WO2015046808A1

WO2015046808A1 - Method for improving downlink control channel reception rate of terminal and apparatus therefor

Info

Publication number: WO2015046808A1
Application number: PCT/KR2014/008697
Authority: WO
Inventors: 박규진; 최우진
Original assignee: 주식회사 케이티
Priority date: 2013-09-27
Filing date: 2014-09-18
Publication date: 2015-04-02

Abstract

The present invention relates to a method for improving a downlink control channel reception rate of a terminal and an apparatus therefor, and more specifically, the method according to one embodiment of the present invention for a base station to configure a search space for an MTC terminal comprises the steps of: configuring a dedicated search space for the MTC terminal in a control region; and transmitting a PDCCH or EPDCCH from the configured dedicated search space.

Description

Method and apparatus for improving downlink control channel reception rate of terminal

The present invention relates to a method and an apparatus for improving a downlink control channel reception rate of a terminal, and more particularly, to provide a technique for increasing a downlink control channel reception rate of a low power terminal by defining a common search space for a low power terminal. do.

Machine Type Communication (MTC) or Machine to Machine (M2M) is communication between devices and things with no or minimal human intervention. "machine" may refer to an entity that does not require direct human intervention or intervention, and "MTC" may refer to a form of data communication that includes one or more such "machines." An example of a "machine" may be a smart meter or vending machine equipped with a mobile communication module, and recently, a smartphone that automatically connects to a network and performs communication without user intervention or intervention depending on the location or situation of the user. With the advent of the portable terminal with the MTC function is also considered as a form of machine.

The MTC terminal may be installed in a place where the radio environment is worse than that of the general terminal. Therefore, the coverage of the MTC terminal should be improved to 20dB or more compared to the coverage of the general terminal.

In order for an MTC terminal to operate in coverage improved by 20 dB or more compared with a general terminal, it is necessary to repeatedly transmit control information and / or data of each physical channel transmitted only in one subframe unit in a plurality of subframes. In addition, when another LTE / LTE-Advanced terminal and the MTC terminal overlap the common search space, an error may occur when the MTC terminal checks the control information.

In order to solve the above problems, the present invention provides a method and apparatus that can increase the probability that the MTC terminal receives common control signaling by newly defining a search space for the MTC terminal.

In order to solve the above-mentioned problems, a method for setting a search space for an MTC terminal by the base station according to an embodiment of the present invention comprises the steps of setting a dedicated search space for the MTC terminal in the control region (control region), and Transmitting the PDCCH or EPDCCH in the established dedicated search space.

According to another embodiment of the present invention, a method of receiving a control channel in a search space for an MTC terminal by the terminal includes calculating a dedicated search space for the MTC terminal in a control region, and the calculated search space. Receiving a PDCCH or EPDCCH in the.

A base station for setting a search space for an MTC terminal according to another embodiment of the present invention, a control unit for setting a dedicated search space for the MTC terminal in a control region, and transmits a PDCCH or EPDCCH in the set dedicated search space And a transmitting unit.

A terminal receiving a control channel in a search space for an MTC terminal according to another embodiment of the present invention is a control unit for calculating a dedicated search space for the MTC terminal in a control region, and the PDCCH or It includes a receiving unit for receiving the EPDCCH.

According to the present invention, the search space for the MTC terminal is newly defined, thereby increasing the probability that the MTC terminal receives the common control signaling.

1 shows an example of a wireless communication system to which an embodiment of the present invention is applied.

2 illustrates a method of blind decoding a PDCCH / EPDCCH by a general terminal and receiving a PDSCH.

3 is a diagram illustrating a case in which a PDCCH for an arbitrary UE is transmitted based on a total of four PDCCH formats for link adaptation.

4 is a diagram illustrating an uplink / downlink scheduling DCI format.

FIG. 5 shows the number of PDCCH candidates monitored for each UE by size (CCE), aggregation level, and USS / CSS.

6 is a diagram illustrating a process of Embodiment 1 in which a base station sets a search space for an MTC terminal according to an embodiment of the present invention.

FIG. 7 is a diagram illustrating a process in which a terminal receives a control channel in a search space set in Embodiment 1 for an MTC terminal according to an embodiment of the present invention.

8 is a diagram illustrating a process of Embodiment 2 in which a base station sets a search space for an MTC terminal according to an embodiment of the present invention.

FIG. 9 is a diagram illustrating a process in which a terminal receives a control channel in a search space set in Embodiment 2 for an MTC terminal according to an embodiment of the present invention.

FIG. 10 is a diagram summarizing a process of operating a base station and a terminal to set a search space for the MTC terminal of FIGS. 6 to 9.

11 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

12 is a view showing the configuration of a user terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In the present specification, the MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. In the present specification, the MTC terminal may mean a terminal supporting low cost (or low complexity) and coverage enhancement. Alternatively, in the present specification, the MTC terminal may mean a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, in the present specification, the MTC terminal may mean a newly defined 3GPP rel-13 low cost (or low complexity) UE category / type for performing LTE-based MTC related operations. Or, in the present specification, the MTC terminal supports enhanced coverage compared to the existing LTE coverage, or supports UE category / type defined in the existing 3GPP rel-12 or lower, or newly defined rel-13 low cost (or lower power consumption). low complexity) can mean UE category / type.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data, and the like. The wireless communication system includes a user equipment (UE) and a base station (base station, BS, or eNB). In the present specification, a user terminal is a comprehensive concept of a terminal in wireless communication. In addition, a user station (UE) in WCDMA and LTE / LTE-Advanced, HSPA, etc., as well as a mobile station (MS) and user interface (UT) in GSM It should be interpreted as a concept that includes a terminal, a subscriber station (SS), and a wireless device.

A base station 20 or a cell generally refers to a station that communicates with a user terminal, and includes a Node-B, an evolved Node-B, an Sector, and a Site. It may be called by other terms such as a base transceiver system (BTS), an access point, an access node, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, in the present specification, the base station 20 or the cell is a partial area covered by a base station controller (BSC) in CDMA, a Node-B in WCDMA, an eNB or a sector (site) in LTE / LTE-Advanced, and the like. Or, it should be interpreted as a comprehensive meaning of function, and encompasses various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range. to be.

Since the various cells listed have a base station for controlling each cell, the base station may be interpreted in two meanings. i) a device providing a megacell, a macrocell, a microcell, a picocell, a femtocell, a small cell with respect to the wireless area, or ii) may indicate the wireless area itself. In i) all devices that provide a given wireless area are controlled by the same entity or interact with each other to cooperatively configure the wireless area to the base station. The eNB, RRH, antenna, RU, LPN, point, transmit / receive point, transmit point, receive point, and the like, according to the configuration of the radio region, become an embodiment of the base station. In ii), the base station may indicate the radio area itself to receive or transmit a signal from a viewpoint of a user terminal or a neighboring base station.

Therefore, megacells, macrocells, microcells, picocells, femtocells, small cells, RRHs, antennas, RUs, low power nodes (LPNs), points, eNBs, transmit / receive points, transmit points, and receive points are collectively referred to as base stations. do.

In the present specification, the user terminal and the base station are two transmitting and receiving entities used to implement the technology or technical idea described in this specification in a comprehensive sense and are not limited by the terms or words specifically referred to. The user terminal and the base station are two types of uplink or downlink transmitting / receiving subjects used to implement the technology or the technical idea described in the present invention, and are used in a generic sense and are not limited by the terms or words specifically referred to. Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

There is no limitation on the multiple access scheme applied to the wireless communication system. Various multiple access techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM-TDMA, OFDM-CDMA Can be used. One embodiment of the present invention can be applied to resource allocation in the fields of asynchronous wireless communication evolving to LTE and LTE-Advanced through GSM, WCDMA, HSPA, and synchronous wireless communication evolving to CDMA, CDMA-2000 and UMB. The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.

In addition, in systems such as LTE and LTE-Advanced, a standard is configured by configuring uplink and downlink based on one carrier or a pair of carriers. The uplink and the downlink include a Physical Downlink Control CHannel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel (PHICH), a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control CHannel (EPDCCH), and the like. Control information is transmitted through the same control channel, and data is configured by a data channel such as a physical downlink shared channel (PDSCH) and a physical uplink shared channel (PUSCH).

On the other hand, control information may also be transmitted using an enhanced PDCCH (EPDCCH or extended PDCCH).

In the present specification, a cell means a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

A wireless communication system to which embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-antenna transmission scheme in which two or more transmission / reception points cooperate to transmit a signal. antenna transmission system), a cooperative multi-cell communication system. The CoMP system may include at least two multiple transmission / reception points and terminals.

The multiple transmit / receive point is at least one having a base station or a macro cell (hereinafter referred to as an eNB) and a high transmission power or a low transmission power in a macro cell region, which is wired controlled by an optical cable or an optical fiber to the eNB. May be RRH.

In the following, downlink refers to a communication or communication path from a multiple transmission / reception point to a terminal, and uplink refers to a communication or communication path from a terminal to multiple transmission / reception points. In downlink, a transmitter may be part of multiple transmission / reception points, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, an EPDCCH, and a PDSCH may be expressed in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, an EPDCCH, and a PDSCH.'

In addition, hereinafter, a description of transmitting or receiving a PDCCH or transmitting or receiving a signal through the PDCCH may be used as a meaning including transmitting or receiving an EPDCCH or transmitting or receiving a signal through the EPDCCH.

That is, the physical downlink control channel described below may mean PDCCH or EPDCCH, and may also be used to include both PDCCH and EPDCCH.

In addition, for convenience of description, the EPDCCH, which is an embodiment of the present invention, may be applied to the portion described as the PDCCH, and the EPDCCH may be applied to the portion described as the EPDCCH as an embodiment of the present invention.

Meanwhile, high layer signaling described below includes RRC signaling for transmitting RRC information including an RRC parameter.

The base station or eNB 20 performs downlink transmission to the terminals 10. The base station or eNB 20 is a downlink control information and uplink such as a physical downlink shared channel (PDSCH), which is a main physical channel for unicast transmission, and scheduling required for reception of the PDSCH. A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a data channel (eg, a physical uplink shared channel (PUSCH)) may be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

Referring to FIG. 1, the base station 20 transmits downlink control information (DCI) to the terminal 10 through a PDCCH / EPDCCH. The DCI may include a downlink scheduling assignment including PDSCH resource information or an uplink scheduling grant including PUSCH resource information.

That is, the base station 20 uses DCI to allocate uplink / downlink data transmission resources to the terminal 10 and transmits the same to the terminal 10 using a downlink control channel. The downlink control channel may be classified into a PDCCH and an EPDCCH according to a location of a transmission resource used for transmitting a DCI.

The PDCCH is transmitted in a control region established through a control format indicator (CFI). The control region is formed over the entire downlink bandwidth and consists of 1 to 4 OFDM symbols for each subframe according to the CFI setting value.

The EPDCCH is transmitted using the remaining transmission resources except for the control region in each subframe. A transmission resource used for EPDCCH transmission may be used only for a subframe predefined with higher layer signaling (for example, RRC (Radio Resource Control)) and a plurality of predefined PRB (Physical Resource Block) pairs for each UE. have.

When transmitting DCI through the PDCCH, a basic transmission resource unit may be referred to as a control channel element (CCE). One CCE may consist of nine Resource Element Groups (REGs), and one REG may consist of four Resource Elements (REs).

When transmitting DCI through EPDCCH, the basic transmission resource unit may be referred to as ECCE (Enhanced CCE). One ECCE is composed of 4 or 8 EREGs (Enhanced REGs) according to cyclic prefix length and / or TDD configuration, and one EREG is a plurality of REs that are variable according to REs used for RS (Reference Signal) transmission. Can be configured.

The base station 20 may set the number of CCEs used to transmit one DCI through the PDCCH according to the channel condition of the terminal. This is called an aggregation level, and 1, 2, 4, or 8 CCEs may be used according to the channel condition of the UE.

In addition, the base station 20 may set the number of ECCEs used when transmitting one DCI through the EPDCCH according to the channel condition of the terminal. This is called an aggregation level, and 1, 2, 4, 8, 16, or 32 ECCEs may be used according to the channel condition of the UE.

As described above, the PDCCH / EPDCCH is composed of a plurality of CCE / ECCE, the base station can transmit a plurality of DCI to a plurality of terminals in every subframe. In this case, the UE does not separately provide CCE / ECCE allocation information (that is, CCE aggregation level information and CCE transmission resource location information used for one DCI transmission) necessary for the UE to receive DCI through PDCCH / EPDCCH. Therefore, the terminal performs blind decoding on the possible coupling level and the CCE / ECCE transmission resource to confirm the DCI transmitted to the terminal.

Since the UE cannot realistically blind-decode all possible CCE / ECCE combinations for each coupling level for all CCEs / ECCEs present in the PDCCH / EPDCCH, the PDCCH configured with pre-defined CCE / ECCE indices for each UE. Blind decoding is performed only on candidate / EPDCCH candidate. The CCE index / ECCE index constituting the PDCCH candidate / EPDCCH candidate for each coupling level may be defined as a function of a coupling level, a value of a Radio Network Temporary Identifier (RNTI), and a slot number (or subframe number). The UE may perform blind decoding only on a limited number of PDCCH candidates / EPDCCH candidates in each subframe per coupling level.

As an example, FIG. 2 illustrates a method of blind decoding a PDCCH / EPDCCH by a general terminal and receiving a PDSCH. Referring to FIG. 2, the UE attempts blind decoding of the PDCCH / EPDCCH for the PDCCH candidate / EPDCCH candidate. A cyclic redundancy check (CRC) is added to the DCI, and the UE checks the CRC to confirm the DCI transmitted to the DCI. When checking the DCI transmitted to itself as a result of the CRC check, the UE acquires downlink scheduling information included in the DCI and decodes the PDSCH using downlink data transmission resources in the same subframe as the subframe in which the DCI is transmitted. do.

2 illustrates blind decoding PDCCH / EPDCCH and obtaining PDSCH scheduling information. In a manner similar to that of FIG. 2, PUSCH scheduling information may also be obtained by blind decoding PDCCH / EPDCCH.

The present invention provides a method and apparatus for configuring a common search space (CSS) for a machine type communication (MTC) terminal in a 3GPP LTE / LTE-Advanced system. In particular, the present invention relates to a method of defining CCEs configuring CSS for an MTC terminal among control channel elements (CCEs) configuring a control region defined for transmitting a downlink control channel PDCCH in each downlink subframe; Provide the device.

In the conventional 3GPP LTE / LTE-Advanced system, a PDCCH defined in a Release 10 or lower system and an EPDCCH newly defined in a Rel-11 system are used as a downlink control information (DCI) transmission channel for a UE. In particular, the LTE / LTE-Advanced base station constituting an arbitrary cell is the first 1 ~ 3 OFDM symbol for each downlink subframe when the system bandwidth is greater than 10 RB (Resource Block) for PDCCH transmission for the terminal in the cell The control region is set through (s) and transmitted to the terminals in the cell through the PCFICH transmitted through the first OFDM symbol of every downlink subframe. However, when the system bandwidth is less than 10 RB, the control region is set through 2 to 4 OFDM symbols for each downlink subframe. Control Channel Element, which is a resource unit for transmitting one PDCCH to the remaining REs except for the Resource Elements (REs) used to transmit PHICH, PCFICH, and RS (Reference Signal) in the control region of the corresponding downlink subframe ) Is configured. At this time, the CCEs constituting the control region are UE-specific search spaces for transmitting PDCCHs containing scheduling control information for the downlink data channel PDSCH or the uplink data channel PUSCH for each UE. Common Search Space (CSS) or Common Search Space (CSS) for transmitting scheduling information about System Information Block (SIB), paging, random access response (RAR), or TPC command control information for uplink power control The CCEs constituting the UE-specific search space are independently set for each UE according to the C-RNTI of the UE, and the CSS is commonly set for all UEs in the cell. . The CSS is composed of a total of 16 CCEs from CCEs 0 to 15 CCEs of each downlink subframe regardless of the size of the control region.

4 is a diagram illustrating an uplink / downlink scheduling DCI format.

Downlink control information (DCI) format means a scheduling grant for uplink / downlink transmission. DCI formats are separately transmitted according to each uplink / downlink transmission method and usage.

PDCCH monitoring on CSS is as follows. When a PDCCH is configured to receive scheduling control information for a system information block (SIB) by a higher layer for an arbitrary UE, that is, decoding of a PDCCH that is CRC scrambled with SI-RNTI. If the terminal is configured to perform decoding, the corresponding UE may transmit four PDCCH candidates and PDCCH format 3 based on PDCCH format 2 through a total of 16 Control Channel Elements (CCEs) constituting CSS of a control region. Decoding is performed based on the DCI format 1C or the DCI format 1A based on the two PDCCH candidates.

Similarly, when the UE is configured to perform decoding on the PDCCH scrambled with the RA-RNTI and the P-RNTI, the corresponding UE may include four PDCCH candidates based on the PDCCH format 2 through a total of 16 CCEs configuring the CSS of the control region. Two PDCCH candidates based on PDCCH format 3 are decoded based on the DCI format 1C or DCI format 1A.

Further, in case of receiving TPC command control information related to uplink power control (UL power control), decoding is performed on CRC scrambled PDCCH with TPC_PUCCH-RNTI and TPC_PUSCH-RNTI for each UE. The UE decodes 4 PDCCH candidates based on

PDCCH format

2 and 2 PDCCH candidates based on PDCCH format 3 through 16 CCEs configuring CSS of a control region based on the DCI format 3 or DCI format 3A. To do this.

UE-specific search space (UE) -specific search space (CS) configuration and CSS settings for each terminal, and the specific details of the number of PDCCH candidates per DCI format and AL (Aggregation Level) to be monitored in each search space is shown in FIG. Is presented in 5 shows the number of PDCCH candidates monitored for each UE by size (CCE), aggregation level, and USS / CSS.

In the conventional 3GPP LTE / LTE-Advanced system, the CSS for transmitting common control information for any normal LTE / LTE-Advanced terminal is defined in each downlink subframe as described above. It consists of the first 16 CCEs among the CCEs constituting the control region. However, in the case of a newly introduced MTC terminal, it is necessary to repetitively transmit a plurality of downlink subframes for common control control information for the corresponding MTC terminals for coverage enhancement. . In this case, when sharing the CSS of the control area defined for the normal LTE / LTE-Advanced terminals for transmitting common control information for the MTC, for the normal LTE / LTE-Advanced terminal in the cell The blocking probability for common control signaling transmission increases exponentially.

The present invention provides a method and apparatus for defining a separate MTC dedicated CSS for the MTC terminal in addition to the conventional CSS for the normal LTE / LTE-Advanced terminal through the control region of the downlink subframe. More specifically, the present invention provides a method for a base station constructing and transmitting a common search space (CSS) for a machine type communication (MTC) terminal, the MTC_CSS-RNTI which is an identifier for identifying a separate MTC dedicated CSS for the MTC terminal or fixed It provides a method and apparatus comprising the step of setting the CSS for the MTC by using the CCE and the step of transmitting a signal including a downlink subframe CSS is set to the terminal. Hereinafter, in the present specification, MTC_CSS-RNTI means an identifier for identifying MTC-only CSS.

The present invention describes the following two embodiments as a method and apparatus for defining CSS for an MTC terminal.

Example 1

In Embodiment 1, MTC_CSS-RNTI for MTC CSS setting may be defined.

MTC_CSS-RNTI for defining CSS for the MTC terminal may be newly defined, and MTC CSS may be defined using the corresponding MTC_CSS-RNTI as one parameter. As an embodiment thereof, a functional formula for generating a UE-specific search space of a UE in a control region of an existing 3GPP LTE / LTE-Advanced system may be utilized.

In the case of a UE configured to receive DCI through PDCCH in an existing 3GPP LTE / LTE-Advanced system, L (where, which is a PDCCH combining level to be monitored for receiving downlink control information in any downlink subframe k,

) USS,

The PDCCH candidate constituting the UE was determined by Equation 1 below.

[Equation 1]

here

Has a value of and cross-carrier scheduling is set,

If cross carrier scheduling is not set,

Has the value of. (only,

Denotes a Carrier Indicator Field (CIF) value included in the DCI.) In addition,

Has the value of,

Denotes the number of PDCCH candidates defined for the UE to monitor for L, which is a coupling level,

Denotes the number of CCEs constituting the PDCCH control region in the corresponding DL subframe k.

Additionally in Equation 1 above

The value is determined by Equation 2 below.

[Equation 2]

Where each

(

Has a value of slot number.

In this case, in order to define the CSS for the MTC terminal,

To determine the value

Can be defined as Additionally, the number of L values and the number of PDCCH candidates, which is a coupling level applied to Equation 1

The value is also defined according to the PDCCH format and the number that the MTC UE should monitor in CSS. That is, in the same manner as the existing terminal, in CSS, four PDCCH candidates are defined to be monitored based on coupling level 4, and two PDCCH candidates are defined to be monitored based on coupling level 8, and each search space is Each of Equations 1 (L = 4,

= 4) and (L = 8,

= 2) can be applied.

The MTC_CSS-RNTI value may be defined to newly define an SI-RNTI value for the MTC terminal, to use this value as a corresponding MTC_CSS-RNTI value, or to define a separate fixed MTC_CSS-RNTI value. Alternatively, the MTC_CSS-RNTI value may be set by the base station to be included in the PBCH for the MTC terminal and transmitted to the terminal. In this case, in order to reduce the amount of information included in the PBCH, only some information for defining the MTC_CSS-RNTI may be included. For example, only LSB 2 bits of MTC_CSS-RNTI are transmitted, and the remaining values except for LSB 2 bits are fixed, or MTC_CSS-RNTI candidates are defined in a manner such as a predetermined table, and MTC_CSS-RNTI to be used in the cell. An index within a table of values may be signaled.

Looking at the process of implementing the first embodiment of the base station and the terminal as follows.

The base station transmits the RNTI to the MTC terminal (S610). The RNTI may be a SI-RNTI value newly defined for the MTC terminal or an MTC_CSS-RNTI value fixed to the MTC terminal. The transmission of the RNTI value may directly transmit the RNTI value or signal an index in a table provided to the MTC terminal in advance.

The base station sets a dedicated search space for the MTC terminal using the promised RNTI value and Equations 1 and 2 (S620). The base station transmits the PDCCH or EPDCCH in the set dedicated search space (S630). The MTC terminal checks the PDCCH or EPDCCH transmitted in the dedicated search space.

The terminal receives the RNTI from the base station (S710). The RNTI may be a SI-RNTI value newly defined for the MTC terminal or an MTC_CSS-RNTI value fixed to the MTC terminal. Receiving the RNTI value may receive the RNTI value directly from the base station or signal the index from the base station among the information, such as a predetermined table received by the MTC terminal from the base station.

The terminal calculates a dedicated search space for the MTC terminal using the received RNTI value and Equations 1 and 2 (S720). In operation S730, a PDCCH or an EPDCCH, which is a control channel transmitted by a base station, is received in the calculated dedicated search space.

Example 2

Embodiment 2 may be implemented using fixed CCEs.

Among the CCEs constituting an arbitrary control region, a specific index of the remaining CCEs except for 16 CCEs of CCE # 0 to CCE # 15 constituting CSS for a normal LTE / LTE-Advanced terminal in a fixed position is determined. The CCEs may be bundled to configure CSS for the MTC terminal.

As an embodiment of this, the total number of CCEs constituting the control region in any downlink subframe k is determined.

In this case, CCE # 0 ~ CCE # (

Of CCEs up to)

) To CCE # (

The last 16 CCEs of) may be fixed with CSS for the MTC terminal.

As another embodiment of configuring the MTC CSS through the fixed CCE, 16 CCEs of CCE # 0 to CCE # 15 that constitute CSS for a normal LTE / LTE-Advanced terminal, followed by CCE # 16 to CCE # 31 16 CCEs may be defined to configure CSS for a corresponding MTC terminal. In this case, however, the total number of CCEs in the corresponding downlink subframe k

If is less than 32, the CSS for the MTC terminal is CCE # 16 ~ CCE # (

), Followed by CCE # 0 ~ CCE # (31-

It can be defined to configure through cyclic shift () up to).

Additionally, in the case of a common control channel transmitted through the CSS defined above, that is, in the case of DCI scrambled with SI-RNTI and RA-RNTI, P-RNTI, or TPC_PUCCH / PUSCH-RNTI, repetition is performed. The number of times made may be implicitly (or implicitly) signaled or explicitly signaled through the PBCH for the MTC terminal. Alternatively, in the case of the common control channel, that is, in case of DCI scrambled with SI-RNTI and RA-RNTI, P-RNTI, or TPC_PUCCH / PUSCH-RNTI, the downlink control channel defined for the MTC terminal in the corresponding cell It can be defined to follow the maximum repetition level or the maximum number of repetitions. In addition, when a UE-specific control channel is transmitted through CSS, the number of repetitions should follow the maximum number of repetitions supported by the cell regardless of the channel environment of the UE. Or may be defined to perform blind decoding based on one or more fixed repetition times.

In summary, if the PDCCH or EPDCCH is DCI scrambled with SI-RNTI, RA-RNTI, P-RNTI, TPC_PUCCH-RNTI, or TPC_PUSCH-RNTI, the number of repetitive transmissions of the PDCCH or EPDCCH is either implicitly or explicitly signaled or is preset. It can be implemented to follow the number of repetitive transmissions.

Although the embodiments of the present invention have been written based on the configuration of CSS for the MTC terminal using 16 CCEs, when the number of CCEs constituting the CSS for the MTC terminal has a number other than 16, It may be included in the scope of the specification.

Looking at the process of implementing the second embodiment of the base station and the terminal as follows.

The base station shares the information on the dedicated search space consisting of one or more CCE or ECCE with the MTC terminal (S810). The sharing scheme may be stored in the MTC terminal during the initial setting of the system, and may be implemented in a manner in which the base station provides information to the terminal, such as higher layer signaling. When the information on the CCE or ECCE constituting the dedicated search space is shared, the base station transmits the PDCCH or EPDCCH for the MTC terminal to the CCE or ECCE constituting the dedicated search space (S820).

FIG. 9 is a diagram illustrating a process in which a terminal receives a control channel in a search space set in Embodiment 2 for an MTC terminal according to an embodiment of the present invention. The MTC terminal shares information on a dedicated search space composed of one or more CCEs or ECCEs with the base station (S910). This sharing scheme is shared in various ways such as the initial setting and higher layer signaling described with reference to FIG. 8. Since the MTC terminal has secured information on a space to be searched, the MTC terminal blindly decodes the CCE or ECCE constituting the dedicated search space to receive the PDCCH or EPDCCH (S920).

The base station 1001 and the terminal 1009 share information about a dedicated search space (S1010). Here, the sharing of information includes sharing the information related to the RNTI described above or indicating a CCE or ECCE index constituting a dedicated search space for the MTC terminal. Based on the shared information, the base station 1001 sets a dedicated search space for the MTC terminal in the control region (S1020). Meanwhile, the terminal 1009 also calculates a dedicated search space for the MTC terminal in the control region based on the shared information (S1030). The base station 1001 transmits the PDCCH or the EPDCCH in the set dedicated search space (S1040). The terminal 1009 receives the PDCCH or EPDCCH transmitted by performing monitoring in the calculated search space (S1050).

When Embodiment 1 is applied to the shared information, the dedicated search space is an area defined using the pre-appointed RNTI as a parameter. Therefore, in step S1030, the terminal 1009 calculates a dedicated search space by using the RNTI previously promised as a parameter. In addition, the RNTI may be a SI-RNTI value newly defined for the MTC terminal or an MTC_CSS-RNTI value fixed to the MTC terminal.

When the second embodiment is applied to the shared information, information on a fixed number of control channel elements (CCEs) or areas consisting of ECCEs may be shared. In this case, in step S1030, the terminal 1009 may perform monitoring in the pre-appointed CCE or ECCE. In addition, when the PDCCH or EPDCCH is DCI scrambled with SI-RNTI, RA-RNTI, P-RNTI, TPC_PUCCH-RNTI, or TPC_PUSCH-RNTI, the number of repetitive transmissions of the PDCCH or EPDCCH is implicitly or explicitly signaled or a preset repetition. It can be configured to follow the number of transmissions.

FIG. 10 illustrates a method and apparatus for configuring CSS for an MTC terminal in a 3GPP LTE / LTE-Advanced system. The base station 1001 configures and transmits CSS for a machine type communication (MTC) terminal 1009. And using the MTC_CSS-RNTI or the fixed CCE, setting the CSS for the MTC and transmitting a signal including the downlink subframe in which the CSS is set to the terminal.

Referring to FIG. 11, the base station 1100 according to another embodiment includes a controller 1110, a transmitter 1120, and a receiver 1130.

The controller 1110 defines a separate MTC dedicated CSS for the MTC terminal in addition to the CSS for the normal LTE / LTE-Advanced terminal through the control region of the downlink subframe required to perform the above-described present invention. To control the overall operation of the base station.

The transmitter 1120 and the receiver 1230 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention.

In more detail, the base station 1100 sets a search space for the MTC terminal. For this purpose, the controller 1110 sets a dedicated search space for the MTC terminal in the control region, and the transmitter 1120 sets the dedicated search space. Transmits the PDCCH or EPDCCH.

In order to implement the first embodiment, the controller 1110 defines a dedicated search space using the RNTI as a parameter as previously promised, and more specifically, the RNTI is a newly defined SI-RNTI value for the MTC terminal or is fixed to the MTC terminal. MTC_CSS-RNTI value can be.

In order to implement the second embodiment, the controller 1110 may set one or more of the control area configured as one or more predetermined control channel elements (CCEs) or ECCEs as a dedicated search space, and the CCE is normal LTE / LTE-. It may be a CCE or ECCE having a predetermined index among CCEs or ECCEs excluding CCE or ECCE constituting a search space for an advanced UE. In addition, when the PDCCH or EPDCCH is DCI scrambled with SI-RNTI, RA-RNTI, P-RNTI, TPC_PUCCH-RNTI, or TPC_PUSCH-RNTI, the number of repetitive transmissions of the PDCCH or EPDCCH is implicitly or explicitly signaled or a preset repetition. It can be configured to follow the number of transmissions.

Referring to FIG. 12, the user terminal 1200 according to another embodiment includes a receiver 1230, a controller 1210, and a transmitter 1220.

The receiver 1230 receives downlink control information, data, and a message from a base station through a corresponding channel.

In addition, the control unit 1210 defines a separate MTC dedicated CSS for the MTC terminal in addition to the existing CSS for the normal LTE / LTE-Advanced terminal through the control region of the downlink subframe required to perform the present invention described above. Control the overall operation of the terminal according to.

The transmitter 1220 transmits uplink control information, data, and a message to a base station through a corresponding channel.

In more detail, the terminal 1200, that is, the MTC terminal receives a control channel in a search space for the MTC terminal. To this end, the controller 1210 calculates a dedicated search space for the MTC terminal in the control region, and the receiver 1230 receives the PDCCH or EPDCCH in the calculated search space. The controller 1210 may perform blind decoding and monitoring in a dedicated search space.

In order to implement Embodiment 1, the control unit 1210 may calculate a dedicated search space using a previously promised RNTI as a parameter. For this purpose, the RNTI is a newly defined SI-RNTI value for the MTC terminal or is transmitted to the MTC terminal. It may be a fixed MTC_CSS-RNTI value.

In order to implement the second embodiment, the controller 1210 may calculate a fixed number of control channel elements (CCEs) or ECCEs in the control area as a dedicated search space, where the CCE is normal LTE. It may be a CCE or ECCE having a predetermined index among CCEs or ECCEs excluding CCEs or ECCEs constituting a search space for the / LTE-Advanced UE. In addition, when the PDCCH or EPDCCH is DCI scrambled with SI-RNTI, RA-RNTI, P-RNTI, TPC_PUCCH-RNTI, or TPC_PUSCH-RNTI, the number of repetitive transmissions of the PDCCH or EPDCCH is implicitly or explicitly signaled or a preset repetition. It can be configured to follow the number of transmissions.

The configuration of the base station and the terminal of FIG. 11 and FIG. 12 described so far implements the function of transmitting and receiving the PDCCH or EPDCCH by configuring CSS for the MTC terminal, and in this process, the MTC using MTC_CSS-RNTI or fixed CCE. The base station implements a function of setting a CSS for the base station and transmitting a signal including a downlink subframe in which the CSS is set to the terminal.

Embodiments have been described above with reference to the drawings, but the present invention is not limited thereto. For example, the MTC terminal is exemplarily described as a terminal, but the present invention is not limited thereto and may be any type of terminal described above.

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

CROSS-REFERENCE TO RELATED APPLICATIONCROSS-REFERENCE TO RELATED APPLICATION

This patent application is filed with the Korean Patent Application No. 10-2013-0115153 filed in Korea on September 27, 2013 and the patent application No. 10-2014-0015726 filed in Korea on February 11, 2014. Priority is claimed under section (a) (35 USC § 119 (a)), all of which is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims

In the method for setting the search space for the MTC terminal in the base station,

The base station setting a dedicated search space for the MTC terminal in a control region; And

Transmitting a PDCCH or an EPDCCH in the set dedicated search space.
The method of claim 1,

And the dedicated search space is an area defined using a pre-appointed RNTI as a parameter.
The method of claim 2,

The RNTI is a SI-RNTI value newly defined for an MTC terminal or an MTC_CSS-RNTI value fixed to the MTC terminal.
The method of claim 1,

The dedicated search space is characterized in that the area consisting of one or more predetermined control channel element (CCE) or ECCE of the control area.
The method of claim 4, wherein

The CCE is a CCE or ECCE having a predetermined index among CCE or ECCE excluding CCE or ECCE constituting a search space for a normal LTE / LTE-Advanced UE.
The method of claim 1,

If the PDCCH or EPDCCH is DCI scrambled with SI-RNTI, RA-RNTI, P-RNTI, TPC_PUCCH-RNTI or TPC_PUSCH-RNTI, the number of repetitive transmissions of the PDCCH or EPDCCH is implicitly or explicitly signaled or a preset repetition. The number of transmissions.
In the method for receiving a control channel in the search space for the MTC terminal,

Calculating, by the terminal, a dedicated search space for the MTC terminal in a control region; And

Receiving a PDCCH or EPDCCH in the calculated search space.
The method of claim 7, wherein

And calculating, by the terminal, the dedicated search space using a pre-appointed RNTI as a parameter.
The method of claim 8,

The RNTI is a SI-RNTI value newly defined for an MTC terminal or an MTC_CSS-RNTI value fixed to the MTC terminal.
The method of claim 7, wherein

And calculating, by the terminal, a fixed search space of a fixed number of control channel elements (CCEs) or ECCEs in the control area.
The method of claim 10,

The CCE is a CCE or ECCE having a predetermined index among CCE or ECCE excluding CCE or ECCE constituting a search space for a normal LTE / LTE-Advanced UE.
The method of claim 7, wherein

If the PDCCH or EPDCCH is DCI scrambled with SI-RNTI, RA-RNTI, P-RNTI, TPC_PUCCH-RNTI or TPC_PUSCH-RNTI, the number of repetitive transmissions of the PDCCH or EPDCCH is implicitly or explicitly signaled or a preset repetition. The number of transmissions.
In the base station for setting the search space for the MTC terminal,

A controller configured to set a dedicated search space for the MTC terminal in a control region; And

And a transmitter for transmitting a PDCCH or an EPDCCH in the set dedicated search space.
The method of claim 13,

And the control unit defines the dedicated search space using a pre-appointed RNTI as a parameter.
The method of claim 14,

The RNTI is a SI-RNTI value newly defined for an MTC terminal or an MTC_CSS-RNTI value fixed to the MTC terminal.
The method of claim 13,

The control unit is a base station, characterized in that for setting the area consisting of one or more predetermined control channel element (CCE) or ECCE of the control area as the dedicated search space.
The method of claim 16,

The CCE is a base station, characterized in that the CCE or ECCE having a predetermined index of the CCE or ECCE other than the CCE or ECCE constituting a search space for a normal LTE / LTE-Advanced terminal.
The method of claim 13,

If the PDCCH or EPDCCH is DCI scrambled with SI-RNTI, RA-RNTI, P-RNTI, TPC_PUCCH-RNTI or TPC_PUSCH-RNTI, the number of repetitive transmissions of the PDCCH or EPDCCH is implicitly or explicitly signaled or a preset repetition. A base station according to the number of transmissions.