KR20070083402A - Method of transmtting signal in base station and method of transmitting feedback information in terminal - Google Patents

Abstract

A method for transmitting signals in a base station and a method for transmitting feedback information in a mobile terminal are provided to decrease the amount of feedback information, transmitted to a base station from a mobile terminal, by previously allocating some precoding matrixes or Tx antennas to each frequency group. A base station segments an allocated frequency band into a plurality of frequency groups. The base station allocates one or more precoding matrixes among a plurality of precoding matrixes to each of the divided frequency groups. The base station receives feedback information from a mobile terminal. The base station transmits signals using the frequency of a frequency group corresponding to the received feedback information and the precoding matrixes allocated to the corresponding frequency group.

Description

Method of transmitting signal of base station and method of transmitting feedback information of terminal {METHOD OF TRANSMTTING SIGNAL IN BASE STATION AND METHOD OF TRANSMITTING FEEDBACK INFORMATION IN TERMINAL}

1 and 3 are diagrams illustrating a frequency allocation method and a precoding matrix allocation method according to the first and second embodiments of the present invention, respectively.

2 is a diagram illustrating a transmission beam pattern according to a column vector of a precoding matrix.

4 is a schematic block diagram of an apparatus for transmitting a base station according to a second embodiment of the present invention.

5, 6 and 8 are diagrams illustrating a frequency allocation method and a transmission antenna allocation method according to the third, fourth and fifth embodiments of the present invention, respectively.

7 is a schematic block diagram of an apparatus for transmitting a base station according to a fourth embodiment of the present invention.

9 and 10 are diagrams illustrating a frequency allocation method and a transmission antenna allocation method according to the sixth and seventh embodiments of the present invention, respectively.

The present invention relates to a method for transmitting a base station signal and a method for transmitting feedback information of a terminal.

Recently, a technique for transmitting data using multiple antennas has been researched to improve downlink data throughput in a communication system. At this time, when the base station of the communication system divides frequency resources into a plurality of frequency groups and allocates a frequency group having good channel characteristics to a plurality of users and transmits data, the total cell transmission amount increases. The gain obtained in this way is referred to as "multi-user diversity gain". However, for this purpose, the terminal obtains channel characteristics for each frequency group and feeds back a frequency group having good channel characteristics to the base station.

Multiple antenna technologies include multiple input multiple output (MIMO) technology, beamforming technology, and antenna selection technology.

MIMO technology is a technology that increases the data rate by transmitting two or more data streams using the same frequency resource, which is effective when the received signal-to-noise ratio of the terminal is large. One such MIMO technique is a precoding MIMO technique that assigns a transmission data stream to a beamforming vector (or precoding vector). Since the base station does not know the transmission channel information, it selects a precoding vector based on information fed back from the terminal. In order to improve the performance of precoding MIMO, it is advantageous to have a large number of precoding vectors. However, as the number of precoding vectors increases, the amount of feedback increases.

The beamforming technique is an effective technique for improving transmission performance when the received signal-to-noise ratio of the terminal is low. Among the beamforming techniques, there is a fixed beamforming technique that selects one of fixed beam patterns. In this beamforming technique, the terminal selects a beam suitable for communication quality improvement among possible transmission beams and then feeds back the selected beam number to the base station. As the number of antennas increases, the number of beams increases, so the amount of feedback increases.

The antenna selection technique is a method in which a terminal transmits a signal only to a corresponding antenna and does not transmit a signal to another antenna when the terminal informs the base station of an antenna number having the best channel characteristics among a plurality of transmitting antennas. The antenna selection technique also has a problem in that the amount of feedback increases as the number of antennas increases.

An object of the present invention is to provide a signal transmission method of a base station and a feedback information transmission method of a terminal which can reduce the amount of uplink feedback information.

In order to solve this problem, according to an embodiment of the present invention, a method for transmitting a signal in a base station having a plurality of transmit antennas is provided. The transmission method comprises the steps of: dividing an allocated frequency band into a plurality of frequency groups, assigning some precoding matrices of the plurality of precoding matrices to each frequency group, receiving feedback information from a terminal, and the plurality of And transmitting a signal using a frequency of a frequency group corresponding to the feedback information among the frequency groups of and a precoding matrix assigned to the corresponding frequency group among the plurality of precoding matrices.

According to another aspect of the present invention, there is provided a method of transmitting a signal, comprising: dividing an allocated frequency band into a plurality of frequency groups, allocating some transmit antennas among a plurality of transmit antennas to each frequency group, and receiving feedback information from a terminal. And transmitting a signal by using a frequency of a frequency group corresponding to the feedback information among the plurality of frequency groups and a transmission antenna assigned to the corresponding frequency group among the plurality of transmission antennas.

According to another feature of the invention, a method for transmitting feedback information from a terminal to a base station having a plurality of transmit antennas is provided. The transmission method comprises the steps of: sharing with the base station information on a portion of an allocated frequency band divided into a plurality of frequency groups and information on some precoding matrices allocated to each frequency group among a plurality of precoding matrices; And transmitting feedback information including information on a frequency group selected from the frequency groups of the base station.

In a transmission method according to another aspect of the present invention, information allocated to a frequency band is divided into a plurality of frequency groups and information on some of the transmission antennas allocated to each frequency group among the plurality of transmission antennas is shared with the base station. And transmitting feedback information including information on a frequency group selected from the plurality of frequency groups to the base station.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless otherwise stated. In addition, the terms “… unit”, “… unit”, “module”, “block”, etc. described in the specification mean a unit that processes at least one function or operation, which is hardware or software or a combination of hardware and software. It can be implemented as.

Now, a method of transmitting a signal of a base station and a method of transmitting feedback information of a terminal according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the embodiment of the present invention, the communication system is described as a communication system using OFDM modulation and demodulation, but the present invention can be applied to other communication systems.

First, a signal transmission method of a base station according to the first and second embodiments of the present invention will be described with reference to FIGS. 1 to 4. In the first and second embodiments of the present invention, for convenience of description, it is assumed that the transmitting apparatus of the base station uses two transmitting antennas to transmit signals in the precoding MIMO scheme. However, the present invention uses different numbers of transmitting antennas. It may be.

1 is a diagram illustrating a frequency allocation method and a precoding matrix allocation method according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a transmission beam pattern according to a column vector of a precoding matrix.

Referring to FIG. 1, the communication system according to the first embodiment of the present invention divides an allocated frequency band into a plurality of frequency groups F1 to F6, and each frequency group is formed of a plurality of adjacent subcarriers. In FIG. 1, it is assumed that the allocated frequency band is divided into six frequency groups F1 to F6 for convenience of description.

A plurality of precoding matrices are assigned to each frequency group, and information on the precoding matrix is shared by the terminal and the base station. The precoding matrix is a matrix having a precoding vector as a column vector, and is an M ㅧ M matrix when the number of transmitting antennas is M. The precoding vector is a predetermined beamforming vector, and the precoding vectors in one precoding matrix are set to be orthogonal to each other. According to an embodiment, a discrete Fourier transform (DFT) matrix such as Equation 1 may be used as two precoding matrices for two transmit antennas.

는 i번째 프리코딩 행렬(

)의 j번째 열 벡터이다.When the two transmitting antennas are separated by two wavelengths λ, the transmission beam pattern for each column vector of the precoding matrix of Equation 1 is as shown in FIG. 2. In Figure 2

Is the i th precoding matrix (

Is the jth column vector of).

When two precoding matrices are allocated to each frequency group F1 to F6 as described above, the terminal may provide information necessary for selecting a frequency group having good channel characteristics among the plurality of frequency groups F1 to F6 (for example, frequency group). Is fed back to the base station. The terminal feeds back information necessary for selecting a precoding vector for forming a transmission beam pattern having good channel characteristics among the transmission beam patterns to the base station. In this case, in the precoding MIMO scheme, since precoding vectors that are orthogonal to each other are used, information necessary for selecting one of two precoding matrices is fed back to the base station.

As described above, according to the first embodiment, since the terminal needs to feed back information required for precoding matrix selection to the base station in addition to information necessary for frequency group selection, the amount of feedback information increases. Hereinafter, an embodiment of reducing the amount of feedback information will be described in detail with reference to FIGS. 3 and 4.

3 is a diagram illustrating a frequency allocation method and a precoding matrix allocation method according to a second embodiment of the present invention, and FIG. 4 is a schematic block diagram of a transmission apparatus of a base station according to the second embodiment of the present invention.

)을 할당하고, 짝수 번째 주파수 그룹(F2, F4, F6)에 두 번째 프리코딩 행렬(

)이 할당한다. 이와 같이, 인접한 두 주파수 그룹 간에 서로 다른 프리코딩 행렬이 할당되면, 페이딩 차 이를 크게 할 수 있다. 따라서 단말은 프리코딩 행렬에 대한 정보를 피드백할 필요 없이 복수의 주파수 그룹 중에서 채널 특성이 좋은 주파수 그룹에 대한 정보를 기지국으로 피드백하면 되므로, 피드백 정보량을 감소시킬 수 있다.As shown in FIG. 3, the base station transmitter according to the second embodiment of the present invention allocates one precoding matrix to each frequency group F1-F6, and provides information about the precoding matrix assigned to the frequency group. Share with the terminal. For example, the base station transmitter transmits a first precoding matrix to an odd frequency group (F1, F3, F5).

) And assign a second precoding matrix to the even-numbered frequency groups (F2, F4, F6).

) Assigns. As such, when different precoding matrices are allocated between two adjacent frequency groups, the fading difference can be increased. Therefore, the terminal may feed back information on a frequency group having good channel characteristics among the plurality of frequency groups to the base station without feeding back information on the precoding matrix, thereby reducing the amount of feedback information.

In order to transmit a signal to the terminal using the feedback information, as shown in FIG. 4, the base station transmitting apparatus includes a controller 110, a multiplexer 120, a plurality of variable modulation and coding units 130, and a plurality of signals. And a beamformer 140, a plurality of summers 150, a plurality of frequency allocators 160, a plurality of transmitters 170, and a plurality of transmit antennas 180. In this case, the plurality of beamformers 140 respectively correspond to the plurality of precoding vectors of the precoding matrix, and the plurality of summers, the plurality of frequency allocators 160, and the plurality of transmitters 170 each have a plurality of transmit antennas. Corresponds to 180.

)를 각각 복수의 빔형성기(140)로 전달한다. 그리고 제어기(110)는 복수의 그룹(F1-F6) 중 수신한 피드백 정보에 포함된 주파수 그룹에 대한 정보를 복수의 주파수 할당기(160)로 전달한다.The controller 110 associates a precoding matrix with each of the plurality of frequency groups F1-F6, and includes a plurality of precoding vectors of the precoding matrix corresponding to the frequency group included in the feedback information received from the terminal.

) Are respectively transmitted to the plurality of beamformers 140. The controller 110 transmits the information on the frequency group included in the feedback information received from the plurality of groups F1 to F6 to the plurality of frequency allocators 160.

The multiplexer 120 separates the plurality of transmission signals generated by the user signal generator (not shown) into groups and transmits the received signals to the corresponding modulation and encoder 130. The number of groups is equal to the number of the plurality of beamformers 140. In the second embodiment of the present invention, since it is assumed that a 2 ㅧ 2 precoding matrix is used, two beamformers 140 are formed, and the multiplexer 120 creates a transmission data stream with odd-numbered transmission signals and even numbers. The first transmission signals make another transmission data stream. The controller 110 determines a modulation and coding scheme (MCS) according to the feedback information from the terminal and provides it to the variable modulation and coding device 130.

Each variable modulator and coder 130 modulates and codes each transmit data stream in an appropriate manner in accordance with the modulation and coding rate information from controller 110 and forwards it to the corresponding beamformer 140. Each beamformer 140 multiplies the transmission data stream transmitted from the variable modulation and coding unit 130 by a precoding vector and delivers the result to the plurality of summers 150. Each summer 150 sums the signals transmitted from the plurality of beamformers 140, and each frequency allocator 160 assigns a frequency of a frequency group designated by the controller 110 to the summed signal. Each transmitter 170 transmits a user signal assigned a frequency through a corresponding antenna 180.

As described above, according to the second embodiment of the present invention, if the terminal only feeds back information on the frequency group, the base station can know the precoding matrix, so that the information amount of feedback transmitted by the terminal is reduced. In this case, when there are N precoding matrices (N is an integer of 3 or more), the base station transmitting apparatus may allocate L precoding matrices smaller than N to each frequency group. Then, since the UE selects one precoding matrix among the L precoding matrices, the amount of feedback information can be reduced compared to the case of selecting one precoding matrix among the N precoding matrices.

In addition to the precoding MIMO scheme, the second embodiment of the present invention may be applied to a fixed beamforming scheme. In this case, since the transmitting apparatus of the base station uses one beamforming vector, that is, a precoding vector, the terminal feeds back information on one precoding vector from the precoding matrix allocated to the selected frequency group as shown in FIG. do. For example, when using a precoding matrix as shown in Equation 1, at least 2 bits are required for the terminal to select one precoding vector and feed back the selected precoding vector to the base station. However, if a precoding matrix is allocated to the frequency group as shown in FIG. 3, since one precoding vector is selected in the precoding matrix to which the UE is allocated, the feedback of the precoding vector having 1-bit information selected is fed back to the base station. can do.

Next, the third to fifth embodiments of transmitting signals using the antenna selection method will be described in detail with reference to FIGS. 5 to 8.

In the third to fifth embodiments of the present invention, for convenience of description, it is assumed that the transmitting apparatus of the base station uses four transmitting antennas to transmit signals in an antenna selection scheme. However, the present invention may use different numbers of transmitting antennas. have.

5 is a diagram illustrating a frequency allocation method and a transmission antenna allocation method according to a third embodiment of the present invention.

Referring to FIG. 5, the base station transmitter according to the third embodiment of the present invention divides the allocated frequency band into a plurality of frequency groups F1-F6, and each of the plurality of transmit antennas A ₁ of the base station transmitter is included in each frequency group. , A ₂ , A ₃ , A ₄ ) are assigned. As such, all of the transmitting antennas A ₁ , A ₂ , A ₃ , and A ₄ of the transmitting apparatus are allocated to each frequency group F ₁ -F 6, and the terminal is a channel among the plurality of frequency groups F 1 -F 6. In addition to the information required for selecting a good frequency group, information necessary for selecting a transmission antenna having good channel characteristics is fed back to the base station. In this case, since information required for selecting a transmission antenna is determined by the number of transmitting antennas of the base station transmitting apparatus, the amount of feedback information increases when there are many transmitting antennas of the base station transmitting apparatus. The fourth and fifth embodiments in which the amount of feedback information can be reduced will be described in detail with reference to FIGS. 6 to 8.

6 and 8 are diagrams showing a frequency allocation method and a transmission antenna allocation method according to the fourth and fifth embodiments of the present invention, respectively, and FIG. 7 is a schematic diagram of an apparatus for transmitting a base station according to a fourth embodiment of the present invention. In block diagram.

As shown in FIG. 6, the base station transmitting apparatus according to the fourth embodiment of the present invention allocates a part of a plurality of transmitting antennas to each frequency group F1-F6, and transmits to the transmitting antennas allocated to each frequency group. Share information with the terminal. For example, the base station transmitting apparatus allocates the first and second transmit antennas A ₁ and A ₂ to the odd frequency groups F1, F3, and F5 among the four transmit antennas, and transmits the third and fourth transmit antennas. Assign (A ₃ , A ₄ ) to even-numbered frequency groups (F2, F4, F6). In this case, since adjacent frequency groups use different antennas, the fading difference can be increased. In addition, since the terminal selects one transmit antenna from two transmit antennas instead of four transmit antennas, the terminal may feed back information about the transmit antenna in one bit.

In order to transmit a signal to the terminal using the feedback information, as shown in FIG. 7, the base station transmitting apparatus includes a controller 210, an antenna selection switch 220, a plurality of variable modulation and coding units 230, and a plurality of signals. The frequency allocator 260, a plurality of transmitters 270, and a plurality of transmit antennas 280. In this case, the plurality of variable modulator and coder 230, the plurality of frequency allocator 260, and the plurality of transmitters 270 correspond to the plurality of transmit antennas 280, respectively.

The controller 210 corresponds to each of the plurality of frequency groups F1 to F6 as shown in FIG. 6, and determines the transmission antenna selected by the terminal from the frequency group and antenna selection information included in the feedback information received from the terminal. do. The controller 210 controls the antenna selection switch 220 to transmit the user's transmission signal transmitted from the user signal generator (not shown) to the variable modulation and coding unit 230 corresponding to the transmission antenna selected by the terminal. do. The controller 210 determines the modulation and coding rate according to the feedback information from the terminal and provides the modulation and coding rate to the variable modulation and coding unit 230.

Each variable modulation and coding unit 230 modulates and codes each transmission signal in an appropriate manner according to the modulation and coding rate information from the controller 210 and then forwards it to the corresponding frequency allocator 260. Each frequency allocator 260 assigns a frequency of a frequency group designated by the controller 210 to a modulated and coded signal. Each transmitter 270 transmits a user signal assigned a frequency through a corresponding antenna 280.

As described above, according to the fourth embodiment of the present invention, when the terminal feeds back only information on the frequency group and information on the antenna to be selected from the transmission antennas allocated to the frequency group, the base station can know the transmission antenna selected by the terminal. The amount of feedback information sent by the terminal is reduced.

In the fourth embodiment of the present invention, although some transmit antennas are allocated to each frequency group among the plurality of transmit antennas, and the terminal selects one transmit antenna from among the transmit antennas allocated to the corresponding frequency group, one transmit antenna is allocated to each frequency group. Only transmit antennas of may be allocated.

Specifically, as shown in FIG. 8, the base station transmitting apparatus according to the fifth embodiment of the present invention allocates one transmitting antenna among a plurality of transmitting antennas to each frequency group F1-F6, and assigns each transmitting group. The information on the transmitted antenna is shared with the terminal. For example, the base station transmitting apparatus allocates the _first transmit antenna A ₁ to the first and fifth frequency groups F1 and F5 among the four transmit antennas, and assigns the second transmit antenna A2 to the second and sixth antennas. time frequency groups (F2, F6) is assigned to, and three transmission antennas (a ₃₎ assigned to the assigned to the 3-frequency group (F3), and a fourth transmit antenna (a ₄₎ a fourth frequency group (F4) do. Then, when the terminal selects only the frequency group, the transmitting antenna is selected together, so that the terminal does not need to feed back information for selecting the transmitting antenna to the base station.

The fourth and fifth embodiments of the present invention can also be applied to the MIMO scheme, which will be described with reference to FIGS. 9 and 10.

9 and 10 are diagrams illustrating a frequency allocation method and a transmission antenna allocation method according to the sixth and seventh embodiments of the present invention, respectively. In the sixth and seventh embodiments of the present invention, for convenience of description, it is assumed that the transmitting apparatus of the base station uses two antennas among the four transmitting antennas to transmit a signal in the MIMO scheme. You can also use

9, the base station transmitting apparatus according to the sixth embodiment of the present invention allocates a plurality of transmission antenna combinations (for example, two) required for the MIMO scheme to each frequency group (F1-F6), Information on a transmission antenna allocated to each frequency group is shared with the terminal. For example, the base station transmitting apparatus combines the first and second transmitting antennas (A ₁ , A ₂ ) and the first and third transmitting antennas (A ₁ , A ₃ ) of the four transmitting antennas 1 and 4 times. Assigned to frequency groups F1 and F4, and combinations of 1 and 4 transmit antennas A ₁ and A ₄ and 2 and 3 transmit antennas A ₂ and A ₃ combinations of frequency groups 2 and 5 Assign to (F2, F5) and combine the _2nd and 4th transmit antennas (A ₂ , A ₄ ) and the 3rd and 4th transmit antennas (A ₃ , A ₄ ) to the 3rd and 6th frequency group (F3). , F6). In this way, the terminal does not need to select two transmit antennas from the four transmit antennas, but only one combination having good channel characteristics among the two combinations assigned to each frequency group.

Referring to FIG. 10, the base station transmitting apparatus according to the seventh embodiment of the present invention assigns each frequency group F1-F6 to one number of transmission antenna combinations (for example, two) required for the MIMO scheme. In addition, information about a transmission antenna allocated to each frequency group is shared with the terminal. For example, the base station transmitting apparatus allocates the first and second transmitting antennas A ₁ and A ₂ to the first frequency group F1 among the four transmitting antennas, and transmits the first and third transmitting antennas A _1. , A ₃ ) assign the combination to frequency group 2 (F2), and transmit antennas 1 and 4 (A ₁ , A ₄ ) to the frequency group (F3), and transmit 2 and 3 Assign antenna (A ₂ , A ₃ ) combination to frequency group 4 (F4), assign antenna 2 and 4 (A ₂ , A ₄ ) combination to frequency group (F5), and assign And a fourth transmit antenna (A ₃ , A ₄ ) combination is assigned to a sixth frequency group (F6). In this way, the terminal does not need to select two transmit antennas among the four transmit antennas, but only a frequency group.

Embodiments of the present invention are not implemented only through the above-described apparatus and / or method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiments of the present invention, a recording medium on which the program is recorded, and the like. Such implementations may be readily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the embodiment of the present invention, by pre-assigning a precoding matrix or a transmitting antenna to each frequency group, the amount of information fed back to the base station by the terminal can be reduced.

Claims (15)

In the method for transmitting a signal in a base station having a plurality of transmitting antennas, Dividing the allocated frequency band into a plurality of frequency groups, Allocating some precoding matrices of the plurality of precoding matrices to each frequency group, Receiving feedback information from the terminal, and Transmitting a signal using a frequency of a frequency group corresponding to the feedback information among the plurality of frequency groups and a precoding matrix assigned to the corresponding frequency group among the plurality of precoding matrices. Transmission method comprising a. The method of claim 1, And a precoding matrix assigned to each of two adjacent frequency groups among the plurality of frequency groups. The method of claim 1, And a precoding matrix of the plurality of precoding matrices is assigned to each frequency group. The method of claim 1, The feedback information includes information about one precoding matrix of the partial precoding matrix, The transmitting may include transmitting the signal by using a precoding matrix corresponding to the feedback information among precoding matrices allocated to the corresponding frequency group. The method of claim 1, The feedback information includes information on one column vector in the partial precoding matrix, The transmitting may include transmitting the signal using a column vector corresponding to the feedback information among precoding matrices assigned to the corresponding frequency group. In the method for transmitting a signal in a base station having a plurality of transmitting antennas, Dividing the allocated frequency band into a plurality of frequency groups, Assigning some transmit antennas of the plurality of transmit antennas to each frequency group, Receiving feedback information from the terminal, and Transmitting a signal by using a frequency of a frequency group corresponding to the feedback information among the plurality of frequency groups and a transmission antenna assigned to the corresponding frequency group among the plurality of transmission antennas; Transmission method comprising a. The method of claim 6, And a transmission antenna allocated to each of two adjacent frequency groups among the plurality of frequency groups. The method of claim 6, And a transmission antenna of one of the transmission antennas is assigned to each frequency group. The method of claim 6, The feedback information includes information about one transmit antenna of the some transmit antennas, The transmitting may include transmitting the signal using a transmission antenna corresponding to the feedback information among transmission antennas allocated to the corresponding frequency group. The method of claim 6, Each of the frequency groups is assigned a transmission antenna combination consisting of at least two transmission antennas, And the transmitting step comprises transmitting the signal using a combination of transmit antennas assigned to the corresponding frequency group. The method of claim 6, A plurality of transmit antenna combinations are assigned to each frequency group, each transmit antenna combination comprising at least two transmit antennas of the partial transmit antennas, The feedback information includes information on one transmission antenna combination among the plurality of transmission antenna combinations. The transmitting may include transmitting the signal by using a transmission antenna combination corresponding to the feedback information among a plurality of transmission antenna combinations allocated to the corresponding frequency group. A method for transmitting feedback information to a base station having a plurality of transmitting antennas by a terminal, Sharing information, in which the allocated frequency band is divided into a plurality of frequency groups, and information on some precoding matrices allocated to each frequency group among a plurality of precoding matrices, with the base station; and Transmitting feedback information including information on a frequency group selected from the plurality of frequency groups to the base station Transmission method comprising a. The method of claim 12, The feedback information further includes information about a column vector selected from a plurality of column vectors of the partial precoding matrix. A method for transmitting feedback information to a base station having a plurality of transmitting antennas by a terminal, Sharing information, in which the allocated frequency band is divided into a plurality of frequency groups, and information on some of the transmit antennas allocated to each frequency group among the plurality of transmit antennas, with the base station; and Transmitting feedback information including information on a frequency group selected from the plurality of frequency groups to the base station Transmission method comprising a. The method of claim 14, The feedback information further includes information about a transmission antenna selected from the partial transmission antennas.

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