1410 may additionally include an R field in addition to the carrier maximum transmit power field as in various embodiments of FIG. 11.

On the other hand, the MAC control element 1410 may have a form including a maximum transmit power field and a cell index field as in various embodiments according to FIG. 12 except for the field mapping indicator 1415.

The MAC control element 1410 may include or may not include at least one of the first carrier maximum transmit power field and the second carrier maximum transmit power field. Here, the first carrier maximum transmit power field is a field for indicating a carrier maximum transmit power value when considering type 1 for the UL PCC belonging to the main serving cell. On the other hand, the second carrier maximum transmit power field is a field indicating a carrier maximum transmit power value when considering type 2 for the UL PCC belonging to the main serving cell. FIG. 14 illustrates a case in which the MAC control element 1410 includes only one carrier maximum transmit power field for UL PCC.

As an example, when at least one of the variation in the maximum transmission power of type 1 and type 2 is greater than or equal to a threshold, the MAC control element 1410 includes both a first carrier maximum transmit power field and a second carrier maximum transmit power field. . On the other hand, when the amount of change in carrier maximum transmit power of both type 1 and type 2 is smaller than the threshold value, the MAC control element 1410 does not include both the first carrier maximum transmit power field and the second carrier maximum transmit power field.

As another example, assume that the terminal is currently set in the type 1 mode by the base station to transmit only the PUSCH. At this time, if the amount of change in the maximum transmission power of the type 1 carrier is greater than or equal to the threshold, the MAC control element 1410 includes the first carrier maximum transmission power field, otherwise it does not.

15 is a block diagram illustrating a structure of a field mapping indicator according to an embodiment of the present invention.

Referring to FIG. 15, the field mapping indicator 1500 has an 8-bit length in the case of an octet structure. The 8 bits indicate whether the carrier maximum transmit power field of CC0, CC1, CC2, ..., CC7 is included in order from the rightmost. CC0 always represents the main serving cell and CC1 to CC7 are based on the serving cell index of the secondary serving cell. When the value of each bit is '1', it indicates that the carrier maximum transmit power field for the UL CC of the corresponding serving cell is included in the MAC control element.

At this time, when the bit value corresponding to CC0 is '1', only when the UE is set to the type 2 mode in which the PUSCH and the PUCCH are simultaneously transmitted through the main serving cell, type 1 for the UL CC of the main serving cell. For example, this indicates that a carrier maximum transmit power field for Type 2 is included in a MAC control element. On the other hand, when not set to the type 2 mode, only the carrier maximum transmit power field for the type 1 for the UL CC of the main serving cell is included in the MAC control element.

3. Reporting procedure of maximum carrier power

16 is a flowchart illustrating a method of reporting a maximum carrier power according to an embodiment of the present invention.

Referring to FIG. 16, the base station transmits an uplink grant to the terminal (S1600). 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. An example of an uplink grant is shown in Table 9.

In Table 9, a new data indicator (NDI) is 1 bit and indicates whether a corresponding uplink grant is for new data transmission or retransmission of existing data. If the new data indicator is for retransmission, the uplink grant only allocates resources for retransmission of existing data. In this case, the terminal cannot report the maximum carrier power. Therefore, in order for the terminal to report the maximum carrier power to the base station, it is necessary to use a resource allocated for new uplink data. That is, the new data indicator needs to indicate that the uplink grant is for new data transmission.

The terminal calculates a carrier maximum transmit power for the configured UL CC (S1605), and generates carrier maximum transmit power information (P _{cmax , c} Information) including a carrier maximum transmit power field for the UL CC (S1610). The carrier maximum transmit power information is a message of an upper layer, and may be any one of a MAC PDU, a Radio Link Control (RLC) PDU, and an RRC message. When the carrier maximum transmit power information is a MAC PDU, the carrier maximum transmit power information may include the MAC control element illustrated in FIGS. 11 to 15.

The terminal transmits the carrier maximum transmit power information to a base station through an uplink resource allocated by the uplink grant (S1615).

17 is a flowchart illustrating a method of reporting a maximum transmission power of a carrier by a terminal according to an embodiment of the present invention.

Referring to FIG. 17, the terminal checks whether a triggering condition regarding reporting of the maximum carrier power is satisfied (S1700). The triggering condition is a case where there is a CC whose change amount ΔP _{cmax , c} , which is a difference between the amount of power determined in the maximum carrier power reference table (hereinafter, referred to as a reference table) and the maximum carrier power, is greater than or equal to a threshold. A reference table is information about a maximum carrier power amount shared by a terminal and a base station in advance based on a current component carrier combination and resource allocation (RB and MCS level). The reference table may be a default value defined in the standard according to a unique specification of the terminal.

In order to determine whether the received uplink grant is for transmitting new uplink data, the terminal checks the value of the new data indicator field included in the uplink grant (S1705). If the new data indicator field value is '1', the uplink grant is for transmitting new data, and if it is '0', it is for retransmission of existing data.

If the new data indicator field value is '0', the terminal checks uplink data to be retransmitted in the HARQ buffer from information in the HARQ entity and retransmits the uplink data to the base station (S1710).

If the new data indicator field value is '1', the terminal updates the reference table with the calculated maximum carrier power value (S1715). Here, the portion of the current component carrier combination and resource allocation in the reference table is updated. Step S1715 can be subdivided as follows. The upper layer (upper layer) of the terminal instructs the calculation of the carrier maximum transmission power to the lower layer (lower layer). Thereafter, the lower layer calculates a carrier maximum transmit power value and reports the upper layer. The upper layer stores the reported carrier maximum transmit power value in the HARQ buffer. The upper layer may be any one of an L2 layer, that is, a MAC layer, an RLC layer, or an RRC layer, and the lower layer may be a physical layer or a MAC layer. The HARQ buffer is a buffer for storing the MAC PDU.

The terminal checks whether the carrier maximum transmission power can be reported from the received uplink grant (S1720). Step S1720 may be subdivided as follows. The terminal checks the uplink resource information in the received uplink grant and calculates the amount of resources that can be transmitted in the corresponding subframe. At this time, the maximum carrier power is reported in the corresponding subframe in consideration of the transmission priority of data currently stored in the uplink buffer, the priority of transmission of other MAC control element data, and the priority of the maximum carrier power report. Check whether it is possible.

If the maximum transmission power of the carrier can be reported, the terminal generates the maximum transmission power information of the carrier (S1725). The carrier maximum transmit power information includes a carrier maximum transmit power field. The carrier maximum transmit power information may be a MAC PDU or a MAC control element.

The terminal transmits the maximum carrier power information to the base station by using the uplink resource indicated by the received uplink grant (S1730). The carrier maximum transmit power information may be transmitted together with other new uplink data.

18 is a flowchart illustrating a method of reporting a maximum carrier power by a terminal according to another embodiment of the present invention. Unlike FIG. 17, FIG. 18 is characterized in that the reference table is updated under a condition of receiving an ACK indicating reception success for the maximum carrier power information from the base station.

Referring to FIG. 18, the terminal checks whether a triggering condition regarding reporting of the maximum carrier power is satisfied (S1800). The triggering condition is a case where there is a CC whose change amount ΔP _{cmax , c} , which is a difference between the amount of power determined in the reference table and the maximum amount of carrier maximum transmission power, is greater than or equal to a threshold. This is the same as step S1700.

The terminal checks the value of the new data indicator field included in the uplink grant in order to determine whether the received uplink grant is for transmitting new uplink data (S1805). This is the same as step S1705.

If the new data indicator field value is '0', the UE checks uplink data to be retransmitted in the HARQ buffer from information in the HARQ entity and retransmits the uplink data to the base station (S1810). This is the same as step S1710.

If the new data indicator field value is '1', the terminal checks whether the carrier maximum transmission power can be reported from the received uplink grant (S1815). This is the same as step S1720.

If the maximum transmission power of the carrier can be reported, the terminal generates the maximum transmission power information of the carrier (S1820). This is the same as step S1725.

The terminal transmits the carrier maximum transmit power information to the base station by using the uplink resource indicated by the received uplink grant (S1825). This is the same as step S1730. The carrier maximum transmit power information may be transmitted together with other new uplink data.

The terminal receives from the base station an ACK indicating successful reception of the maximum carrier power information (S1830). If the base station does not successfully receive the carrier maximum transmit power information, it may be necessary to newly calculate the carrier maximum transmit power. When the base station updates the reference table after confirming that the base station has successfully received the maximum transmission power information, performance degradation due to unnecessary updating of the reference table can be prevented.

The terminal updates the reference table with the calculated carrier maximum transmit power value (S1835). Here, the portion of the current component carrier combination and resource allocation in the reference table is updated. This is the same as step S1715.

19 is a flowchart illustrating a method of receiving a report of a carrier maximum transmit power by a base station according to an embodiment of the present invention.

Referring to FIG. 19, the base station transmits an uplink grant to the terminal (S1900). The uplink grant includes a new data indicator as shown in Table 9 above. The base station sets a new data indicator based on the following criteria. As an example, the base station determines whether a message for requesting uplink scheduling, such as a scheduling request, has been received from the terminal. As another example, the buffer state report value checks whether there is an error in the previously transmitted data.

Based on these criteria, the base station can determine whether to configure the uplink grant for new data or for retransmission. At this time, the new data indicator field value is set so that the UE can recognize whether it is an uplink grant for transmitting new data. If the uplink grant for new data is configured, the base station sets the new data indicator field value to '1', and if the uplink grant is configured for retransmission, it is set to '0'.

The base station receives uplink data (S1905). If the base station transmits an uplink grant for new data to the terminal, the base station determines whether the uplink data includes carrier maximum transmit power information. If the uplink data is a MAC PDU, the base station may determine whether the base station includes the maximum carrier power information using the LCID field value in the MAC subheader.

When the uplink data includes carrier maximum transmit power information, the base station extracts the carrier maximum transmit power information (S1910), interprets the carrier maximum transmit power field, and updates the information in the reference table (S1915). At this time, the base station stores the updated reference table in the UE context.

When the base station successfully receives and extracts the maximum carrier power information, the base station transmits an ACK to the terminal (S1920).

4. Maximum transmitting power reporting device and receiving device

20 is a block diagram illustrating a terminal for reporting a maximum carrier power and a base station for receiving according to an embodiment of the present invention.

Referring to FIG. 20, the terminal 2000 includes a downlink information receiver 2005, a triggering condition determiner 2010, a maximum carrier power calculation unit 2015, a maximum carrier power information generation unit 2020, and a reference table. A storage unit 2025 and an uplink information transmitter 2030 are included.

The downlink information receiver 2005 receives an uplink grant from the base station 2050. An example of an uplink grant is shown in Table 9 above. In addition, the downlink message information receiver 2005 receives an ACK from the base station 2050 indicating successful reception of the maximum carrier power information.

The triggering condition determiner 2010 determines whether the triggering condition is satisfied. The triggering condition is a case where there is a CC whose change amount ΔP _{cmax , c} , which is a difference between the amount of power determined in the reference table and the current maximum transmit power amount, is greater than or equal to a threshold.

The carrier maximum transmit power calculation unit 2015 calculates a carrier maximum transmit power for each CC. The CC may be set in the terminal 2000. Alternatively, the CC is set in the terminal 2000 and may be activated. The CC is also a UL PCC and / or a UL SCC. The carrier maximum transmit power calculation unit 2015 informs the carrier maximum transmit power information generation unit 2020 of the calculated carrier maximum transmit power for each CC.

The maximum carrier power information generation unit 2020 determines whether the maximum carrier power information can be inserted into the new data when the uplink grant is for new data transmission. If insertion is possible, the carrier maximum transmit power information generation unit 2020 generates the carrier maximum transmit power information. The method of generating the maximum carrier power information by the carrier maximum transmission power information generation unit 2020 will be described in detail in the above section 1 and 2.

When the triggering condition is satisfied, the reference table storage unit 2025 updates the reference table by reflecting the maximum carrier power amount in the reference table.

The uplink information transmitter 2030 transmits the generated carrier maximum transmit power information by using an uplink resource indicated by the uplink grant.

The base station 2050 includes a scheduling unit 2055, a downlink information transmitter 2060, an uplink information receiver 2065, and a reference table storage 2070.

The scheduling unit 2055 performs uplink scheduling. Uplink scheduling means that the terminal 2000 determines uplink parameters such as uplink resources, MCS, and redundancy version (RV) required for performing uplink transmission. An uplink grant is configured as a result of uplink scheduling.

The downlink information transmitter 2060 transmits an uplink grant configured by the scheduling unit 2055 to the terminal 2000 as a message. In addition, the downlink information transmitter 2060 may transmit an ACK indicating successful reception of the maximum carrier power information received from the terminal 2000 to the terminal 2000.

The uplink information receiver 2065 receives carrier maximum transmit power information from the terminal 2000.

The reference table storage unit 2070 finds a carrier maximum transmit power value for each CC from the carrier maximum transmit power information, and updates the reference table by reflecting the carrier maximum transmit power value in an existing reference table.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (18)

In the transmission method of the maximum transmission power information by the terminal in a multi-component carrier system,
Calculating a maximum transmit power output from an uplink component carrier;
Generating a medium access control (MAC) message including a first field indicating a value of the maximum transmit power; And
Transmitting the MAC message to a base station,
The MAC message includes a MAC control element, the MAC control element is configured in octets, and a single octet includes the first field. Method of transmitting power information. The method of claim 1,
The one octet further includes at least one of a second field indicating an index for the uplink component carrier and a third field for distinguishing a type of a physical channel transmitted on the uplink component carrier. Transmission method of transmission power information. The method of claim 1,
The one octet further comprises a reserved field, characterized in that the maximum transmission power information transmission method. The method of claim 1,
The MAC control element further includes a fourth field in a bitmap format, and the fourth field indicates whether the MAC control element includes a maximum transmit power field for an uplink component carrier corresponding to the corresponding bit. Characterized in that, the maximum transmission power information transmission method. The method of claim 1,
The uplink component carrier, characterized in that the active, the maximum transmission power information transmission method. The method of claim 1,
The MAC control element comprises a first field for all uplink component carriers configured in the terminal, the maximum transmission power information transmission method. The method of claim 1,
Receiving an uplink grant indicating the uplink resource for the MAC message from the base station;
The MAC message is transmitted through the uplink resource, the maximum transmission power information transmission method. The method of claim 7, wherein
The uplink grant includes a new data indicator, and the new data indicator indicates that the uplink grant is for transmission of new uplink data. The method of claim 1,
Triggering the transmission of the MAC message, characterized in that it further comprises, the maximum transmission power information transmission method. The method of claim 9,
And transmitting the MAC message when a change amount that is a difference between the maximum transmit power and the previous maximum transmit power is greater than or equal to a threshold. The method of claim 1,
And updating a reference table for storing the maximum transmit power values for all uplink component carriers set in the terminal. In the method of receiving the maximum transmission power information by the base station in a multi-component carrier system,
Transmitting an uplink grant indicating an uplink resource for transmission of new uplink data to the terminal; And
Receiving a MAC message from the terminal through the uplink resources,
The MAC message includes a MAC control element, the MAC control element is configured in octets, one octet includes a first field, and the first field is the maximum output from an uplink component carrier configured in the terminal. A method of receiving maximum transmission power information, characterized by indicating a value of transmission power. The method of claim 12,
The one octet further includes at least one of a second field indicating an index for the uplink component carrier and a third field for distinguishing a type of a physical channel transmitted on the uplink component carrier. Receiving method of transmission power information. The method of claim 13,
The physical channel includes at least one of a physical uplink shared channel (PUSCH) and a physical uplink control channel (PUCCH), the maximum transmission power information receiving method. The method of claim 12,
The MAC control element further includes a fourth field in a bitmap format, and the fourth field indicates whether the MAC control element includes a maximum transmit power field for an uplink component carrier corresponding to the corresponding bit. Characterized in that the maximum transmission power information receiving method. In the terminal for transmitting the maximum transmission power information in a multi-component carrier system,
Downlink information for receiving from the base station an acknowledgment (ACK) indicating that the base station successfully receives the maximum transmit power information indicating the maximum transmit power output from the uplink grant and uplink component carrier for transmission of new uplink data Receiving unit;
A maximum transmission power calculation unit for calculating the maximum transmission power;
A maximum transmission power information generation unit for generating the maximum transmission power information in the form of a MAC message; And
An uplink information transmitter for transmitting the maximum transmission power information to the base station,
The MAC message includes a MAC control element, wherein the MAC control element is configured in octets, and one octet includes a first field indicating the maximum transmission power. In the base station receiving the maximum transmission power information in a multi-component carrier system,
A scheduling unit configured to determine an uplink parameter required for the UE to perform uplink transmission, and to configure an uplink grant using the determined uplink parameter;
An uplink information receiver configured to receive the maximum transmission power information from the terminal; And
An ACK indicating that the maximum transmission power information has been successfully received from the terminal, and a downlink information transmitter for transmitting the uplink grant to the terminal,
The maximum transmission power information is indicative of the maximum transmission power that can be output from the uplink component carrier configured in the terminal, characterized in that it has a format of a MAC message. The method of claim 17,
The MAC message includes a MAC control element, wherein the MAC control element is configured in units of octets, and one octet includes a first field indicating the maximum transmit power.

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