KR20120015879A - Apparatus and method for transmitting information on power coordination in multiple component carrier system - Google Patents

Abstract

PURPOSE: A device for transmitting power coordination information in a multiple component carrier system and a method thereof are provided to reduce a scheduling error of a base station due to ambiguous power coordination. CONSTITUTION: When a PCR(Power Coordination Report) field can be transmitted, a terminal generates a MAC(Medium Access Control) PDU(Protocol Data Unit) including the PCR field(S1415,S1420). The terminal transmits the MAC PDU to a base station using the resource allocated by UL(UpLink) grant(S1425). The MAC PDU includes a MAC sub header and the PCR field. The PCR field includes power coordination information.

Description

Apparatus and method for transmitting power control information in multi-element carrier system {APPARATUS AND METHOD FOR TRANSMITTING INFORMATION ON POWER COORDINATION IN MULTIPLE COMPONENT CARRIER SYSTEM}

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

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

Another technical problem of the present invention is to provide an apparatus and method for designing power regulation in a multi-component carrier system.

Another technical problem of the present invention is to provide an apparatus and method for generating a MAC PDU including information on power adjustment in a multi-component carrier system.

Another technical problem of the present invention is to provide an apparatus and method for transmitting information indicating transmission of information on power adjustment in a multi-component carrier system. Another technical problem of the present invention is to provide a method for performing scheduling using information on power adjustment in a multi-component carrier system.

According to an aspect of the present invention, there is provided a method of transmitting information regarding power adjustment by a terminal in a multi-component carrier system. The method includes generating information on power adjustment informing the amount or range of power adjustment for adjusting uplink maximum transmission power required by the terminal, and a medium access control (MAC) PDU including information on the power adjustment. Generating a (Protocol Data Unit), and transmitting the MAC PDU to a base station. The MAC PDU includes a MAC subheader and a Power Coordination Report field, the power coordination report field includes information about the power coordination, and the MAC subheader is the power coordination report field. It includes logical channel identification information (Logical Channel ID; LCID) indicating.

According to another aspect of the present invention, there is provided a method of receiving information regarding power adjustment by a base station in a multi-element carrier system. The method includes transmitting an uplink grant including scheduling parameters related to uplink transmission of the terminal to the terminal, and receiving, from the terminal, a MAC PDU generated based on the scheduling parameter. The MAC PDU includes a MAC subheader and a power coordination report field, the MAC subheader includes logical channel identification information indicating the power coordination report field, and the power coordination report field is an uplink required for the terminal. It contains information about power adjustment, which tells you the amount or range of power adjustment that adjusts the maximum transmit power.

According to still another aspect of the present invention, there is provided an apparatus for transmitting information regarding power adjustment in a multi-component carrier system. The apparatus includes an uplink grant receiver for receiving an uplink grant including scheduling parameters for uplink transmission, and information about power adjustment for indicating an amount or range of power adjustment for adjusting uplink maximum transmit power for a terminal. An information generation unit for generating power adjustment, a MAC PDU generation unit for configuring a MAC PDU as a power adjustment report field including information on the power adjustment based on a resource situation allocated by the uplink grant, and the And a MAC PDU transmitter that transmits the MAC PDU based on the scheduling parameter for the uplink transmission and the amount or range of the power adjustment.

According to still another aspect of the present invention, there is provided an apparatus for receiving information regarding power adjustment in a multi-component carrier system. The apparatus includes an uplink grant transmitter for transmitting an uplink grant including scheduling parameters for uplink transmission, a MAC PDU receiver for receiving a MAC PDU including a MAC subheader and a power adjustment report field, and the uplink transmission A scheduling unit for determining a scheduling parameter for the. The power coordination report field includes information on power coordination indicating an amount or range of power coordination adjusting uplink maximum transmission power for a terminal, and the MAC subheader indicates a logical channel indicating the power coordination report field. Contains identification information.

By explicitly informing the base station of the range of power coordination in a multi-component carrier system, the scheduling error of the base station due to ambiguity of the power coordination can be reduced, and the scheduling is adaptively applied to the maximum transmit power for each given terminal or component carrier. There is an effect that can be performed. In particular, by signaling information on power adjustment determined in consideration of the communication environment of the terminal, the scheduling efficiency of the scheduler is maximized.

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 PDU for power coordination report according to another embodiment of the present invention.
12 is a block diagram illustrating a structure of a MAC PDU for power coordination report according to another embodiment of the present invention.
13 is a flowchart illustrating a method of transmitting information about power adjustment according to an embodiment of the present invention.
14 is a flowchart illustrating a method of transmitting information about power adjustment by a terminal according to an embodiment of the present invention.
15 is a flowchart illustrating a method of receiving information regarding power adjustment by a base station according to an embodiment of the present invention.
16 is a block diagram illustrating an apparatus for transmitting and receiving information on power adjustment in a multi-element carrier system 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, ..., CC #N 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, CC # 1, which are aggregated CCs, exist in band # 1, and CC # 2 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 the difference between the maximum transmit power P _max 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.

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).

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 transmit power P _max of the terminal is composed of P _PH 605, P _PUSCH 610, and P _PUCCH 615. That is, the power is defined as P _PH 605 in P _max except for P _PUSCH 610 and P _PUCCH 615. 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.

Referring to FIG. 7, the set maximum transmit power P _max of the terminal corresponds to the maximum transmit power P _{CC # 1} , P _{CC # 2} , ..., for each CC # 1, CC # 2, ..., CC #N. It is equal to the sum of P _{CC #N} . Generalizing the maximum transmit power for each CC is as follows.

P _PH 705 of _{CC # 1} is equal to P _{CC # 1-} P _PUSCH 710-P _PUCCH 715, and P _PH 720 of _{CC #n} is P _{CC #n} -P _{PUSCH 725-} Same as 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.

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 coordination (PC) of the terminal. The power adjustment means reducing the maximum transmission power set in the terminal within a predetermined allowable range and 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.

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 cannot exceed the configured maximum UE transmit power (PC _MAX ) of the configured UE. In the example of FIG. 8, since the final transmit power is smaller than the PC _MAX value 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, an excess power estimation value error 855 by P _{Cmax _H} -P _Cmax occurs. 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. Accordingly, the terminal needs to reduce the set maximum transmission power, which is called power coordination (PC).

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)).

Here, the hardware configuration within the terminal includes RF, and may be called an RF chain. The RF includes a combination of a power amplifier, a filter, an antenna, and the like among the hardware configurations of the terminal. In addition, RF may be defined by each of the power amplifier, the filter, and the antenna. One RF may be configured in one terminal, or multiple RFs may be configured in one terminal. For example, one terminal is provided with one antenna, and the antenna is connected to a first power amplifier connected to a first filter, and at the same time, the antenna is connected to a second power amplifier connected to a second filter. In this case, the one terminal configures two RF chains.

When the uplink transmission bandwidth is determined, the signal is controlled to transmit the signal only for the bandwidth set by the filter. At this time, the wider the bandwidth, the greater the number of taps (eg, registers) constituting the filter. To meet the ideal filter characteristics, the filter's design complexity and size increase exponentially, even with the same bandwidth.

Therefore, interference power for a band that should not be transmitted in the uplink may occur due to the characteristics of the filter. To reduce such interference power, it is necessary to reduce the interference power generated by reducing the maximum transmission power through power adjustment.

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

Where, P _max is the maximum transmit power set in the UE, P _{max -L} is the minimum value, P _{max -H} of P _max is a maximum value of P _max. More specifically, P _{max -L} and P _{max -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 _{max -H} of the maximum transmit power P _max may be 23 dB corresponding to the power class 3. The minimum value P _max-L of the maximum transmit power P _max is obtained by subtracting the power adjustment amount (PC, 900) and the additional power adjustment amount (APC, 905) from the maximum value (P _{max -H} ). That is, the terminal decreases the minimum value P _{max -L} of the maximum transmission power P _max by using the power adjustment amount PC 900 and the additional power adjustment amount APC 905. The maximum transmit power P _max is determined between the maximum value P _{max -H} and the minimum value P _{max -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 base station does not know the power adjustment amount PC, the maximum transmission power according to the power adjustment amount PC may not be exactly known. However, 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 power adjustment.

Hereinafter, the definition of the information on the power adjustment, the transmission structure and the transmission method of the information on the power adjustment will be described in detail.

1. Information on power adjustment

If the communication environment is not diverse, the power adjustment range can be covered by 1 dB to 2 dB. In this case, since the base station easily predicts the range of power adjustment, there is no problem in scheduling without additional information on power adjustment.

However, the terminal may be in various communication environments that are specifically defined by a combination of the number of aggregated CCs, the number of available RFs, the modulation scheme, the allocated frequency bandwidth, and the amount of resource blocks. For example, one communication environment is specified with two CCs, one RF, 16QAM modulation, 20 MHz bandwidth, 10 resource blocks, and another communication environment is one CC, one RF, QPSK modulation, 10 MHz bandwidth, five It is specified as a resource block. In other words, each communication environment can have a very large number of cases.

Different communication environments inevitably require different variations in power regulation. Accordingly, the terminal needs to support various amounts or ranges of power adjustment for various communication environments, and the base station needs to know the amount or range of various power adjustments supported by the terminal to perform accurate scheduling. For accurate scheduling, the base station needs information about power coordination.

The information on power adjustment is information that directly or indirectly informs the amount or range of adjusting the uplink maximum transmit power for the terminal. If the information about the power adjustment is a power adjustment table index to be described later, or a parameter indicating the hardware characteristics of the terminal, the amount or range of the power adjustment is not directly informed to the base station, but the base station based on the information the amount of power adjustment Or the range can be known indirectly. The following table shows the range of power adjustment for each scheduling parameter condition. This represents the power adjustment amount in the case of power class 3.

Modulation Channel bandwidth / Transmission bandwidth configuration (RB) PC
(dB) 1.4
MHz 3.0
MHz 5
MHz 10
MHz 15
MHz 20
MHz QPSK > 5 > 4 > 8 > 12 > 16 > 18 ≤1 16 QAM ≤5 ≤4 ≤8 ≤12 ≤16 ≤18 ≤2 16 QAM > 5 > 4 > 8 > 12 > 16 > 18 ≤2

Referring to Table 1, modulation, channel bandwidth, and resource block (RB) are parameters required for uplink scheduling of a base station. The power regulation (PC) shall satisfy the requirements of Table 1.

For example, if a modulation of 16 QAM (Quadrature Amplitude Modulation) and 18 RB are scheduled for a terminal in a 20 MHz system, the maximum value of the power adjustment amount of the terminal is 2 dB. Therefore, the terminal may be designed to reduce the set maximum transmission power by 2 dB.

The power adjustment information is required for the terminal in a communication environment formed by the number of component carriers set in the terminal, the number of radio frequency (RF) supported for the terminal, and uplink scheduling parameters for the terminal. Directly or indirectly indicates the amount of reduction in uplink maximum transmit power. In order to reduce the scheduling error of the base station due to the ambiguity of the power adjustment, the terminal needs to report information about the power adjustment to the base station.

Hereinafter, reporting information on power adjustment to a base station is called a power coordination report (PCR). The structure of the message for power coordination reporting is as follows:

2. Structure of messages for power coordination reporting

The power adjustment information is a MAC message generated at the MAC layer. Accordingly, the terminal performs a power adjustment report by using an uplink resource allocated by an uplink grant as shown in Table 2 below.

Referring to Table 2, the uplink grant is information corresponding to format 0 of downlink control information (DCI) transmitted through a PDCCH and includes information such as RB, modulation and coding scheme (MCS), and TPC. do.

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. 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 PCR (Power Coordination Report) MAC control element for power coordination report. There is one LCID field for each MAC SDU, MAC control element or padding. Table 3 is an example of an LCID field.

Index LCID values 00000 CCCH 00001-01010 Identity of the logical channel 01011-11000 Reserved 10110 Power Coordination Report 10111 UL activation / deactivation 11000 DL 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 3, the LCID field value of 10110 indicates that the MAC control element is a PCR MAC control element according to the present invention.

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

Referring to FIG. 11, a power adjustment report field (PCR field) 1100 in a payload of a MAC PDU may include a reserved bit 1105, a power adjustment report indicator (PCR Indicator) 1110, and a power adjustment table index ( PC table index, 1115). The payload may be a PCR MAC control element or may be a MAC Service Data Unit (SDU).

The power adjustment report field 1100 is a field in the MAC PDU that contains information about power adjustment. If the information about the power adjustment corresponds to the contents, the power adjustment report field 1100 corresponds to a structure that carries information about the power adjustment.

The redundant bit 1105 and the power adjustment report indicator 1110 may each be 1 bit, and the power adjustment table index 1115 may be 6 bits.

As an example, the power adjustment report indicator 1110 indicates as 1 bit whether the corresponding payload is a power adjustment report field 1100 of a terminal unit or a power adjustment report field 1100 of a CC unit. For example, if the power adjustment report indicator 1110 is 0, the corresponding payload is the power adjustment report field 1100 of the terminal unit, and if 1, the payload is the power adjustment report field 1100 of the CC unit. The power adjustment in CC units means that the amount of power adjustment is determined for each CC by the terminal when considering a frequency band defined in CC units.

As another example, if the RF power adjustment is defined in the wireless communication system, the power adjustment report indicator 1110 is 1 bit and the corresponding payload is the power adjustment report field 1100 of the terminal unit or the power adjustment report field of the RF unit. (1100). For example, if the power adjustment report indicator 1110 is 0, the corresponding payload is the power adjustment report field 1100 of the terminal unit, and if 1, the payload is the power adjustment report field 1100 of the RF unit. The power adjustment of the RF unit means that the amount of power adjustment is determined for each RF by the terminal when considering a frequency band supported by each RF.

If the power adjustment table is defined irrespective of the number of CCs or the number of RFs, the power adjustment report indicator 1110 is reserved.

The power adjustment table index is an index indicating a power adjustment table. The power adjustment table is a table indicating the amount or range of power adjustment required by the terminal for each communication environment. The communication environment is formed by at least one of a scheduling parameter for the terminal, the number of component carriers configured in the terminal, and the number of RFs that the terminal can support. Table 4 below is an example of the power adjustment table.

Modulation Channel bandwidth /
Transmission bandwidth configuration (RB) PC (dB) 1.4 MHz 2.5 MHz 5 MHz 10 MHz 15 MHz 20 MHz # CCs = 1,
# RF = 1 QPSK > 5 > 4 > 8 > 12 > 16 > 18 ≤1 16QAM ≤5 ≤4 ≤8 ≤12 ≤16 ≤18 ≤1 16QAM > 5 > 4 > 8 > 12 > 16 > 18 ≤2 # CCs = 2,
# RF = 1 QPSK, QPSK > 5,> 5 > 4,> 4 > 8,> 8 > 12,> 12 > 16,> 16 > 18,> 18 3≤x≤4 QPSK, 16QAM > 5, ≤5 > 4, ≤4 > 8, ≤8 > 12, ≤ 12 > 16, ≤16 > 18, ≤18 3≤x≤4 QPSK, 16QAM > 5,> 5 > 4,> 4 > 8,> 8 > 12,> 12 > 16,> 16 > 18,> 18 5≤x≤6 16QAM × 2 ≤5, ≤5 ≤4, ≤4 ≤8, ≤8 ≤12, ≤12 ≤16, ≤16 ≤18, ≤18 3≤x≤4 16QAM × 2 > 5, ≤5 > 4, ≤4 > 8, ≤8 > 12, ≤12 > 16, ≤16 > 18, ≤18 5≤x≤6 16QAM × 2 > 5,> 5 > 4,> 4 > 8,> 8 > 12,> 12 > 16,> 16 > 18,> 18 8≤x≤10 # CCs = 2,
# RF = 2




QPSK, QPSK > 5,> 5 > 4,> 4 > 8,> 8 > 12,> 12 > 16,> 16 > 18,> 18 ≤2 QPSK, 16QAM > 5, ≤5 > 4, ≤4 > 8, ≤8 > 12, ≤12 > 16, ≤16 > 18, ≤18 3≤x≤5 QPSK, 16QAM > 5,> 5 > 4,> 4 > 8,> 8 > 12,> 12 > 16,> 16 > 18,> 18 5≤x≤7 16QAM × 2 ≤5, ≤5 ≤4, ≤4 ≤8, ≤8 ≤12, ≤12 ≤16, ≤16 ≤18, ≤18 5≤x≤7 16QAM × 2 > 5, ≤5 > 4, ≤4 > 8, ≤8 > 12, ≤12 > 16, ≤16 > 18, ≤18 7≤x≤9 16QAM × 2 > 5,> 5 > 4,> 4 > 8,> 8 > 12,> 12 > 16,> 16 > 18,> 18 9≤x≤11 ...
...
...
...
# CCs = 5,
# RF = 2

QPSK, QPSK,
QPSK, QPSK,
QPSK >5,>5,>
5,>5,> 5 >4,> 4
,>4,>
4,> 4 > 8,> 8,> 8,> 8,> 8 >12,> 1
2,>12,>
12,> 12 >16,> 16
,>16,> 1
6,> 16 >18,> 1
8,>18,>
18,> 18 ≤2 QPSK, QPSK,
QPSK, QPSK,
16QAM >5,>5,>
5,> 5, ≤
5 >4,> 4
,>4,>
4, ≤4 > 8,> 8,> 8,> 8, ≤8 >12,> 1
2,>12,>
12, ≤12 >16,> 16
,>16,> 1
6, ≤16 >18,> 1
8,>18,>
18, ≤18 2≤x≤4 .
.
. .
.
. .
.
. .
.
. .
.
. .
.
. .
.
. .
.
. 16QAM × 5 >5,>5,>
5,>5,> 5 >4,> 4
,>4,>
4,> 4 > 8,> 8,> 8,> 8,> 8 >12,> 1
2,>12,>
12,> 12 >16,> 16
,>16,> 1
6,> 16 >18,> 1
8,>18,>
18,> 18 10≤x≤1
2

Referring to Table 4, #CCs is the number of CCs actually set among all CCs that can be aggregated to the UE, and #RF is the number of RFs that are actually used among all RFs that can be supported. Table 4 shows the amount of power adjustment (PC) in the communication environment under various conditions specified by the number of CCs, the number of RFs, the modulation, the channel bandwidth, and the number of resource blocks (RBs) for the terminal. Or define a range.

Assume a communication environment with # CCs = 5 and # RF = 2 configured in a terminal. If 5 CCs are modulated into QPSK, QPSK, QPSK, QPSK, and 16QAM in a 20 MHz system for a UE, and 20 RBs are scheduled for 5 CCs, respectively, the range of power adjustment of the UE is 2 dB to 4 dB. Therefore, the terminal can reduce the set maximum transmission power to 2dB ~ 4dB.

Table 4 is an example of a power adjustment table showing a case in which the total number of CCs that can be aggregated in a terminal, a power class of 3, and two supportable RFs is an element, which determines a unique specification of the terminal. This may be fixedly stored in the terminal at design time.

Thus, a new power adjustment table can be defined by the new combination of the number of aggregateable CCs, the number of RFs that can be supported, and the power class. However, since the base station cannot know this, the terminal transmits a power adjustment table index as shown in Table 5 to the base station as information on power adjustment.

index One 2 ... N-1 N Table number Table 1 Table 2 ... Table N-1 Table N

Referring to Table 5, assuming that N power adjustment tables such as Table 4 are defined in the current system according to the terminal specification, each power adjustment table is indexed. Since the terminal only needs to transmit the power adjustment table index to the base station as the power adjustment information, the overhead can be significantly reduced as compared with the case of transmitting all N power adjustment tables. In this case, the terminal and the base station should store the power adjustment table and the index of each power adjustment table in all cases supported by the system in the memory. If the number of power adjustment tables is N, N indexes representing all of them are also required. The number of bits that can represent all N indices is ceiling (log ₂ (N)). Where ceiling (x) is the smallest integer greater than x. For example, if there are 32 tables, ceiling (log ₂ (32)) = 6, so the power adjustment information is 6 bits.

The base station can know the communication environment set in the terminal. Therefore, when the terminal informs the base station of only the power adjustment table index, the base station can indirectly know the amount or range of power adjustment according to the communication environment in the power adjustment table indicated by the power adjustment table index. The base station may set the scheduling parameter so as not to exceed the maximum transmission power of the uplink of the terminal based on the amount or range of power adjustment and the surplus power report by the terminal.

12 is a block diagram illustrating a structure of a MAC PDU for power coordination report according to another embodiment of the present invention.

Referring to FIG. 12, a power coordination report field (PCR field 1200) in a payload of a MAC PDU may include a power coordination report indicator (PCR indicator) 1205, a UE power class field 1210, and an aggregated CC. The number field of the Aggregatable CCs (1215) and the number field of the supportable RF chain (No. of RF chain, 1220). The payload may be a PCR MAC control element or may be a MAC SDU. The power adjustment report indicator 1205 and the power class field 1210 of the terminal may each be 1 bit, and the number field 1215 of the aggregateable CCs and the number field 1220 of the supportable RF chains may each be 3 bits.

The power class field 1210 of the terminal refers to the class of the terminal classified based on the maximum transmission power that the terminal can transmit in the uplink. In the example of FIG. 11, only two power class fields 1210 of the terminal are defined. As an example, when the power class field 1210 of the terminal indicates 0, the terminal belongs to power class 3. Power class 3 refers to a class having an uplink maximum transmit power of 23 dBm. If the power class field 1210 of the terminal indicates 1, the terminal belongs to power class 4. Power class 4 refers to a class having an uplink maximum transmit power of 28 dBm.

The number of aggregateable CCs has a value of 1-5. Accordingly, if the number field 1215 of the aggregateable CCs is 000, the number of aggregateable CCs is 1, 001, 2, 010, 3, 011, and 4, 100.

The number of RF chains indicates the number of RF chains configured for the UE to transmit a signal in uplink and the number of CCs supported by each RF. The number of RF chains may be expressed as shown in Table 6 below.

Bits RF Count Supportable CC Count 000 One Maximum number of CCs that can be aggregated (MC) 001 2 RF # 1 = 1, RF # 2 = MC-1 010 2 RF # 1 = 2, RF # 2 = MC-2 011 2 RF # 1 = 3, RF # 2 = MC-3 100 3 RF # 1 = 1, RF # 2 = 1, RF # 3 = MC-2 101 3 RF # 1 = 2, RF # 2 = 1, RF # 3 = MC-3 110 3 RF # 1 = 3, RF # 2 = 1, RF # 3 = MC-4 111 3 RF # 1 = 2, RF # 2 = 2, RF # 3 = MC-4

Referring to Table 6, RF # N means an RF number, and does not indicate a specific order, but means a possible configuration.

The power class 1210 of the terminal, the number of aggregateable CCs 1215 and the number of supportable RF chains 1220 are parameters indicating hardware characteristics related to power regulation. The power adjustment table may be specified by a combination of the power class 1210 of the terminal, the number of aggregateable CCs 1215, and the number of supportable RF chains 1220. For example, suppose that the power class 1210 of the terminal, the number of aggregateable CCs 1215, and the number of supportable RF chains 1220 are configured as shown in Table 7 below.

Power class 3 RF 2 Aggregate CC 5

Referring to Table 7, since the power class of the terminal is 3, two supportable RFs and five aggregated CCs can be specified, the power adjustment table of Table 4 may be specified. However, the terminal and the base station should store the power adjustment table in all cases in the memory. The terminal informs the base station of the power adjustment report field 1200 that is composed of various combinations of the power class 1210 of the terminal, the number of aggregateable CCs 1215, and the number of supportable RF chains 1220, and stored in the memory. A power adjustment table specified by the power adjustment report field 1200 may be selected among all power adjustment tables, and uplink scheduling may be performed with reference to the selected power adjustment table.

3. Method of sending message for power adjustment report

The terminal may transmit a message for power adjustment report in the following cases. First, immediately after completion of RRC connection establishment or RRC connection reestablishment, (i) when an uplink grant for transmitting new data by the terminal to uplink is received, (ii) This is a case where a message for power coordination report in MAC PDU format can be transmitted to an uplink resource secured by an uplink grant.

Next, immediately after completion of RRC connection recofiguration, when (i) the terminal receives an uplink grant for transmitting new data in uplink, (ii) an uplink secured by an uplink grant This is a case where a message for power coordination reporting in a MAC PDU format can be transmitted to a resource.

13 is a flowchart illustrating a method of transmitting information about power adjustment according to an embodiment of the present invention. This is a process of transmitting information about power adjustment through the power adjustment report field on the assumption that the RRC connection setting or the CC setting is changed through the RRC connection setting, RRC connection reconfiguration, or RRC connection reconfiguration procedure.

Referring to FIG. 13, the base station transmits an uplink grant to the terminal (S1300). The uplink grant may be configured as shown in Table 2 above. The terminal generates a MAC PDU including a power adjustment report field (PCR field) (S1305). The power adjustment report field is a field for transmitting information on power adjustment. The power adjustment report field may have a structure as illustrated in FIGS. 11 and 12, and the MAC PDU may have a structure as illustrated in FIG. 10.

The terminal transmits the MAC PDU to the base station using the resources allocated by the uplink grant (S1310).

The base station performs uplink scheduling with reference to the information on the power adjustment obtained from the power adjustment report field (S1315).

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

Referring to FIG. 14, the terminal completes an RRC connection procedure such as an RRC connection establishment procedure, an RRC connection reconfiguration procedure, or an RRC connection reconfiguration procedure for adding / removing CCs (S1400).

After the RRC procedures are completed, the terminal may receive an uplink grant from the base station. At this time, the terminal determines whether the received uplink grant is a new uplink grant for the transmission of new uplink data (S1405). This determination may be performed through a 1-bit new data indicator (NDI) included in the uplink grant.

If the new data indicator is 0, the uplink grant is a UL grant for retransmission of previous data, and thus, HARQ (Hybrid Automatic Repeat reQuest) retransmission is performed (S1410). This process is performed as follows. The terminal checks the information to be retransmitted through the information in the HARQ entity. After checking the HARQ information, select information to be retransmitted in the HARQ buffer and retransmit to the base station through the uplink resources based on the uplink grant.

If the new data indicator is 1, since the uplink grant is a new uplink grant for transmitting new data, the UE checks scheduling parameters in the uplink grant and calculates the amount of resources that can be transmitted in the corresponding subframe. At this time, in consideration of the priority of the data currently stored in the uplink buffer, other MAC CE data, and information on power adjustment, it is checked whether the power adjustment report field can be transmitted in the corresponding subframe (S1415).

If the power adjustment report field is transmittable, the terminal generates a MAC PDU including the power adjustment report field (S1420), and transmits the generated MAC PDU to the base station using the resources allocated by the uplink grant ( S1425).

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

Referring to FIG. 15, the base station completes an RRC connection procedure such as an RRC connection establishment procedure, an RRC connection reconfiguration procedure, or an RRC connection reconfiguration procedure for adding / removing CCs (S1500). The RC connection establishment procedure and RRC connection reestablishment procedure may be triggered through paging.

When the RRC connection procedure is completed, the base station transmits a message for requesting uplink scheduling from the terminal, such as a scheduling request (SR) or a buffer state report (BSR) previously received from the terminal, and transmits the existing message. It is determined whether an error of one data or the like constitutes an uplink grant for new data or an uplink grant for retransmission.

The base station sets a new data indicator so that the terminal can determine whether it is an uplink grant for transmitting new uplink data. In case of an uplink grant for transmitting new uplink data, the new data indicator is set to 1, and in case of an uplink grant for retransmission, it is set to 0. For convenience of explanation, it is assumed that the base station transmits an uplink grant for new data.

The base station transmits an uplink grant for new data to the terminal (S1505). The base station receives the MAC PDU from the terminal through the resources allocated according to the uplink grant (S1510). At this time, the base station checks whether the MAC PDU includes a power adjustment report field (PCR field) (S1515). To this end, the base station checks whether the LCID in the subheader of the MAC indicates the PCR MAC control element based on Table 3 above.

If the BS determines that the MAC PDU includes the power adjustment report field, the base station interprets the contents of the power adjustment report field, sets a power adjustment table to be applied to the terminal, and sets the power adjustment table based on the set power adjustment table. The amount or range is determined (S1520). The base station stores the set power adjustment table in the UE context (S1525). Thereafter, the base station performs uplink scheduling based on the determined amount or range of power adjustment.

16 is a block diagram illustrating an apparatus for transmitting and receiving information on power adjustment in a multi-element carrier system according to an embodiment of the present invention.

Referring to FIG. 16, the apparatus 1600 for transmitting power adjustment information includes a power adjustment table storage unit 1605, a power generation information generation unit 1610, a MAC PDU generation unit 1615, and an RRC message transmission / reception unit. 1620, uplink grant receiver 1625 and MAC PDU transmitter 1630.

The power adjustment table storage unit 1605 stores a power adjustment table. Examples of the power adjustment table are shown in Table 1 or Table 4 above.

The information generator 1610 about power regulation generates information about power regulation. The information on power adjustment is information that directly or indirectly informs the amount or range of adjusting the uplink maximum transmit power for the terminal. The information about power adjustment may be a power adjustment table index or a parameter indicating hardware characteristics of the terminal.

The MAC PDU generation unit 1615 determines whether the power adjustment report field can be inserted into the MAC PDU based on the resource situation allocated by the uplink grant, and generates a MAC PDU including the power adjustment report field if insertable.

The RRC message transceiver 1620 may transmit various messages related to RRC connection establishment, for example, an RRC connection establishment message, an RRC connection reestablishment message, or an RRC connection reconfiguration complete message to the receiver 1650 of information on power adjustment. The RRC connection reconfiguration message is received from the device 1650 of the power adjustment information.

The uplink grant receiver 1625 receives an uplink grant from the receiver 1650 of the power adjustment information. An example of an uplink grant is shown in Table 8 below.

The MAC PDU transmitter 1630 transmits the MAC PDU generated by the MAC PDU generation unit to the receiver 1650 of the power adjustment based on the scheduling parameter and the power adjustment information according to the received uplink grant. do.

The apparatus 1650 for receiving power adjustment includes an RRC message transceiver 1655, a scheduling unit 1660, an uplink grant transmitter 1665, and a MAC PDU receiver 1670.

The RRC message transmitter / receiver 1655 transmits an RRC connection reconfiguration message including CC configuration information for CC addition / change to the transmitter 1600 of power adjustment information, or transmits an RRC connection reconfiguration completion message regarding power adjustment. It receives the information from the transmission device 1600.

The scheduling unit 1660 may include an MCS for the power adjustment information 1600 regarding the power adjustment in consideration of a channel condition, a buffer status report, a network condition, a resource use condition, etc. of the transmission device 1600 for power adjustment information; Set scheduling parameters such as TPC and resource allocation information. In particular, the scheduling unit 1660 sets an amount or range of power adjustment from the power adjustment information received from the MAC PDU receiving unit 1670, and performs uplink scheduling accordingly.

The uplink grant transmitter 1665 configures an uplink grant based on a scheduling parameter determined to be valid as a result of the scheduling validity determination, and transmits the configured uplink grant to the transmitter 1600 for information on power adjustment. .

The MAC PDU receiving unit 1670 receives the MAC PDU including the power adjustment report field from the transmitter 1600 of the power adjustment information, and schedules the information about the power adjustment included in the power adjustment report field 1660. Send to).

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 (12)

In the multi-component carrier system, a method for transmitting information on power adjustment by a terminal,
Generating information on power adjustment informing the amount or range of power adjustment for adjusting uplink maximum transmit power required by the terminal;
Generating a medium access control (MAC) protocol data unit (PDU) including information on the power adjustment; And
Transmitting the MAC PDU to a base station;
The MAC PDU includes a MAC subheader and a Power Coordination Report field, the power coordination report field includes information about the power coordination, and the MAC subheader is the power coordination report field. And logical channel identification information (LCID) indicating the power adjustment. The method of claim 1, wherein before transmitting the MAC PDU,
Receiving an uplink grant (uplink grant) including an uplink scheduling parameter from the base station,
And the MAC PDU is transmitted based on the uplink scheduling parameter. The method of claim 1,
The power adjustment report field may include the number of component carriers configured for the terminal or the amount of power adjustment, the number of radio frequency (RF) chains supported for the terminal, and uplink scheduling for the terminal. and an index field indicating a power adjustment table set for each communication environment formed by a (scheduling) parameter. The method of claim 1,
The information on power adjustment includes a field indicating information on the number of component carriers set in the terminal and a field indicating the number of RF chains supported by the terminal. . In the method of receiving information on power adjustment by the base station in a multi-component carrier system,
Transmitting an uplink grant including scheduling parameters for uplink transmission of the terminal to the terminal; And
Receiving a MAC PDU generated from the terminal based on the scheduling parameter,
The MAC PDU includes a MAC subheader and a power coordination report field, the MAC subheader includes logical channel identification information indicating the power coordination report field, and the power coordination report field is an uplink required for the terminal. And information on power adjustment informing the amount or range of power adjustment for adjusting the maximum transmission power. The method of claim 5, wherein
The power adjustment report field is included in a MAC control element in the MAC PDU. The method of claim 5, wherein
The power adjustment report field is included in a MAC Service Data Unit (MAC SDU) in the MAC PDU. The method of claim 5, wherein
The power adjustment report field may be based on at least one of the amount or range of the power adjustment based on the number of component carriers set in the terminal, the number of RF chains supported in the terminal, and an uplink scheduling parameter for the terminal. And an index field indicating a power adjustment table set for each communication environment to be formed. The method of claim 5, wherein
The information on power adjustment includes a field indicating information on the number of component carriers set in the terminal and a field indicating the number of RF chains supported by the terminal. . In the apparatus for transmitting information on power adjustment in a multi-component carrier system,
An uplink grant receiver configured to receive an uplink grant including scheduling parameters related to uplink transmission;
An information generation unit for power adjustment for generating information on power adjustment informing the amount or range of power adjustment for adjusting uplink maximum transmission power for the terminal;
A MAC PDU generation unit configured to configure a MAC PDU as a power adjustment report field including information on the power adjustment based on a resource situation allocated by the uplink grant; And
And a MAC PDU transmitter for transmitting the MAC PDU based on the scheduling parameter for the uplink transmission and the amount or range of the power adjustment. The method of claim 10,
And the MAC PDU generation unit inserts the MAC subheader including logical channel identification information indicating the power adjustment report field into the MAC PDU. An apparatus for receiving information on power adjustment in a multi-component carrier system,
An uplink grant transmitter for transmitting an uplink grant including scheduling parameters for uplink transmission;
A MAC PDU receiving unit which receives a MAC PDU including a MAC subheader and a power adjustment report field; And
A scheduling unit for determining a scheduling parameter for the uplink transmission,
The power coordination report field includes information on power coordination indicating an amount or range of power coordination adjusting uplink maximum transmission power for a terminal, and the MAC subheader indicates a logical channel indicating the power coordination report field. Receiving information, characterized in that for receiving power information receiving apparatus.

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