KR20120010188A - User equiment apparatus and method for transmitting power headroom report in wireless communication system supporting a pluraity of component carriers - Google Patents

Abstract

PURPOSE: A terminal device for transmitting a power head room report in a wireless communication system supporting multiple component carriers and a method thereof are provided to facilitate management of sources in a base station by the efficient construction of PHR information classified into uplink CC and PHR information classified into terminal. CONSTITUTION: PHR information classified into one or more component carriers and information about maximum power reduction of the terminal is transmitted to the base station. The PHR information classified into one or more component carriers includes component carrier index information. The MPR information of the terminal corresponds to a MPR value classified into one or more component carriers or a MPR value classified into one or more component carriers.

Description

TECHNICAL FIELD The terminal apparatus for transmitting a power headroom report (PHHR) in a wireless communication system supporting a plurality of component carriers, and a method for transmitting the power headroom report in wireless communication system supporting a pluraity of component carriers

The present invention relates to wireless communication, and more particularly, to a terminal device and a method for transmitting a power headroom report (PHR) in a wireless communication system supporting a plurality of component carriers (Component Carrier).

As an example of a mobile communication system to which the present invention can be applied, a 3GPP LTE (3rd Generation Partnership Project Long Term Evolution, hereinafter referred to as 'LTE'), and an LTE-Advanced (hereinafter referred to as 'LTE-A') communication system are outlined. Explain.

1 is a diagram schematically illustrating an E-UMTS network structure as an example of a mobile communication system. The Evolved Universal Mobile Telecommunications System (E-UMTS) system is an evolution from the existing Universal Mobile Telecommunications System (UMTS), and is currently being standardized in 3GPP. In general, E-UMTS may be referred to as an LTE (Long Term Evolution) system. For details of technical specifications of UMTS and E-UMTS, refer to Release 8 and Release 9 of the "3rd Generation Partnership Project; Technical Specification Group Radio Access Network", respectively.

Referring to FIG. 1, an E-UMTS is located at an end of a user equipment (UE), a base station (eNode B, eNB), and a network (E-UTRAN) and connected to an external network (Access Gateway, AG). It includes. The base station may transmit multiple data streams simultaneously for broadcast service, multicast service and / or unicast service.

One or more cells exist in one base station. The cell is set to one of bandwidths such as 1.25, 2.5, 5, 10, 15, and 20 MHz to provide downlink or uplink transmission services to multiple terminals. Different cells may be configured to provide different bandwidths. The base station controls data transmission and reception for a plurality of terminals. For downlink (DL) data, the base station transmits downlink scheduling information, which is related to time / frequency domain, encoding, data size, and hybrid automatic repeat and reQuest (HARQ) request for data to be transmitted to the corresponding UE. Give information and more. In addition, the base station transmits uplink scheduling information to the corresponding terminal for uplink (UL) data and informs the user of the time / frequency domain, encoding, data size, and hybrid automatic retransmission request related information. An interface for transmitting user traffic or control traffic may be used between base stations. The core network (Core Network, CN) may be composed of a network node for the user registration of the AG and the terminal. The AG manages the mobility of the UE in units of a tracking area (TA) composed of a plurality of cells.

Wireless communication technology has been developed up to LTE based on Wideband Code Division Multiple Access (WCDMA), but the needs and expectations of users and operators continue to increase. In addition, as other radio access technologies continue to be developed, new technological evolution is required to be competitive in the future. Reduced cost per bit, increased service availability, the use of flexible frequency bands, simple structure and open interface, and adequate power consumption of the terminal are required.

Recently, 3GPP has been working on standardization of follow-up technology for LTE. In the present specification, the above technique is referred to as 'LTE-A'. One of the major differences between LTE and LTE-A systems is the difference in system bandwidth and the introduction of repeaters.

The LTE-A system aims to support broadband of up to 100 MHz, and to this end, carrier aggregation or bandwidth aggregation technology is used to achieve broadband using multiple frequency blocks. Doing.

Carrier aggregation (or carrier aggregation) allows multiple frequency blocks to be used as one large logical frequency band in order to use a wider frequency band. The bandwidth of each frequency block may be defined based on the bandwidth of the system block used in the LTE system. Each frequency block is transmitted using a component carrier.

Although the carrier aggregation technology is adopted in the LTE-A system, which is the next generation communication system, the existing technology cannot support the uplink power control operation of the terminal in the multi-carrier system. How the terminal should report the PHR (Power Headroom Report) for the multi-carrier, and at this time has not been studied how the PHR configuration method and format for PHR transmission.

An object of the present invention is to provide a method for a terminal to transmit a power headroom report (PHR) in a wireless communication system supporting a plurality of component carriers.

Another object of the present invention is to provide a terminal apparatus for transmitting a power headroom report (PHR) in a wireless communication system supporting a plurality of component carriers.

The technical problems to be solved by the present invention are not limited to the technical problems and other technical problems which are not mentioned can be understood by those skilled in the art from the following description.

In order to achieve the above technical problem, a method for transmitting a power headroom report (PHR) by a terminal in a wireless communication system supporting a plurality of component carriers according to the present invention, PHR for at least one component carrier And transmitting information about maximum power reduction (MPR) of the terminal to a base station, wherein the at least one component carrier-specific PHR information includes component carrier index information. The MPR information may be a sum of the MPR value of the at least one component carrier or the MPR value of the at least one component carrier. The PHR information for each of the at least one component carrier may further include PHR type information. The PHR type includes a first type PHR and a second type PHR, and the first type PHR and the second type PHR may be sequentially represented by the following Equations A and B, respectively. ] Is type 1 PHR = Pcmax-P _PUSCH , and [Equation B] is type 2 PHR = Pcmax-P _PUCCH -P _PUSCH , where Pcmax is a terminal transmission maximum power value configured for each component carrier. It is a transmission maximum power value configured in the terminal, P _PUSCH represents a power value used to transmit the PUSCH, P _PUCCH represents a power value used to transmit the PUCCH. The PHR information on the secondary cell (Scell) corresponding to the secondary component carrier (Secondary CC) of the at least one component carrier may be the second type PHR. The PHR information on the primary cell (Pcell) corresponding to the primary carrier (Primary CC) of the at least one component carrier may include the first type PHR and the second type PHR. The PHR information for each of the at least one component carrier or the maximum power reduction (MPR) information of the terminal may be transmitted when a PUSCH transmission occurs in a specific component carrier among the at least one component carrier.

The method may further include transmitting PHR information for each terminal to the base station, wherein the PHR information for each terminal is a power sum of a scheduled PUSCH (Physical Uplink Shared CHannel) at a predetermined maximum maximum power of the terminal. Subtracting any one of a sum of scheduled PUCCHs, a sum of PUSCHs in an Scell corresponding to an unscheduled secondary component carrier, and a sum of PUCCHs of a Pcell corresponding to an unscheduled primary component carrier. May correspond to a value.

In addition, the PHR information for each of the at least one component carrier and the PHR information for each terminal may be transmitted through the same PHR MAC Control Element (CE CE) format. The PHR MAC CE format may include a field for distinguishing PHR information for each component carrier and PHR information for each terminal and a field for a PHR value. The PHR MAC CE format for the PHR information for each of the at least one component carrier further includes a field including the component carrier index information, and the field for the PHR value includes at least one of a first type PHR value and a second type PHR value. It may include one. The at least one component carrier may be all component carriers assigned to the terminal or scheduled component carriers.

In order to achieve the above technical problem, a terminal device for transmitting a power headroom report (PHR) in a wireless communication system supporting a plurality of component carriers according to the present invention, at least one component carrier PHR Including a transmitter for transmitting the information and the maximum power reduction (MPR) information of the terminal to the base station,

The PHR information for each of the at least one component carrier includes component carrier index information, and the MPR information of the terminal may be the sum of the MPR value for the at least one component carrier or the MPR value for the at least one component carrier. The PHR information for each of the at least one component carrier may further include PHR type information. The transmitter may further transmit terminal-specific PHR information to the base station. In this case, the at least one component-carrier PHR information and the terminal-specific PHR information may be transmitted through the same PHR MAC Control Element (CE CE) format. The PHR MAC CE format may include a field for distinguishing PHR information for each component carrier and PHR information for each terminal and a field for a PHR value.

According to various embodiments of the present disclosure, power headroom of a terminal required for a base station and a base station supporting a downlink / uplink multicarrier system is configured, and efficiently configured uplink CC-specific PHR information and terminal-specific PHR information For example, the resource management of the base station can be facilitated and the maximum power limitation of the terminal can be minimized.

Effects obtained in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description in order to provide a thorough understanding of the present invention, provide an embodiment of the present invention and together with the description, illustrate the technical idea of the present invention.
1 is a diagram schematically illustrating an E-UMTS network structure as an example of a mobile communication system.
2 is a block diagram showing the configuration of the base station 205 and the terminal 210 in the wireless communication system 200.
3 is a diagram illustrating a structure of a radio frame used in a 3GPP LTE system as an example of a mobile communication system.
4 is a diagram illustrating the structure of downlink and uplink subframes of a 3GPP LTE system as an example of a mobile communication system.
FIG. 5 illustrates an example of a PHR MAC CE (Control Element) in Rel-8 / 9 of 3GPP LTE, which is an example of a mobile communication system.
6 is a diagram illustrating a configuration example of a PHR MAC CE to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system.
FIG. 7 is a diagram illustrating another configuration example of PHR MAC CE to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system.
FIG. 8 is a diagram illustrating an example of PHR MAC CE format 1 for a Pcell to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system.
FIG. 9 is a diagram illustrating an example of PHR MAC CE format 2 for an Scell to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system.
FIG. 10 is a diagram illustrating another configuration example of a PHR MAC CE format to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details. For example, the following detailed description will be described in detail on the assumption that the mobile communication system is a 3GPP LTE, LTE-A system, but is also applied to any other mobile communication system except for the specific matters of 3GPP LTE, LTE-A. Applicable

In some instances, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention. In addition, the same components will be described with the same reference numerals throughout the present specification.

In the following description, it is assumed that the UE collectively refers to a mobile stationary or stationary user equipment such as a UE (User Equipment), an MS (Mobile Station), and an AMS (Advanced Mobile Station). In addition, it is assumed that the base station collectively refers to any node of the network side that communicates with the terminal such as a Node B, an eNode B, a base station (BS), and an access point (AP). In the present specification, the description will be based on 3GPPL LTE and LTE-A systems, but the contents of the present invention can be applied to various other communication systems.

In a mobile communication system, a user equipment can receive information through a downlink from a base station, and the terminal can also transmit information through an uplink. The information transmitted or received by the terminal includes data and various control information, and various physical channels exist depending on the type of information transmitted or received by the terminal.

2 is a block diagram showing the configuration of the base station 205 and the terminal 210 in the wireless communication system 200.

Although one base station 205 and one terminal 210 are shown to simplify the wireless communication system 200, the wireless communication system 200 may include one or more base stations and / or one or more terminals. .

Referring to FIG. 2, the base station 205 includes a transmit (Tx) data processor 215, a symbol modulator 220, a transmitter 225, a transmit / receive antenna 230, a processor 280, a memory 285, and a receiver ( 290, symbol demodulator 295, and receive data processor 297. The terminal 210 transmits (Tx) the data processor 265, the symbol modulator 270, the transmitter 275, the transmit / receive antenna 235, the processor 255, the memory 260, the receiver 240, and the symbol. Demodulator 255, receive data processor 250. Although antennas 230 and 235 are shown as one at the base station 205 and the terminal 210, respectively, the base station 205 and the terminal 210 are provided with a plurality of antennas. Accordingly, the base station 205 and the terminal 210 according to the present invention support a multiple input multiple output (MIMO) system. In addition, the base station 205 according to the present invention may support both a single user-MIMO (SU-MIMO) and a multi-user-MIMO (MU-MIMO) scheme.

On the downlink, the transmit data processor 215 receives the traffic data, formats the received traffic data, codes it, interleaves and modulates (or symbol maps) the coded traffic data, and modulates the symbols ("data"). Symbols "). The symbol modulator 220 receives and processes these data symbols and pilot symbols to provide a stream of symbols.

The symbol modulator 220 multiplexes the data and pilot symbols and sends it to the transmitter 225. In this case, each transmission symbol may be a data symbol, a pilot symbol, or a signal value of zero. In each symbol period, pilot symbols may be sent continuously. The pilot symbols may be frequency division multiplexed (FDM), orthogonal frequency division multiplexed (OFDM), time division multiplexed (TDM), or code division multiplexed (CDM) symbols.

Transmitter 225 receives the stream of symbols and converts it into one or more analog signals, and further adjusts (eg, amplifies, filters, and frequency upconverts) the analog signals to provide a wireless channel. Generates a downlink signal suitable for transmission through the antenna, and then, the antenna 230 transmits the generated downlink signal to the terminal.

In the configuration of the terminal 210, the antenna 235 receives the downlink signal from the base station and provides the received signal to the receiver 240. Receiver 240 adjusts the received signal (eg, filtering, amplifying, and frequency downconverting), and digitizes the adjusted signal to obtain samples. The symbol demodulator 245 demodulates the received pilot symbols and provides them to the processor 255 for channel estimation.

The symbol demodulator 245 also receives a frequency response estimate for the downlink from the processor 255 and performs data demodulation on the received data symbols to obtain a data symbol estimate (which is an estimate of the transmitted data symbols). Obtain and provide data symbol estimates to a receive (Rx) data processor 250. Receive data processor 250 demodulates (ie, symbol de-maps), deinterleaves, and decodes the data symbol estimates to recover the transmitted traffic data.

 The processing by the symbol demodulator 245 and the receiving data processor 250 are complementary to the processing by the symbol modulator 220 and the transmitting data processor 215 at the base station 205, respectively.

The terminal 210 is on the uplink, and the transmit data processor 265 processes the traffic data to provide data symbols. The symbol modulator 270 may receive and multiplex data symbols, perform modulation, and provide a stream of symbols to the transmitter 275. Transmitter 275 receives and processes the stream of symbols to generate an uplink signal. The antenna 235 transmits the generated uplink signal to the base station 205.

At the base station 205, an uplink signal is received from the terminal 210 through the antenna 230, and the receiver 290 processes the received uplink signal to obtain samples. The symbol demodulator 295 then processes these samples to provide received pilot symbols and data symbol estimates for the uplink. The received data processor 297 processes the data symbol estimates to recover the traffic data sent from the terminal 210.

Processors 255 and 280 of each of the terminal 210 and the base station 205 instruct (eg, control, coordinate, manage, etc.) operations at the terminal 210 and the base station 205, respectively. Respective processors 255 and 280 may be connected to memory units 260 and 285 that store program codes and data. The memory 260, 285 is coupled to the processor 280 to store the operating system, applications, and general files.

The processors 255 and 280 may also be referred to as a controller, a microcontroller, a microprocessor, a microcomputer, or the like. The processors 255 and 280 may be implemented by hardware or firmware, software, or a combination thereof. When implementing embodiments of the present invention using hardware, application specific integrated circuits (ASICs) or digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) configured to perform the present invention. Field programmable gate arrays (FPGAs) may be provided in the processors 255 and 280.

Meanwhile, when implementing embodiments of the present invention using firmware or software, the firmware or software may be configured to include a module, a procedure, or a function for performing the functions or operations of the present invention, and to perform the present invention. The firmware or software configured to be may be provided in the processors 255 and 280 or may be stored in the memory 260 and 285 and driven by the processors 255 and 280.

The layers of the air interface protocol between the terminal and the base station between the wireless communication system (network) are based on the lower three layers of the open system interconnection (OSI) model, which is well known in the communication system. ), And the third layer L3. The physical layer belongs to the first layer and provides an information transmission service through a physical channel. A Radio Resource Control (RRC) layer belongs to the third layer and provides control radio resources between the UE and the network. The terminal and the base station may exchange RRC messages through the wireless communication network and the RRC layer.

3 is a diagram illustrating a structure of a radio frame used in a 3GPP LTE system as an example of a mobile communication system.

Referring to FIG. 3, one radio frame has a length of 10 ms (327200 Ts) and consists of 10 equally sized subframes. Each subframe has a length of 1 ms and consists of two slots. Each slot has a length of 0.5 ms (15360 Ts). Here, Ts represents a sampling time and is represented by Ts = 1 / (15 kHz x 2048) = 3.2552 x 10 -8 (about 33 ns). The slot includes a plurality of OFDM symbols or SC-FDMA symbols in the time domain and a plurality of resource blocks in the frequency domain.

In an LTE system, one resource block (RB) includes 12 subcarriers x 7 (6) OFDM symbols or SC-FDMA (Single Carrier-Frequency Division Multiple Access) symbols. Transmission time interval (TTI), which is a unit time for transmitting data, may be determined in units of one or more subframes. The structure of the above-described radio frame is only an example, and the number of subframes included in the radio frame or the number of slots included in the subframe, the number of OFDM symbols or SC-FDMA symbols included in the slot may be variously changed. have.

4 is a diagram illustrating the structure of downlink and uplink subframes of a 3GPP LTE system as an example of a mobile communication system.

Referring to FIG. 4A, one downlink subframe includes two slots in the time domain. Up to three OFDM symbols of the first slot in the downlink subframe are control regions to which control channels are allocated, and the remaining OFDM symbols are data regions to which a Physical Downlink Shared Channel (PDSCH) is allocated.

Downlink control channels used in 3GPP LTE systems include a Physical Control Format Indicator Channel (PCFICH), a Physical Downlink Control Channel (PDCCH), and a Physical Hybrid-ARQ Indicator Channel (PHICH). The PCFICH transmitted in the first OFDM symbol of the subframe carries information about the number of OFDM symbols (that is, the size of the control region) used for transmission of control channels in the subframe. Control information transmitted through the PDCCH is called downlink control information (DCI). DCI indicates uplink resource allocation information, downlink resource allocation information, and uplink transmission power control command for arbitrary UE groups. The PHICH carries an ACK (Acknowledgement) / NACK (Negative Acknowledgement) signal for an uplink HARQ (Hybrid Automatic Repeat Request). That is, the ACK / NACK signal for the uplink data transmitted by the UE is transmitted on the PHICH.

Now, a PDCCH which is a downlink physical channel will be described.

The base station controls resource allocation and transmission format of PDSCH (also referred to as DL grant), resource allocation information of PUSCH (also referred to as UL grant) through PDCCH, and transmit power control for any terminal and individual terminals in a group. A set of Control (TPC) commands and activation of Voice over Internet Protocol (VoIP) can be sent. The base station may transmit a plurality of PDCCHs in the control region, and the terminal may monitor the plurality of PDCCHs. The PDCCH consists of an aggregation of one or more consecutive Control Channel Elements (CCEs). The base station may transmit the PDCCH configured with one or a plurality of consecutive CCEs through the control region after subblock interleaving. CCE is a logical allocation unit used to provide a PDCCH with a coding rate according to a state of a radio channel. The CCE corresponds to a plurality of resource element groups. The format of the PDCCH and the number of possible bits of the PDCCH are determined by the correlation between the number of CCEs and the coding rate provided by the CCEs.

Control information transmitted through the PDCCH is called downlink control information (DCI). Table 1 below shows DCI according to DCI format.

DCI format 0 indicates uplink resource allocation information, DCI formats 1 to 2 indicate downlink resource allocation information, and DCI formats 3 and 3A indicate uplink transmission power control (Tmit Power Control, TPC) for arbitrary UE groups. ) Command.

DCI format 3 / 3A includes TPC commands for a plurality of terminals. For DCI format 3 / 3A, the base station masks the TPC-ID in the CRC. The TPC-ID is an identifier that the terminal demasks to monitor a PDCCH carrying a TPC command. The TPC-ID may be referred to as an identifier used by the UE to decode the PDCCH in order to confirm whether or not the TPC command is transmitted on the PDCCH. The TPC-ID may be defined by reusing existing identifiers C-RNTI (Radio Network Temporary Identifier), PI-RNTI, SC-RNTI, RA-RNTI, or may be defined as a new identifier. The TPC-ID differs from C-RNTI, which is an identifier for a specific terminal, in that it is an identifier for a specific set of terminals in a cell, and also different from PI-RNTI, SC-RNTI, and RA-RNTI, which is an identifier for all terminals in a cell. . This is because when the DCI includes a TPC command for N terminals, only the N terminals need to receive the TPC commands. If the DCI includes TPC commands for all terminals in the cell, the TPC-ID becomes an identifier for all terminals in the cell.

The UE finds a TPC-ID by monitoring a set of PDCCH candidates in a search space in a subframe. In this case, the TPC-ID may be found in the common search space or may be found in the UE sepcific search space. The common search space is a search space searched by all terminals in a cell, and the terminal specific search space refers to a search space searched by a specific terminal. If the CRC error is not detected by demasking the TPC-ID in the corresponding PDCCH candidate, the UE may receive a TPC command on the PDCCH.

Defines an identifier for the PDCCH carrying only a plurality of TPC commands, TPC-ID. When the UE detects the TPC-ID, the UE receives a TPC command on the corresponding PDCCH. The TPC command is used to adjust the transmit power of the uplink channel. Therefore, it is possible to prevent transmission failure to the base station due to erroneous power control or interference to other terminals.

Hereinafter, a brief description will be made of a method of mapping a resource for transmitting a PDCCH by a base station in a 3GPP LTE system.

이다). PDCCH는 다음 표 2에 나타낸 바와 같이 다중 포맷을 지원한다. n개의 연속 CCE들로 구성된 하나의 PDCCH는 i mod n =0을 수행하는 CCE부터 시작한다(여기서 i는 CCE 번호이다). 다중 PDCCH들은 하나의 서브프레임으로 전송될 수 있다. In general, the base station may transmit scheduling assignment information and other control information through the PDCCH. The physical control channel may be transmitted in one aggregation or a plurality of continuous control channel elements (CCEs). One CCE includes nine Resource Element Groups (REGs). The number of REGs not allocated to the Physical Control Format Indicator CHhannel (PCFICH) or the Physical Hybrid Automatic Repeat Request Indicator Channel (PHICH) is N _RBG . The available CCEs in the system are from 0 to N _CCE -1 (where

to be). The PDCCH supports multiple formats as shown in Table 2 below. One PDCCH composed of n consecutive CCEs starts with a CCE that performs i mod n = 0 (where i is a CCE number). Multiple PDCCHs may be transmitted in one subframe.

Referring to Table 2, the base station may determine the PDCCH format according to how many areas, such as control information, to send. The UE may reduce overhead by reading control information in units of CCE.

Referring to FIG. 4B, an uplink subframe may be divided into a control region and a data region in the frequency domain. The control region is allocated to a physical uplink control channel (PUCCH) that carries uplink control information. The data area is allocated to a Physical Uplink Shared CHannel (PUSCH) for carrying user data. In order to maintain a single carrier characteristic, one UE does not simultaneously transmit a PUCCH and a PUSCH. PUCCH for one UE is allocated to an RB pair in one subframe. RBs belonging to the RB pair occupy different subcarriers in each of two slots. The RB pair assigned to the PUCCH is frequency hopped at the slot boundary.

Hereinafter, a process for sending a PDCCH to a terminal by a base station in an LTE system will be described.

The base station determines the PDCCH format according to the downlink control information (DCI) to be sent to the terminal, and attaches a CRC (Cyclic Redundancy Check) to the control information. The CRC is masked with a unique identifier (referred to as RNTI (Radio Network Temporary Identifier)) according to the owner or purpose of the PDCCH. If the PDCCH is for a specific terminal, a unique identifier of the terminal, for example, a C-RNTI (Cell-RNTI) may be masked to the CRC. Or, if the PDCCH for a paging message (paging message), a paging indication identifier, for example, P-RNTI (Paging-RNTI) may be masked to the CRC. If it is a PDCCH for system information, a system information identifier and a system information-RNTI (SI-RNTI) may be masked to the CRC. A random access-RNTI (RA-RNTI) may be masked to the CRC to indicate a random access response that is a response to the transmission of the random access preamble of the UE. Table 3 below shows examples of identifiers masked on the PDCCH.

When the C-RNTI is used, the PDCCH carries control information for a specific specific terminal, and when another RNTI is used, the PDCCH carries common control information received by all or a plurality of terminals in a cell. The base station performs channel coding on the DCI to which the CRC is added to generate coded data. The base station performs rate matching according to the number of CCEs allocated to the PDCCH format. The base station then modulates the encoded data to generate modulation symbols. The base station then maps modulation symbols to physical resource elements.

The 3rd Generation Partnership Project (3GPP) refers to the next generation wireless communication system of the LTE system as a Long Term Evolution-Advanced (LTE-A) system and is designed to enable high speed and large data transmission. The LTE-A system employs carrier aggregation (CA) technology, thereby aggregating a plurality of component carriers (CCs) to execute transmission, thereby improving transmission bandwidth of the terminal. Improve and increase the efficiency of use of the frequency. LTE-A system can use a single carrier (single carrier) used in the existing LTE Rel-8 / 9 at the same time by using a plurality of carriers (ie multi-carrier) in a bundle, it is possible to extend the bandwidth to 100MHz. In other words, the carrier defined as a component carrier (or element carrier) up to 20 MHz in the existing LTE LTE Rel-8 / 9, and up to five component carriers (CC) through a carrier aggregation technology The terminal can be used.

Current carrier aggregation (or carrier aggregation) technology mainly has the following characteristics.

(1) It supports aggregation of contiguous component carriers and supports aggregation of discontinuous component carriers.

(2) The number of carrier aggregations of the uplink and the downlink may be different. If it is to be compatible with the previous system, the uplink and the downlink may configure the same number of component carriers.

(3) A different amount of component carriers may be configured for uplink / downlink to obtain different transmission bandwidths.

(4) For the terminal, each component carrier (CC) independently transmits one transport block, and is provided with an independent hybrid automatic repeat reQuest (HARQ) mechanism.

Unlike conventional LTE systems using one carrier, carrier aggregation using a plurality of component carriers (CCs) requires a method of effectively managing component carriers. In order to efficiently manage component carriers, component carriers may be classified according to roles and features. The component carrier may be divided into a primary component carrier (PCC) and a secondary component carrier (SCC). A primary component carrier (PCC) is defined as one component carrier for each terminal as a component carrier which is the center of management of the component carrier when using multiple component carriers. Such a main component carrier (PCC) may be referred to as a primary cell (Pcell) or the like.

And other component carriers except one primary component carrier (PCC) are defined as secondary component carriers (SCC). The secondary component carrier (SCC) may be referred to as a secondary cell (Scell) or the like. The primary component carrier may serve as a core carrier for managing the aggregated total component carriers, and the remaining secondary component carriers may play a role of providing additional frequency resources to provide a high data rate. For example, the base station may be connected through the primary component carrier (RRC) for signaling with the terminal. Provision of information for security and higher layers may also be made through the primary component carrier. In fact, when only one component carrier exists, the corresponding component carrier will be the main component carrier, and in this case, it can play the same role as the carrier of the existing LTE system.

The base station may allocate and notify an activated component carrier (ACC) to the terminal among a plurality of component carriers. As a result, the UE can know the active component carrier (ACC) assigned to it. In the present invention, the terminal needs to report a power headroom report (PHR) to the base station for each carrier in an active component carrier (ACC) assigned thereto. However, for an unscheduled carrier among one or more active component carriers assigned to the terminal, the terminal may send a virtual power headroom report (virtual PHR).

Hereinafter, a method of signaling a power control message to a terminal by the base station so that the terminal can report the power headroom (PH) according to the carrier aggregation technology employed in the LTE-A system will be described.

According to the current 3GPP standards (3GPP TS 36.321, 36.213, 36.133), the media access control (MAC) control element transmitted by the terminal includes a buffer status report (BSR) control element and a power headroom report. (Power Headroom Report, PHR) control element. The buffer status report control element is generated by a buffer status report process, and reports the amount of data in the uplink buffer of the terminal to the base station providing the service. The power headroom report (PHR) control element is generated by a power headroom report process, and the terminal reports the current power state (power remaining amount) to the base station. The base station can effectively distribute radio resources and execute scheduling decisions according to information such as uplink buffer status and power headroom reported by the terminal.

In general, the terminal may trigger (or generate) a power headroom report (PHR) when the following event occurs.

(1) When the timer prohibitPHR-Timer prohibiting the power headroom report (PHR) is stopped and the change of the transmission path loss using the terminal is greater than the preset value DL_PathlossChange.

(2) Periodic Report Timer When the PeriodicPHR-Timer expires, this situation is referred to as Periodic Power Headroom Report (Periodic PHR). After generating the power headroom report, if the terminal has the newly transmitted uplink transmission resources distributed by the base station in the current transmission time interval, the corresponding power headroom report control element from the power headroom value obtained at the physical layer Create a timer and restart the timer prohibitPHR-Timer.

In addition, if the generated is a periodic power boundary headroom report, restart the periodic report timer PeriodicPHR-Timer. For the detailed operation of the power headroom report process, reference may be made to related technical standards (3GPP TS 36.321, 36.213, 36.133).

There may be two types of power headroom report (PHR) that the terminal reports to the base station. One is a type 1 PHR, which can be defined as PHR = Pcmax-P _PUSCH . Here, Pcmax is a terminal transmission maximum power value configured for each component carrier and may be expressed as including a CC index such as Pcmax, c. P _PUSCH represents a power value used to transmit a PUSCH. Type 2 PHR may be defined as PHR = Pcmax-P _PUCCH -P _PUSCH . Similarly, Pcmax is a terminal transmission maximum power value configured for each component carrier, P _PUSCH represents a power value used to transmit a PUSCH, and P _PUCCH represents a power value used to transmit a PUCCH.

In addition, in relation to reporting the PHR of the UE, a maximum power reduction (MPR) value may be considered. When requested by RAN2, triggers for PHR, whether two types of PHR are always transmitted in the same subframes or different subframes, the bit size used for the PHR, in which CC It may be discussed whether the PHR is sent. If, in RAN2, type 2 PHR may be derived as for a subframe in which the PUCCH is not actually transmitted, PUCCH format 1A is used as the reference format. When type 2 PHR is derived for the subframe in which the PUCCH is transmitted, the PUCCH format used for type 2 PHR is the PUCCH format actually transmitted.

Next, contents related to PHR in RAN 2 will be described.

There should be one dl-PathlossChange parameter for each terminal. In addition, there should be one periodicPHR-Timer timer for each terminal, and it is configured with one value, and there is one timer valid for the terminal in all CCs. The UE is allowed to transmit a PHR report on any uplink CC, for example, the PHR of CC1 may be transmitted on CC2. And only one prohibitPHR-Timer value is configured. There is one timer running per CC.

In addition, the terminal may transmit to the base station as a type 1 PHR for the PHR for the Scell. In a Pcell, if parallel PUCCH and PUSCH assignments are not supported, Type 1 PHR may be used for the Pcell and Scell. Where PHR is the same as in Rel-8 / 9. On the contrary, if parallel PUCCH and PUSCH allocation is supported, if PUCCH and PUSCH transmission is on a Pcell in this TTI, the UE can transmit a Type 1 PHR and a Type 2 PHR together with the base station to the Pcell.

If parallel PUCCH and PUSCH allocation is supported and only PUSCH transmission is on the Pcell in this TTI, the UE may transmit the Type 1 PHR and Type 2 PHR together with the Pcell to the base station or transmit only the Type 1 PHR. If parallel PUCCH and PUSCH allocation are supported and only PUCCH transmission is on the Pcell in this TTI, the UE may not transmit the PHR in the Pcell. When the PHR report is triggered, the terminal may report the PHR for all configured CC.

The configured maximum terminal output power PCMAX may be defined as shown in Equation 1 below and may be a limited value.

_{Here, P CMAX _L = MIN {P} EMAX _H - T C, P PowerClass -MPR- A-MPR - ΔT C} _{and, PCMAX_H = MIN {PEMAX _H,} P PowerClass} a, T (P _CMAX) are provided in Table 4 ( P may be defined as _CMAX tolerance) may be applied to P and P _{CMAX CMAX _L _H} individually. PEMAX_H is the value given in the IE P-Max defined in the mobile communication standard document 3GPP TS 36.214. P _PowerClass represents the maximum terminal power described without considering the tolerance. P _PowerClass may be _informed by the base station to the terminal. A-MPR may be signaled by the base station to the terminal. The ΔT _C value may be a predefined value. T _C = 1.5 dB or T _C = 0.

P _CMAX
( dBm ) Tolerance  T ( P _CMAX )
( dB ) 21 ≤ P _CMAX ≤ 23 2.0 20 ≤ P _CMAX <21 2.5 19 ≤ P _CMAX <20 3.5 18 ≤ P _CMAX <19 4.0 13 ≤ P _CMAX <18 5.0 8 ≤ P _CMAX <13 6.0 -40 ≤ P _CMAX <8 7.0

Equation 2 defines a power headroom (PH) of a valid terminal for a subframe of the index i, and corresponds to a type 1 PHR.

Here, P _CMAX represents the transmission power of the configured UE, M _PUSCH (i) is a parameter indicating the bandwidth of the PUSCH resource allocation expressed by the number of effective resource blocks for the subframe of the index i, a value assigned by the base station. P _{O _ PUSCH} (j) is the cell-specific nominal component P _{O _ NOMINAL _ PUSCH} (j) provided from the upper layer and the terminal-specific component P _{O _ UE _ PUSCH} (j) provided from the higher layer. A parameter configured as a sum, which is a value that a base station informs a terminal. α (j) is a cell-specific parameter provided by the upper layer and transmitted by the base station in 3 bits, and when j = 0 or 1, α∈ {0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1} When j = 2, α (j) = 1. α (j) is a value that the base station informs the terminal.

PL is a downlink path loss (or signal loss) estimate calculated by the terminal in dB and is represented by PL = referenceSignalPower-higher layer filteredRSRP. f (i) is a value indicating the current PUSCH power control adjustment state and may be expressed as a current absolute value or an accumulated value.

The power headroom (PH) consists of 64 levels of values 1dB apart from -23 decibels (40dB) to 40dB, and is passed from the physical layer to the upper layer. The PH MAC control element is identified by the MAC PDU subheader. An example of the power headroom (PH) reported by the terminal from the base station is shown in Table 5 below.

PH Power headroom level 0 POWER_HEADROOM_0 One POWER_HEADROOM_1 2 POWER_HEADROOM_2 3 POWER_HEADROOM_3 … … 60 POWER_HEADROOM_60 61 POWER_HEADROOM_61 62 POWER_HEADROOM_62 63 POWER_HEADROOM_63

The base station may be assigned an activated component carrier (ACC) for the terminal among the plurality of component carriers. The terminal knows the active component carrier (ACC) allocated to it in advance through signaling or the like.

Hereinafter, the contents of the PUCCH format defined in 3GPP LTE Rel-8 and uplink transmission power of the UE will be described. The PUCCH is an uplink control channel carrying uplink control information and cannot be transmitted simultaneously with the PUSCH due to a single carrier characteristic in the LTE system. However, in the LTE-A system, as a multicarrier is introduced, a specific component carrier (eg, a main component carrier or a Pcell) may be transmitted together with the PUSCH. PUCCH supports a number of formats, and the PUCCH formats supported in LTE Release 8 are shown in Table 6 below. Here, the PUCCH formats 2a and 2b support only normal CP.

To summarize the conclusions and additional discussions of the RAN1 and RAN2 described above, the base station needs to receive both the CC-specific PHR and the terminal-specific PHR from the terminal. This is because it is difficult for the base station to know the maximum power limit of the terminal only by the PHR information for each CC. That is, the base station does not know the power level for the scheduled PUSCH / PUCCH (s). The root cause is that the base station does not know the maximum power of a specific component carrier called P _{CMAX , c} constituting per CC PHR (per CC PHR). Therefore, specific methods are needed to support this. For example, the method may be a method of configuring PHR information, an operation method, a method of transmitting information of a terminal, or the like.

The present invention proposes a method for configuring PHR information, an operation method, and a method for transmitting information of a terminal in a terminal and a base station supporting a downlink / uplink multicarrier system.

The terminal may perform PH reporting to the base station as a type 1 PHR and a type 2 PHR by the CC-based PHR, and the base station may determine a resource allocation method during the next scheduling of the corresponding terminal by using the PHR information for each CC. However, it is difficult for the base station to predict the maximum power limit of the terminal based only on the type 1 PHR and the type 2 PHR of the CC-specific PHR. Due to this problem, PHR for each terminal is additionally required. However, in order for the terminal PHR to play a role, P _CMAX of Equation 3 below needs to be defined as a value known to the base station. P _CMAX may be set to a terminal specific or common value. If the base station does not know the P _CMAX value, there may still be uncertainty about whether the base station can know the maximum power limit of the terminal even if the terminal PHR is transmitted to the base station.

_{Here, P CMAX, P PUSCHc (i} ), P PUSCHc (i) values are different from Pcmax described above in a linear value (linear value). If the base station does not know the P _CMAX value, the PHR per terminal may not play a significant role in the base station to know the maximum power limit of the terminal. Alternatively, if the base station to know the P _CMAX values, for example, min {P _UEMAX, P _UMAX (power class)} of P higher layer signaling P _UEMAX system dependent maximum power level (system dependant Max. Power level) is sent to the Knowing a fixed value such as _UMAX , PHR per terminal may be meaningful in knowing the maximum power limit of the terminal. Here, P _UMAX represents the maximum terminal power with power reduction due to modulation order, network signaling value and location around the band edge, and P _UMAX is P when IE P-Max is not signaled. Same as _CMAX .

P _{CMAX , c} required when the UE calculates Type 1 PHR and Type 2 PHR of CC-specific PHR is selected by the UE from a value within a low boundary and a high boundary like P _CMAX defined in LTE rel 8/9. Will be used. This is affected by Maximum Power Reduction (MPR) (modulation class and scheduled bandwidth (i.e. resource size)), and additional MPR (Additional MPR) depending on transmission of adjacent component carriers, depending on each transmission scenario. This is because ΔT _C (delta Tolerance) (1.5 dB decrease in case of FUL_low, FUL_low + 4 MHz and FUL_high and FUL_high-4 MHz) is applied.

Since one of these three elements MPR, A-MPR, and ΔT _C (delta tolerance) is a value that the base station does not know, the base station cannot know the maximum power level for each CC of the terminal. That is, the base station does not know which transmission power level the terminal uses. For this reason, when the PHR for each terminal is needed, P _CMAX as mentioned in Equation 2 above. The value should be defined as a value known to the base station. The base station should be able to predict whether the base station 2 satisfies Equation 2 to help the base station next scheduling to solve the problem of only PHR for each CC. In the present invention, the term "terminal PHR" is used as defined in Equation 4, unlike the type 1 PHR, type 2 PH.

Where P _UEMAX Is the total maximum power of the UE, X is (1) the sum of powers of all scheduled PUSCHs, (2) the sum of all scheduled PUCCHs, (3) the sum of PUSCHs in all unscheduled Scells, and (4) scheduling It may be represented by any one of the sum of the PUCCHs of the Pcell that is not, or (5) may be represented by any combination of (1) to (4).

As described in Equation 4 and the above description, it may be defined as an operation of a power sum of scheduled PUSCHs / PUCCHs and a value known to a base station such as PUEMAX, and if information on unscheduled CCs is needed, It is also possible to configure the PHR for each UE by selectively including some / all of the power information for the unscheduled CCs.

As an embodiment of the present invention, an example of PHR transmission of a terminal will be described with reference to Equation 4 above.

In each scheduled Scell (primary cell, used as the name of the cell or CC other than the Pcell), the terminal transmits a type 1 PHR, in the Pcell (ie primary CC) the terminal is always the type A PHR and a type 2 PHR are transmitted together, and the UE-specific PHR corresponding to Equation 4 considers only the power sum of scheduled PUSCHs / PUCCHs (that is, a combination of (1) and (2)). Can be configured to transmit.

In addition, in a system in which a PUCCH is transmitted only in a Pcell, the base station should be able to know PHR information or a transmission power level of the PUCCH. This is useful for the next scheduling in terms of the maximum power of the terminal. There is a method of using a scheduled PUCCH power according to whether PUCCH is transmitted when PHR triggering, and a method of using a PUCCH power value in a predetermined reference format in a non-scheduled situation. Of course, a method of using only a reference format is possible regardless of whether PUCCH is transmitted or not. Alternatively, a method of combining the two may be possible.

In the case of the PHR for each terminal defined in Equation 4 above, the UE may always transmit or may be configured to transmit only when the Type 1 PHR and the Type 2 PHR are simultaneously transmitted. In addition, in the Pcell and the Scell, the UE transmits only the Type 1 PHR, and in the method of configuring the UE-specific PHR together with the CC-specific PHR, the UE newly defines a value obtained by subtracting the power of the PUCCH from the value known to the BS and the UE. It is also possible. PUCCH power at this time can also be configured in various combinations as mentioned above.

Hereinafter, a method of configuring PHR information when the UE transmits PHR will be described. The method of configuring the PHR information may be configured by using a combination of all the methods mentioned below. 5 is a diagram illustrating an example of a PHR MAC CE (Control Element) in Rel-8 / 9 of 3GPP LTE as an example of a mobile communication system, and FIG. 6 is a PHR MAC to be applied in 3GPP LTE Rel-10 as an example of a mobile communication system. It is a figure which shows the structural example of CE.

First, the terminal may use the existing PHR MAC CE format PHR per terminal. The PHR for each terminal may be regardless of which uplink CC the terminal transmits. As can be seen in FIG. 5, 6 bits of the 8 bits of the existing PHR are used for PH classification and 2 bits remain as a reserved room (R). Therefore, if a distinction is needed between the formats such as the PHR of the LTE rel8 / 9 terminal, the terminal may distinguish between the PH of the LTE rel8 / 9 terminal and the PHR for each terminal by using the remaining 2 bits or 1 bit. Can be.

In this case, the type 1 PHR and the type 2 PHR may be defined in a new type of PHR MAC CE format as shown in FIG. 6. This is to support the case where it is transmitted from another uplink CC. When the PHR information is configured as shown in FIG. 6, 16 bits are used, and the UE is used to distinguish one type (a field indicated by 'T') of the PHR type (that is, whether it is a type 1 PHR or a type 2 PHR). , 3 bits (field marked 'cell index') can be used for identifying CC index. Of course, it is also possible to extend the number of CC using the reserved bit (field indicated by 'R').

In summary, when the PHR transmitted from the terminal to the base station is composed of a plurality of combinations of type 1 PHR, type 2 PHR, and PHR for each terminal, the PHR configuration for each terminal may be used in the form of a partial modification of FIG. 5 or 5. The CC-specific PHR configuration can be used as the structure shown in FIG. Alternatively, in the case where the PHR for each terminal and the PHR for each CC are used only in the form of FIG. 6, the terminal increases the number of bits for PHR type classification to 2 bits to configure the type 1 PHR, type 2 PHR, and PHR for each terminal. Can be transmitted to the base station. In this case, the cell index field (ie, CC index field) of the PHR for each terminal may be replaced with a reserved bit or used for other purposes. In addition, assuming that cross-carrier scheduling is not applied to a PHR, a type 1 PHR, a type 2 PHR, and a terminal using 2 bit reserved bits of the existing 8 bit PHR of FIG. 5. PHR can be used separately.

FIG. 7 is a diagram illustrating another configuration example of PHR MAC CE to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system.

As shown in FIG. 7, 3GPP LTE Rel-10 PHR MAC CE may be configured. Although the amount of information is increased to 16 bits compared to the conventional one, two types of PH information can be configured with one PHR MAC CE. Referring to FIG. 7, the CC index is composed of 3 bits (a field indicated by 'cell'), and thus the UE may transmit a base station to distinguish up to eight UL CCs (UL CCs). If the CC index is UL primary CC (UL Primary CC), if the type 1 PHR and type 2 PHR should be sent at the same time, it can be configured in a predetermined method for PH1 and PH2. For example, the terminal may include the type 1 PHR information in the 'PH1' field, and include the type 2 PHR information in the 'PH2' field to transmit to the base station.

In a CC that is not a primary UL CC (ie, a Scell corresponding to a CC in which the UE may only transmit a Type 2 PHR), the UE may transmit the Type 2 PHR only in one of PH1 or PH 2, One field (eg PH1) can be left blank. Alternatively, instead of leaving PH1 empty, PHR information for each terminal may be configured to be transmitted to the base station in an empty place when the PH of the Scell is configured. In FIG. 7, the 'R' field may indicate a reserved bit, the 'Cell' field may indicate a CC index, and the PH field may indicate a type 1 PHR and type 2 PHR information.

8 is a diagram illustrating an example of PHR MAC CE format 1 for a Pcell to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system, and FIG. 9 is a diagram for Scell to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system. FIG. 1 shows an example of a PHR MAC CE format 2. FIG.

The PHR formats shown in FIGS. 8 and 9 are divided into Pcell and Scell. The UE needs to transmit two different types of PHR information simultaneously or separately in the Pcell, and may use the PHR MAC CE format 1 shown in FIG. 8. On the contrary, since the UE does not need to transmit both the type 1 PHR and the type 2 PHR in the Scell, the UE can use the PHR MAC CE format 2 configured as shown in FIG. 9 because the UE needs to transmit the PHR value for each CC. In FIG. 9, the UE uses 2 bits (a field indicated by 'R'), which is a reserved bit in 3GPP LTE Rel-8 / 9, for CC index classification so that the base station can easily distinguish it even when transmitted from different uplink CCs. Can be. This supports only up to five uplink CCs. In this case, the PHR information for each terminal may use a partially modified form of FIG. 5 or FIG. 5.

FIG. 10 is a diagram illustrating another configuration example of a PHR MAC CE format to be applied in 3GPP LTE Rel-10, which is an example of a mobile communication system.

The configuration of the PHR MAC CE format shown in FIG. 10 is modified by partially modifying the configuration of the PHR MAC CE format shown in FIG. For example, the "R" field has grown to 2 bits and the "cell" field has shrunk to 2 bits. That is, the PHR MAC CE format of FIG. 10 is composed of 16 bits, each of reserved bits (fields indicated by 'R') and CC index bits (fields indicated by 'cell'), each of two bits, and the positions thereof are composed of various combinations. can do. In addition, PH1 and PH2 may be defined and used in a predetermined method when transmitting a PHR defined as a type 1 PHR or a type 2 PHR in a CC (for example, a PCC or a Pcell) in which a PUCCH is transmitted. In the CCs (eg, SCC or Scell) transmitting only Type 2 PHR, the UE uses only one of the PH1 field and the PH 2 field by a predetermined method, and one field is left empty (for example, PH1), or It is also possible to include the PHR for each terminal in the empty field and transmit the same.

Since there may be no scheduled PUSCH / PUCCH when defining Type 1 PHR / Type 2 PHR or additional types in the formats constituting all 3GPP LTE Rel-10 PHR MAC CEs, the UE may be referred to as a reference format. In addition, the base station and the terminal may configure the PH using a PHR MAC CE format of a predetermined format. An indicator (1 bit or more) that distinguishes this may be included in the PHR configuration. Then, the base station confirms whether the reference format is used through the indicator and uses it to determine the next scheduling. In this case, the indicator may use, for example, a reserved bit (a field indicated by 'R') in the proposed methods.

The logical channel ID (LCID) for the PHR of each CC may be used by applying a CC specific or UE common method.

In summary, only one PHR MAC CE format may be defined and used, or a plurality of PHR MAC CE formats may be defined and used. For configured CCs, when PHR triggering occurs, the UE should perform PHR reporting. In this case, the UE may perform PHR reporting only when a PUSCH is allocated to at least one uplink CC among the configured CCs. That is, when PHR triggering occurs, if PUSCH transmission does not occur in at least one CC among the configured CCs, the UE does not perform PHR reporting. In this case, the UE may not report both PHR per UE and PHR per CC. In addition, even in the above situation, the terminal should transmit the PHR for each terminal. That is, when more than one PUSCH is transmitted, the terminal transmits the terminal PHR. This helps in the next scheduling of the base station in multiple uplink CCs.

When there are multiple configured CCs and PHR triggering occurs, it may be desirable to improve system performance by sending PHR for all configured CCs. However, since the PH information is basically transmitted together during the PUSCH uplink transmission, when the scheduled PUSCH is relatively small, the control overhead increases, which may make it difficult to transmit at once. Whether to report only PH scheduled CC or PHR for all CCs as a function of the number of scheduled PUSCH and the number of configured CC can be determined between the UE and the base station.

Alternatively, a method of transmitting a reference PHR and implicitly / explicitly configuring a difference from the remaining CCs in addition to the above-described format format may be reported to the base station due to the above information increase problem.

Alternatively, the terminal may define a compact PHR MAC CE format to transmit with fewer bits than the existing PHR or transmit PHR for multiple CCs with the same number of bits.

Alternatively, the terminal may omit PHR transmission to the Scell. Alternatively, only when it is necessary to transmit PHR to one CC, it may be decided not to transmit PHR for a CC other than the corresponding CC, or in this case, to follow the same PHR transmission procedure and method as the existing Rel-8.

A description will be given of the timing point at which the terminal reports the PHR or MPR (hereinafter, MPR and A-MPR) values for each terminal to the base station. This aims to minimize uplink scheduling overhead. Among the above, there is a part dealing with the information on the PHR transmission method when the PHR triggering occurs. It has been described that the PHR reporting of the UE is possible only when transmitting at least one PUSCH among several uplink CCs, and the information to be sent is a method of transmitting PHR per CC for all CCs and an actually allocated CC. We mentioned that there is a way to send only PHRs for the fields. However, in some cases, it may be difficult for the terminal to send several types of PHR. In order to solve this problem, a time point for transmitting a PHR for each terminal may be defined as the following case.

First, the terminal may transmit the PHR per terminal when the MPR is changed. In this case, the UE may report the MPR to the base station for all, some, or specific uplink CCs. In this case, it is possible to reduce the overhead when the MPR is changed to static / semi-static. In this case, the PHR information for each terminal may be indicated through a physical layer or a higher layer.

In the second case, the terminal may transmit the PHR for each terminal to the base station when the MPR is changed and the PHR for each CC is transmitted. This may be the case when the MPR is changed in the past including the time when the CC-specific PHR is transmitted.

As a third case of transmitting a PHR for each terminal, the terminal may transmit the PHR for each terminal when simultaneous transmission occurs in two or more uplink CCs. Even in this case, the UE may report the MPR to the base station for all, some, or specific uplink CCs. Similarly, the overhead can be reduced if the MPR is static or semi-static. In this case, the PHR information for each terminal may be indicated through a physical layer or a higher layer. In addition, even when the MPR is changed in the past when the simultaneous transmission occurs in two or more uplink CCs, the terminal may transmit the PHR for each terminal to the base station.

For example, suppose a transmission occurs together with a PUSCH in CC1 and a PUSCH in CC2. In a situation where a UE transmits a PUSCH and a PUCCH in a Pcell (primary CC) and a PUSCH can be transmitted in an Scell, when the UE transmits only a PUCCH in a Pcell but does not report PHR, PHR occurs only in the Scell. On the contrary, when the terminal always sends Type 1 PHR and Type PHR 2, it is meaningful to transmit the PHR for each terminal even though only PUCCH transmission.

In addition to the method of transmitting the PHR for each terminal, the terminal may report the MPR value generated in each CC to the base station. For example, assume that there are two uplink CCs (CC 1 and CC 2). Here, P1 is CC 1 total power, PHR 1 is the PH of CC 1, MPR 1 is the total MPR of CC 1, P2 is CC 2 total power, PHR 2 is the PH of CC 2, MPR 2 is the total of CC 2 Let's call it MPR. Then, the relationship as shown in the following expression (5) is established.

Here, Pcmax, 1 is the maximum power configured in the terminal in CC 1, Pcmax, 2 is the maximum power configured in the terminal in CC 2.

Through the relationship as shown in Equation 5, the base station can predict the power situation of the terminal by using the MPR value instead of the PHR per terminal. Therefore, the terminal may report MPR1 + MPR2 to the base station instead of for each terminal. At this time, the MPR value of the individual CCs may be transmitted or reported as the sum of the MPR values of the CCs. The time point at which the UE transmits the MPR may be transmitted together with the method of transmitting the MPR values whenever the MPR values change and the time of transmitting the PHR for each CC after the MPR value is changed. In this case, transmitting the MPR transmission together with the PHR for each CC reuses an existing method transmitted through a higher layer. Alternatively, the MPR transmission may be fed back through a physical layer.

As described above, according to the embodiments of the present invention, the power headroom of a terminal required for a base station and a terminal supporting a downlink / uplink multicarrier system is configured, and uplink CC-specific PHR information and terminal-specific PHR By efficiently organizing the information, resource management of the base station is facilitated. In addition, the maximum power limitation situation of the terminal can be minimized.

The embodiments described above are the components and features of the present invention are combined in a predetermined form. Each component or feature is to be considered optional unless stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to combine some of the components and / or features to form an embodiment of the invention. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is obvious that the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship in the claims or as new claims by post-application correction.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

Claims (15)

In a method for transmitting a power headroom report (PHR) in a terminal in a wireless communication system supporting a plurality of component carriers (Component Carrier),
Transmitting at least one component carrier-specific PHR information and information on a maximum power reduction (MPR) of the terminal to a base station;
The PHR information for each of the at least one component carrier includes component carrier index information, and the MPR information of the terminal is a sum of the at least one component carrier MPR value or the at least one component carrier MPR value, power headroom report. Transmission method. The method of claim 1,
The at least one component carrier-specific PHR information further includes PHR type information. The method of claim 2,
The PHR type includes a first type PHR and a second type PHR,
The first type PHR and the second type PHR are sequentially represented by the following equations A and B, respectively:
Equation A
Type 1 PHR = Pcmax-P _PUSCH
Equation B
Type 2 PHR = Pcmax-P _PUCCH -P _PUSCH
Here, Pcmax is a transmission maximum power value configured in the terminal for each component carrier, P _PUSCH represents a power value used to transmit the PUSCH, P _PUCCH represents a power value used to transmit the PUCCH. The method of claim 3, wherein
The PHR information for the secondary cell (Scell) corresponding to the secondary component carrier (Secondary CC) of the at least one component carrier, the second type PHR, power headroom report transmission method. The method of claim 3, wherein
PHR information on a primary cell (Pcell) corresponding to a primary carrier (Primary CC) of the at least one component carrier includes the first type PHR and the second type PHR, power headroom report transmission method . The method of claim 1,
The PHR information for each of the at least one component carrier or the maximum power reduction (MPR) information of the terminal is transmitted when a PUSCH transmission occurs in a specific component carrier among the at least one component carrier. The method of claim 1,
Transmitting the PHR information for each terminal to the base station;
The PHR information for each terminal corresponds to a sum of powers of scheduled physical uplink shared channels (PUSCHs), sums of scheduled physical uplink control channels (PUCCHs), and unscheduled secondary component carriers at predefined total maximum powers of the terminals. A power headroom report transmission method corresponding to a value obtained by subtracting any one of a sum of PUSCHs in an Scell and a sum of PUCCHs of a Pcell corresponding to an unscheduled primary component carrier. The method according to claim 2 or 7,
The PHR information for each of the at least one component carrier and the PHR information for each terminal are transmitted through the same PHR MAC Control Element (CE) format. The method of claim 8,
The PHR MAC CE format includes a field for distinguishing PHR information for each component carrier and PHR information for each terminal and a field for a PHR value. The method of claim 9,
The PHR MAC CE format for the PHR information for each of the at least one component carrier further includes a field including the component carrier index information, and the field for the PHR value includes at least one of a first type PHR value and a second type PHR value. A method for transmitting a power headroom report, comprising one. The method of claim 1,
Wherein the at least one component carrier is all component carriers assigned to the terminal or is a scheduled component carrier. A terminal device for transmitting a power headroom report (PHR) in a wireless communication system supporting a plurality of component carriers,
It includes a transmitter for transmitting at least one component carrier PHR information, PHR information for each terminal or maximum power reduction (MPR) information of the terminal to the base station,
The PHR information for each of the at least one component carrier includes component carrier index information, and the MPR information of the terminal is a sum of the at least one component carrier MPR value or the at least one component carrier MPR value. The method of claim 12,
The PHR information for each of the at least one component carrier further includes PHR type information. The method of claim 12,
The transmitter further transmits PHR information for each terminal to a base station,
The PHR information for each of the at least one component carrier and the PHR information for each terminal are transmitted through the same PHR MAC Control Element (CE CE) format. The method of claim 14,
The PHR MAC CE format includes a field for distinguishing PHR information for each component carrier and PHR information for each terminal and a field for a PHR value.

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