KR101356518B1 - Method for setting a precoder in open loop mimo system - Google Patents

Abstract

In an open loop MIMO system, a feedback method of a user equipment is provided. The method includes the steps of being notified of one of a plurality of modes determined according to the type of resource to be used for feedback from the base station; Selecting a precoding matrix from a codebook subset corresponding to the informed mode and feeding back feedback information by applying the selected precoding matrix, wherein different codebook subsets are configured for each of the plurality of modes; The codebook subset is configured by extracting a predetermined number of elements from a base codebook based on a predetermined criterion considering characteristics of each of the modes.

DRU, CRU, Precoder

Description

METHODO FOR SETTING A PRECODER IN OPEN LOOP MIMO SYSTEM}

The present invention relates to a method for setting a precoder in a cellular system and in an open loop multiple antenna system.

First, a description will be given of a multi-antenna (hereinafter referred to as "MIMO") technique to which the present invention is applied.

In short, MIMO is short for "Multiple Input Multiple Output", and it is possible to improve the transmit / receive data efficiency by adopting multiple transmit antennas and multiple receive antennas. Say how it is. That is, the present invention is applied to a technique of collecting pieces of fragmentary data received from various antennas without relying on a single antenna path in order to receive one entire message. Such a MIMO technique can improve the data transmission speed in a specific range or increase the system range for a specific data transmission speed. In other words, MIMO technology is a next-generation mobile communication technology that can be widely used in user equipment (UE) and repeaters of mobile communication. The technology overcomes the limitations of mobile communication, which has reached its limit due to data communication expansion. It is attracting attention with the technology that it can do.

1 is a diagram showing a configuration of a general multi-antenna system.

As shown in FIG. 1, if the number of antennas is simultaneously increased at the transmitting / receiving end, the theoretical channel transmission capacity increases in proportion to the number of antennas, unlike the case where a plurality of antennas are used only at the transmitter and the receiver. .

Since the theoretical capacity increase of the MIMO system has been proven in the mid-1990s, various technologies have been actively researched to improve the actual data transmission rate. Some of these technologies have already been applied to a variety of technologies such as third generation mobile communication and next generation wireless LAN And is reflected in the standard of wireless communication.

The research trends related to multi-antennas up to now include information theory study related to calculation of multi-antenna communication capacity in various channel environments and multiple access environments, study of wireless channel measurement and modeling of MIMO system, improvement of transmission reliability and improvement of transmission rate And research on space-time signal processing technology.

MIMO technology uses a "spatial diversity" scheme that improves transmission reliability by using symbols that pass through various channel paths, and a "spatial diversity" which improves a transmission rate by simultaneously transmitting a plurality of data symbols using multiple transmit antennas. "Spatial multiplexing". In addition, researches on how to appropriately combine these two methods to obtain the advantages of each are being studied in recent years.

In general, the MIMO mode allowed by the system is one more space resource, so depending on how to allocate the space resource, Single User MIMO (SU-MIMO) and Multi User MIMO (MU-MIMO). Divided.

2 is a diagram illustrating an architecture of downlink MIMO in a transmitting end. As shown in FIG. 2, the MIMO encoder 201 maps L (≧ 1) layers to a stream of M _t (≧ L). The stream is input to the precoder 202. The layer is defined by a coding and modulation path input to the MIMO encoder 201. The stream is also defined as the output of the MIMO encoder 201 passing through the precoder 202.

The precoder 202 maps the stream to the antenna by generating antenna specific data symbols according to the selected MIMO mode.

A subcarrier mapper 203 maps antenna specific data to OFDM symbols.

Layer to stream mapping is performed by the MIMO encoder 201. The MIMO encoder 201 is a batch processor operating on M input symbols at a time. The input to the MIMO encoder 201 may be represented by an Mⅹ1 vector as shown in Equation 1 below.

는 하나의 일괄(batch)에서의 i번째 입력 심볼을 나타낸다. 상기 입력 심볼의 레이어 대 스트림 사상은 우선 공간 차원(space dimension)에서 이루어진다. In Equation (1)

Denotes the i th input symbol in one batch. The layer-to-stream mapping of the input symbols takes place first in the space dimension.

MIMO STC(Space Time Coding) 행렬로 나타낼 수 있다. First, as shown in Equation 2 below, the output of the MIMO encoder 201,

It can be represented by a MIMO STC (Space Time Coding) matrix.

는 스트림의 개수이며,

는 하나의 MIMO 블록이 차지하는 부반송파의 개수이다.

는 MIMO 인코더(201)의 출력이고,

는 입력 레이어 벡터이고,

는 STC 행렬이다.At this time,

Is the number of streams,

Is the number of subcarriers occupied by one MIMO block.

Is the output of the MIMO encoder 201,

Is the input layer vector,

Is an STC matrix.

는 아래의 수학식 3과 같이 행렬로 표현된다.Also

Is expressed as a matrix as shown in Equation 3 below.

In SU-MIMO transmission, the STC rate is defined as in Equation 4 below.

In MU-MIMO transmission, the STC rate per layer corresponds to one.

There are three formats of the MIMO encoder 201: Space Frequency Block Code (SFBC), Vertical Encoding (VE), and Horizontal Encoding (HE).

In Space Frequency Block Code (SFBC) encoding, an input to the MIMO encoder 201 may be represented by a 2 ⅹ 1 vector as shown in Equation 5 below.

The MIMO encoder 201 generates an SFBC matrix as shown in Equation 6 below.

는 2x2 행렬이고, SFBC 행렬

는 두 개의 연속한(consecutive) 부반송파(subcarrier)를 점유한다.At this time,

Is a 2-by-2 matrix, and the SFBC matrix

Occupies two consecutive subcarriers.

In vertical encoding, the inputs and outputs of the MIMO encoder 201 are represented by Mⅹ1 vectors as shown in Equation 7 below.

는 하나의 일괄(batch)에서의 i번째 입력 심볼이고, 수직적 인코딩에 대하여,

은 동일한 레이어에 속한다. At this time,

Is the i th input symbol in one batch, and for vertical encoding,

Belongs to the same layer.

In horizontal encoding, the inputs and outputs of the MIMO encoder 201 are represented by Mⅹ1 vectors as shown in Equation 8 below.

는 하나의 일괄(batch)에서의 i번째 입력 심볼이고, 수직적 인코딩에 대하여,

은 서로 다른 레이어에 속한다.At this time,

Is the i th input symbol in one batch, and for vertical encoding,

Belong to different layers.

A method of mapping a stream to an antenna is described in detail as follows.

프리코더,

가 곱해진다. 프리코더의 출력은

행렬, z로 표시된다. 스트림을 안테나에 사상하는 방법은 아래의 수학식 9와 같다.Mapping the stream to the antenna is performed by the precoder 202. The output of the MIMO encoder 201 is

Precoder,

≪ / RTI > The output of the precoder

A matrix, denoted by z . The method of mapping the stream to the antenna is as shown in Equation 9 below.

는 전송 안테나의 개수를 나타내고, z_{j ,k} 는 k 번째 부반송파 상에서 j번째 물리 안테나를 통해 전송되는 출력 심볼을 나타낸다.At this time,

Denotes the number of transmit antennas, z _{j , k} Denotes an output symbol transmitted through a j th physical antenna on a k th subcarrier.

Precoding includes non-adaptive precoding and adaptive precoding.

In the non-adaptive precoding scheme, the precoding matrix is N _t Ⅹ M _t The matrix is W (k), where N _t is the number of transmit antennas, M _t is the number of streams, and k is the physical index of the subcarrier to which W (k) is applied. The matrix W is selected from a subset of precoders of size N _W of the base codebook for a given rank. The matrix W is every N ₁ P _SC according to Equation 10 below. It varies every four consecutive physical subcarriers, and the matrix W does not depend on the number of subframes. N _{t t} ⅹM precoding matrix W (k) is applied to the sub-carrier k is selected as a code word of the index i from the open-loop codebook subset of rank M _t. In this case, i is given by Equation 10 below.

In the open loop region, matrix W is every N ₁ P _SC It changes every four consecutive physical subcarriers. The default value of N is N ₁ . N ₂ is optional and N ₂ Use does not require additional signaling.

On the other hand, in adaptive precoding, the precoder W is obtained from the feedback of the user equipment.

In codebook based precoding (codebook feedback), there are three feedback modes, which correspond to a base mode, an adaptive mode, and a differential mode.

In TDD (Time Division Duplex) sounding based precoding, the value of W is obtained from the sounding feedback of the user equipment. There may be several downlink MIMO modes, for example, as shown in Table 1 below.

Mode index Description Reference Mode 0 OL SU-MIMO (SFBC with non-adaptive precoder) Mode 1 OL SU-MIMO (SM with non-adaptive precoder) Mode 2 CL SU-MIMO (SM with adaptive precoder) Mode 3 OL MU-MIMO (SM with non-adaptive precoder) Mode 4 CL MU-MIMO (SM with adaptive precoder) Mode 5-7 n / a n / a

In SU-MIMO, one resource unit (RU) is assigned to only one user and only one Forward Error Correction (FEC) block is present at the input of the MIMO encoder 201 (vertical at the transmitting end. vertical) MIMO encoding). In vertical MIMO encoding, data streams transmitted to multiple antennas are all generated from one user information bit and go through the same FEC block.

On the other hand, in MU-MIMO, one RU can be allocated to multiple users, and a plurality of FEC blocks exist at the input of the MIMO encoder 201 (horizontal MIMO encoding at the transmitting end). Equivalent). In horizontal MIMO encoding, different symbols transmitted over multiple antennas are initially generated from different information bits and then subjected to different FEC blocks and modulation.

In general, when the number of users is small, the performance of SU-MIMO is good, and when the number of users is large, the performance of MU-MIMO is good. The SU-MIM and MU-MIMO are classified into a closed loop MIMO (CL-MIMO) and an open loop MIMO (OL-MIMO), respectively. CL-MIMO technology is used between a user equipment and a base station. While the MIMO technology is applied based on the information on the formed channel, etc., the OL-MIMO technology mainly uses the MIMO technology for the purpose of diversity gain when the reliability of the feedback information is limited because of the fast moving speed. Apply.

There are two major modes of subchannelization of IEEE 802.16m. The first mode is a localized mode, and a subband Contiguous Resource Unit (CRU) is generally used, and the second mode is a diversity mode, and a distributed resource unit (DRU) is generally used. However, a miniband CRU may be used in two ways, localization or diversity mode.

As described above, although various modes exist for subchannelization, the precoding matrix W is conventionally used without distinguishing each mode. There is a problem that the precoding matrix is not optimized for each mode due to the use of a common precoding matrix without considering the characteristics of resources allocated according to modes.

The problem to be solved by the present invention is to apply the optimal precoding matrix according to the type of resources allocated.

In an open loop MIMO system according to an aspect of the present invention for solving the above problems, a feedback method of a user equipment, the method comprising the steps of: receiving a notification from one of a plurality of modes determined according to the type of resources to be used for feedback from the base station; Selecting a precoding matrix from a codebook subset corresponding to the informed mode and feeding back feedback information by applying the selected precoding matrix, wherein different codebook subsets are configured for each of the plurality of modes; The codebook subset is configured by extracting a predetermined number of elements from a base codebook based on a predetermined criterion considering characteristics of each of the modes.

In an open loop MIMO system according to another aspect of the present invention, a method for allocating a resource to a user equipment includes one of a plurality of modes indicating a type of resource to be used by a base station when the user equipment feeds back feedback information. Notifying to the device; Receiving feedback information to which a selected precoding matrix is applied from a codebook subset corresponding to the notified mode; And allocating resources to the user device by using the received feedback information, wherein different codebook subsets are configured for each of the plurality of modes, and the codebook subset is configured to characterize each of the plurality of modes. A predetermined number of elements are extracted from the base codebook based on the predetermined criteria considered.

In an open loop MIMO system according to another aspect of the present invention, a user equipment for feeding back feedback information includes: a receiving unit receiving one of a plurality of modes determined according to a type of resource to be used for feeding back from a base station; A processing unit which selects a precoding matrix from a codebook subset corresponding to the notified mode and generates feedback information by applying the selected precoding matrix; And a transmitter for transmitting the generated feedback information, wherein the receiver, the processor, and the transmitter are electrically connected to each other, and different codebook subsets are configured for each of the plurality of modes, and the codebook subset is the A predetermined number of elements are extracted from a base codebook based on a predetermined criterion in consideration of characteristics of each mode.

The plurality of modes include a localized mode and a diversity mode, wherein the localized mode uses a subband CRU (Contiguous Resource Unit) as a logical resource unit during transmission, and the diversity mode is used for transmission. A distributed resource unit (DRU) may be used as the logical resource unit.

The codebook subset corresponding to the localization mode may be configured by extracting a predetermined number of elements satisfying constant modulus characteristics from the basic codebook.

The codebook subset corresponding to the diversity mode may be configured by extracting a predetermined number of elements having a maximum chordal distance from the basic codebook.

In the present invention, the performance of the system can be improved by applying the optimal precoder to the allocated resource according to the type.

The following embodiments are a combination of the components and features of the present invention in a predetermined form, each component or feature may be considered optional unless otherwise stated, each component or feature is different It may be implemented in a form that is not combined with the components or features, and may also combine some components and / or features to form an embodiment of the present invention, the operation of the described in the embodiments of the present invention The order may vary, and some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment.

In the description of the drawings, there is no description of procedures or steps that may obscure the gist of the present invention, nor is any description of steps or steps that can be understood by those skilled in the art.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention, and are not intended to limit the scope of the invention.

First, a resource used in a wireless mobile communication system will be described.

In a wireless mobile communication system, resources are generally maintained in a relatively good channel by successive arrangements in terms of frequency and area suitable for applications in which resources allocated in an actual physical area are uniformly distributed in terms of frequency to obtain diversity gain. In the case of IEEE 802.16e, the former is supported by a name such as PUSC (Partial Usage of SubCHannel) or FUSC (Full Usage of SubCHannel), and the latter is Band AMC (Adaptive). It is served under the same name as Modulation and Coding Scheme.

Meanwhile, in the case of IEEE802.16m, the former is divided into a distributed resource unit (DRU) and the latter is divided into a contiguous resource unit (CRU), which can be simultaneously displayed in one subframe. A physical resource unit (PRU) is a basic physical unit for resource allocation, a logical resource unit (LRU) is a basic logical unit, and the DRU and CRU correspond to LRUs. The DRU includes a group of subcarriers scattered across distributed resource allocations within a frequency partition. In addition, the CRU includes a group of consecutive subcarriers throughout the resource allocation.

3 is a diagram illustrating a process in which a PRU is mapped to an LRU.

Hereinafter, a process of mapping a PRU to an LRU will be described with reference to FIG. 3.

As shown in FIG. 3, PRUs are first divided into subbands and minibands. In FIG. 3, PRUs divided into subbands are PRU _SBs and PRUs divided into minibands are PRU _MBs. Is displayed. PRU _SB is suitable for frequency selective allocation because it continuously allocates PRUs on frequency, and PRU _MB is also suitable for frequency diverse allocation, It is permutated.

_SB PRU is defined as the spirit and the CRU that the PRU-based _SB spirit subband CRU (based subband CRU) in the CRU. PRU _MB is Through a permutation (permutation) process (PRU _MB in FIG. 3 of this permutation is represented by PPRU _MB) is mapped to the DRU, wherein a portion of the PPRU _MB is mapped to the CRU, with a PPRU _MB spirit CRU Is defined as a miniband based CRU.

The DRU is suitable for OL-MIMO, which can easily obtain diversity gain in MIMO mode, and the subband-based CRU is suitable for CL-MIMO serviced by applying channel conditions, while the miniband-based CRU (miniband based) CRU) may apply CL-MIMO or OL-MIMO.

In addition, the resource region allocated to the actual user equipment corresponds to any one of subband-based CRUs or DRUs, and it is considered that none of the subband-based CRUs and DRUs are allocated. Because the user equipment in the fast moving state is advantageous to be allocated to the DRU because the state of the channel changes rapidly, it is preferable that the user equipment is allocated resources to the DRU, and the channel state is good and the channel state changes slowly. This is because the user equipment that is present is preferably allocated resources to the CRU.

In the case of IEEE802.16m, subchannelization can be divided into a localized mode and a diversity mode. Localization mode is generally assigned with subband-based CRUs and diversity mode is typically assigned with DRUs. Miniband CRUs may also be used in localization mode or diversity mode. That is, the type of resources used differs depending on the localization mode and the diversity mode. Therefore, in terms of performance of the system, it is not preferable to use the same precoding matrix according to each mode.

The present invention proposes a method for configuring different codebook subsets according to localization mode and diversity mode in order to optimize the performance of the system.

C (Nt, Mt, Nw) is a codebook, Nt is the number of transmit antennas, Mt is the number of streams, and Nw is the codeword of the codebook. Assume that it represents the number of.

When a codebook used in localization mode is called C_localized (Nt, Mt, Nw1), it is assumed that C_localized (Nt, Mt, Nw1) is transmitted using Equation (10) or Equation 10 or precoding is performed using the codebook. CQI or MCS level can be set. Where Nt is the number of transmit antennas, Mt is the number of streams, and Nw1 is the number of bits for representing the index of the precoding matrix included in the codebook.

As described above, C_localized (Nt, Mt, Nw1) used in the localization mode to apply the precoding matrix having good performance in the localization mode uses the same as the CL-MIMO base codebook or a predetermined criterion in the CL-MIMO base codebook. By extracting the precoding matrix according to the C_localized (Nt, Mt, Nw1) used in the localization mode can be configured.

At this time, as a reference for extracting the precoding matrix from the CL-MIMO codebook to construct C_localized (Nt, Mt, Nw1), for example, only those having constant modulus characteristics among the CL-MIMO base codebook elements are used. Can be based on extraction.

The diversity mode sets the CQI or MCS level by assuming that C_diversity (Nt, Mt, Nw2) is transmitted using Equation 10 or that precoding is to be performed in such a manner. Here, Nw2 represents the number of bits for representing the index of the precoding matrix included in the codebook. Nw1 and Nw2 may be different.

Assuming that u (Nt, M) is a unitary matrix consisting of NtⅹM and W1 and W2 are elements of u (Nt, M), the codal distance may be defined as in Equation 11 below.

As a criterion for selecting a precoding matrix constituting the codebook C_diversity (Nt, Mt, Nw2) used in the diversity mode, matrices for maximizing the chordal distance in the CL-MIMO codebook may be selected. . Maximizing the codal distance means that the matrices existing in the codebook operate successfully on various channels, and thus can be used as a criterion for selecting a precoding matrix constituting the codebook used in diversity mode.

Hereinafter, when the number of transmit antennas is 4 and the rank is 2, a method of extracting a precoding matrix from the basic codebook and configuring a codebook subset according to each mode will be described.

Table 2 below shows a basic CL-MIMO codebook for configuring a codebook subset according to diversity mode and localization mode.

In the basic CL-MIMO codebook shown in Table 2, the precoding matrix from m = 0 to m = 15 satisfies the constant modulus. That is, the precoding matrices from m = 0 to m = 15 satisfy the constant modulus characteristics when the sum of the magnitudes of the outputs of the precoding matrices to each antenna is the same. Accordingly, the codebook subset in the localization mode may be configured by extracting the precoding matrices from m = 0 to m = 15. That is, C_localized (4, 2, 4), which is a codebook subset to be used in the localized mode from the basic CL-MIMO codebook, may be configured.

Meanwhile, in the diversity mode, a codebook subset may be configured by extracting a precoding matrix that maximizes codal distance. For example, in the diversity mode by extracting a precoding matrix corresponding to m = 23, m = 29, m = 25, and m = 27 that satisfies a condition for maximizing codal distance in the basic SU-MIMO codebook. You can configure the subset of codebooks you use.

Although the basic codebook of Table 2 has been described as an example, a codebook subset for each mode may be configured using the same method in the case of a different number of transmit antennas and ranks.

Referring to the operation of the present invention in the downlink and uplink as follows.

4 is a flowchart illustrating a resource allocation method in downlink according to an embodiment of the present invention. First, when the base station requests feedback from the user equipment, the downlink notifies one of a localization mode and a diversity mode, which is a mode to be applied when the user equipment feeds back (step 401). That is, when the base station requests feedback information from the user equipment, the base station notifies which mode (either localization mode or diversity mode) the user equipment will feedback the feedback information when the feedback information is fed back. The user device notified of the mode with the feedback request selects a precoder from the codebook subset corresponding to the notified mode and applies the precoder to transmit feedback information (step 402). The feedback information may correspond to information for setting a CQI or MCS level. The base station allocates resources to the user equipment by using the feedback information (step 403). In this case, as described above, different codebook subsets are configured for each mode, and the precoder may be selected from different codebook subsets according to modes.

5 is a flowchart illustrating a data transmission method in uplink according to an embodiment of the present invention. In uplink, the base station sets a mode (localization mode or diversity mode) to be applied when the user equipment transmits data in the uplink, sets the CQI or MCS level according to the mode, and uses the mode set in the user equipment. The device is notified (step 501). The mode may be directly informed to the user device using control information, or implicitly informed to the user device according to a subchannelization rule. The user device selects a precoding from the codebook subset corresponding to the notified mode and applies the precoder to transmit data in uplink (step 502). In this case, as described above, different codebook subsets are configured for each mode, and the precoder may be selected from different codebook subsets according to modes.

6 is a block diagram illustrating a configuration of a device applicable to a base station and a user equipment and capable of performing the above-described method. As shown in FIG. 6, the device 60 includes a processing unit 61, a memory unit 62, a radio frequency (RF) unit 63, a display unit 64, and a user interface unit 65. . The layer of physical interface protocol is performed in the processing unit 61. The processing unit 61 provides a control plane and a user plane. The function of each layer can be performed in the processing unit 61. The memory unit 62 is electrically connected to the processing unit 61 and stores an operating system, an application, and a general file. If the device 60 is a user device, the display unit 64 may display a variety of information, and may be implemented by using a known liquid crystal display (LCD), an organic light emitting diode (OLED), or the like. The user interface unit 65 can be configured in combination with known user interfaces such as keypads, touch screens, and the like. The RF unit 63 is electrically connected to the processing unit 61 and transmits or receives a radio signal.

That is, various operations performed for communication with a user equipment in a network consisting of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than 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, etc. Also, in the present invention, a user equipment (UE) is referred to as a 'mobile'. Mobile device ("MS"), and "mobile station (MS)" is to be replaced with terms such as subscriber station (SS), mobile subscriber station (MSS), or mobile device (mobile terminal). Can be.

On the other hand, the user device of the present invention PDA (Personal Digital Assistant), cellular phone, PCS (Personal Communication Service) phone, GSM (Global System for Mobile) phone, WCDMA (Wideband CDMA) phone, MBS (Mobile Broadband System) phone And the like can be used.

Embodiments of the present invention may be implemented through various means, for example, embodiments of the present invention may be implemented by hardware, firmware (firmware), software or a combination thereof.

For a hardware implementation, the method according to embodiments of the present invention may be implemented in 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 (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

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

The invention may be embodied in other specific forms without departing from the spirit and essential features of the invention, and thus, the above detailed description should not be construed as limited in all respects and should be considered as illustrative. The scope should be determined by reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention, and furthermore, the claims which do not expressly refer to the claims are combined. The embodiments may be constructed or incorporated into new claims by post-application correction.

The present invention can be used for a user device or a network device used in a wireless access system.

1 is a diagram showing a configuration of a general multi-antenna system.

2 is a diagram illustrating an architecture of downlink MIMO in a transmitting end.

3 is a diagram illustrating a process in which a PRU is mapped to an LRU.

4 is a flowchart illustrating a resource allocation method in downlink according to an embodiment of the present invention.

5 is a flowchart illustrating a data transmission method in uplink according to an embodiment of the present invention.

6 is a block diagram illustrating a configuration of a device applicable to a base station and a user equipment and capable of performing the above-described method.

Claims (22)

In the open loop multi-input multiple output (MIMO) system, the user equipment provides feedback to the base station, Receiving a feedback request from the base station; And And transmitting feedback information set by using a precoding matrix according to the feedback request to the base station, If the feedback request corresponds to a localized mode in which a subband based contiguous resource unit is used for resource allocation, the precoding matrix is a first defined for the localization mode. If the feedback request is included in a codebook subset and the feedback request corresponds to a diversity mode in which a distributed resource unit is used for resource allocation, the precoding matrix is defined for the diversity mode. Included in the second codebook subset, How to do feedback. The method of claim 1, Each of the first codebook subset and the second codebook subset consists of a predetermined number of elements in a basic codebook defined for closed loop MIMO; How to do feedback. The method of claim 1, The first codebook subset consists of a predetermined number of elements satisfying constant modulus characteristics among the elements of the basic codebook defined for closed loop MIMO. How to do feedback. The method of claim 1, The second codebook subset is composed of a predetermined number of elements having a maximum chordal distance among elements of a basic codebook defined for closed loop MIMO. How to do feedback. In the open-loop multiple input multiple output (MIMO) system, the base station receives the feedback performed by the user equipment, Transmitting a feedback request to the user device; And Receiving feedback information set by using the precoding matrix according to the feedback request from the user device, If the feedback request corresponds to a localized mode in which a subband based contiguous resource unit is used for resource allocation, the precoding matrix is a first defined for the localization mode. If the feedback request is included in a codebook subset and the feedback request corresponds to a diversity mode in which a distributed resource unit is used for resource allocation, the precoding matrix is defined for the diversity mode. Included in the second codebook subset, How to receive feedback. The method of claim 5, Each of the first codebook subset and the second codebook subset consists of a predetermined number of elements in a basic codebook defined for closed loop MIMO; How to receive feedback. In the open loop multi-input multiple output (MIMO) system, the user equipment provides feedback to the base station, Processing unit; And An RF unit electrically connected to the processing unit to receive a radio frequency (RF) signal, The RF unit receives a feedback request from the base station and transmits feedback information set by using a precoding matrix according to the feedback request to the base station, If the feedback request corresponds to a localized mode in which a subband based contiguous resource unit is used for resource allocation, the precoding matrix is a first defined for the localization mode. If the feedback request is included in a codebook subset and the feedback request corresponds to a diversity mode in which a distributed resource unit is used for resource allocation, the precoding matrix is defined for the diversity mode. Included in the second codebook subset, User device. The method of claim 7, wherein Each of the first codebook subset and the second codebook subset consists of a predetermined number of elements in a basic codebook defined for closed loop MIMO; User device. In the open-loop multiple input multiple output (MIMO) system, the base station receives the feedback performed by the user equipment, Processing unit; And An RF unit electrically connected to the processing unit to receive a radio frequency (RF) signal, The RF unit transmits a feedback request to the user equipment, receives feedback information set by using a precoding matrix according to the feedback request, from the user equipment. If the feedback request corresponds to a localized mode in which a subband based contiguous resource unit is used for resource allocation, the precoding matrix is a first defined for the localization mode. If the feedback request is included in a codebook subset and the feedback request corresponds to a diversity mode in which a distributed resource unit is used for resource allocation, the precoding matrix is defined for the diversity mode. Included in the second codebook subset, Base station. 10. The method of claim 9, Each of the first codebook subset and the second codebook subset consists of a predetermined number of elements in a basic codebook defined for closed loop MIMO; Base station. In an open loop multiple input multiple output (MIMO) system, a user equipment transmits uplink data to a base station, Precoding the uplink data with a precoding matrix; And Transmitting the precoded uplink data to the base station using the resources allocated to the user equipment, If the resource is a first type resource for a localized mode in which a subband based contiguous resource unit is used for resource allocation, the precoding matrix is defined for the localization mode. The precoding matrix is included in the first codebook subset and the resource is a second type resource for a diversity mode in which a distributed resource unit is used for resource allocation. Included in the second codebook subset defined for the city mode, Uplink transmission method. 12. The method of claim 11, Each of the first codebook subset and the second codebook subset consists of a predetermined number of elements in a basic codebook defined for closed loop MIMO; Uplink transmission method. 13. The method according to claim 11 or 12, Receiving, from the base station, information indicating which of the localization mode and the diversity mode is applied to the resource allocated to the user equipment; Uplink transmission method. In an open loop multiple input multiple output (MIMO) system, a base station receives uplink data from a user equipment, Receiving the uplink data from the user equipment by using a precoding matrix and resources allocated to the user equipment, If the resource is a first type resource for a localized mode in which a subband based contiguous resource unit is used for resource allocation, the precoding matrix is defined for the localization mode. The precoding matrix is included in the first codebook subset and the resource is a second type resource for a diversity mode in which a distributed resource unit is used for resource allocation. Included in the second codebook subset defined for the city mode, Uplink reception method. The method of claim 14, Each of the first codebook subset and the second codebook subset consists of a predetermined number of elements in a basic codebook defined for closed loop MIMO; Uplink reception method. The method according to claim 14 or 15, And transmitting, to the user device, information indicating which mode of the localization mode and the diversity mode is applied to the resource allocated to the user device. Uplink reception method. In an open loop multiple input multiple output (MIMO) system, a user equipment transmits uplink data to a base station, Processing unit; And An RF unit electrically connected to the processing unit to receive a radio frequency (RF) signal, The RF unit transmits the uplink data precoded by the precoding matrix to the base station by using the resources allocated to the user equipment. If the resource is a first type resource for a localized mode in which a subband based contiguous resource unit is used for resource allocation, the precoding matrix is defined for the localization mode. The precoding matrix is included in the first codebook subset and the resource is a second type resource for a diversity mode in which a distributed resource unit is used for resource allocation. Included in the second codebook subset defined for the city mode, User device. 18. The method of claim 17, Each of the first codebook subset and the second codebook subset consists of a predetermined number of elements in a basic codebook defined for closed loop MIMO; User device. The method according to claim 17 or 18, The RF unit receives, from the base station, information indicating which mode of the localization mode and the diversity mode is applied to the resource allocated to the user equipment. User device. In an open loop multiple input multiple output (MIMO) system, a base station receives uplink data from a user equipment, Processing unit; And An RF unit electrically connected to the processing unit to receive a radio frequency (RF) signal, The RF unit receives the uplink data from the user equipment by using a precoding matrix and resources allocated to the user equipment. If the resource is a first type resource for a localized mode in which a subband based contiguous resource unit is used for resource allocation, the precoding matrix is defined for the localization mode. The precoding matrix is included in the first codebook subset and the resource is a second type resource for a diversity mode in which a distributed resource unit is used for resource allocation. Included in the second codebook subset defined for the city mode, Base station. 21. The method of claim 20, Each of the first codebook subset and the second codebook subset consists of a predetermined number of elements in a basic codebook defined for closed loop MIMO; Base station. The method of claim 20 or 21, The RF unit transmits, to the user equipment, information indicating which mode of the localization mode and the diversity mode is applied to the resource allocated to the user equipment. Base station.

Images