KR20140035782A - Method for transmitting control information, transmission/reception point thereof, method for receiving control information and terminal thereof - Google Patents

Abstract

The present invention relates to a method for transmitting control information of a transmission and reception point for a terminal receiving downlink control information through a downlink control channel which is introduced into a data area, a method for receiving control information of the terminal, and devices thereof. Provided are a resource mapping method and device for an enhanced control channel element (ECCE) of a enhanced physical downlink control channel (EPDCCH).

Description

Method of transmitting control information of a transmission and reception point, a transmission and reception point thereof, a method of receiving control information of a terminal, and a terminal thereof

The present invention relates to a method for transmitting control information of a transmission / reception point for a terminal for receiving downlink control information through a downlink control channel introduced into a data region, a method for receiving control information of a terminal, and apparatuses thereof.

In a wireless communication system capable of transmitting data to more users, the increase in system capacity is limited due to the resources of the conventional limited control region, thereby increasing the need for transmitting downlink control information through a downlink control channel located in the data region.

On the other hand, to a new control channel element for allocating a downlink control channel located in the data area corresponding to a control channel element for allocating a downlink control channel in an existing control area. Resource allocation method is required.

The present invention provides an Enhanced Control Channel Element (ECCE) / Enhanced Resource Element Group (EREG) mapping method for downlink control channel transmission in the data domain. It also provides a method and apparatus for indexing ECCE in any concentrated Enhanced Physical Downlink Control Channel (EPDCCH) set.

The present invention is a method for transmitting control information of a transmission / reception point for transmitting control information to a terminal through a data region of a physical resource block pair of a subframe. The remainder divided by 4 of the enhanced resource groups composed of resource elements having the same index for the resource elements assigned the index is the remainder divided by 2 or the resource element groups corresponding to the same index. Allocating control channel elements to resource element groups corresponding to the same index, and transmitting control information to the terminal through at least one control channel element among the control channel elements. Provide a method.

The present invention is a method of receiving control information of a terminal for receiving control information from a transmission / reception point through a data region of a physical resource block pair of a subframe. The remainder divided by 4 of the Enhanced Resource Groups consisting of resource elements having the same index for the Resource Elements assigned the index is assigned to the Resource Element Groups corresponding to the same index, or 2 Receiving a radio signal through at least one control channel element of the control channel elements allocated to the resource element groups corresponding to the same index divided by the terminal and the step of obtaining the control information from the radio signal Provides a method of receiving control information.

The present invention is a transmission / reception point for transmitting control information to a terminal through a data region of a physical resource block pair of a subframe. A resource element in which 16 numbers in the resource block pair are repeated with frequency priority is assigned. The remainder divided by 4 of the Resource Element Groups consisting of resource elements having the same index with respect to the (Resource Element) corresponds to the same index, or the remainder divided by 2 corresponds to the same index. And a control unit for allocating control channel elements to resource element groups, and a transmitting unit for transmitting control information to the terminal through at least one control channel element among the control channel elements.

The present invention provides a terminal for receiving control information from a transmission / reception point through a data region of a physical resource block pair of a subframe. The remainder divided by 4 of the enhanced resource groups composed of resource elements having the same index for the resource elements is allocated to the resource element groups corresponding to the same index, or the remainder divided by 2 is the same index. It provides a terminal comprising a receiving unit for receiving a radio signal through at least one control channel element of the control channel elements assigned to the resource element groups corresponding to the control unit for obtaining the control information from the radio signal.

1 illustrates an example of a wireless communication system to which embodiments are applied.
FIG. 2 illustrates one resource block pair in the case of a normal cyclic prefix (CP) as an example of a structure of a downlink resource in a Long Term Evolution (LTE) or LTE-Advanced (LTE-A) system.
3 illustrates an example of RE (Resource Element) mapping of an EREG-indexed PRB (physical resource block) pair with symbol-based cyclic shift to one transmit antenna port (cell-specific reference signal port (CRS) .
FIG. 4 is an example of RE mapping of PRREG pairs EREG indexed with symbol reference cyclic shifts for two transmit antenna ports (CRS ports 0, 1).
FIG. 5 is an example of RE mapping of a PRREG pair EREG indexed with symbol reference cyclic shift for four transmit antenna ports (CRS ports 0, 1, 2, 3).
FIG. 6 shows an example of RE mapping of PRREG pairs indexed to EREG without cyclic shift for one transmit antenna port (CRS port 0).
FIG. 7 illustrates an example of RE mapping of PRREG pairs indexed to EREG without cyclic shift for two transmit antenna ports (CRS ports 0 and 1).
FIG. 8 is an example of RE mapping of PRREG pairs EREG indexed without cyclic shift for four transmit antenna ports (CRS ports 0, 1, 2, 3).
9 is a diagram illustrating EREG mapping of the centralized EPDCCH set according to the first and second embodiments.
10 is a flowchart illustrating a method for transmitting control information of a transmission / reception point according to an embodiment of the present invention.
11 is a flowchart illustrating a method for receiving control information of a terminal according to another embodiment of the present invention.
12 is a diagram illustrating a configuration of a transmission and reception point according to another embodiment of the present invention.
13 is a diagram illustrating a configuration of a terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

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 transmission / reception point. In the present specification, a user terminal is a generic concept meaning a terminal in wireless communication. In addition, user equipment (UE) in WCDMA, LTE, and HSPA, as well as mobile station (MS) in GSM, user terminal (UT), and SS It should be interpreted as a concept that includes a subscriber station, a wireless device, and the like.

A transmission / reception point generally refers to a station communicating with a user terminal, and includes a base station (BS) or a cell, a node, a node-B, an evolved node-B, and a sector. ), A site, a base transceiver system (BTS), an access point, an access point, a relay node, a remote radio head (RRH), and a radio unit (RU).

That is, in the present specification, a base station or a cell is interpreted in a comprehensive sense to indicate some areas or functions covered by a base station controller (BSC) in CDMA, a NodeB in WCDMA, an eNB or a sector (site) in LTE, and the like. It is meant to cover various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, remote radio head (RRH), and radio unit (RU) communication range.

In this specification, a user terminal and a transmission / reception point are used in a generic sense as two transmission / reception entities used to implement the technology or technical idea described in the present specification, and are not limited by the terms or words specifically referred to. The user terminal and the transmission and reception point is used in a comprehensive sense as two (uplink or downlink) transmission and reception subjects used to implement the technology or the technical idea described in the present invention 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 are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes 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- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-A, the uplink and downlink are configured on the basis of one carrier or carrier pair to form a standard. The uplink and downlink transmit control information through a control channel such as 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 And a data channel such as a Physical Downlink Shared CHannel (PDSCH), a Physical Uplink Shared CHannel (PUSCH), and the like.

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. In the present specification, a transmission / reception point refers to a transmission point for transmitting / transmitting a signal or a reception point for receiving a signal, and a combination of these.

1 illustrates an example of a wireless communication system to which embodiments are applied.

Referring to FIG. 1, a wireless communication system 100 to which embodiments are applied includes a coordinated multi-point transmission / reception system (CoMP system) or cooperative system in which two or more transmission / reception points cooperate to transmit a signal. It may be a coordinated multi-antenna transmission system, a cooperative multi-cell communication system. The CoMP system 100 may include at least two transmission / reception points 110 and 112 and terminals 120 and 122.

The transmit / receive point has a high transmission power or a low transmission power in a macro cell region, which is connected to an eNB or a macro cell (macro cell 110, hereinafter referred to as an 'eNB') and an eNB 110 by a wired or optically controlled cable. It may be at least one RRH 112 having a. The eNB 110 and the RRH 112 may have the same cell ID or may have different cell IDs.

Hereinafter, downlink (downlink) means a communication or communication path from the transmission and reception points (110, 112) to the terminal 120, the uplink (uplink) from the terminal 120 to the transmission and reception points (110, 112) Or a communication path. In downlink, the transmitter may be part of the transmission / reception points 110 and 112 and the receiver may be part of the terminals 120 and 122. In uplink, the transmitter may be part of the terminal 120 and the receiver may be part of the transmission / reception points 110 and 112.

Hereinafter, a situation in which signals are transmitted and received through channels such as a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), and the like, may be used. Sometimes, PDSCH is transmitted and received.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

In wireless communication, one radio frame (radioframe) consists of 10 subframes, and one subframe consists of two slots. The radio frame has a length of 10 ms and the subframe has a length of 1.0 ms. In general, a basic unit of data transmission is a subframe unit, and downlink or uplink scheduling is performed in units of subframes. One slot includes seven (or normal cyclic prefix) or 6 (or extended CP) orthogonal frequency division modulation (OFDM) symbols in the time domain.

In the wireless communication, the frequency domain may be configured by, for example, a subcarrier unit of 15 kHz interval.

In downlink, time-frequency resources may be configured in units of resource blocks (RBs). The resource block may consist of one slot on the time axis and 180 kHz (12 subcarriers) on the frequency axis. One subcarrier (two slots) on the time axis A resource consisting of 12 subcarriers on the frequency axis may be referred to as a resource block pair (RBP). The total number of resource blocks varies according to system bandwidth.

A Resource Element (RE) can be composed of one OFDM symbol on the time axis and one subcarrier on the frequency axis. One resource block pair may include 14 × 12 resource elements or 12 × 12 resource elements.

FIG. 2 illustrates one resource block pair in the case of a normal cyclic prefix (CP) as an example of a structure of a downlink resource in a Long Term Evolution (LTE) or LTE-Advanced (LTE-A) system.

Referring to FIG. 2, in the case of a normal CP, one resource block pair includes 14 OFDM symbols (l = 0 to 13) and 12 subcarriers (k = 0 to 11). In the example of FIG. 2, a region (l = 0 to 2) consisting of three OFDM symbols in front of fourteen OFDM symbols belonging to one resource block pair includes physical control format information channel (PCFICH) and physical hybrid ARQ indicator (PHICH). A control region 210 allocated for a control channel such as a CHannel), a physical downlink control channel (PDCCH), etc., and the remaining regions (l = 3 to 13) are allocated for a data channel such as a physical downlink shared channel (PDSCH). It may be a data region 220. Although three OFDM symbols are shown in FIG. 2 for the control region 210, it is possible to assign 1 to 4 OFDM symbols for the control region 210. The size information of the OFDM symbol of the control region 210 may be transmitted through the PCFICH.

The PDCCH may be transmitted over the entire system band, and the PDSCH may be transmitted on a resource block basis. The user terminal may first check the PDCCH set for the user, and if there is no data corresponding to the user, take a micro sleep mode to reduce power consumption of the user terminal in the data area 120.

Referring to FIG. 2, a reference signal may be mapped to a specific resource element of downlink. That is, the common reference signal or cell-specific reference signal (CRS) 230, the demodulation reference signal or the UE-specific reference signal (DeModulation Reference Signal or UE-specific Reference Signal) in the downlink DM-RSs 232 and 234 and a Channel Status Information Reference Signal (CSI-RS) may be transmitted. In FIG. 2, only the CRS 230 and the DM-RSs 232 and 234 are shown for convenience of description.

The CRS 230 in the control region 210 may be used for channel estimation for decoding the PDCCH, and the CRS 230 in the data region 220 may be used for downlink channel measurement. Channel estimation for data decoding of the data region 220 may be performed using the DM-RSs 232 and 234. The DM-RSs 232 and 234 are multiplexed with reference signals for a plurality of layers using orthogonal codes. For example, in the case of four layer transmission, an orthogonal code having a length of 2 may be applied to two reference signal resource elements consecutive in the time axis, and two different reference signals may be multiplexed for each reference signal group. In the case of layer transmission, four orthogonal signals having a length of 4 may be applied to four reference signal resource elements distributed in the time axis, thereby multiplexing four different reference signals for each reference signal group.

In case of one or two layer transmission, since only one DM-RS group 1 232 can transmit the reference signal of each layer, the other DM-RS group 2 234 can be used as data transmission. have. DM-RS corresponding to each layer is transmitted by applying the same precoding applied to the layer. This enables decoding of data at the receiving end (terminal) without the information of precoding applied at the transmitting end (base station).

In a wireless communication system, a control channel is required to efficiently use limited resources. However, the resources of the control area 210 reduce the resources of the data area 220 used for data transmission as overhead of the system. In an OFDM-based LTE system, one resource block pair consists of 14 or 12 OFDM symbols, of which up to three OFDM symbols are used for the control region 210 and the remaining OFDM symbols are used for the data region 220. I use it. Meanwhile, in the LTE-A system capable of transmitting data to more users, the increase in system capacity may be limited due to the resources of the conventional limited control area 210. Therefore, an increase in control channel resources is inevitable, and thus a control channel transmission / reception method for multiple users using a spatial division multiplexing technique in the data region 220 may be considered. This method is to transmit and receive a control channel in the data area 220. For example, the control channel transmitted in the data region 220 may be called EPDCCH (Extended PDCCH or Enhanced PDCCH), but is not limited thereto.

In the existing 3GPP LTE / LTE-A rel-8 / 9/10 system, all UEs receive 1 ~ 3 OFDM symbols (system band> 10PRBs) or 2 ~ in front of a downlink subframe to receive a downlink DCI. It depends on the Physical Downlink Control Channel (PDCCH) transmitted on 4 OFDM symbols (system band ≤ 10 PRBs). A basic unit of the PDCCH transmission for an arbitrary terminal is a control channel element (CCE), and one CCE is composed of nine resource element groups (REG). One REG includes REs excluding REs (Resource Elements) to which PCFICH and PHICH, which are other physical channels existing in the PDCCH region of the DL subframe, and a cell-specific reference signal (CRS) For example, by grouping four consecutive REs on the frequency axis.

EPDCCH, which is newly introduced in 3GPP LTE / LTE-A release 11 and subsequent systems, is transmitted through a PDSCH region of a downlink pilot time slot (DwPTS) of a downlink subframe or a special subframe unlike the legacy PDCCH. For each UE configured to receive downlink control information (DCI) through the corresponding EPDCCH, each M group of M PRBs (M is a natural number less than or equal to the number of PRBs of one or more full bands) It is defined to assign up to K configured EPDCCH sets in a corresponding cell up to K (the maximum value of K may be one of 2, 3, 4 & 6). In addition, each EPDCCH set configured for a certain UE may have a different K value.

Depending on the EPDCCH transmission type, the EPDCCH set may be a localized type and also a distributed type. The aforementioned X may be 1 or 2 ⁿ (n = 1, 2, 3, 4 in the centralized type). , 5), but is not limited thereto. Meanwhile, X may be 2, 4, 8, or 16 in a distributed form, but is not limited thereto.

Meanwhile, K (K = 1) ePDCCH sets may be allocated to one UE. Since each ePDCCH set is distributed type or centralized type, KL centralized type ePDCCH and KD distributed for one UE. An ePDCCH of type can be allocated. That is, KL + KD = K can be obtained.

An EREG (Enhanced REG) / ECCE (Enhanced CCE) may be introduced into the EPDCCH corresponding to the concept of REG and CCE of the conventional PDCCH for EPDCCH transmission resource mapping for an arbitrary terminal.

According to the newly introduced EREG / ECCE, not only a frame structure type, a subframe configuration, a CP (Cyclic Prefix) length but also a legacy PDCCH control are set for one PRB pair constituting each EPDCCH set A total of 16 EREGs from EREG # 0 to EREG # 15 are configured in the corresponding PRB pair irrespective of whether or not the reference signal (for example, CRS, CSI-RS, PRS, etc.) can do.

Specifically, for a normal CP for one PRB pair constituting an arbitrary EPDCCH set, 16 numbers are allocated to 144 REs excluding 24 REs for a DM-RS among a total of 12 x 14 = 168 REs. EREG indexing can be done from 0 to 15 in frequency first and then time manner. Likewise, in the case of the extended CP, for the 128 REs except for the 16 REs for the DM-RS out of the 12 x 12 = 144 REs constituting one PRB pair, 16 numbers are allocated in the frequency first and then time manner, the EREG can be indexed from 0 to 15.

Examples of EREG indexing in one PRB pair constituting an arbitrary EPDCCH set in a downlink subframe corresponding to a normal CP are shown in FIGS. 3 to 8 below. However, in Figs. 3 to 8 below, portions indicated by hatches and not indicated by numbers indicate REs used for DM-RS, and portions indicated by numbers indicated by grids or hatched and indicated by REs to which CRSs are transmitted. Indicates.

3 illustrates an example of RE mapping of a PRREG pair EREG indexed with a symbol reference cyclic shift with respect to one transmit antenna port (CRS port 0).

Referring to FIG. 3, EREGs are indexed in a frequency-preferential manner from 0 to 15, indexes are indexed by a symbol-based cyclic shift, and indices 12 of the second symbol are indexed adjacent to the index 11 of the first symbol . In the same manner, index 8 of the third symbol is indexed adjacent to index 7 of the second symbol.

The PRB pair shown in FIG. 3 is for CRS port 0 and CRSs are mapped to eight REs as shown in FIG. 3. The CRS may be mapped to another location by frequency shifts.

FIG. 4 shows an example of RE mapping of a PRREG pair EREG indexed with symbol-based cyclic shifts for two transmit antenna ports (CRS ports 0, 1), and FIG. 5 shows four transmit antenna ports (CRS ports 0, 1, An example of RE mapping of PRREG pairs EREG indexed with symbol reference cyclic shift for 2, 3).

The REs shown in FIGS. 4 and 5 are indexed with symbol-based cyclic shifts in the same manner as shown in FIG. 3, and FIG. 4 shows eight additional CRS ports 0, 1 in addition to the CRS shown in FIG. CRSs are mapped to REs, and in FIG. 5, CRSs are further mapped to eight REs in addition to the CRSs shown in FIG. 4 for CRS ports 0, 1, 2, and 3.

3 to 5 described above are examples of applying a cyclic shift (cyclic shift) when EREG indexing for each OFDM symbol, and FIGS. 6 to 8 to be described below are examples of not applying a cyclic shift. .

FIG. 6 shows an example of RE mapping of an EREG indexed PRB pair without cyclic shift for one transmit antenna port (CRS port 0), and FIG. 7 shows cyclic for two transmit antenna ports (CRS ports 0, 1). RE mapping example of an EREG indexed PRB pair without shift, and FIG. 8 is an exemplary RE mapping example of an EREG indexed PRB pair without cyclic shift for four transmit antenna ports (CRS ports 0, 1, 2, and 3). .

6 to 8 are CRSs mapped in the same manner as the CRS mappings of FIGS. 3 to 5, respectively. However, there is a difference in the way of indexing.

Referring to FIG. 6, EREG is indexed in a frequency-prioritized manner from 0 to 15. Also, index 12 of the second symbol is indexed adjacent to index 11 of the first symbol by indexing without symbol-based cyclic shift. It is being indexed away. In the same way, index 8 of the third symbol, which is the next order of index 7 of the second symbol, is indexed without being contiguous.

In FIGS. 3 to 8, REs having the same index are grouped into one EREG. Therefore, a total of 16 EREGs are allocated from EREG # 0 to EREG # 15 for one PRB pair. 3 to 8 illustrate an example of a PRB pair of a normal CP, but in the same manner, 16 EREGs are allocated to EREG # 0 to EREG # 15 for the PRB pair of the extended CP.

3 to 8, each of the EREG # 0, EREG # 1,... Set in one PRB pair. , And EREG # 15 may each be composed of nine REs. However, the number of REs that can be actually used for EPDCCH transmission for each EREG may vary according to the number of transmit antenna ports (CRS port number) and the legacy PDCCH size, as shown in the above figure.

Referring to FIG. 3 again, if there are nine REs corresponding to index # 0, but the third region is set as a control region, EPDCCH cannot be transmitted to the REs of the region, except for the RE corresponding to this region. And EREG # 0 consists of all six available REs. In the case of EREG corresponding to index # 1, there are 9 REs indexed by # 1, but 5 can be used in EREG # 1 except for the RE where the third control region and the CRS are mapped (see the upper right of FIG. 3). It will consist of an RE.

The ECCE, which is the basic unit of the EPDCCH transmission, can be composed of N EREGs, respectively, according to the subframe type and the CP length. Specifically, the N value may be determined as follows.

First, N = 4 may be set for 3, 4 and 8 of the special subframes corresponding to the normal subframe and the normal CP corresponding to the normal CP. That is, in this case, a total of 4 ECCEs can be constituted by four EREGs for 16 EREGs constituting one PRB pair.

In other cases, the normal subframe corresponding to the extended CP, the special subframes 1, 2, 6, 7 and 9 corresponding to the normal CP, and the special subframes 1, 2, 3, 5 and 6, N = 8. In this case, a total of 2 ECCEs can be constituted by eight EREGs for 16 EREGs constituting one PRB pair.

In the case of the conventional PDCCH, in the case of a random DL subframe, transmission is performed through the previous 1 to 3 OFDM symbols or 2 to 4 OFDM symbols, and 9 REGs constitute one CCE. . Therefore, PDCCH CCEs may be configured with 9 × 4 = 36 REs.

However, in the case of EPDCCH, as described with reference to FIGS. 3 to 8, the legacy control region size (ie, legacy PDCCH size) and REs used as other reference signals such as CRS and CSI-RS are not considered. Since indexing is performed, the number of REs that can be actually used for EPDCCH transmission varies depending on the size of the legacy control region and the presence of other reference signals in any downlink subframe.

That is, the number of REs available for EPDCCH transmission may vary for each EREG. Therefore, in the case of ECCE which is a basic unit of actual EPDCCH transmission, there is a possibility that an imbalance occurs in the number of REs actually available for each ECCE.

In view of such a problem, the present invention provides a method of mapping EREGs constituting each ECCE. In particular, the present invention provides an ECCE / EREG mapping method in a localized type of EPDCCH set.

Specifically, the present invention provides a method for configuring each ECCE in a PRB pair constituting a localized type EPDCCH set as described above. In particular, the present invention considers the legacy PDCCH and CRS transmitted through the DwPTS region of all downlink subframes and special subframes, and optimal ECCE / EREG mapping considering the number of REs that can be used for EPDCCH transmission in a corresponding PRB pair. Provide a method.

Example 1 ECCE Configuration with N Consecutive EREGs

Embodiment 1 provides a method of configuring N consecutive EREGs as one ECCE in one PRB pair constituting the EPDCCH set, and thus a method of indexing the ECCE.

Table 1 is a table listing the number of available REs for each EREG according to each CRS port configuration when the legacy PDCCH size is 1.

 Table 1 summarizes EREG indexing based on which cyclic shift is not applied. Since one ECCE is composed of four EREGs (N = 4) in the corresponding subframe, when configuring four ECREGs in succession according to Embodiment 1 to configure one ECCE, each of the EREGs that constitutes each ECCE and The number of available REs for each ECCE is as shown in Table 2.

For four transmit antenna ports (4 Tx CRS), there are 26 usable REs of 1 ^st ECCE and 33 usable REs of 4 ^th ECCE, up to 7 REs from each other. As such, there is a large imbalance between the available REs constituting each ECCE.

This has similar characteristics when the legacy PDCCH sizes are 2 (Table 3) and 3 (Table 5).

Table 3 summarizes the number of available REs for each EREG according to each CRS port configuration when the legacy PDCCH size is 2. In case of configuring one ECCE by combining four consecutive EREGs in the situation as shown in Table 3, the number of EREGs constituting each ECCE and the number of REs available for each ECCE is shown in Table 4.

There are 22 usable REs of 1 ^st ECCE and 29 usable REs of 4 ^th ECCE for four transmission antenna ports (4 Tx CRS).

Table 5 summarizes the number of available REs for each EREG according to each CRS port configuration when the legacy PDCCH size is 3. In case of configuring one ECCE by combining four consecutive EREGs in the situation as shown in Table 5, the number of EREGs constituting each ECCE and the available REs for each ECCE is configured as shown in Table 6.

There are 18 usable REs of 1 ^st ECCE and 25 usable REs of 4 ^th ECCE for four transmission antenna ports (4 Tx CRS).

Accordingly, when the EPDCCH set is a localized type in any EPDCCH set composed of M physical resource block (PRB) groups (a group of X PRBs) (X is 2, 4, 8, or 16), ECCEs constituting the EPDCCH set may be configured as follows according to the first embodiment.

In more detail, for the M PRBs constituting any centralized EPDCCH set, the ECCE configured according to the first embodiment may be indexed in ascending order from the lowest PRB pair (PRB pair having the smallest PRB index).

Referring to (a) of FIG. 9, a 1 ^st ECCE consisting of EREG # 0 to EREG # 3 in the lowest PRB pair becomes ECCE # 0, and a 2 ^nd ECCE consisting of EREG # 4 to EREG # 7 is ECCE # 1, respectively. , EREG # 8 ~ is the 3 ^rd ECCE consisting EREG # 11 ECCE # 2, EREG # 12 ~ EREG # 15 4 th ECCE consisting are each indexed by the ECCE # 3. Subsequently, in the PRB pair having the second lowest PRB index, each of 1 ^st , 2 ^nd , 3 ^rd , and 4 ^th consisting of EREG # 0 ~ 3, EREG # 4 ~ 7, EREG # 8 ~ 11, and EREG # 12 ~ 15, respectively ECCEs are indexed into ECCE # 4, ECCE # 5, ECCE # 6, and ECCE # 7, respectively. In this way, up to four ECCEs configured in the PRB pair having the last Mth lowest PRB index, ECCE # (4M-4), ECCE # (4M-3), ECCE # (4M-2), and ECCE # (4M- In 1), ECCE indexing of the centralized EPDCCH set and EREG mapping constituting each ECCE may be performed.

Alternatively, M PRBs constituting an arbitrary centralized EPDCCH set may be sequentially indexed from 1 ^st ECCEs consisting of EREG # 0, # 1, # 2, and # 3 in each PRB pair.

Referring to (b) of FIG. 9, M ECCEs ranging from 1 ^st ECCE consisting of EREG # 0 to EREG # 3 of the lowest PRB to ECCE consisting of EREG # 0 to EREG # 3 of the Mth lowest PRB index (large PRB index) In this case, the indexes may be indexed from ECCE # 0 to ECCE # (M-1) in order of the PRB including the corresponding ECCEs. Then EREG # 4, # 5, # 6, # 7 , like for the M 2 ^nd ECCE consisting of lowest PRB pairs from largest to PRB pairs from each ECCE #M in ascending ECCE # (2M-1 in each PRB pairs Indexing), and then indexing ECCE # 2M to ECCE # (3M-1) in the ascending order of PRB index for 3 ^rd ECCEs consisting of EREG # 8 to EREG # 11 of each PRB pair, and finally As such, the 4 ^th ECCEs consisting of EREG # 12 to EREG # 15 of each PRB pair may be indexed up to ECCE # 3M to ECCE # (4M-1).

[Example 2] ECCE configuration with the same EREG divided by 4 (or 2)

As can be seen from the above, constituting a single ECCE by simply tying up four consecutive EREGs results in a large imbalance of the number of REs actually available for each ECCE. In fact, the biggest reason for the imbalance is that the use of 12 consecutive REs corresponding to one OFDM symbol is determined according to the legacy PDCCH size. That is, a gap occurs between an EREG corresponding to 12 consecutive REs among 16 EREGs and four consecutive EREGs not corresponding thereto.

In order to solve this problem, Embodiment 2 provides a method of configuring one ECCE by taking an EREG index value of modulo 4 in one PRB pair constituting the EPDCCH set, dividing by 4, and combining the same EREG indexes.

Accordingly, each ECCE may be configured as follows.

EREG #n with 1 ^st ECCE: (n mod 4) = 0

2 ^nd ECCE: EREG #n with (n mod 4) = 1

3 ^rd ECCE: EREG #n with (n mod 4) = 2

4 ^th ECCE: EREG #n with (n mod 4) = 3

At this time, n = 0,1,2, ..., 15, where n is the EREG index shown in FIGS.

I.e., 1 ^st ECCE in the PRB pair in any EPDCCH set is EREG # 0, EREG # 4, EREG # 8, is composed of EREG # 12, 2 ^nd ECCE is EREG # 1, EREG # 5, EREG # 9, EREG is composed of # 13, 3 ^rd ECCE is EREG # 2, EREG # 6, EREG # 10, is composed of EREG # 14, 4 ^th ECCE is EREG # 3, EREG # 7, EREG # 11, composed of EREG # 15 do. When the ECCE is configured in this way, the available REs according to the legacy PDCCH sizes for each ECCE are calculated as follows.

When the legacy PDCCH size is 1, the number of EREGs constituting each ECCE and available REs for each ECCE is configured as shown in Table 7.

When the legacy PDCCH size is 2, the number of EREGs constituting each ECCE and available REs for each ECCE is configured as shown in Table 8.

When the legacy PDCCH size is 3, the number of EREGs constituting each ECCE and available REs for each ECCE is configured as shown in Table 9.

As such, when modulo 4 is used in one PRB pair constituting the EPDCCH set, four EREGs having the same EREG index value are bundled to form one ECCE to solve the imbalance between the number of available REs between the ECCEs. Can be.

This may be equally applied even if a cyclic shift is performed when indexing an EREG for each OFDM symbol.

Accordingly, when the EPDCCH set is a localized type in any EPDCCH set composed of M PRB (Physical Resource Block) groups, ECCEs constituting the EPDCCH set may be configured as follows according to the second embodiment. have.

Even based on Embodiment 2, 1 ^st ECCE of the lowest PRB pair (PRB pair with the smallest PRB index) for M PRBs constituting the centralized EPDCCH set according to the two methods based on Embodiment 1 (the in the embodiment the PRB pairs according to example 2 EREG # 0, # 4, # 8, # 12 as configured ECCE) from the M-th lowest PRB index (that is, largest PRB index) for having PRB pair of the 4 ^th ECCE (the PRB ECCE indexing may be performed with ECCE # 0, ECCE # 1, .., ECCE # (4M-1) up to a pair of ECEs # 3, 7, 11, and 15 (ECCE).

Referring to FIG. 9A again, for 1 M PRBs constituting each arbitrary centralized EPDCCH set, 1 ^st ECCE composed of EREG # 0, # 4, # 8, and # 12 of the lowest PRB pair is 2 ^nd ECCE indexed with ECCE # 0, EREG # 1, # 5, # 9, # 13 indexed with ECCE # 1, 3 ^rd ECCE with EREG # 2, # 6, # 10, # 14 and A 4 ^th ECCE consisting of EREG # 3, # 7, # 11, and # 15 can be indexed into ECCE # 2 and ECCE # 3, respectively. Then, it is indexed to the respective ECCE # 4 ~ # 7 ECCE in the same sequence in the 2 ^nd lowest PRB pair. In this way, the 4 ^th ECCE of the PRB pair having the last Mth lowest PRB index (ECCE consisting of EREG # 3, 7, 11, and 15 of the PRB pair) is set to ECCE # (4M-1). Can be indexed.

Referring back to FIG. 9A as another method, ECCEs are sequentially ordered from 1 ^st ECCEs (ECCEs consisting of EREG # 0, # 4, # 8, and # 12 in each PRB pair) of each PRB pair. Index # 0 to ECCE # (M-1), then index ECCE #M to ECCE # (2M-1) in the same order for the 2 ^nd ECCEs of each PRB pair, as well as for each PRB pair It can be indexed as ECCE # 2M to ECCE # (3M-1) for 3 ^rd ECCEs and ECCE # 3M to ECCE # (4M-1) for the last 4 ^th ECCEs of each PRB pair.

Up to now, the downlink subframe (normal subframe) and the special subframe (3,4,8) of the normal CP corresponding to the case where the number of EREG constituting the one ECCE is 4 (that is, when N = 4 above) An ECCE / EREG mapping method and an ECCE indexing method according to any centralized EPDCCH set applicable to (normal CP) have been described.

Similarly, the downlink subframe (normal subframe) of the extended CP corresponding to the case where the number of EREGs constituting one ECCE is 8 (that is, when N = 8), special subframes 1,2,6, The same ECCE / EREG mapping method and corresponding ECCE indexing method may be applied to the centralized EPDCCH set configured in 7,9 (normal CP) and special subframes 1,2,3,5,6 (extended CP). .

That is, in Embodiment 1, instead of configuring four ECCEs by tying four consecutive EREGs out of 16 EREGs configuring the PRB pair for any PRB pair configuring each centralized EPDCCH set, 8 The two EREGs may be bundled to configure 1 ^st ECCE (EREG # 0 to EREG # 7) and 2 ^nd ECCE (EREG # 8 to EREG # 15), respectively. Likewise, in Embodiment 2, four EREGs having the same EREG index value are obtained when modulo 4 is applied to 16 EREGs constituting the PRB pair for any PRB pair constituting any centralized EPDCCH set. Each ECCE can be configured with eight EREGs having the same EREG index value when modulo 2 is taken instead of forming one ECCE each. That is, 1 ^st ECCE is configured with (EREG # 0, # 2, # 4, # 6, # 8, # 10, # 12, # 14) in the corresponding PRB pair, and (EREG # 1, # 3, # 5, # 7, # 9, # 11, # 13, it is possible to # 15) constituting the 2 ^nd to the ECCE. Based on this, the ECCE indexing method in the corresponding EPDCCH set is also the same as N = 4, and for each ECCE / EREG mapping method, a PRB pair having ^1st ECCE to largest PRB index configured in the PRB pair having the lowest PRB index Up to 2 ^nd ECCE can be indexed by ECCE # 0, ECCE # 1, ...., ECCE # (2M-1), respectively.

10 is a flowchart illustrating a method for transmitting control information of a transmission / reception point according to an embodiment of the present invention.

Referring to FIG. 10, a transmission / reception point for transmitting control information to a UE through a data region of a PRB pair (Physical Resource Block pair) of a subframe is indexed by repeatedly repeating 16 numbers in a resource block pair with frequency priority. Resource element groups or 2 corresponding to the same index are divided by 4 out of EREGs (Enhanced Resource Groups) consisting of resource elements having the same index with respect to resource elements (RE) assigned to Control channel elements (ECCE, Enhanced Control Channel Elements) are allocated to resource element groups corresponding to the same index.

An example of an index assigned to a PRB pair may refer to the foregoing description with reference to FIGS. 3 to 8. 3 and 6, the EREG is indexed in a frequency-prioritized manner to numbers from 0 to 15. In the embodiment shown in FIG. 3, index 12 of the second symbol is indexed from index 11 of the first symbol by indexing with a symbol reference cyclic shift. In the embodiment shown in FIG. 6, the second symbol is indexed without the symbol reference cyclic shift. Is not indexed adjacent to index 11 of the first symbol.

The transmission / reception point may allocate ECCEs to EREGs having a remainder divided by 4 of the EREGs corresponding to the same index or EREGs having a remainder divided by 2 equal to the same index.

For example, EREGs # 0, # 4, # 8, and # 12 may constitute one ECCE for allocating ECCEs with EREGs corresponding to the same index divided by 4, and EREGs # 1 and #. Another ECCE as 5, # 9, # 13, another ECCE as EREG # 2, # 6, # 10, # 14, another ECCE as EREG # 3, # 7, # 11, # 15 Can be configured.

As another example, EREGs # 0, # 2, # 4, # 6, # 8, # 10, # 12, and # 14 are equivalent to allocating ECCE to EREGs whose remainder divided by 2 corresponds to the same index. ECCE may be configured, and EREGs # 1, # 3, # 5, # 7, # 9, # 11, # 13, and # 15 may configure another ECCE.

The transmission and reception point transmits control information to the terminal through at least one control channel element among the control channel elements (S920).

The control information may be transmitted through an EPDCCH, which is a control channel transmitted in the data region 220, and the EPDCCH is allocated to the at least one control channel element in a resource block pair.

The RB pair to which control information is transmitted may be one PRB of an EPDCCH set including M PRB groups. Depending on the EPDCCH transmission type, the EPDCCH set may be a localized type and also a distributed type. The aforementioned X may be 1 or 2 ⁿ (n = 1, 2, 3, 4 in the centralized type). , 5), but is not limited thereto.

The RB pair for transmitting control information may configure one downlink EPDCCH set in a centralized manner with one or more RB pairs.

11 is a flowchart illustrating a method for receiving control information of a terminal according to another embodiment of the present invention.

Referring to FIG. 11, a terminal receiving control information from a transmission / reception point through a data region of a physical resource block pair of a subframe repeats 16 numbers in a resource block pair with frequency priority and assigns an index to the resource. The remainder divided by 4 of the Resource Element Groups consisting of resource elements having the same index for the Resource Elements are allocated to the Resource Element Groups corresponding to the same index, or the remainder divided by 2 is the same. In operation S1010, a wireless signal is received through at least one control channel element among control channel elements allocated to resource element groups corresponding to the index. In operation S1020, the terminal may acquire control information from the received wireless signal.

An example of an index assigned to a PRB pair may refer to the foregoing description with reference to FIGS. 3 to 8. 3 and 6, the EREG is indexed in a frequency-prioritized manner to numbers from 0 to 15. In the embodiment shown in FIG. 3, index 12 of the second symbol is indexed from index 11 of the first symbol by indexing with a symbol reference cyclic shift. In the embodiment shown in FIG. 6, the second symbol is indexed without the symbol reference cyclic shift. Is not indexed adjacent to index 11 of the first symbol.

The transmission / reception point may allocate ECCEs to EREGs having a remainder divided by 4 of the EREGs corresponding to the same index or EREGs having a remainder divided by 2 equal to the same index.

For example, EREGs # 0, # 4, # 8, and # 12 may constitute one ECCE for allocating ECCEs with EREGs corresponding to the same index divided by 4, and EREGs # 1 and #. Another ECCE as 5, # 9, # 13, another ECCE as EREG # 2, # 6, # 10, # 14, another ECCE as EREG # 3, # 7, # 11, # 15 Can be configured.

As another example, EREGs # 0, # 2, # 4, # 6, # 8, # 10, # 12, and # 14 are equivalent to allocating ECCE to EREGs whose remainder divided by 2 corresponds to the same index. ECCE may be configured, and EREGs # 1, # 3, # 5, # 7, # 9, # 11, # 13, and # 15 may configure another ECCE.

12 is a diagram illustrating a configuration of a transmission and reception point according to another embodiment of the present invention.

Referring to FIG. 12, a transmission / reception point 1100 for transmitting control information to a terminal through a data area of a physical resource block pair of a subframe includes a control unit 1110, a transmitter 1120, and a receiver 1130. And the like.

The control unit 1110 repeats 16 numbers in a resource block pair with frequency priority and 4 out of an enhanced resource group including resource elements having the same indexes for resource elements assigned with an index. Control channel elements are allocated to resource element groups corresponding to the same index or the remainder divided by 2 corresponds to the same index.

Herein, the RB pair may configure one downlink control channel set in a localized manner with at least one RB pair. In addition, the indexes of the resource element groups allocated to the control channel elements are {0,4,8,12}, {1,5,9,13}, {2,6,10,14} and {3,7, respectively. , 11,15} or {0,2,4,6,8,10,12, 14} and {1,3,5,7,9,11,13, 15}, respectively.

In addition, the control unit 1220 controls the operation of the overall transmission and reception point according to the ECCE / EREG mapping method for the EPDCCH transmission required to perform the above-described present invention and the ECCE indexing in any centralized EPDCCH set.

The transmitter 1120 transmits control information to the terminal through at least one control channel element among the control channel elements.

The transmitter 1120 and the receiver 1030 are used to transmit and receive signals, messages, data, and information necessary for carrying out the present invention.

13 is a diagram illustrating a configuration of a terminal according to another embodiment of the present invention.

Referring to FIG. 13, a terminal 1200 that receives control information from a transmission / reception point through a data area of a physical resource block pair of a subframe includes a receiver 1210, a controller 1220, and a transmitter 1230. And the like.

The receiver 1210 repeats 16 numbers in a resource block pair with frequency priority and 4 out of enhanced Resource Groups composed of resource elements having the same index with respect to resource elements assigned with an index. Receive a radio signal through at least one control channel element among control channel elements in which the remainder divided by 2 is allocated to resource element groups corresponding to the same index, or the remainder divided by 2 is allocated to resource element groups corresponding to the same index. do.

Herein, the RB pair may configure one downlink control channel set in a localized manner with at least one RB pair. In addition, the indexes of the resource element groups allocated to the control channel elements are {0,4,8,12}, {1,5,9,13}, {2,6,10,14} and {3,7, respectively. , 11,15} or {0,2,4,6,8,10,12,14} and {1,3,5,7,9,11,13,15}, respectively.

The controller 1220 obtains control information from the radio signal received by the receiver 1210. In addition, the control unit 1220 controls the overall operation of the UE according to the ECCE / EREG mapping method for receiving the EPDCCH required to carry out the present invention and the ECCE indexing in any centralized EPDCCH set.

The transmitter 1230 and the receiver 1210 are used to transmit and receive signals, messages, data, and information necessary for carrying out the above-described present invention with a transmission / reception point.

The contents related to the standard specification mentioned in the above-mentioned embodiments are omitted for the sake of brevity and constitute a part of this specification. Therefore, it is to be understood that the content of some of the contents related to the above standard is added to or included in the scope of the present invention.

Specifically, the following documents, which are attached below, form a part of this specification as part of already published documents. Therefore, it is to be understood that the content of the above standard content and portions of the standard documents are added to or contained in the scope of the present invention.

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

Claims (16)

A control information transmission method of a transmission / reception point for transmitting control information to a terminal through a data region of a physical resource block pair of a subframe,
The remainder obtained by dividing 16 numbers from the resource block pairs by frequency first and then dividing by 4 of the enhanced resource groups composed of resource elements having the same index for the resource elements assigned the indexes Allocating control channel elements to resource element groups corresponding to the same index or resource element groups corresponding to the same index divided by two; And
And transmitting control information to the terminal through at least one control channel element among the control channel elements. The method of claim 1,
The resource block pair is configured to configure one downlink control channel (enhanced Physical Downlink Control Channel) set in a localized manner with one or more other resource block pairs (transmitted control point transmission method). The method of claim 1,
The indexes of the resource element groups allocated to the control channel elements are {0,4,8,12}, {1,5,9,13}, {2,6,10,14} and {3,7, Control information transmission method of a transmission and reception point, characterized in that. The method of claim 1,
The indexes of the resource element groups allocated to the control channel elements are {0,2,4,6,8,10,12,14} and {1,3,5,7,9,11,13,15}, respectively. Control information transmission method of a transmission and reception point characterized in that. A control information receiving method of a terminal for receiving control information from a transmission / reception point through a data region of a physical resource block pair of a subframe,
The remainder obtained by dividing 16 numbers from the resource block pairs by frequency first and then dividing by 4 of the enhanced resource groups composed of resource elements having the same index for the resource elements assigned the indexes Receiving a radio signal through at least one control channel element among control channel elements allocated to resource element groups corresponding to the same index or divided by 2 and allocated to resource element groups corresponding to the same index; And
And receiving the control information from the radio signal. 6. The method of claim 5,
The resource block pairs are configured with one or more resource block pairs in a localized manner (localized) in one downlink control channel (enhanced Physical Downlink Control Channel) set, characterized in that for receiving the control information. 6. The method of claim 5,
The indexes of the resource element groups allocated to the control channel elements are {0,4,8,12}, {1,5,9,13}, {2,6,10,14} and {3,7, 11, 15} method for receiving control information of a terminal, characterized in that. 6. The method of claim 5,
The indexes of resource element groups allocated to the control channel elements are {0,2,4,6,8,10,12,14} and {1,3,5,7,9,11,13,15}, respectively. Method of receiving control information of a terminal, characterized in that. A transmission / reception point for transmitting control information to a terminal through a data region of a physical resource block pair of a subframe.
The remainder obtained by dividing 16 numbers from the resource block pairs by frequency first and then dividing by 4 of the enhanced resource groups composed of resource elements having the same index for the resource elements assigned the indexes A control unit for allocating control channel elements to resource element groups corresponding to the same index or resource element groups corresponding to the same index divided by two; And
And a transmitter for transmitting control information to the terminal through at least one control channel element among the control channel elements. 10. The method of claim 9,
The resource block pair is a transmission and reception point, characterized in that the configuration of one downlink control channel (enhanced Physical Downlink Control Channel) set in a localized manner with one or more other resource block pair. 11. The method of claim 10,
The indexes of the resource element groups allocated to the control channel elements are {0,4,8,12}, {1,5,9,13}, {2,6,10,14} and {3,7, 11, 15} transmission and reception point, characterized in that. The method of claim 1,
The indexes of resource element groups allocated to the control channel elements are {0,2,4,6,8,10,12,14} and {1,3,5,7,9,11,13,15}, respectively. Transmission point characterized in that. A terminal for receiving control information from a transmission / reception point through a data region of a physical resource block pair of a subframe,
The remainder obtained by dividing 16 numbers from the resource block pairs by frequency first and then dividing by 4 of the enhanced resource groups composed of resource elements having the same index for the resource elements assigned the indexes A receiver configured to receive a radio signal through at least one control channel element among control channel elements allocated to resource element groups corresponding to the same index or divided by 2 and allocated to resource element groups corresponding to the same index; And
And a control unit for obtaining the control information from the radio signal. 14. The method of claim 13,
The RB pair is configured to configure one downlink physical downlink control channel set in a localized manner with at least one RB pair. 14. The method of claim 13,
The indexes of the resource element groups allocated to the control channel elements are {0,4,8,12}, {1,5,9,13}, {2,6,10,14} and {3,7, 11,15}. 14. The method of claim 13,
The indexes of resource element groups allocated to the control channel elements are {0,2,4,6,8,10,12,14} and {1,3,5,7,9,11,13,15}, respectively. Terminal characterized in that the.

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