WO2011132960A2 - Method and apparatus for monitoring a control channel in a wireless communication system - Google Patents

Abstract

The present invention relates to a method for monitoring a PDCCH in a system that supports a carrier junction, the method comprising: receiving from a base station a first indicator that indicates at least one PDCCH monitoring component carrier among a plurality of component carriers; monitoring a plurality of candidate PDCCHs through the at least one PDCCH monitoring component carrier that is indicated by the first indicator; and receiving downlink control information through a PDCCH that has successfully performed a blind decoding among the plurality of candidate PDCCHs.

Description

Method and apparatus for monitoring control channel in wireless communication system

TECHNICAL FIELD The present disclosure relates to wireless communications, and in particular, to a method and apparatus for monitoring a control channel in a wireless communication system supporting a plurality of component carriers.

3GPP LTE (3rd Generation Partnership Project Long Term Evolution, hereinafter referred to as 'LTE'), LTE-Advanced (hereinafter referred to as 'LTE-A') communication as an example of a mobile communication system to which the contents proposed in this specification can be applied. Outline the system.

One or more cells exist in one base station. The cell is set to one of the bandwidth of 1.25MHz, 2.5MHz, 5MHz, 10MHz, 15MHz, 20MHz, etc. for one carrier to provide a downlink / uplink transmission service to multiple terminals. In this case, different cells may be configured to provide different bandwidths. The base station controls data transmission and reception for a plurality of terminals. The base station transmits downlink scheduling information for downlink data and informs the user equipment of time / frequency domain, encoding, data size, and hybrid automatic repeat and reQuest (HARQ) related information. 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.

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 is working on standardization of subsequent technologies 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 for this purpose, carrier aggregation (or carrier aggregation) or bandwidth aggregation (or bandwidth aggregation) (which achieves broadband using multiple frequency blocks) ( carrier aggregation or bandwidth aggregation) technology is used. Carrier aggregation allows the use of multiple frequency blocks as one large logical frequency band 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.

As carrier aggregation technology is adopted in the LTE-A system, which is a next-generation communication system, a method for a terminal to receive a signal from a base station or a repeater in a system supporting a plurality of carriers is required.

The present specification provides a method for signaling linkage information between a component carrier (CC) on which a PDCCH is transmitted and a component carrier (CC) on which a PDSCH and / or a PUSCH is transmitted when cross carrier scheduling is activated in a system supporting carrier conjugation. There is a purpose.

The present disclosure provides a method for monitoring a PDCCH in a system supporting carrier concatenation, the method comprising: receiving from a base station a first indicator indicating at least one PDCCH monitoring component carrier of a plurality of component carriers; Monitoring for a plurality of candidate PDCCHs on at least one PDCCH monitoring component carrier indicated by the first indicator; And receiving downlink control information through the PDCCH having successfully decoded blind among the plurality of candidate PDCCHs.

The monitoring may include performing blind decoding on the plurality of candidate PDCCHs, and performing the blind decoding may perform CRC demasking on each candidate PDCCH using a unique identifier (RNTI). do.

In addition, the downlink control information is characterized in that the downlink grant (DL grant) or uplink grant (UL grant).

In addition, the present specification is a step of receiving a second indicator from the base station indicating a PDSCH component carrier and / or a PUSCH component carrier of a plurality of component carriers; And

Receiving a PDSCH from the base station or transmitting a PUSCH to the base station through a component carrier indicated by the received second indicator.

In addition, the PDSCH component carrier and / or PUSCH component carrier is characterized in that the linkage is configured with one PDCCH monitoring component carrier.

The first and second indicators may be transmitted through an RRC message from the base station.

The method may further include receiving component carrier configuration information supported by the base station from the base station.

The component carrier configuration information may include at least one of downlink component carrier assignment information and uplink component carrier assignment information.

The downlink component carrier allocation information may further include downlink component carrier number information and index information indicating downlink component carriers, and the uplink component carrier allocation information includes uplink component carrier number information and uplink component carriers. Characterized in that it further comprises index information indicating.

The downlink and uplink component carrier assignment information may be activated downlink and uplink component carrier assignment information.

The first indicator may also include information of a PDSCH component carrier and / or a PUSCH component carrier that can be scheduled by each PDCCH monitoring component carrier indicated by the first indicator.

The information on the PDSCH component carrier and / or PUSCH component carrier may be configured in a bitmap form.

The second indicator may include information on each PDSCH component carrier indicated by the second indicator and / or a PDCCH monitoring component carrier configured with a linkage with the PUSCH component carrier.

The PDCCH monitoring component carrier information may be configured in the form of a logical index of a downlink component carrier.

The first and second indicators may be configured in an index or bitmap form indicating each component carrier.

The sizes of the first and second indicators may be determined according to the number of component carriers of at least one of downlink and uplink supported by the base station.

The first and second indicators may be transmitted from the base station when cross carrier scheduling is activated.

In addition, the present specification provides a terminal for monitoring a PDCCH in a system supporting carrier bonding, comprising: a wireless communication unit for transmitting and receiving a radio signal with an outside; And a control unit connected to the wireless communication unit, wherein the control unit controls the wireless communication unit to receive a first indicator indicating at least one PDCCH monitoring component carrier from a base station among a plurality of component carriers, and the first indicator Control to monitor a plurality of candidate PDCCHs through at least one indicated PDCCH monitoring component carrier, and receive downlink control information through a PDCCH having successfully decoded blind among the plurality of candidate PDCCHs; It characterized by controlling the wireless communication unit.

The control unit controls the wireless communication unit to receive, from the base station, a second indicator indicating a PDSCH component carrier and / or a PUSCH component carrier among a plurality of component carriers, and indicates a component carrier indicated by the received second indicator. The wireless communication unit is controlled to receive a PDSCH from the base station or to transmit a PUSCH to the base station.

In addition, the PDSCH component carrier and / or PUSCH component carrier is characterized in that the linkage is configured with one PDCCH monitoring component carrier.

In the present specification, by transmitting linkage information between a component carrier (CC) on which a PDCCH is transmitted and a component carrier (CC) on which a PDSCH and / or a PUSCH is transmitted, the terminal may transmit a corresponding PDCCH monitoring CC and a corresponding PDSCH CC and / or a PUSCH CC. Since decoding is performed only for the above, there is an effect of reducing the total number of times of blind decoding.

In addition, the present specification has the effect of reducing the power consumption (latency) of the terminal due to the reduction in the number of blind decoding as described above.

1 is a block diagram illustrating a wireless communication system.

2 is a block diagram of a terminal and a base station according to an embodiment of the present disclosure.

FIG. 3 is a diagram for explaining physical channels used in a 3GPP system and a general signal transmission method using the same. FIG.

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

FIG. 5 is a diagram illustrating a structure of downlink and uplink subframes of a 3GPP LTE system as an example of a mobile communication system. FIG.

6 illustrates a downlink time-frequency resource grid structure used in the present invention.

7 is a block diagram showing a configuration of a PDCCH.

8 illustrates an example of resource mapping of a PDCCH.

9 illustrates CCE interleaving in a system band.

10 is an exemplary diagram illustrating monitoring of a PDCCH.

FIG. 11A is a diagram illustrating a concept of managing a multicarrier by a plurality of MACs in a base station, and FIG. 11B is a diagram for explaining a concept of managing a multicarrier by a plurality of MACs in a terminal.

FIG. 12A illustrates a concept of managing a multicarrier by one MAC in a base station, and FIG. 12B illustrates a concept of managing a multicarrier by a single MAC in a terminal. .

13 illustrates an example of a multicarrier.

14 illustrates an example of cross-carrier scheduling.

15 (a) and (b) illustrate a DL CC included in a PDCCH monitoring CC set.

FIG. 11 illustrates a link method between CCs transmitting PDSCH / PUSCH. FIG.

16 illustrates an example of a CC set according to an embodiment of the present specification.

17 (a) and (b) are diagrams illustrating an example in which a link set between CC sets and CCs is set according to an embodiment of the present specification.

18 (a) and (b) illustrate a method of transmitting PDCCH monitoring CC information and a scheduled CC (PDSCH CC / PUSCH CC) information transmission method that may be scheduled in a PDCCH monitoring CC according to one embodiment of the present specification;

19 (a) to (c) are examples illustrating a logical index of a downlink component carrier (DL CC) used for PDCCH monitoring CC transmission according to an embodiment of the present specification.

20 (a) to (c) illustrate an example of transmitting a PDSCH CC / PUSCH CC bitmap and information on a PDCCH monitoring CC in each PDSCH CC / PUSCH CC according to one embodiment of the present specification;

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present 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 the 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 addition, in the following description, it is assumed that a terminal collectively refers to a mobile or fixed user terminal device such as a user equipment (UE), a mobile station (MS), and an advanced mobile station (AMS). 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, and an Access Point (AP). The repeater may be referred to as a relay node (RN), a relay station (RS), a relay, or the like.

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

1 is a block diagram illustrating a wireless communication system.

1 may be a network structure of an Evolved-Universal Mobile Telecommunications System (E-UMTS). The E-UMTS system may be referred to as Long Term Evolution (LTE) or LTE-A system. Wireless communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

Referring to FIG. 1, an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) includes a base station (BS) 20 that provides a control plane and a user plane.

The UE 10 may be fixed or mobile and may be called by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device, and the like.

The base station 20 generally refers to a fixed station communicating with the terminal 10, and may be referred to as other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), and an access point. have. One or more cells may exist in one base station 20. An interface for transmitting user traffic or control traffic may be used between the base stations 20.

Hereinafter, downlink means communication from the base station 20 to the terminal 10, and uplink means communication from the terminal 10 to the base station 20.

The base stations 20 may be connected to each other through an X2 interface. The base station 20 is connected to an Evolved Packet Core (EPC), more specifically, a Mobility Management Entity (MME) / Serving Gateway (S-GW) 30 through an S1 interface. The S1 interface supports a many-to-many-relation between the base station 20 and the MME / SAE gateway 30.

2 is a block diagram illustrating elements of a terminal and a base station.

The terminal 10 includes a control unit 11, a memory 12, and a radio communication (RF) unit 13.

The terminal also includes a display unit, a user interface unit, and the like.

The controller 11 implements the proposed function, process and / or method. Layers of the air interface protocol may be implemented by the controller 11.

The memory 12 is connected to the control unit 11 and stores a protocol or parameter for performing wireless communication. That is, it stores the terminal driving system, the application, and the general file.

The RF unit 13 is connected to the control unit 11 and transmits and / or receives a radio signal.

In addition, the display unit displays various information of the terminal, and may use well-known elements such as liquid crystal display (LCD) and organic light emitting diodes (OLED). The user interface may be a combination of a well-known user interface such as a keypad or a touch screen.

The base station 20 includes a control unit 21, a memory 22, and a radio frequency unit (RF) unit 23.

The control unit 21 implements the proposed function, process and / or method. Layers of the air interface protocol may be implemented by the controller 21.

The memory 22 is connected to the control unit 21 to store a protocol or parameter for performing wireless communication.

The RF unit 23 is connected to the control unit 21 to transmit and / or receive a radio signal.

The controllers 11 and 21 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and / or a data processing device. The memories 12 and 22 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media and / or other storage devices. The RF unit 13 and 23 may include a baseband circuit for processing a radio signal. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function. The module may be stored in the memories 12 and 22 and executed by the controllers 11 and 21.

The memories 12 and 22 may be inside or outside the controllers 11 and 21, and may be connected to the controllers 11 and 21 by various well-known means.

FIG. 3 is a diagram for describing physical channels used in a 3GPP system and a general signal transmission method using the same.

When the UE is powered on or enters a new cell, the UE performs an initial cell search operation such as synchronizing with the base station (S301). To this end, the terminal may receive a Primary Synchronization Channel (P-SCH) and a Secondary Synchronization Channel (S-SCH) from the base station to synchronize with the base station and obtain information such as a cell ID. have. Thereafter, the terminal may receive a physical broadcast channel from the base station to obtain broadcast information in a cell. Meanwhile, the terminal may receive a downlink reference signal (DL RS) in the initial cell search step to check the downlink channel state.

After the initial cell search, the UE acquires more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) according to the information on the PDCCH. It may be (S302).

On the other hand, if the first access to the base station or there is no radio resource for signal transmission, the terminal may perform a random access procedure (RACH) for the base station (steps S303 to S306). To this end, the UE may transmit a specific sequence to the preamble through a physical random access channel (PRACH) (S303 and S305), and receive a response message for the preamble through the PDCCH and the corresponding PDSCH ( S304 and S306). In the case of contention-based RACH, a contention resolution procedure may be additionally performed.

After performing the above-described procedure, the UE performs a PDCCH / PDSCH reception (S307) and a physical uplink shared channel (PUSCH) / physical uplink control channel (Physical Uplink) as a general uplink / downlink signal transmission procedure. Control Channel (PUCCH) transmission (S308) may be performed. Information transmitted by the terminal to the base station through the uplink or received by the terminal from the base station includes a downlink / uplink ACK / NACK signal, a channel quality indicator (CQI), a precoding matrix index (PMI), and a rank indicator (RI). Include. In the 3GPP LTE system, the terminal may transmit the above-described information, such as CQI / PMI / RI through the PUSCH and / or PUCCH.

4 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. 4, 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) = 3.1552 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 a SC-FDMA (Single Carrier-Frequency Division Multiple Access) symbol. 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.

FIG. 5 is a diagram illustrating the structure of downlink and uplink subframes in a 3GPP LTE system as an example of a mobile communication system.

Referring to FIG. 5A, 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 PCFICH (Physical Control Format Indicator Channel), PDCCH (Physical Downlink Control Channel), PHICH (Physical Hybrid-ARQ Indicator Channel). 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 (Not-Acknowledgement) signal for an uplink HARQ (Hybrid Automatic Repeat Request). That is, the ACK / NACK signal for the uplink data transmitted by the terminal is transmitted on the PHICH.

Hereinafter, the PDCCH which is a downlink physical channel will be briefly described.

A detailed description of the PDCCH will be described below with reference to FIGS. 7 to 10.

The base station sets a resource allocation and transmission format of the PDSCH (also referred to as a DL grant), a resource allocation information of the PUSCH (also referred to as a UL grant) through a PDCCH, a set of transmission power control commands for an arbitrary terminal and individual terminals in a group. And activation of Voice over Internet Protocol (VoIP). A plurality of PDCCHs may be transmitted in the control region, and the terminal may monitor the plurality of PDCCHs. The PDCCH consists of an aggregation of one or several consecutive Control Channel Elements (CCEs).

The PDCCH composed of one or several consecutive CCEs may be transmitted 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.

Table 1

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 transmit power control (TPC) commands for arbitrary UE groups. .

In the LTE system, a brief description will be given of a method for mapping a resource for transmitting a PDCCH by a base station.

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 RBGs not allocated to the Physical Control Format Indicator CHhannel (PCFICH) or the Physical Hybrid Automatic Repeat Request Indicator Channel (PHICH) is NREG. 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 3 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.

TABLE 2

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. Similarly, the repeater can also read control information and the like in units of R-CCE. In the LTE-A system, a resource element (RE) may be mapped in units of a relay-control channel element (R-CCE) to transmit an R-PDCCH for an arbitrary repeater.

Referring to FIG. 5B, 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.

6 illustrates a downlink time-frequency resource grid structure used in the present invention.

The downlink signal transmitted in each slot

×

Subcarriers and

It is used as a resource grid structure composed of orthogonal frequency division multiplexing (OFDM) symbols. here,

Represents the number of resource blocks (RBs) in downlink,

Represents the number of subcarriers constituting one RB,

Denotes the number of OFDM symbols in one downlink slot.

The size of depends on the downlink transmission bandwidth configured within the cell.

≤

≤

Must be satisfied. here,

Is the smallest downlink bandwidth supported by the wireless communication system.

Is the largest downlink bandwidth supported by the wireless communication system.

= 6

= 110, but is not limited thereto. The number of OFDM symbols included in one slot may vary depending on the length of a cyclic prefix (CP) and the interval of subcarriers. In case of multi-antenna transmission, one resource grid may be defined per one antenna port.

Each element in the resource grid for each antenna port is called a resource element (RE) and is uniquely identified by an index pair (k, l) in the slot.

Where k is the index in the frequency domain, l is the index in the time domain and k is 0, ...,

Has a value of -1 and l is 0, ...,

It has any one of -1.

The resource block shown in FIG. 6 is used to describe a mapping relationship between certain physical channels and resource elements. The RB may be represented by a physical resource block (PRB) and a virtual resource block (VRB). The one PRB is a time domain

Contiguous OFDM symbols and frequency domain

It is defined as two consecutive subcarriers. here

and

May be a predetermined value. E.g

and

Can be given as Table 1 below. So one PRB

×

It consists of four resource elements. One PRB may correspond to one slot in the time domain and 180 kHz in the frequency domain, but is not limited thereto.

TABLE 3

PRB is at 0 in the frequency domain

It has a value up to -1. The relation between the PRB number nPRB in the frequency domain and the resource element (k, l) in one slot is

Satisfies.

The size of the VRB is equal to the size of the PRB. The VRB may be defined by being divided into a localized VRB (LVRB) and a distributed VRB (DVRB). For each type of VRB, a pair of VRBs in two slots in one subframe are assigned together with a single VRB number nVRB.

The VRB may have the same size as the PRB. Two types of VRBs are defined, the first type being a localized VRB (LVRB) and the second type being a distributed VRB (DVRB). For each type of VRB, a pair of VRBs are allocated over two slots of one subframe with a single VRB index (hereinafter may also be referred to as VRB number). In other words, belonging to the first slot of the two slots constituting one subframe

VRBs from 0 each

Is assigned an index of any one of -1, and belongs to the second one of the two slots

VRBs likewise start with 0

The index of any one of -1 is allocated.

As described above, the radio frame structure, the downlink subframe and the uplink subframe, and the downlink time-frequency resource lattice structure described in FIGS. 2 to 4 may also be applied between the base station and the repeater.

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

7 is a block diagram showing the configuration of a PDCCH.

The base station determines the PDCCH format according to the DCI to be sent to the terminal, attaches a cyclic redundancy check (CRC) to the DCI, and unique identifier according to the owner or purpose of the PDCCH (this is called a Radio Network Temporary Identifier) Mask 710 to the CRC.

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. Alternatively, if the PDCCH is for a paging message, a paging indication identifier, for example, P-RNTI (P-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 (RARNTI) 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. TPC-RNTI may be masked to the CRC to indicate a transmit power control (TPC) command for a plurality of terminals.

If the C-RNTI is used, the PDCCH carries control information for the corresponding specific UE (called UE-specific control information), and if another RNTI is used, the PDCCH is shared by all or a plurality of terminals in the cell. (common) carries control information.

Coded DCI with CRC added to generate coded data

(720). Encoding includes channel encoding and rate matching.

The coded data is modulated to generate modulation symbols (730).

The modulation symbols are mapped to a physical resource element (RE) (740). Each modulation symbol is mapped to an RE.

8 shows an example of resource mapping of a PDCCH.

Referring to FIG. 8, R0 represents a reference signal of the first antenna, R1 represents a reference signal of the second antenna, R2 represents a reference signal of the third antenna, and R3 represents a reference signal of the fourth antenna.

The control region in the subframe includes a plurality of control channel elements (CCEs). The CCE is a logical allocation unit used to provide a coding rate according to the state of a radio channel to a PDCCH and corresponds to a plurality of resource element groups (REGs). The REG includes a plurality of resource elements. The format of the PDCCH and the number of bits of the PDCCH are determined according to the correlation between the number of CCEs and the coding rate provided by the CCEs.

One REG (denoted as quadruplet in the figure) contains four REs and one CCE contains nine REGs. {1, 2, 4, 8} CCEs may be used to configure one PDCCH, and each element of {1, 2, 4, 8} is called a CCE aggregation level.

A control channel composed of one or more CCEs performs interleaving in units of REGs and is mapped to physical resources after a cyclic shift based on a cell ID.

9 shows an example of distributing CCEs in a system band.

Referring to FIG. 9, a plurality of logically continuous CCEs are input to an interleaver. The interleaver performs a function of mixing input CCEs in REG units.

Accordingly, frequency / time resources constituting one CCE are physically dispersed in the entire frequency / time domain in the control region of the subframe. As a result, the control channel is configured in units of CCE, but interleaving is performed in units of REGs, thereby maximizing frequency diversity and interference randomization gain.

10 is an exemplary diagram illustrating monitoring of a PDCCH.

In 3GPP LTE, blind decoding is used to detect the PDCCH. Blind decoding is a method of demasking a desired identifier in a CRC of a received PDCCH (which is called a PDCCH candidate), and checking a CRC error to determine whether the corresponding PDCCH is its control channel. The UE does not know where its PDCCH is transmitted using which CCE aggregation level or DCI format at which position in the control region.

A plurality of PDCCHs may be transmitted in one subframe. The UE monitors the plurality of PDCCHs in every subframe. In this case, the monitoring means that the UE attempts to decode the PDCCH according to the monitored PDCCH format.

In 3GPP LTE, a search space is used to reduce the burden of blind decoding. The search space may be referred to as a monitoring set of the CCE for the PDCCH. The UE monitors the PDCCH in the corresponding search space.

The search space is divided into a common search space and a UE-specific search space. The common search space is a space for searching for a PDCCH having common control information. The common search space includes 16 CCEs up to CCE indexes 0 to 15 and supports a PDCCH having a CCE aggregation level of {4, 8}. However, PDCCHs (DCI formats 0 and 1A) carrying UE specific information may also be transmitted in the common search space. The UE-specific search space supports a PDCCH having a CCE aggregation level of {1, 2, 4, 8}.

Table 4 below shows the number of PDCCH candidates monitored by the UE.

Table 4

The size of the search space is determined by Table 4, and the starting point of the search space is defined differently from the common search space and the terminal specific search space. The starting point of the common search space is fixed irrespective of the subframe, but the starting point of the UE-specific search space is for each subframe according to the terminal identifier (eg, C-RNTI), the CCE aggregation level and / or the slot number in the radio frame. Can vary. When the start point of the terminal specific search space is in the common search space, the terminal specific search space and the common search space may overlap.

At the aggregation level LL {1,2,3,4}, the search space S ^(L) k is defined as a set of PDCCH candidates. The CCE corresponding to the PDCCH candidate m of the search space S ^(L) k is given as follows.

Equation 1

Where i = 0,1, ..., L-1, m = 0, ..., M ^(L) -1, NCCE, k can be used to transmit the PDCCH in the control region of subframe k. The total number of CCEs. The control region includes a set of CCEs numbered from 0 to N _{CCE, k} −1. M ^(L) is the number of PDCCH candidates at CCE aggregation level L in a given search space. In the common search space, Y _k is set to zero for two aggregation levels, L = 4 and L = 8. In the UE-specific search space of the aggregation level L, the variable Y _k is defined as follows.

Equation 2

Where Y ₋₁ = n _RNTI ≠ 0, A = 39827, D = 65537, k = floor (n _s / 2), n _s is a slot number in a radio frame.

When the UE monitors the PDCCH using the C-RNTI, a DCI format and a search space to be monitored are determined according to a transmission mode of the PDSCH.

Table 5 below shows an example of PDCCH monitoring configured with C-RNTI.

Table 5

Hereinafter, a multiple carrier system will be described.

The 3GPP LTE system supports a case where the downlink bandwidth and the uplink bandwidth are set differently, but this assumes one component carrier (CC).

This means that 3GPP LTE is supported only when the bandwidth of the downlink and the bandwidth of the uplink are the same or different in the situation where one CC is defined for the downlink and the uplink, respectively. For example, the 3GPP LTE system supports up to 20MHz and may be different in uplink bandwidth and downlink bandwidth, but only one CC is supported in the uplink and the downlink.

Spectrum aggregation (or bandwidth aggregation, also known as carrier aggregation) supports a plurality of CCs. Spectral aggregation is introduced to support increased throughput, to prevent cost increases due to the introduction of wideband radio frequency (RF) devices, and to ensure compatibility with existing systems. For example, if five CCs are allocated as granularity in a carrier unit having a 20 MHz bandwidth, a bandwidth of up to 100 MHz may be supported.

Spectral aggregation can be divided into contiguous spectral aggregation where aggregation is between successive carriers in the frequency domain and non-contiguous spectral aggregation where aggregation is between discontinuous carriers. The number of CCs 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 component carrier may be referred to as a 'cell'.

'Cell' means a combination of downlink resources and optionally uplink resources. The linking between the carrier frequency of the downlink resources and the carrier frequency of the uplink resources can be known as system information transmitted through the downlink resources.

That is, a 'cell' may mean a pair of a downlink component carrier and an uplink component carrier or only a downlink component carrier. Here, the uplink component carrier refers to a component carrier in which a linkage is set with the downlink component carrier.

That is, 'cell' may be used as a concept for a pair of DL CC and UL CC or as a term meaning DL CC.

Also, the term 'cell' should be distinguished from 'cell' as an area covered by a base station that is generally used. Hereinafter, a 'cell' and a component carrier CC may be used interchangeably, and in this case, the expression 'cell' refers to the component carrier CC described above.

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

The configuration of a physical layer (PHY) and layer 2 (layer 2 (MAC)) for transmission for a plurality of uplink or downlink carrier bands allocated from the point of view of an arbitrary cell or terminal is illustrated in FIG. 11. And as shown in FIG. 12.

FIG. 11A illustrates a concept of managing a multicarrier by a plurality of MACs in a base station, and FIG. 11B illustrates a concept of managing a multicarrier by a plurality of MACs in a terminal.

As shown in (a) and (b) of FIG. 11, each carrier may be controlled 1: 1 by each MAC. In a system supporting multiple carriers, each carrier may be used contiguously or non-contiguous. This can be applied to the uplink / downlink irrespective. The TDD system is configured to operate N multiple carriers including downlink and uplink transmission in each carrier, and the FDD system is configured to use multiple carriers for uplink and downlink, respectively. In the case of the FDD system, asymmetric carrier merging may be supported in which the number of carriers and / or the bandwidth of the carriers are merged in uplink and downlink.

FIG. 12A illustrates a concept of managing a multicarrier by a single MAC in a base station, and FIG. 12B illustrates a concept of managing a multicarrier by a single MAC in a terminal. .

12 (a) and 12 (b), one MAC manages and operates one or more frequency carriers to perform transmission and reception. Frequency carriers managed in one MAC do not need to be contiguous with each other, which is advantageous in terms of resource management. In FIGS. 12A and 12B, one PHY means one component carrier for convenience. Here, one PHY does not necessarily mean an independent radio frequency (RF) device. In general, one independent RF device means one PHY, but is not limited thereto, and one RF device may include several PHYs.

In addition, a series of physical downlink control channels for transmitting control information of L1 / L2 control signaling generated from the packet scheduler of the MAC layer to support the configuration of FIGS. 12A and 12B. channel, PDCCH) may be transmitted by mapping to a physical resource in an individual component carrier.

In this case, in particular, the PDCCH for channel allocation or grant-related control information related to PDSCH or PUSCH (Physical Uplink Shared Channel) transmission unique to each UE is classified and encoded according to component carriers to which the corresponding physical shared channel is transmitted. It can be generated as a PDCCH. This is referred to as separate coded PDCCH. Alternatively, control information for physical shared channel transmission of various component carriers may be configured and transmitted as one PDCCH, which is referred to as a joint coded PDCCH.

In order to support downlink or uplink carrier aggregation, a base station is configured such that a PDCCH and / or PDSCH for transmitting control information and / or data transmission can be transmitted uniquely for a specific terminal or repeater, or the PDCCH And / or component carriers that are subject to measurement and / or reporting as preparation for performing connection establishment for PDSCH transmission. This is expressed as component carrier allocation for any purpose.

In this case, when the base station controls the component carrier allocation information in the L3 RRM (radio resource management), the RRC signaling (terminal-specific or repeater-specific RRC signaling) unique to a series of terminals or repeaters according to dynamic characteristics of the control (dynamic) It may be transmitted through the L1 / L2 control signaling or through a series of PDCCHs or through a series of dedicated physical control channels for transmitting only this control information.

13 shows an example of a multicarrier.

Although there are three DL CCs and three UL CCs, the number of DL CCs and UL CCs is not limited. PDCCH and PDSCH are independently transmitted in each DL CC, and PUCCH and PUSCH are independently transmitted in each UL CC.

Hereinafter, a multiple carrier system refers to a system supporting multiple carriers based on spectral aggregation, as described above.

Adjacent spectral and / or non-adjacent spectral aggregation may be used in a multi-carrier system, and either symmetric or asymmetric aggregation may be used.

In a multi-carrier system, linkage between a DL CC and a UL CC may be defined. The linkage may be configured through EARFCN information included in the downlink system information, and is configured using a fixed DL / UL Tx / Rx separation relationship. The linkage refers to a mapping relationship between a DL CC through which a PDCCH carrying an UL grant is transmitted and a UL CC using the UL grant.

Alternatively, the linkage may be a mapping relationship between a DL CC (or UL CC) in which data for HARQ is transmitted and a UL CC (or DL CC) in which HARQ ACK / NACK signal is transmitted. The linkage information may be informed to the terminal by the base station as part of a higher layer message or system information such as an RRC message. The linkage between the DL CC and the UL CC may be fixed but may be changed between cells / terminals.

The split coded PDCCH means that the PDCCH can carry control information such as resource allocation for PDSCH / PUSCH for one carrier. That is, the PDCCH and PDSCH, the PDCCH and the PUSCH correspond to 1: 1 respectively.

A joint coded PDCCH means that one PDCCH can carry resource allocation for PDSCH / PUSCH of a plurality of CCs. One PDCCH may be transmitted through one CC or may be transmitted through a plurality of CCs.

Hereinafter, for convenience, an example of split coding based on the downlink channel PDCCH-PDSCH will be described. However, this may also be applied to the relationship of PDCCH-PUSCH.

In a multi-carrier system, CC scheduling is possible in two ways.

The first is that a PDCCH-PDSCH pair is transmitted in one CC. This CC is called a self-secheduling CC. In addition, this means that the UL CC on which the PUSCH is transmitted becomes the CC linked to the DL CC on which the corresponding PDCCH is transmitted.

That is, the PDCCH allocates PDSCH resources on the same CC or allocates PUSCH resources on a linked UL CC.

Second, regardless of the DL CC on which the PDCCH is transmitted, the DL CC on which the PDSCH is transmitted or the UL CC on which the PUSCH is transmitted is determined. That is, the PUSCH is transmitted on a DL CC in which the PDCCH and the PDSCH are different from each other, or on a UL CC not linked with the DL CC in which the PDCCH is transmitted. This is called cross-carrier scheduling.

The CC on which the PDCCH is transmitted may be referred to as a PDCCH carrier, a monitoring carrier, or a scheduling carrier, and the CC on which the PDSCH / PUSCH is transmitted may be referred to as a PDSCH / PUSCH carrier or a scheduled carrier.

Cross-carrier scheduling may be activated / deactivated for each terminal, and the terminal on which cross-carrier scheduling is activated may receive a DCI including CIF. The UE may know which scheduled CC the PDCCH received from the CIF included in the DCI is control information.

The DL-UL linkage predefined by cross-carrier scheduling may be overriding. That is, cross-carrier scheduling may schedule a CC other than the linked CC regardless of the DL-UL linkage.

14 shows an example of cross-carrier scheduling.

It is assumed that DL CC # 1 and UL CC # 1 are linked, DL CC # 2 and UL CC # 2 are linked, and DL CC # 3 and UL CC # 3 are linked.

The first PDCCH 1401 of the DL CC # 1 carries the DCI for the PDSCH 1402 of the same DL CC # 1. The second PDCCH 1411 of the DL CC # 1 carries the DCI for the PDSCH 1412 of the DL CC # 2. The third PDCCH 1421 of the DL CC # 1 carries the DCI for the PUSCH 1422 of the UL CC # 3 that is not linked.

For cross-carrier scheduling, the DCI of the PDCCH may include a carrier indicator field (CIF). CIF indicates a DL CC or UL CC scheduled through DCI. For example, the second PDCCH 1411 may include a CIF indicating DL CC # 2. The third PDCCH 1421 may include a CIF indicating the UL CC # 3.

Alternatively, the CIF of the third PDCCH 1421 may be notified of the CIF value corresponding to the DL CC, not the CIF value corresponding to the UL CC.

That is, the CIF of the third PDCCH 1421 may indicate the DL CC # 3 linked with the UL CC # 3, thereby indirectly indicating the UL CC # 3 scheduled by the PUSCH. This is because if the DCI of the PDCCH includes the PUSCH scheduling and the CIF indicates the DL CC, the UE may determine that the PUSCH is scheduled on the UL CC linked with the DL CC. Through this, it is possible to indicate a larger number of CCs than a method of notifying all DL / UL CCs using a CIF having a limited bit length (for example, 3 bit length CIF).

A UE using cross-carrier scheduling needs to monitor PDCCHs of a plurality of scheduled CCs for the same DCI format in a control region of one scheduling CC. For example, if a transmission mode of each of the plurality of DL CCs is different, a plurality of PDCCHs for different DCI formats may be monitored in each DL CC. Even if the same transmission mode is used, if the bandwidth of each DL CC is different, a plurality of PDCCHs can be monitored because the payload size of the DCI format is different under the same DCI format.

As a result, when cross-carrier scheduling is possible, the UE needs to monitor PDCCHs for the plurality of DCIs in the control region of the monitoring CC according to the transmission mode and / or bandwidth for each CC. Therefore, it is necessary to configure the search space and PDCCH monitoring that can support this.

First, in the multi-carrier system, the following terms are defined.

UE DL CC set: a set of DL CCs scheduled for the UE to receive PDSCH

UE UL CC set: a set of UL CCs scheduled for the UE to transmit a PUSCH

PDCCH monitoring set: A set of at least one DL CC that performs PDCCH monitoring. The PDCCH monitoring set may be the same as the UE DL CC set or may be a subset of the UE DL CC set. The PDCCH monitoring set may include at least one of DL CCs in the UE DL CC set. Alternatively, the PDCCH monitoring set may be defined separately regardless of the UE DL CC set. The DL CC included in the PDCCH monitoring set may be configured to always enable self-scheduling for the linked UL CC.

The UE DL CC set, the UE UL CC set, and the PDCCH monitoring set may be set to cell-specific or UE-specific.

When cross-carrier scheduling is not activated in the carrier aggregation system, it means that the PDCCH monitoring CC set is always the same as the UE-specific DL CC set. In this case, the PDCCH monitoring CC set does not need to be indicated through separate signaling.

On the other hand, when cross-carrier scheduling is activated, the PDCCH monitoring CC set should be defined within the UE-specific DL CC set. Therefore, in this case, separate signaling for the PDCCH monitoring CC set may be necessary.

15 (a) and (b) show a link method between a DL CC included in a PDCCH monitoring CC set and a CC transmitting a PDSCH / PUSCH. 15 (a) and (b) assume that all DL CCs are paired with UL CCs.

[Option 1]

Referring to FIG. 15A, Method 1 is a method in which each CC (hereinafter, referred to as PDSCH / PUSCH CC) for transmitting PDSCH / PUSCH is scheduled through one DL CC. That is, the UE needs to monitor only one DL CC for the PDSCH / PUSCH CC. In a DL CC having a CIF, the UE monitors a PDCCH, and the PDCCH of the DL CC may be scheduled for at least one of a PDSCH for the same DL CC and / or a PUSCH of an UL CC linked to the DL CC.

[Option 2]

Referring to FIG. 15B, Method 2 is a method in which a PDSCH / PUSCH CC may be scheduled through one or more DL CCs. The PDSCH / PUSCH CC may be scheduled through only one DL CC in each subframe, but may be scheduled through different DL CCs in different subframes. In a DL CC having a CIF in which a UE monitors a PDCCH, the PDCCH may be scheduled for at least one of a PDSCH of the same DL CC and / or a PUSCH of a linked UL CC. Method 2 does not increase the number of blind decoding of the PDCCH and / or the CRC false detection rate of the PDCCH compared to a system without CIF.

If the UE assumes 12 blind decoding attempts in a common search space of each CC, in case of non cross-carrier scheduling, the maximum number of blind decoding attempts per CC is 44 times. do. In the case of cross-carrier scheduling, the maximum number of blind decoding attempts can be calculated as follows.

Equation 3

In Equation 3, M represents the number of DL CCs of the PDCCH monitoring CC set.

Each DL CC of the PDCCH monitoring CC set is i = 0, 1,... N (i) represents the number of DL CCs that can be scheduled from DL CC i.

For example, assume that there are two DL CCs (hereinafter referred to as PDCCH monitoring DL CCs) in a PDCCH monitoring CC set and four CCs (that is, PDSCH / PUSCH CCs) transmitting PDSCH / PUSCH. In this case, it is assumed that the size of the common search space of the PDCCH monitoring DL CC for the PDSCH / PUSCH CC is the same as that of the non-cross carrier scheduling.

In the case of Method 1, since the UE repeats blind decoding two PDCCH monitoring DL CCs twice for two PDSCH / PUSCH CCs, the maximum number of blind decoding attempts is 2 × 2 × 44 = 176. On the other hand, in the case of method 2, since the UE needs to blind decode two PDCCH monitoring DL CCs for four PDSCH / PUSCH CCs, the maximum number of blind decoding attempts is 4 × 2 × 44 = 352 times. That is, Method 2 should attempt a much larger number of blind decoding than Method 1.

As shown in FIG. 15 (a) (linkage option 1), each scheduled CC (PDSCH / PUSCH CC) may be scheduled in only one scheduling CC (PDCCH monitoring CC). Has the potential to

Hereinafter, in the present specification, when cross-carrier scheduling is activated, a signaling method for supporting the form of linkage method 1 shown in FIG. 15 (a) will be described in detail.

16 illustrates an example of a CC set according to an embodiment of the present specification.

If there is a UE DL / UL CC set and a PDCCH monitoring set (PDCCH monitoring CC (s)) for each UE, a PDCCH-PDSCH and a PDCCH-PUSCH are included between the CCs included in the UE DL / UL CC set and the PDCCH monitoring set. Linkage can be set.

Referring to FIG. 16, four DL CCs (DL CC # 1, # 2, # 3, # 4) as the UE DL CC set, two UL CCs (UL CC # 1, # 2) as the UE UL CC set, Assume that two DL CCs (DL CC # 2, # 3) are allocated to an arbitrary UE as a PDCCH monitoring set.

In this case, DL CC # 2 in the PDCCH monitoring set transmits PDCCH for PDSCH and PUSCH to be transmitted to DL CC # 1, # 2 of the UE DL CC set, and UL CC # 1 of the UE UL CC set, and PDCCH monitoring set The DL CC # 3 in the UE may transmit DL CC # 3, # 4 of the UE DL CC set, a PDSCH to be transmitted to UL CC # 2 of the UE UL CC set, and a PDCCH for the PUSCH.

That is, as shown in FIG. 16, vertically hatched CCs (DL CC # 1, DL CC # 2, UL CC # 1) have a linkage of PDCCH and PDSCH / PUSCH transmission, and horizontally hatched CCs (DL CC # 3, DL CC # 4, UL CC # 2) may have a linkage of PDCCH and PDSCH / PUSCH transmission.

Linkage information between such PDCCH monitoring CCs and shared channel (PDSCH / PUSCH) transmission CCs may be determined according to cell-specific linkage or transmitted through UE-specific signaling. May be

In addition, after setting only the linkage between the PDCCH transmission CC and the PDSCH transmission CC and the linkage between the PDCCH transmission CC and the PUSCH transmission CC, but only the linkage between the PDCCH transmission CC and the PDSCH transmission CC, the PUSCH transmission is included in the linkaged set. It may be said that it is limited to a UL CC set linked with PDSCH transmission CCs. In this case, the PUSCH transmission CCs linked with the PDSCH transmission CCs may be linked UL CCs through SIB2 linking with the PDSCH transmission CC.

If there is no linkage information between the PDCCH transmission CC and the shared channel transmission CC, decoding to find scheduling assignment information for shared channels that can be transmitted to all UE DL / UL CC sets in all DL CCs configured as the PDCCH monitoring set. You have to try. This requires excessive blind decoding operation and is undesirable in terms of power consumption and latency of the terminal.

As described above, in order to support the PDCCH-PDSCH / PUSCH linkage type shown in option 1 of FIG. 15 (a), the base station transmits the following information for each terminal.

1. Information on PDCCH monitoring CC

That is, the base station transmits a first indicator indicating the PDCCH monitoring CC to the terminal. Here, the first indicator indicates information on the PDCCH monitoring CC.

(1) The base station may transmit a logical DL CC index to the terminal to indicate which CC the PDCCH monitoring CC is.

Here, the base station may use a fixed size bits to inform one monitoring CC to the terminal. For example, 3 bits may be used as the size of the first indicator.

In addition, the base station may inform the terminal of one or more monitoring CCs (x bits (number of bits of fixed size) * number of PDCCH monitoring CCs).

(2) When only one PDCCH monitoring CC is allowed, the base station can transmit the PDCCH monitoring CC index to the terminal through a fixed bit field size.

(3) The base station transmits a maximum of x bits (for example, 5 bits, assuming that up to 5 DL CCs are supported in LTE-A) to the UE in a PDCCH monitoring CC indication field, and which DL CC is a scheduling CC in the form of a bitmap. Can be specified as (scheduling CC). Here, x represents the number of DL CCs supported by the base station.

That is, the base station may set the CC used as the PDCCH monitoring CC as an example, '1', and the CC other than the PDCCH monitoring CC as '0' to transmit to the terminal. The setting of '1' and '0' may be reversed.

(4) If the UE knows information about a cell-specific carrier configuration (for example, DL CC configuration information of a corresponding cell) in the process of accessing a cell and making an RRC connection, the base station determines the number of DL CCs supported by the cell. Information on scheduling CC may be informed to the terminal in a bitmap form with a corresponding bit size.

For example, if the number of DL CCs configured in a specific cell is 4, the PDCCH monitoring CC may be informed to the UE in the form of a bitmap using 4 bits.

(5) The base station may inform the terminal using the CIF which CC is the PDCCH monitoring CC. Here, the CIF may be used when there is a CIF mapped for each DL CC from the terminal's point of view.

2. Information about PDSCH / PUSCH (scheduled) CC

That is, the base station may transmit a second indicator indicating a CC for transmitting the PDSCH / PUSCH to the terminal. Here, the second indicator refers to information on a PDSCH CC / PUSCH CC.

(1) The base station transmits information on PDSCH CC / PUSCH CCs to the terminal.

(2) The base station may transmit information on the DL / UL CC set and the DL / UL active CC set to the terminal.

(3) The base station may transmit a logical downlink CC index (logical DL CC index) to indicate to which UE the PDSCH CC / PUSCH CC.

Here, the base station may use fixed x bits to inform one PDSCH CC or PUSCH CC. For example, the second indicator may use a size of 3 bits.

In addition, the base station may use as many bits as (x bits * number of scheduled CCs) to inform the terminal of one or more scheduled CCs.

(4) The base station transmits fixed x bits (for example, 5 bits, assuming that up to 5 DL CCs are supported in LTE-A) to the UE through a PDSCH CC indication field, and which DL CC is a PDSCH in the form of a bitmap. Can be used as a CC.

For example, the base station may inform the terminal by setting the CC, which is not the '1' PDSCH CC, as '0' for the CC used as the PDSCH CC. The setting of '1' and '0' may be reversed. Here, x denotes the number of DL CCs supported by the base station.

The base station may transmit only the information on the PDSCH CC to the terminal without transmitting the PUSCH CC indication to the terminal, and implicitly inform the terminal of the UL CCs linked with the PDSCH CC as a PUSCH CC. In this case, DL / UL linkage may be both linking through SIB 2 or dedicated linking set to UE-specificity.

(5) The base station transmits fixed x bits (eg, 5 bits, assuming that up to 5 UL CCs are supported in LTE-A) to the UE through a PUSCH CC indication field, and any UL CC in the form of a bitmap is transmitted to the PUSCH CC. You can also specify if it is used. Here, x represents the number of DL CCs supported by the base station.

For example, for a CC used as a PUSCH CC, for example, a CC other than a PUSCH CC may be set to '0' to inform the UE.

(6) If the UE knows the information about the cell-specific carrier configuration (for example, DL CC configuration information of the cell) during the RRC connection and the UE accesses the cell, the bit size corresponding to the number of CCs supported by the cell Information about scheduling CC in bitmap format can be indicated.

As an example, if the number of DL / UL CCs configured in a specific cell is four, each of 4 DL bits may inform the UE of the PDSCH or the PUSCH CC in the form of a bitmap.

3. PDCCH-PDSCH / PDCCH-PUSCH linkage information for at least one of a PDSCH CC and a PUSCH CC that can be scheduled in each of the one or more PDCCH monitoring CCs

First, information transmission (first indicator) for PDCCH monitoring CC may use the method proposed in 1. above. That is, the PDCCH monitoring CC information may be transmitted in the form of an index or a bitmap of the CC.

Hereinafter, a CC set and an inter-CC linkage configuration illustrated in FIG. 17 are described as a method of transmitting information on a scheduled CC (PDSCH CC / PUSCH CC) that can be scheduled in each scheduling CC based on a scheduling CC as an example. Let's explain.

17 (a) and (b) illustrate an example in which a link set between CC sets and CCs is set according to an embodiment of the present specification.

The following description will be described by taking an example in which a CC set and linkages between CCs shown in FIGS. 17A and 17B are set. However, it is obvious that the method proposed in the present specification is not limited to the CC set and linkage setting between the CCs shown in FIGS. 17A and 17B.

As shown in FIG. 17, five DL CCs (DL CC # 1, # 2, # 3, # 4, # 5) as the UE DL CC set, and five UL CCs as the UL UL CC set (UL CC # 1, It can be seen that two DL CCs (DL CC # 2, # 3) are allocated to the UE as # 2, # 3, # 4, # 5, and PDCCH monitoring set.

In addition, the DL CC # 2 in the PDCCH monitoring set transmits the PDCCH for the PDSCH of the DL CC # 1 / # 2 in the UE DL CC set and the PDCCH for the PUSCH of the UL CC # 2 in the UE UL CC set.

In addition, the DL CC # 3 in the PDCCH monitoring set transmits the PDCCH for the PDSCH of the DL CC # 3 / # 4 in the UE DL CC set and the PDCCH for the PUSCH of the UL CC # 3 in the UE UL CC set.

18 (a) and (b) illustrate a method for transmitting scheduled CC (PDSCH CC / PUSCH CC) information that can be scheduled in PDCCH monitoring CC information transmission and PDCCH monitoring CC according to an embodiment of the present specification.

First, it is assumed that the link set between the CC set and the CC is set as shown in FIG. 17, and the base station transmits the PDCCH monitoring CC information to the terminal in the form of a bitmap using a fixed number of bits. Here, the fixed number of bits may be determined according to the number of CCs of the DL CC set and / or the UL CC set. In FIG. 18, it can be seen that PDCCH monitoring CC information is set to 5 bits.

As shown in FIG. 18 (a), since CC # 2 and CC # 3 are assumed as the PDCCH monitoring CC, it can be seen that the PDCCH monitoring CC bitmap transmitted by the base station to the terminal is '01100'.

Here, '0' in the PDCCH monitoring CC bitmap indicates that the corresponding CC does not correspond to the PDCCH monitoring CC, and '1' indicates that the corresponding CC corresponds to the PDCCH monitoring CC.

Here, the PDCCH monitoring CC bitmap transmitted by the base station may include information on a PDSCH CC / PUSCH CC that can be scheduled by each PDCCH monitoring CC.

In this case, an information configuration on which DL / UL CC is used as a PDSCH / PUSCH CC by each PDCCH CC may be represented in a bitmap form.

For example, among the candidate DL / UL CCs (CC # 1 to # 5), a CC to schedule PDSCH / PUSCH is set to '1' and a CC not to be scheduled is set to '0' to configure a bitmap. Can be.

That is, as shown in FIG. 18B, the PDSCH CCs that can be scheduled in the PDCCH monitoring CC # 2 are the CC # 1 and the CC # 2, so the schedulable PDSCH CC bitmaps included in the PDCCH monitoring CC # 2 are included. The information is '11000', and since the PUSCH CC that can be scheduled in the PDCCH monitoring CC # 2 is CC # 2, it can be seen that the schedulable PUSCH CC bitmap information included in the PDCCH monitoring CC # 2 is '01000'. .

Also, since the PDSCH CCs that can be scheduled in the PDCCH monitoring CC # 3 are CC # 3 and CC # 4, the schedulable PDSCH CC bitmap information included in the PDCCH monitoring CC # 3 is '00110', and the PDCCH monitoring CC # Since the PUSCH CC that can be scheduled in 3 is CC # 3, it can be seen that the schedulable PUSCH CC bitmap information included in the PDCCH monitoring CC # 3 is '00100'.

As shown in (b) of FIG. 18, it can be seen that there is no CC to be scheduled in the corresponding PDCCH CC by always transmitting fields fixed to '0' for the CC not transmitting the PDCCH.

In addition, the bitmap scheme illustrated in FIG. 18 is a method of using a fixed bit length regardless of the number of PDSCH / PUSCH CCs that can be scheduled in one PDCCH monitoring CC.

If the index of the PDSCH / PUSCH CC that can be scheduled in the PDCCH monitoring CC is transmitted instead of the bitmap, the UE-specific CC allocation information bit length is changed according to the number of scheduled CCs that can be transmitted in one scheduling CC.

Assuming that the total number of CC of PDSCH / PUSCH schedule information shown in FIG. 18 is five DL / UL, respectively, the scheduled CC (PDSCH CC / PUSCH CC) information that can be scheduled in the PDCCH monitoring CC information and the PDCCH monitoring CC. The total number of is as follows.

(1) PDSCH CC-PDCCH CC linkage information transmission: 5bit (PDCCH CC bitmap) + 25bits ((5bit for PDSCH CC bitmap per 5 PDCCH CCs)), total 30bits,

(2) PUSCH CC-PDCCH CC linkage information transmission: A total of 30 bits are used as 5 bits (PDCCH CC bitmap) + 25 bits ((5 bits for PUSCH CC bitmap per 5 PDCCH CCs)).

4. Transmission of linkage information on which CC is the PDCCH monitoring CC to which the scheduled CC can be scheduled in each PDSCH CC / PUSCH CC.

19 (a) to (c) illustrate a logical index of a downlink component carrier (DL CC) used for PDCCH monitoring CC transmission according to an embodiment of the present specification.

index) is an example.

First, FIGS. 19A to 19C will be described with reference to FIGS. 17A and 17B.

Referring to FIG. 19 (a), the base station sets indexes of DL CCs # 1 to # 5 usable for PDCCH monitoring CC transmission to '000', '001', '010', '011', and '100', respectively. Can be set.

FIG. 19B illustrates a logical index corresponding to each of DL CCs # 1 to # 5 when '000' is reserved among the logical indexes of the DL CC of FIG. 19 (a).

Referring to FIG. 19 (b), the base station sets the indexes of DL CCs # 1 to # 5 usable for PDCCH monitoring CC transmission to '001', '010', '011', '100', and '101', respectively. Can be set.

19 (c) shows a logical index corresponding to each of DL CCs # 1 to # 5 when '111' is reserved among the logical indexes of the DL CC of FIG. 19 (a).

Referring to FIG. 19 (c), the base station sets indexes of DL CCs # 1 to # 5 usable for PDCCH monitoring CC transmission to '000', '001', '010', '011', and '100', respectively. Can be set.

As shown in FIG. 19 (b) to (c), the reserved state is not used for logical index representation.

20 (a) to (c) illustrate an example of transmitting a PDSCH CC / PUSCH CC bitmap and a method of transmitting information on a PDCCH monitoring CC in each PDSCH CC / PUSCH CC according to an embodiment of the present specification.

First, FIG. 20 will be described with reference to a logical index of a DL CC shown in FIGS. 19A to 19C.

FIG. 20 illustrates a method for notifying from which scheduling CC a shared channel (PDSCH CC / PUSCH CC) of each scheduled CC can be transmitted based on the information on the scheduled CC. That is, it shows a method of notifying which scheduling CC a search space of each scheduled CC is configured based on information on the scheduled CC.

In addition, information transmission for the PDSCH CC / PUSCH CC may use the methods described in 2. above. That is, information transmission on the PDSCH CC / PUSCH CC may be configured in the form of an index or a bitmap and transmitted to the terminal.

First, the base station generates a logical index for the DL CC to which the PDCCH monitoring CC is transmitted. Here, the number of bits for expressing the logical index is fixed. For example, it can be fixed to 3 bits.

Hereinafter will be described with reference to the logical index for the DL CC shown in Figure 19 (a) to (c).

That is, as shown in FIG. 19 (a), the base station can allocate a logical index of 3 bits for each DL CC. In this case, as shown in FIGS. 19 (b) to (c), one of the states that can be made into the number of bits used for logical index allocation may be reserved.

Next, the base station configures an information bitmap for the PDSCH / PUSCH scheduled CC using bits corresponding to a fixed number of DL CCs (for example, 5 bits for 5 CCs).

In this case, the base station may perform only an indication for the PDSCH CC, only an indication for the PUSCH CC, or both an indication for the PDSCH CC and the PUSCH CC.

Here, it is assumed that the configuration and linkage of the PDCCH monitoring CC and the PDSCH / PUSCH CC are set as shown in FIG. 17.

As shown in FIG. 20A, the PDSCH CC bitmap may be represented by '11110' and the PUSCH CC bitmap may be represented by '01100'.

Next, the base station includes index information on which DL CC is used as the scheduling CC in the PDSCH CC / PUSCH CC bitmap.

That is, information configuration on which DL CC each PDSCH CC uses as a scheduling CC and information configuration on which DL CC each PUSCH CC uses as a scheduling CC is as shown in FIGS. 20B and 20C.

First, as shown in FIG. 20 (b), when '000' is reserved among the logical indexes of the DL CC, the PDSCH CC bitmap '11110' indicates that the index of the scheduling CC of each PDSCH CC is '010' (DL CC). # 2), '010', '011' (DL CC # 3), '011', and '000'. Here, '000' uses the reserved logical index. In other words, the reserved logical index indicates that the scheduling CC will not be allocated.

In addition, when '111' is reserved among the logical indexes of the DL CC, the PDSCH CC bitmap '11110' indicates that the scheduling CC index of each PDSCH CC is' 001 '(DL CC # 2),' 001 ', and' 010, respectively. '(DL CC # 3),' 010 ', and' 111 '.

Here, '111' uses the reserved logical index. In other words, the reserved logical index indicates that the scheduling CC will not be allocated.

Similarly, as shown in FIG. 20 (c), when '000' is reserved among the logical indexes of the DL CCs, the PUSCH CC bitmap '01100' has an index of the scheduling CC of each PUSCH CC '000' and '010, respectively. '(DL CC # 2),' 011 '(DL CC # 3),' 000 ', and' 000 '.

Here, '000' uses the reserved logical index. In other words, the reserved logical index indicates that the scheduling CC will not be allocated.

In addition, when '111' is reserved among the logical indexes of the DL CCs, the PUSCH CC bitmap '01100' indicates that the scheduling CC indexes of each PUSCH CC are '111', '001' (DL CC # 2), and '010', respectively. '(DL CC # 3),' 111 ', and' 111 '.

Here, '111' uses the reserved logical index. In other words, the reserved logical index indicates that the scheduling CC is not allocated.

In FIGS. 20B and 20C, the reserved '000' or '111' may always be transmitted for the CC set to '0' in the PDSCH / PUSCH bitmap.

That is, as shown in FIGS. 20A to 20C, a PDSCH / PUSCH CC indication may be made through a bitmap and a PDCCH CC on which each PDSCH / PUSCH CC can be scheduled may be informed through a logical CC index of the CC. have.

In this case, the CC logical index of the PDCCH CC capable of scheduling the PDSCH / PUSCH CC set to '1' (or '0' when the assigned CC is toggled to '0') is transmitted.

In addition, in order to prevent a change in the bit size according to the number of PDSCH / PUSCH CCs, a specific state of the logical index is reserved and the PDSCH / PUSCH CC bitmap is set to '0' (CCs that will not transmit PDSCH / PUSCH for the CC). For the CC, the reserved logical CC index may be transmitted at all times. It can also be nulled if you don't reserve a particular state.

In the example of FIG. 20, in the case where it is assumed that the number of CCs is a total of five DL / ULs each and 3 bits are used to represent a DL CC logical index through which a PDCCH monitoring CC is transmitted, PDSCH / PUSCH CC information and each PDSCH CC / The total number of information about the PDCCH monitoring CC in the PUSCH CC is as follows.

(1) PDSCH CC-PDCCH CC linkage information transmission: 5bit (PDSCH CC bitmap) + 15bits ((3bit for CC index representation per 5 CCs)), total 20bits,

(2) PUSCH CC-PDCCH CC linkage information transmission: A total of 20 bits may be used as 5 bits (PUSCH CC bitmap) + 15 bits ((3 bits for CC index representation per 5 CCs)).

In the case of using the example method in FIG. 20, when the DL / UL scheduled CC is added and removed, CC management is easy because only the PDCCH monitoring CC logical index for the added and removed CC is changed and signaled. In addition, regardless of the change in the CIF value of the DL / UL CC (a field indicating which PDSCH / PUSCH CC scheduling information of the corresponding DCI in the PDCCH DCI), CC addition, removal, etc. can be freely performed. In addition, the same information may be transmitted with a smaller number of bits than a method of indicating which PDSCH / PUSCH CCs are scheduled in the scheduling CC.

The salping PDCCH monitoring CC information and PDSCH CC / PUSCH CC information may be transmitted in a dedicated signaling method for each terminal through higher layer signaling such as UE-specific RRC signaling.

This means that cross-carrier scheduling is enabled / disabled for each terminal, and the assignment of PDCCH monitoring CC and the linkage of PDSCH / PUSCH CC that can be scheduled in the corresponding PDCCH monitoring CC need to be changed dynamically from the terminal perspective. Because there is no.

In addition, the UE-specific carrier assignment information is the LTE-A terminal capable of carrier aggregation (CA) after the cell search (cell search), the initial access (initial access) process, that is, DL-UL CC (in this case, the DL-UL CC pair may be a DL PCC, a UL PCC pair, and may be a DL CC that has performed initial access and a UL CC linked to the SIB2.) After the RRC connection is established, to be transmitted through RRC signaling. Can be. In addition, the above information may be transmitted through RRC signaling in DL PCC.

Claims (26)

1. In a system supporting carrier bonding, a method for monitoring a PDCCH,

   Receiving from the base station a first indicator indicating at least one PDCCH monitoring component carrier of the plurality of component carriers;

   Monitoring for a plurality of candidate PDCCHs on at least one PDCCH monitoring component carrier indicated by the first indicator; And

   And receiving downlink control information through the PDCCH which has successfully decoded blind among the plurality of candidate PDCCHs.
2. The method of claim 1, wherein the monitoring comprises:

   Performing blind decoding on the plurality of candidate PDCCHs, wherein performing blind decoding performs CRC demasking on each candidate PDCCH using a unique identifier (RNTI).
3. The method of claim 1, wherein the downlink control information,

   A downlink grant or a DL grant.
4. The method of claim 3, wherein

   Receiving a second indicator from the base station indicating a PDSCH component carrier and / or a PUSCH component carrier among a plurality of component carriers; And

   Receiving a PDSCH from the base station or transmitting a PUSCH to the base station on a component carrier indicated by the received second indicator.
5. The method of claim 4, wherein

   Wherein the PDSCH component carrier and / or the PUSCH component carrier are configured with a linkage with one PDCCH monitoring component carrier.
6. The method according to claim 1 or 4, wherein the first and second indicators,

   And is transmitted via an RRC message from the base station.
7. The method of claim 1,

   And receiving component carrier configuration information supported by the base station from the base station.
8. The method of claim 7, wherein

   The component carrier configuration information includes at least one of downlink component carrier assignment information and uplink component carrier assignment information.
9. The method of claim 8,

   The downlink component carrier assignment information further includes downlink component carrier number information and index information indicating a downlink component carrier, and the uplink component carrier assignment information indicates uplink component carrier number information and uplink component carrier. And further comprising index information.
10. The method of claim 8,

    And the downlink and uplink component carrier assignment information is activated downlink and uplink component carrier assignment information.
11. The method of claim 1, wherein the first indicator,

    And information on a PDSCH component carrier and / or a PUSCH component carrier that can be scheduled by each PDCCH monitoring component carrier indicated by the first indicator.
12. The method of claim 11,

    The information of the PDSCH component carrier and / or PUSCH component carrier is configured in the form of a bitmap.
13. The method of claim 4, wherein the second indicator,

    And information on each PDSCH component carrier and / or PUSCH component carrier indicated by the second indicator and PDCCH monitoring component carrier for which linkage is set.
14. The method of claim 13,

    The information of the PDCCH monitoring component carrier is configured in the form of a logical index of the downlink component carrier.
15. The method according to claim 1 or 4,

    The first and second indicators are configured in the form of an index or a bitmap indicating each component carrier.
16. The method according to claim 1 or 4,

    The size of the first and second indicators is determined according to the number of component carriers of at least one of downlink and uplink supported by the base station.
17. The method according to claim 1 or 4, wherein the first and second indicators,

    When cross carrier scheduling is enabled, the method is transmitted from the base station.
18. In a system supporting carrier concatenation, a terminal for monitoring a PDCCH,

    A wireless communication unit for transmitting and receiving wireless signals with the outside; And

    Including a control unit connected to the wireless communication unit, The control unit,

    Controlling the wireless communication unit to receive, from a base station, a first indicator indicating at least one PDCCH monitoring component carrier among a plurality of component carriers, the plurality of candidate PDCCHs through at least one PDCCH monitoring component carrier indicated by the first indicator; And control the wireless communication unit to monitor downlink control information and to receive downlink control information through a PDCCH that has successfully decoded blinds among the plurality of candidate PDCCHs.
19. The method of claim 18, wherein the downlink control information,

    UE, characterized in that the DL grant (DL grant) or UL grant (UL grant).
20. The method of claim 19, wherein the control unit,

    Controlling the wireless communication unit to receive, from the base station, a second indicator indicating a PDSCH component carrier and / or a PUSCH component carrier among a plurality of component carriers,

    And controlling the wireless communication unit to receive a PDSCH from the base station or to transmit a PUSCH to the base station through a component carrier indicated by the received second indicator.
21. The method of claim 20,

    The PDSCH component carrier and / or PUSCH component carrier, characterized in that the linkage is configured with one PDCCH monitoring component carrier.
22. The method of claim 18, wherein the first indicator,

    And a PSCHCH component carrier indicated by the first indicator includes information on a PDSCH component carrier and / or a PUSCH component carrier that can be scheduled.
23. The method of claim 20, wherein the second indicator,

    And a PDDC component carrier indicated by the second indicator and / or a PUSCH component carrier and information on a PDCCH monitoring component carrier for which linkage is set.
24. The method of claim 18 or 20,

    And the first and second indicators are configured in an index or bitmap form indicating each component carrier.
25. The method of claim 18 or 20,

    The sizes of the first and second indicators are determined according to the number of component carriers of at least one of downlink and uplink supported by the base station.
26. The method of claim 18 or 20, wherein the first and second indicators,

    And when cross carrier scheduling is activated, the terminal is transmitted from the base station.

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