KR20140019386A - Method for base station transmitting control signal to user equipment in multiple-antenna wireless communication system and apparatus for same - Google Patents

Abstract

The present invention relates to a wireless communication system, and more particularly, to a method for a base station transmitting a control signal to a terminal in a multiple-antenna wireless communication system and an apparatus therefor. According to an embodiment of present invention, the method for the base station transmitting the control signal to the user equipment in a multi-input multi-output (MIMO) wireless communication system comprises the following steps: forming a resource element group (REG) in four consecutive resource element units in the ascending order of a sub-carrier index, excluding resource elements (RE) for channel state information reference signals (CSI-RS); allocating a transmission resource to the control signal in the resource element group units; and transmitting the control signal, to which the transmission resource is allocated, to the user equipment, wherein the channel state information reference signal can be defined via eight logical antenna ports.

Description

METHOD FOR BASE STATION TRANSMITTING CONTROL SIGNAL TO USER EQUIPMENT IN MULTIPLE-ANTENNA WIRELESS COMMUNICATION SYSTEM AND APPARATUS FOR SAME}

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting a control signal to a terminal by a base station in a multi-antenna wireless communication system.

MIMO (Multiple-Input Multiple-Output) is a method of using a plurality of transmission antennas and a plurality of reception antennas, and the transmission / reception efficiency of data can be improved by this method. That is, by using a plurality of antennas at the transmitting end or the receiving end of the wireless communication system, the capacity can be increased and the performance can be improved. Hereinafter, MIMO may be referred to as 'multiple antennas' in this document.

In multi-antenna technology, it does not rely on a single antenna path to receive a whole message. Instead, in multi-antenna technology, the data is completed by combining the data fragments received from the various antennas. With multi-antenna technology, it is possible to increase the data transmission rate within a cell area of a specified size, or to increase system coverage while ensuring a certain data transmission rate. Further, this technique can be widely used for mobile communication terminals, repeaters, and the like. The multi-antenna technique can overcome the transmission limit in the conventional mobile communication using a single antenna.

A schematic diagram of a typical multiple antenna (MIMO) communication system is shown in FIG. N _T transmission antennas are provided at the transmitting end and N _R reception antennas are provided at the receiving end. When a plurality of antennas are used in both the transmitting end and the receiving end, the theoretical channel transmission capacity is increased as compared with the case where a plurality of antennas are used for either the transmitting end or the receiving end. The increase in the channel transmission capacity is proportional to the number of antennas. Therefore, the transmission rate is improved and the frequency efficiency is improved. Assuming that the maximum transmission rate in the case of using one antenna is R _o , the transmission rate when using multiple antennas is theoretically expressed by the following equation Can be increased by multiplying the rate R _o by the rate increase R _i . Where R _i is the smaller of N _T and N _R.

For example, in a MIMO communication system using four transmit antennas and four receive antennas, the transmission rate can be theoretically four times that of a single antenna system. Since the theoretical capacity increase of such a multi-antenna system was proved in the mid-1990s, various techniques for practically improving the data transmission rate have been actively researched so far. Some of these technologies have already been used for the third generation mobile communication and the next generation wireless LAN And the like.

The research trends related to multi-antennas to date include information theory studies related to calculation of multi-antenna communication capacity in various channel environments and multiple access environments, research on wireless channel measurement and modeling of multi-antenna systems, and improvement of transmission reliability and transmission rate And research on space-time signal processing technology for various applications.

In order to explain the communication method in the multi-antenna system more specifically, it can be expressed as follows when it is mathematically modeled. As shown in FIG. 1, it is assumed that there are N _T transmit antennas and N _R receive antennas. First of all, regarding transmission signals, if there are N _T transmission antennas, the maximum transmission possible information is N _T , so that the transmission information can be represented by a vector as shown in the following Equation 2.

에 있어 전송 전력을 다르게 할 수 있으며, 이때 각각의 전송 전력을

라 하면, 전송 전력이 조정된 전송 정보를 벡터로 나타내면 하기의 수학식 3과 같다.On the other hand,

The transmission power may be different for each transmission power. In this case,

, The transmission information whose transmission power is adjusted is represented by a vector as shown in the following equation (3).

를 전송 전력의 대각행렬

를 이용하여 나타내면 하기의 수학식 4와 같다.Also,

A diagonal matrix of transmit power

The following equation (4) can be obtained.

에 가중치 행렬

가 적용되어 실제 전송되는 N_T 개의 송신신호(transmitted signal)

가 구성되는 경우를 고려해 보자. 여기서, 가중치 행렬은 전송 정보를 전송 채널 상황 등에 따라 각 안테나에 적절히 분배해 주는 역할을 수행한다. 이와 같은 전송신호

는 벡터

를 이용하여 하기의 수학식 5와 같이 나타낼 수 있다. 여기서

는

번째 송신안테나와

번째 정보 간의 가중치를 의미한다.

는 가중치 행렬(Weight Matrix) 또는 프리코딩 행렬(Precoding Matrix)이라고 불린다.On the other hand,

A weighting matrix

The N _T transmitted signals, which are actually transmitted,

. Here, the weight matrix plays a role of appropriately distributing the transmission information to each antenna according to the transmission channel condition and the like. Such a transmission signal

Vector

Can be expressed by the following equation (5). here

The

With the first transmit antenna

It means the weight between the first information.

Is called a weight matrix or a precoding matrix.

In general, the physical meaning of the rank of a channel matrix is the maximum number that can transmit different information in a given channel. Therefore, since the rank of a channel matrix is defined as the minimum number of independent rows or columns, the rank of the matrix is larger than the number of rows or columns. Can not. For example, the rank ( H ( H )) of the channel matrix H is limited as shown in Equation (6).

In addition, each of the different information sent using the multi-antenna technology will be defined as a 'stream' or simply 'stream'. Such a 'stream' may be referred to as a 'layer'. The number of transport streams can then, of course, be no greater than the rank of the channel, which is the maximum number that can send different information. Therefore, the channel matrix H can be expressed by Equation (7) below.

Here, "# of streams" represents the number of streams. Note, however, that one stream may be transmitted over more than one antenna.

There may be several ways to map one or more streams to multiple antennas. This method can be described as follows according to the type of the multi-antenna technique. When one stream is transmitted through multiple antennas, it can be viewed as a space diversity scheme. When multiple streams are transmitted through multiple antennas, it can be regarded as a spatial multiplexing scheme. Of course, a hybrid of spatial diversity and spatial multiplexing is possible.

Based on the above discussion, a method and apparatus for transmitting a control signal to a terminal by a base station in a multi-antenna wireless communication system will now be proposed.

In a multi-input multi-output (MIMO) wireless communication system according to an aspect of the present invention, a base station transmits a control signal to a terminal, the channel state indicator reference signal (Channel State Information-RS; CSI-RS) Forming a resource element group (REG) in units of four resource elements consecutively in ascending order of subcarrier indexes, excluding resource elements (RE), and transmitting the resource element group Allocating a resource to the control signal and transmitting a control signal to which the transmission resource is allocated to the terminal, wherein the channel state indicator reference signal may be defined through eight logical antenna ports.

Meanwhile, in a method of transmitting a control signal to a terminal by a base station in a multi-input multi-output (MIMO) wireless communication system according to another aspect of the present invention, at least one channel state indicator reference signal (Channel State Information-RS) A group of resource element groups in units of four resource elements consecutively in ascending order of subcarrier indexes, except for an orthogonal frequency division multiple (OFDM) symbol (OFDM) symbol including a resource element (RE) for a CSI-RS. Forming a Resource Element Group (REG), allocating a transmission resource to the control signal on a resource element group basis, and transmitting a control signal to which the transmission resource is allocated to the terminal. The indicator reference signal can be defined through eight logical antenna ports.

In the base station for transmitting a control signal to a terminal in a multi-input multi-output (MIMO) wireless communication system according to another aspect of the present invention, a channel state indicator reference signal (CSI-) Except for Resource Elements (REs), resource element groups (REGs) are formed in units of four resource elements consecutively in ascending order of subcarrier indexes, and transmitted in units of resource element groups. A processor for allocating a resource to the control signal and a transmitting module for transmitting the control signal to which the transmission resource is allocated to the terminal, wherein the channel state indicator reference signal may be defined through eight logical antenna ports.

Meanwhile, another aspect of the present invention provides a base station for transmitting a control signal to a terminal in a multi-input multi-output (MIMO) wireless communication system, comprising: at least one channel state indicator reference signal (Channel State Information-RS); Except for Orthogonal Frequency Division Multiple (OFDM) symbols including Resource Element (RE) for CSI-RS, resource element group (Resource element unit) in units of four resource elements consecutively in ascending order of subcarrier index An element group (REG), a processor for allocating a transmission resource to the control signal on a resource element group basis, and a transmission module for transmitting the control signal to which the transmission resource is allocated to the terminal. The reference signal may be defined through eight logical antenna ports.

According to an embodiment of the present invention, a base station can effectively transmit a control signal to a terminal in a multi-antenna wireless communication system. The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

1 is a block diagram of a general multi-antenna (MIMO) communication system.
2 is a diagram showing a control plane and a user plane structure of a radio interface protocol between a UE and an E-UTRAN based on the 3GPP radio access network standard.
3 is a view for explaining a physical channel used in a 3GPP system and a general signal transmission method using the same.
4 is a diagram illustrating a structure of a radio frame used in an LTE system.
5 is a diagram illustrating a structure of a downlink radio frame used in an LTE system.
6 is a diagram illustrating a structure of an uplink subframe used in an LTE system.
7 is a diagram illustrating various methods of mapping codewords to layers.
FIG. 8 is a diagram illustrating a structure of a reference signal in an LTE system supporting downlink transmission using four antennas.
9 is a diagram illustrating the configuration of a relay backhaul link and a relay access link in a wireless communication system.
10 is a diagram illustrating an example of relay resource division.
FIG. 11 (a) is a diagram illustrating a reference signal pattern in a 3GPP Release 8 system. FIG.
FIG. 11B is a diagram illustrating a reference signal pattern in a 3GPP Release 9 system or a 3GPP Release 10 system.
12 is a diagram illustrating a general REG indexing order.
13 is a diagram showing the configuration of a CSI-RS in accordance with the present invention.
FIG. 14 is a diagram illustrating an example of an REG indexing sequence in a 5 CSI-RS configuration according to the present invention.
FIG. 15 is a diagram illustrating an example of an REG indexing sequence in a 4 CSI-RS configuration according to the present invention.
FIG. 16 is a diagram illustrating an example of an REG indexing sequence in a 3 CSI-RS configuration in connection with the present invention.
FIG. 17 is a view showing another example of an REG indexing order in a 3 CSI-RS configuration according to the present invention.
FIG. 18 is a diagram illustrating another example of an REG indexing order in a 3 CSI-RS configuration according to the present invention.
FIG. 19 is a diagram illustrating another example of an REG indexing order in a 3 CSI-RS configuration according to the present invention.
FIG. 20 is a diagram illustrating an example of an REG indexing sequence in a 4 CSI-RS configuration according to the present invention.
FIG. 21 is a view showing another example of an REG indexing order in a 4 CSI-RS configuration according to the present invention.
FIG. 22 is a diagram illustrating still another example of an REG indexing order in a 4 CSI-RS configuration according to the present invention.
FIG. 23 is a diagram illustrating another example of an REG indexing order in a 4 CSI-RS configuration according to the present invention.
FIG. 24 illustrates another example of an REG indexing order in a 4 CSI-RS configuration according to the present invention.
25 is a diagram illustrating an example of a block diagram of a terminal device according to an embodiment of the present invention.

Hereinafter, the structure, operation and other features of the present invention will be readily understood by the embodiments of the present invention described with reference to the accompanying drawings. The embodiments described below are examples in which technical features of the present invention are applied to a 3GPP system.

Although the present specification describes an embodiment of the present invention using an LTE system and an LTE-A system, embodiments of the present invention may be applied to any communication system corresponding to the above definition. In addition, although the present invention is described with reference to the FDD scheme, the embodiments of the present invention can be easily modified to the H-FDD scheme or the TDD scheme.

2 is a diagram showing a control plane and a user plane structure of a radio interface protocol between a UE and an E-UTRAN based on the 3GPP radio access network standard. The control plane refers to a path through which control messages used by a UE and a network are transferred. The user plane means a path through which data generated in the application layer, for example, voice data or Internet packet data, is transmitted.

The physical layer as the first layer provides an information transfer service to an upper layer using a physical channel. The physical layer is connected to a medium access control layer (upper layer) through a transport channel. Data moves between the MAC layer and the physical layer over the transport channel. Data is transferred between the transmitting side and the receiving side physical layer through the physical channel. The physical channel utilizes time and frequency as radio resources. Specifically, the physical channel is modulated in an OFDMA (Orthogonal Frequency Division Multiple Access) scheme in a downlink, and is modulated in an SC-FDMA (Single Carrier Frequency Division Multiple Access) scheme in an uplink.

The Medium Access Control (MAC) layer of the second layer provides a service to a radio link control (RLC) layer, which is an upper layer, through a logical channel. The RLC layer of the second layer supports reliable data transmission. The Packet Data Convergence Protocol (PDCP) layer of the second layer is used to efficiently transmit IP packets such as IPv4 and IPv6 on a wireless interface with a narrow bandwidth, And performs header compression to reduce information.

The Radio Resource Control (RRC) layer located at the bottom of the third layer is defined only in the control plane. The RRC layer is responsible for the control of logical channels, transport channels and physical channels in connection with the configuration, re-configuration and release of radio bearers (RBs). RB denotes a service provided by the second layer for data transmission between the UE and the network. To this end, the terminal and the RRC layer of the network exchange RRC messages with each other. If there is an RRC connection (RRC Connected) between the UE and the RRC layer of the network, the UE is in the RRC Connected Mode, otherwise it is in the RRC Idle Mode. The Non-Access Stratum (NAS) layer at the top of the RRC layer performs functions such as session management and mobility management.

One cell constituting the base station eNB is set to one of the bandwidths of 1.25, 2.5, 5, 10, 15, 20Mhz and the like to provide a downlink or uplink transmission service to a plurality of terminals. Different cells may be configured to provide different bandwidths.

A downlink transmission channel for transmitting data from a network to a terminal includes a BCH (Broadcast Channel) for transmitting system information, a PCH (Paging Channel) for transmitting a paging message, a downlink SCH (Shared Channel) for transmitting user traffic or control messages, have. In case of a traffic or control message of a downlink multicast or broadcast service, it may be transmitted through a downlink SCH, or may be transmitted via a separate downlink multicast channel (MCH). Meanwhile, the uplink transmission channel for transmitting data from the UE to the network includes a random access channel (RACH) for transmitting an initial control message and an uplink SCH (shared channel) for transmitting user traffic or control messages. A logical channel mapped to a transport channel is a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH) Traffic Channel).

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

When the terminal is turned on or newly enters a cell, the terminal performs an initial cell search operation such as synchronizing with the base station (S301). To this end, the terminal receives a primary synchronization channel (P-SCH) and a secondary synchronization channel (S-SCH) from a base station and synchronizes with the base station and acquires information such as a cell ID have. Then, the terminal can receive the physical broadcast channel from the base station and acquire the in-cell broadcast information. Meanwhile, the UE can receive the downlink reference signal (DL RS) in the initial cell search step to check the downlink channel state.

Upon completion of the initial cell search, the UE receives more detailed system information by receiving a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Control Channel (PDSCH) according to the information on the PDCCH (S302).

On the other hand, if the base station is initially connected or there is no radio resource for signal transmission, the mobile station can perform a random access procedure (RACH) on the base station (steps S303 to S306). To do this, the UE transmits a specific sequence through a Physical Random Access Channel (PRACH) (S303 and S305), and receives a response message for the preamble on the PDCCH and the corresponding PDSCH S304 and S306). In case of the contention-based RACH, a contention resolution procedure can be additionally performed.

The UE having performed the procedure described above transmits PDCCH / PDSCH reception (S307), Physical Uplink Shared Channel (PUSCH) / Physical Uplink Control Channel Control Channel (PUCCH) transmission (S308). In particular, the UE receives downlink control information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for the UE, and formats are different according to the purpose of use.

Meanwhile, the control information that the UE transmits to the base station through the uplink or receives from the base station includes a downlink / uplink ACK / NACK signal, a channel quality indicator (CQI), a precoding matrix index (PMI) ) And the like. In the case of the 3GPP LTE system, the UE can transmit control information such as CQI / PMI / RI as described above through PUSCH and / or PUCCH.

4 is a diagram illustrating a structure of a radio frame used in an LTE system.

Referring to FIG. 4, a radio frame has a length of 10 ms (327200 · T _s ) and consists of 10 equally sized subframes. Each subframe has a length of 1 ms and is composed of two slots. Each slot has a length of 0.5 ms (15360 · T _s ). Here, T _s represents the sampling time, and is represented by Ts = 1 / (15 kHz x 2048) = 3.2552 x 10 ^-8 (about 33 ns). A slot includes a plurality of OFDM symbols in a time domain and a plurality of resource blocks (RB) in a frequency domain. In the LTE system, one resource block includes 12 subcarriers x 7 (6) OFDM symbols. A TTI (Transmission Time Interval), which is a unit time at which data is transmitted, may be defined in units of one or more subframes. The structure of the radio frame is merely an example, and the number of subframes included in a radio frame, the number of slots included in a subframe, and the number of OFDM symbols included in a slot can be variously changed.

5 is a diagram illustrating a structure of a downlink radio frame used in an LTE system.

Referring to FIG. 5, the downlink radio frame includes 10 subframes having an equal length. In the 3GPP LTE system, a subframe is defined as a basic time unit of packet scheduling for the entire downlink frequency. Each subframe is divided into a time interval (control region) for transmitting scheduling information and other control information, and a time interval (data region, data region) for downlink data transmission. The control region begins with the first OFDM symbol of the subframe and includes one or more OFDM symbols. The size of the control region may be set independently for each subframe. The control region is used to transmit L1 / L2 (layer 1 / layer 2) control signals. The data area is used to carry downlink traffic.

6 is a diagram illustrating a structure of an uplink subframe used in an LTE system.

Referring to FIG. 6, a subframe 600 having a length of 1 ms, which is a basic unit of LTE uplink transmission, is composed of two 0.5 ms slots 601. Assuming the length of a normal cyclic prefix (CP), each slot is composed of seven symbols 602 and one symbol corresponds to one SC-FDMA symbol. The resource block 603 is a resource allocation unit corresponding to 12 subcarriers in the frequency domain and one slot in the time domain. The structure of an uplink subframe of LTE is largely divided into a data region 604 and a control region 605. Here, the data region refers to a series of communication resources used for transmitting data such as voice, packet, etc. transmitted to each terminal, and corresponds to the remaining resources except for the control region in the subframe. The control region refers to a set of communication resources used for transmitting a downlink channel quality report from each terminal, a reception ACK / NACK for a downlink signal, an uplink scheduling request, and the like.

As shown in the example of FIG. 6, an area 606 in which a sounding reference signal can be transmitted in one subframe is an interval in which a SC-FDMA symbol is positioned last on the time axis in one subframe. It is transmitted through the data transmission band. Sounding reference signals of various terminals transmitted in the last SC-FDMA of the same subframe can be distinguished from cyclic shift values. In addition, an area 507 in which a DM (Demodulation) -Reference Signal is transmitted in one subframe includes a middle SC-FDMA symbol, that is, a fourth SC-FDMA symbol and an eleventh SC-FDMA symbol in one slot. Is a section, and is transmitted through the data transmission band on the frequency.

7 is a diagram illustrating various methods of mapping codewords to layers.

Referring to FIG. 7, there are various methods for mapping codewords to layers. When MIMO transmission is performed, the transmitter must determine the number of codewords according to the layer. The number of codewords and layers refers to the number of different data sequences and the rank of the channel, respectively. The transmitting end needs to map the codeword to the layer as appropriate.

Hereinafter, the reference signal will be described in more detail. In general, a reference signal already known by the transmitting side and the receiving side together with data is transmitted from the transmitting side to the receiving side for channel measurement. The reference signal not only informs the channel measurement but also the modulation technique, thereby performing the demodulation process. A reference signal is divided into a dedicated RS (DRS) for a BS and a UE, that is, a common reference signal (CRS), which is a UE-specific reference signal and a cell specific reference signal for all UEs in the cell. In addition, the cell specific reference includes a reference signal for measuring and reporting the CQI / PMI / RI in the terminal to the base station, which is called a channel state information-RS (CSI-RS).

FIG. 8 is a diagram illustrating a structure of a reference signal in an LTE system supporting downlink transmission using four antennas. In particular, FIG. 8A illustrates a case of normal cyclic prefix, and FIG. 8B illustrates a case of extended cyclic prefix.

Referring to FIG. 8, 0 to 3 described in the grid mean a common reference signal (CRS), which is a cell specific reference signal transmitted for channel measurement and data demodulation corresponding to each of antenna ports 0 to 3, and the cell specific reference. The signal CRS may be transmitted to the terminal not only in the data information region but also in the entire control information region.

In addition, 'D' described in the grid means a downlink DM-RS (DM-RS), which is a UE-specific RS, and supports single antenna port transmission through a data region, that is, a PDSCH. The UE receives an indication of the existence of the UE-specific RS through an upper layer.

On the other hand, the RS mapping rule to the resource block (RB) can be represented by the following equation (8) to (10). Equation 8 is an expression for representing the CRS mapping rule. Equation 9 is an equation for representing a mapping rule of a DRS to which a general CP is applied, and Equation 10 is an equation for representing a mapping rule of a DRS to which an extended CP is applied.

, ns,

는 각각 하향링크에 할당된 RB 의 수, 슬롯 인덱스의 수, 셀 ID 의 수를 나타낸다. RS 의 위치는 주파수 도메인 관점에서 V_shift 값에 따라 달라진다.In Equations 8 to 10, k and p represent subcarrier indexes and antenna ports, respectively.

, ns,

Denotes the number of RBs, the number of slot indices, and the number of cell IDs, respectively. The position of RS depends on the V _shift value in terms of frequency domain.

The LTE-A system, which is a standard for the next generation mobile communication system, is expected to support CoMP (Coordinated Multi Point) method, which was not supported in the existing standard, to improve data rate. Here, the CoMP system refers to a system in which two or more base stations or cells cooperate with each other to communicate with the terminal in order to improve communication performance between the terminal and the base station (cell or sector) in the shadow area.

The CoMP scheme can be classified into cooperative MIMO joint processing (CoMP-Joint Processing, CoMP-JP) and CoMP-Coordinated Scheduling / Beamforming (CoMP-CS / CB).

In the case of downlink, in a joint processing (CoMP-JP) scheme, a terminal may simultaneously receive data from each base station performing CoMP and may improve reception performance by combining signals received from each base station. . Alternatively, in the cooperative scheduling / beamforming scheme (CoMP-CS), the UE can receive data via beamforming through one base station instantaneously.

In the joint processing (CoMP-JP) scheme in the uplink, each base station can simultaneously receive the PUSCH signal from the terminal. In contrast, in cooperative scheduling / beamforming scheme (CoMP-CS), only one base station receives a PUSCH, where the decision to use the cooperative scheduling / beamforming scheme is determined by the cooperative cells (or base stations). .

On the other hand, if the channel state between the base station and the terminal is poor, a relay (RN) between the base station and the terminal can be installed to provide a radio channel having a better channel state to the terminal. In addition, by introducing and using a repeater in a cell boundary region having a poor channel state from the base station, it is possible to provide a faster data channel and expand the cell service area. As such, the repeater is currently widely used as a technique introduced for eliminating the radio shadow area in a wireless communication system.

The past method has recently been developed in a more intelligent manner than that limited to the function of a repeater simply amplifying and transmitting a signal. Furthermore, the repeater technology is a technology necessary for reducing the base station expansion cost and the backhaul network maintenance cost in the next generation mobile communication system, while expanding service coverage and improving data throughput. As the repeater technology gradually develops, it is necessary to support the repeater used in the conventional wireless communication system in the new wireless communication system.

In the 3GPP LTE-A (3rd Generation Partnership Project Long Term Evolution-Advanced) system, the role of forwarding the link connection between the base station and the terminal to the repeater is introduced. The link will be applied. The connection link portion between the base station and the repeater is defined as a backhaul link. It is referred to as a backhaul downlink in which FDD (Frequency Division Duplex) or TDD (Time Division Duplex) transmission is performed using downlink resources, and FDD or TDD transmission is performed using uplink resources It can be expressed as a backhaul uplink.

9 is a diagram illustrating the configuration of a relay backhaul link and a relay access link in a wireless communication system.

Referring to FIG. 9, two types of links having different attributes are applied to respective uplink and downlink carrier frequency bands as a repeater is introduced to forward a link between a base station and a terminal. The connection link portion established between the base station and the repeater is defined and represented as a relay backhaul link. When a backhaul link is transmitted using resources of a frequency division duplex (FDD) or a downlink subframe (Time Division Duplex, TDD), the backhaul link is represented by a backhaul downlink, Frequency band or an uplink sub-frame (in the case of FDD) and a resource in the uplink sub-frame (in the case of TDD), it can be expressed as a backhaul uplink.

On the other hand, the connection link portion established between the relay and the series of terminals is defined and represented as a relay access link. When the relay access link is transmitted using the downlink frequency band (in the case of the FDD) or the downlink sub-frame (in the case of the TDD), an access downlink is expressed as an access downlink and an uplink frequency band (in the case of an FDD) Or access uplink when transmission is performed using uplink sub-frames (in the case of TDD) resources.

The RN may receive information from the base station via a relay backhaul downlink and may transmit information to the base station via a relay backhaul uplink. In addition, the repeater can transmit information to the terminal through the relay access downlink and receive information from the terminal through the relay access uplink.

On the other hand, with respect to the use of the band (or spectrum) of the repeater, the case where the backhaul link operates in the same frequency band as the access link is referred to as 'in-band', and the backhaul link and the access link are referred to as different frequency bands Is referred to as an " out-band ". (Hereinafter referred to as a legacy terminal) operating in accordance with an existing LTE system (e.g., Release-8) in both the in-band and the out-band must be able to access the donor cell.

Depending on whether the terminal recognizes the repeater, the repeater can be classified as either a transparent repeater or a non-transparent repeater. Transparent means a case where the terminal does not recognize whether it communicates with the network through a repeater, and non-transparent means when the terminal recognizes whether or not the terminal communicates with the network through a repeater.

Regarding the control of the repeater, it may be classified into a repeater composed of a part of the donor cell or a repeater controlling the cell itself.

A repeater configured as a part of a donor cell may have a repeater identifier (ID), but does not have a repeater own cell identity. When at least a part of RRM (Radio Resource Management) is controlled by the base station to which the donor cell belongs (although the remaining parts of the RRM are located in the repeater), it is referred to as a relay configured as part of the donor cell. Preferably, such a repeater may support a legacy terminal. For example, various types of smart repeaters, decode-and-forward relays, L2 (second layer) repeaters, and type-2 repeaters are examples of such repeaters.

In the case of a repeater that controls the cell by itself, the repeater controls one or several cells, each of the cells controlled by the repeater is provided with a unique physical layer cell identity, and the same RRM mechanism can be used. From a terminal perspective, there is no difference between accessing cells controlled by a repeater and cells controlled by a general base station. Preferably, a cell controlled by such a repeater may support a legacy terminal. For example, self-backhauling repeaters, L3 (third layer) repeaters, type 1 repeaters and type 1a repeaters are such repeaters.

A Type-1 repeater controls a plurality of cells as an in-band repeater, and each of these plurality of cells appears as a separate cell distinct from the donor cell in the terminal's end. In addition, the plurality of cells have their own physical cell IDs (defined in LTE Release-8), and the repeater may transmit its own synchronization channel, reference signal, and the like. In the case of a single-cell operation, the UE receives scheduling information and HARQ feedback directly from the repeater and may transmit its control channel (scheduling request (SR), CQI, ACK / NACK, etc.) to the repeater. Also, for legacy terminals (terminals operating in accordance with the LTE Release-8 system), the Type-1 repeater appears to be a legacy base station (a base station operating according to the LTE Release-8 system). That is, it has backward compatibility. For the terminals operating according to the LTE-A system, the type-1 repeater can be regarded as a base station different from the legacy base station, and can provide a performance improvement.

The Type-1 repeater has the same features as the above-described Type-1 repeater except that it operates out-of-band. The operation of the type-1a repeater may be configured to minimize or eliminate the impact on L1 (first layer) operation.

The type-2 repeater is an in-band repeater and does not have a separate physical cell ID and thus does not form a new cell. The Type-2 repeater is transparent to the legacy terminal, and the legacy terminal does not recognize the presence of the Type-2 repeater. The type-2 repeater may transmit the PDSCH, but not at least the CRS and the PDCCH.

On the other hand, in order for the repeater to operate in-band, some resources in the time-frequency space must be reserved for the backhaul link and this resource may be set not to be used for the access link. This is called resource partitioning.

The general principle of resource partitioning in a repeater can be described as follows. The backhaul downlink and access downlinks may be multiplexed on a carrier frequency in a time division multiplexing (TDM) manner (i.e., only one of the backhaul downlink or access downlink is activated at a particular time). Similarly, the backhaul uplink and access uplink may be multiplexed on a carrier frequency in a TDM fashion (i.e., only one of the backhaul uplink or access uplink is active at a particular time).

The backhaul link multiplexing in the FDD can be described as the backhaul downlink transmission being performed in the downlink frequency band and the backhaul uplink transmission being performed in the uplink frequency band. Backhaul link multiplexing in TDD can be explained as backhaul downlink transmission is performed in the downlink subframe of the base station and the repeater, and backhaul uplink transmission is performed in the uplink subframe of the base station and the repeater.

In the case of an in-band repeater, for example, when a backhaul downlink reception from a base station and a downlink transmission to an access terminal are simultaneously performed in a predetermined frequency band, a signal transmitted from the transmitting end of the repeater is received Signal interference or RF jamming may occur at the RF front-end of the repeater. Similarly, if reception of an access uplink from a terminal in a predetermined frequency band and transmission of a backhaul uplink to a base station are simultaneously performed, signal interference may occur at the front end of the repeater. Thus, in a repeater, simultaneous transmission and reception in one frequency band may require sufficient separation between the received signal and the transmitted signal (e. G., Spacing the transmit and receive antennas sufficiently geographically (e. Is not provided.

One solution to this problem of signal interference is to have the repeater operate so that it does not transmit a signal to the terminal while it is receiving a signal from the donor cell. That is, a gap can be created in the transmission from the repeater to the terminal, and during this gap, the terminal (including the legacy terminal) can be set not to expect any transmission from the repeater. This gap can be set by constructing a MBSFN (Multicast Broadcast Single Frequency Network) subframe

10 is a diagram illustrating an example of relay resource division.

In FIG. 10, a downlink (ie, access downlink) control signal and data are transmitted from a repeater to a user equipment as a first subframe, and a second subframe is an MBSFN subframe in a control region of a downlink subframe. The control signal is transmitted from the repeater to the terminal, but no transmission is performed from the repeater to the terminal in the remaining areas of the downlink subframe. In the case of the legacy UE, since the physical downlink control channel (PDCCH) is expected to be transmitted in all downlink subframes (that is, in the repeater, the legacy UE in its area receives the PDCCH in every subframe and measures the function). It is necessary to support to perform the), in order to properly operate the legacy terminal it is necessary to transmit the PDCCH in all downlink subframes. Thus, even on a subframe (second subframe 1020) configured for downlink (i.e., backhaul downlink) transmission from the base station to the repeater, the first N (N = 1, 2 or 3) OFDM symbols of the subframe In the interval, the repeater needs to perform access downlink transmission rather than receiving the backhaul downlink. On the other hand, since the PDCCH is transmitted from the repeater to the terminal in the control region of the second subframe, backward compatibility with respect to the legacy terminal served by the repeater may be provided. In the remaining areas of the second subframe, the repeater may receive the transmission from the base station while no transmission is performed from the repeater to the terminal. Therefore, through the resource division method, it is possible to prevent the access downlink transmission and the backhaul downlink reception from being performed simultaneously in the in-band repeater.

The second sub-frame using the MBSFN sub-frame will be described in detail. The control region of the second subframe may be referred to as a relay non-hearing section. The repeater non-listening interval refers to a period in which a repeater transmits an access downlink signal without receiving a backhaul downlink signal. This interval may be set to one, two or three OFDM lengths as described above. In the repeater non-listening period, the repeater may perform access downlink transmission to the terminal and receive the backhaul downlink from the base station in the remaining areas. At this time, since the repeater can not simultaneously perform transmission and reception in the same frequency band, it takes time for the repeater to switch from the transmission mode to the reception mode. Therefore, the guard time GT needs to be set so that the repeater performs transmission / reception mode switching in the first partial section of the backhaul downlink reception region. Similarly, even if the repeater is operative to receive the backhaul downlink from the base station and to transmit the access downlink to the terminal, the guard time GT for the receive / transmit mode switching of the repeater can be set. The length of this guard time can be given as the value of the time domain and can be given, for example, as a value of k (k? 1) time samples (Ts), or set to one or more OFDM symbol lengths have. Alternatively, the guard time of the last part of the subframe may or may not be defined, if the repeater backhaul downlink subframe is set consecutively or according to a predetermined subframe timing alignment relationship. In order to maintain backward compatibility, the guard time can be defined only in the frequency domain set for the backhaul downlink subframe transmission (when the guard time is set in the access downlink interval, the guard time can not support the legacy terminal). In the backhaul downlink reception interval excluding the guard time, the repeater may receive the PDCCH and the PDSCH from the base station. It can be represented by R-PDCCH (Relay-PDCCH) and R-PDSCH (Relay-PDSCH) in the sense of a repeater dedicated physical channel.

On the other hand, the repeater can operate as a terminal. The mode in which the repeater operates as a terminal may be referred to as a terminal mode.

When the repeater operates as a terminal, the R-PDCCH may be represented as an E-PDCCH. In addition, when the repeater operates as a terminal, the R-PDSCH may be represented as an E-PDSCH.

In this case, the E-PDCCH or the E-PDSCH may be mapped to resources without considering slots.

The basic unit that forms the R-PDCCH and interleaves several R-PDCCHs together is called R-REG. In the LTE system, the REG is composed of four REs, but the R-REG of the backhaul downlink for the relay node may be configured the same or differently.

In addition, when the repeater operates as a terminal, a unit configuring an E-PDCCH and interleaving several E-PDCCHs together may be referred to as an E-REG or REG.

FIG. 11 (a) shows a reference signal pattern in a 3GPP Release 8 system, and FIG. 11 (b) shows a reference signal pattern in a 3GPP Release 9 system or a 3GPP Release 10 system.

Referring to (a) of FIG. 11, CRSs exist for antenna ports 0, 1, 2, and 3, respectively. Of particular note is that the number of REs allocated to CRSs for antenna ports 0 and 1 and the number of REs allocated to CRSs for antenna ports 2 and 3 are different, especially OFDM symbol indexes # 0 and # 1 that cannot be used as backhaul resources. There are many REs assigned to CRS.

11B illustrates a case in which the DM-RS is added and symbol indices # 0 to # 2 cannot be used for backhaul data transmission, but the number of unavailable symbols may vary.

12 is an illustration of a typical REG indexing order.

Referring to FIG. 12, REG indexing is generally performed in a time-priority manner as in (a) or a frequency-priority manner as in (b). As a variation, the REG indexing is performed by grouping a certain number of symbols and then time-first or by the unit of the bundle. A hybrid method that performs indexing with frequency priority may also be considered.

On the other hand, it is an object of the present invention to provide a method of mapping the R-PDCCH to the REG. Another object of the present invention is to provide a method of mapping an E-PDCCH to a REG when the repeater operates as a terminal.

There are various ways to map R-PDCCH to REG using REG concept. Considerations in REG mapping include CRS and CSI-RS.

The RE in which the CRS is present may be considered as unavailable RE and may be excluded from the R-PDCCH mapping.

In addition, the RE where the CSI-RS is located may be considered as unavailable RE and may be excluded from the R-PDCCH mapping.

On the other hand, the CSI-RS may assume that all 8 ports REs are unavailable REs and may exclude them from the R-PDCCH mapping under the assumption that all 8 ports exist.

In particular, a zero power RE muted in the CSI-RS pattern may also be considered as unavailable RE and may be excluded from the R-PDCCH mapping.

However, the present invention is not limited to the above description, and the CSI RS configuration that is actually transmitted may be applied to a configuration different from the 8 ports assumed above.

First, the CSI-RS may be configured as shown in FIG. 13. Referring to FIG. 13, 8 port CSI-RSs may be configured and transmitted to a total of five different locations.

According to the present invention, when DL resource assignment is transmitted to a first slot and UL scheduling grant is transmitted to a second slot assuming 8 port CSI-RS shown in FIG. 13, R-PDCCH is mapped in REG units in order. Provide a way to do it.

However, as described above, when the repeater operates as a terminal, the R-PDCCH may be represented by an E-PDCCH, and when the repeater operates as a terminal, the R-PDSCH may be represented by an E-PDSCH. In addition, the E-PDCCH or the E-PDSCH may be mapped to resources without considering slots.

Hereinafter, a method of mapping R-PDCCHs in order of REG units will be described in detail with reference to FIGS. 14 to 24.

FIG. 14 is a diagram illustrating an example of an REG indexing sequence in a 5 CSI-RS configuration according to the present invention.

Referring to FIG. 14, the first slot includes a REG configuration including CRS and an REG configuration including 8 port CSI-RS.

That is, 6 consecutive REs can be bundled into one REG and used for REG indexing.

In the case of indexing in this manner, the REG index may be assigned as illustrated in the first slot of FIG. 14.

In addition, in the second slot, CSI-RS transmission symbols including only CSI-RS REs exist in symbols # 9 and # 10.

In this case, there is no REG configuration or REG indexing for these two symbols.

However, since CSI-RS of symbols # 12 and # 13 occupy only 4RE per symbol, 6 consecutive REs including 2RE can be configured as one REG.

Meanwhile, FIG. 15 shows an example of an REG indexing order of the 4 CSI-RS configuration in symbols # 9, # 10, # 12, and # 13.

16 illustrates an example of an REG indexing sequence in the 3 CSI-RS configuration in symbols # 9 and # 10.

Next, FIG. 17 illustrates an example in which three CSI-RSs are configured over a first slot and a second slot.

In this case, since R-PDCCH REG is a requirement to configure symbols # 9 and # 10, 6 consecutive REs can be configured as one REG to perform indexing as shown.

18 illustrates another example of the REG indexing order in the 3 CSI-RS configuration.

19 illustrates another example of the REG indexing order in the 3 CSI-RS configuration in connection with the present invention.

20 illustrates a case where four CSI-RSs are configured.

In this case, when there is no CSI-RS of the first slot or when there is no CSI-RS of symbols # 12 and # 13, three REGs are configured per OFDM symbol as in symbol # 4.

In FIG. 20, 6 consecutive REs are configured as one REG to generate 2 REGs.

In particular, when two CSI-RSs are configured in symbols # 9 and # 10 as shown in FIG. 20, since the remaining two pairs of 2 REs are far from each other, it may be difficult to use the R-PDCCH.

In addition, FIG. 23 assumes a case where mapping is performed by forming a Space Frequency Block Coding (SFBC) block in units of 2 REs, and one REG can be added to symbols # 9 and # 10, respectively.

The 3GPP LTE standard uses Space Frequency Block Coding (SFBC), a frequency domain version of Space Time Block Code (STBC), and Space Frequency Block Coding (SFBC) operates in pairs of adjacent subcarriers. It is defined for two transmit antennas. If four transmit antennas are applied, a combination of SFBC and frequency switched by transmit diversity may be used.

In addition, FIG. 22 illustrates another example of an REG indexing order in a 4 CSI-RS configuration in connection with the present invention.

Meanwhile, FIG. 23 illustrates a case where two 8-port CSI-RS REs are assumed to be symbols # 9 and # 10.

In addition, FIG. 24 illustrates another example of an REG indexing order in a 4 CSI-RS configuration in connection with the present invention.

In this case, in order to use four available REs existing in the corresponding OFDM, 12 consecutive REs may be bundled and used as one REG.

In this case, the corresponding REG index may be 2 and 3, respectively. In addition, a method of using only four available bundles may also be used.

23 is the same as the current REG indexing. However, since FIG. 24 configures REG without including the position of CSI-RS, the REG index is pushed backward so that the REG index becomes # 5 and # 6.

Therefore, the REG is composed of 4 REs excluding the RS RE, and may include 4 consecutive Res, 6 consecutive REs, and 12 consecutive REs when the RS RE is included.

In REG indexing, it is assumed that indexing is performed by considering the position of RS.

In case of configuring REF only with consecutive available 4RE except RS RE, REG index order different from drawing is obtained when time-first indexing method is applied.

Meanwhile, according to another embodiment of the present invention, R-PDCCH REG mapping may be performed according to the following method.

First, as shown in FIGS. 17 to 19, when it is assumed that one or more 8 port CSI-RSs are configured in symbol # 9 and # 10 (actual transmission may be different), the R-PDCCH is not mapped to the corresponding subframe. May be applied.

17 to 19, when one or more 8 port CSI-RSs should be assumed to be configured in symbol # 9 and # 10 (actual transmission may be different), the R-PDCCH is not mapped to the corresponding slot. May be used.

17 to 19, when one or more 8 port CSI-RSs should be assumed to be configured in symbol # 9 and # 10 (actual transmission may be different), R-PDCCH is mapped to a corresponding OFDM symbol. An alternative method may be used.

Meanwhile, according to another embodiment of the present invention, R-PDCCH REG mapping may be performed according to the following method.

First, as shown in FIGS. 20 to 22, when it is assumed that two or more 8 port CSI-RSs are configured in symbol # 9 and # 10 (actual transmission may be different), the R-PDCCH is not mapped to the corresponding subframe. May be applied.

In addition, when it is assumed that two or more 8 port CSI-RSs are configured in symbol # 9 and # 10 as shown in FIGS. 20 to 22 (actual transmission may be different), R-PDCCH is not mapped to a corresponding slot. May be used.

In addition, when it is assumed that two or more 8 port CSI-RSs are configured in symbol # 9 and # 10 as shown in FIGS. 20 to 22 (actual transmission may be different), R-PDCCH is mapped to a corresponding OFDM symbol. An alternative method may be used.

Meanwhile, according to another embodiment of the present invention, R-PDCCH REG mapping may be performed according to the following method.

First, as shown in FIGS. 14 to 16, when it is assumed that three or more 8 port CSI-RSs are configured in symbol # 9 and # 10 (actual transmission may be different), the R-PDCCH is not mapped to the corresponding subframe. May be applied.

In addition, as shown in FIGS. 14 to 16, when it is assumed that two or more 8 port CSI-RSs are configured in symbol # 9 and # 10 (actual transmission may be different), the R-PDCCH is not mapped to the corresponding slot. May be used.

14 to 16, when two or more 8 port CSI-RSs should be assumed to be configured in symbol # 9 and # 10 (actual transmission may vary), the R-PDCCH is mapped to the corresponding OFDM symbol. An alternative method may be used.

Meanwhile, in the above description of the present invention, the REG indexes of the first slot and the second slot are independently defined. However, depending on the implementation, it is also possible to integrate two slots and index into one REG index.

In addition, when the R-PDCCH is a new type of PDCCH mapped over two slots, it is preferable to index both slots with one REG index.

In addition, as described above, when the repeater operates as a terminal, the R-PDCCH may be represented by the E-PDCCH, and the R-PDSCH may be represented by the E-PDSCH. In addition, the E-PDCCH or the E-PDSCH may be mapped to resources without considering slots.

25 is a block diagram of a terminal device according to one embodiment of the present invention.

Referring to FIG. 25, the terminal device 1200 includes a processor 1210, a memory 1220, an RF module 1230, a display module 1240, and a user interface module 1250.

The terminal device 1200 is shown for convenience of description and some modules may be omitted. In addition, the terminal device 1200 may further include necessary modules. In addition, in the terminal device 1200, some modules may be classified into more granular modules. The processor 1210 is configured to perform operations according to embodiments of the present invention illustrated with reference to the figures.

In detail, the processor 1210 may perform an operation required to multiplex the control signal and the data signal. Detailed operations of the processor 1210 may refer to the contents described with reference to FIGS. 1 to 30.

Memory 1220 is coupled to processor 1210 and stores an operating system, applications, program code, data, and the like. The RF module 1230 is connected to the processor 1210 and performs a function of converting a baseband signal into a radio signal or a radio signal into a baseband signal. To this end, the RF module 1230 performs analog conversion, amplification, filtering, and frequency up conversion, or vice versa. Display module 1240 is coupled to processor 1210 and displays various information. Display module 1240 may use well known elements such as, but not limited to, a Liquid Crystal Display (LCD), a Light Emitting Diode (LED), and an Organic Light Emitting Diode (OLED). The user interface module 1250 is connected to the processor 1210 and may be configured with a combination of well known user interfaces such as a keypad, a touch screen, and the like.

The embodiments described above are those in which the elements and features of the present invention are combined in a predetermined form. Each component or feature shall be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to construct embodiments of the present invention by combining some of the elements and / or features. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is clear that the claims that are not expressly cited in the claims may be combined to form an embodiment or be included in a new claim by an amendment after the application.

In this document, the embodiments of the present invention have been mainly described with reference to the data transmission / reception relationship between the terminal and the base station. The specific operation described herein as being performed by the base station may be performed by its upper node, in some cases. That is, it is apparent that various operations performed for communication with a terminal in a network including a plurality of network nodes including a base station can be performed by a network node other than the base station or the base station. A base station may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. In addition, the terminal may be replaced by terms such as a UE (User Equipment), a Mobile Station (MS), and a Mobile Subscriber Station (MSS).

Embodiments in accordance with the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) field programmable gate arrays, processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. that performs the functions or operations described above. The software code can be stored in a memory unit and driven by the processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various well-known means.

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

In the multi-antenna wireless communication system as described above, a method for transmitting a control signal to a relay node and an apparatus therefor have been described with reference to an example applied to a 3GPP LTE system. It is possible to apply.

Claims (18)

A method for transmitting a control signal from a base station to a terminal in a multi-input multi-output (MIMO) wireless communication system,
Resource Element Group in units of four resource elements consecutively in ascending order of subcarrier index, except for Resource Element (RE) for Channel State Information Reference Signal (CSI-RS) REG);
Allocating a transmission resource to the control signal on a resource element group basis; And
And transmitting the control signal to which the transmission resource is allocated to the terminal.
And the channel state indicator reference signal is defined through eight logical antenna ports. The method of claim 1,
And the resource element group is indexed in a time-first manner. 3. The method of claim 2,
The resource element group is indexed (indexing) is carried out in units of slots, control signal transmission method. The method of claim 1,
And the resource element for the channel state indicator reference signal comprises a resource element for the channel state indicator reference signal with an allocated transmit power of zero. 5. The method of claim 4,
And the channel state indicator reference signal of which the allocated transmission power is 0 is a channel state indicator reference signal of at least one neighboring base station. A method for transmitting a control signal from a base station to a terminal in a multi-input multi-output (MIMO) wireless communication system,
Ascending order of subcarrier indices, except for Orthogonal Frequency Division Multiple (OFDM) symbols containing Resource Elements (REs) for one or more Channel State Information Reference Signals (CSI-RS) Forming a resource element group (REG) in units of four consecutive resource elements;
Allocating a transmission resource to the control signal on a resource element group basis; And
And transmitting the control signal to which the transmission resource is allocated to the terminal.
And the channel state indicator reference signal is defined through eight logical antenna ports. The method according to claim 6,
Wherein the excluded OFDM symbol comprises a resource element for one, two or three or more channel state indicator reference signals. The method according to claim 6,
And the resource element group is indexed in a time-first manner. The method according to claim 6,
And the resource element for the channel state indicator reference signal comprises a resource element for the channel state indicator reference signal with an allocated transmit power of zero. In the base station for transmitting a control signal to a terminal in a multi-input multi-output (MIMO) wireless communication system,
Resource Element Group in units of four resource elements consecutively in ascending order of subcarrier index, except for Resource Element (RE) for Channel State Information Reference Signal (CSI-RS) REG), and allocates a transmission resource to the control signal on a resource element group basis; And
A transmission module for transmitting a control signal allocated to the transmission resource to the terminal,
And the channel state indicator reference signal is defined through eight logical antenna ports. 11. The method of claim 10,
And the resource element group is indexed in a time-first manner. 12. The method of claim 11,
The resource element group is characterized in that the indexing (indexing) is performed on a slot basis. The method of claim 10,
And the resource element for the channel state indicator reference signal includes a resource element for the channel state indicator reference signal with an allocated transmit power of zero. The method of claim 13,
Wherein the channel state indicator reference signal with the allocated transmit power equal to zero is a channel state indicator reference signal of at least one neighboring base station. In the base station for transmitting a control signal to a terminal in a multi-input multi-output (MIMO) wireless communication system,
Ascending order of subcarrier indices, except for Orthogonal Frequency Division Multiple (OFDM) symbols containing Resource Elements (REs) for one or more Channel State Information Reference Signals (CSI-RS) A processor configured to form a resource element group (REG) in units of four consecutive resource elements, and to allocate a transmission resource to the control signal on a resource element group basis; And
A transmission module for transmitting a control signal allocated to the transmission resource to the terminal,
And the channel state indicator reference signal is defined through eight logical antenna ports. The method of claim 15,
Wherein the excluded OFDM symbol comprises a resource element for one, two or three or more channel state indicator reference signals. The method of claim 15,
And the resource element group is indexed in a time-first manner. 16. The method of claim 15,
And the resource element for the channel state indicator reference signal includes a resource element for the channel state indicator reference signal with an allocated transmit power of zero.

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