KR20100005171A - Method for operating multi input multi output based on multimode codebook, transmitting and receiving apparatus for supporting that method - Google Patents

Abstract

PURPOSE: A method for operating multi input multi output based on a multimode codebook, and a transmitting and receiving apparatus for supporting the method are provided to use codebooks with different sizes according to various MIMO mode types, thereby reducing complexity according to index search. CONSTITUTION: A codebook determiner(410) decides one between the first and second codebooks according to a MIMO mode type of the entire system. A channel estimator(420) analyzes a channel characteristic from a transmitted signal. The channel estimator generates channel state information. A precoding matrix selector(430) selects a precoding matrix based on the channel state information.

Description

Method for Operating Multi Input Multi Output based on Multimode Codebook, Transmitting and Receiving Apparatus for Supporting That Method}

The present invention relates to a wireless communication system, and more particularly, to a method and system for operating MIMO in a wireless communication system.

The IEEE 802 committee is planning to develop a technical standard for IEEE 802. 16m, which is an advanced technology standard than the current mobile WiMAX, as the next-generation standard of WiBro / Mobile WiMAX. The IEEE 802.16m is 100Mbps for mobile and 1Gbps for fixed. Aim for transmission.

In such IEEE 802.16m, MIMO (Multi Input Multi Output) for transmitting data using a plurality of transmit / receive antennas may be applied to implement higher spectral efficiency and data rate as in IEEE 802.16d / e. . In this case, MIMO refers to a plurality of antennas of a base station and a terminal, which transmits data through multiple paths. The receiver detects a signal received through each path to reduce interference, and the transmitter reduces transmission efficiency through space-time diversity and spatial multiplexing. Means a communication method that can increase.

Such a MIMO may be classified into a space time transmit diversity (STTD) and a spatial multiplexing (SM) mode according to a method of allocating symbols to be transmitted to a plurality of antennas.

In this case, the STTD repeatedly transmits two different symbols by repeatedly changing the phase of each symbol and an antenna to transmit each symbol, and an Alamouti method is typical. Fading is performed according to space. Mitigation ensures a relatively stable and improved transmission rate.

On the other hand, SM is a method of simultaneously transmitting and receiving a plurality of different symbols through a plurality of antennas, typically the BLAST method, and increases the data rate.

In the IEEE 802.16d / e based wireless communication system, STTD and SM can be selectively transmitted, whereas in the IEEE 802.16m based wireless communication system, the environment of the communication system to which the MIMO mode is applied and the environment of such communication system Since there is no method for operating the MIMO mode in the following, a specific method is required.

Disclosure of Invention The present invention has been made in an effort to solve the above problems, and to provide a multimode codebook based MIMO operating method and system capable of determining various MIMO mode types applicable to a wireless communication system.

 Another object of the present invention is to provide a method and system for operating a multimode codebook based MIMO capable of operating a closed loop based MIMO mode using an efficient codebook under various MIMO mode types.

MIMO mode operating method using a multi-mode codebook according to an aspect of the present invention for achieving the above object, determines any one of the first and second codebook according to the type of Multi Input Multi Output (MIMO) mode of the entire system Making; Selecting a precoding matrix from the determined codebook based on estimated channel state information; And feeding back a first index for the selected precoding matrix to the transmitter.

In an embodiment, the MIMO mode type of the entire system includes a first MIMO mode type in which all MIMO modes of each transmitting apparatus are spatial multiplexing (SM), and the MIMO mode of any one of the transmitting apparatuses is SM and the other The MIMO mode is characterized by including a second MIMO type of Space Time Transmit Diversity (STTD).

In the codebook determining step, when the MIMO mode type of the entire system is a first MIMO mode type, a codebook having a smaller size is determined among the first and second codebooks, and the MIMO mode type of the premise system is set to the first. In the case of the 2 MIMO type, a codebook having a larger size among the first and second codebooks is selected, wherein any one of the first and second codebooks is generated using another subset. The first codebook includes 64 precoding matrices, and the second codebook includes eight precoding matrices.

The method of operating a MIMO mode using the multi-mode codebook described above may further include determining a second index indicating the selected codebook, and in the first index feedback step, the second index together with the first index. It characterized in that the feedback to the transmitter. In one embodiment, the second index is characterized in that the size of one bit (Bit).

Meanwhile, in the precoding matrix selection step, the precoding matrix having the highest SINR is selected from the determined codebook.

The method of operating a MIMO mode using the multi-mode codebook described above may further include detecting transmission data transmitted from at least one transmitter based on the selected precoding matrix and the estimated channel state information. It is done.

According to another aspect of the present invention, there is provided a method of operating a MIMO mode using a multimode codebook, the method comprising: receiving feedback from a receiving apparatus, a first index for a precoding matrix and a second index for a codebook; Selecting a precoding matrix corresponding to the first index from a codebook corresponding to the value of the second index among first and second codebooks; Precoding the transmission data to be transmitted to the receiver by using the selected precoding matrix; And transmitting the precoded transmission data through a plurality of transmission antennas.

A receiver supporting the MIMO mode operating method using multiple codebooks according to another aspect of the present invention for achieving the above object is a codebook for determining any one of the first and second codebooks according to the MIMO mode type of the entire system Decision unit; A channel estimator for generating channel state information by analyzing channel characteristics from a signal transmitted from a transmitter; And selecting a precoding matrix from the codebook determined by the codebook determiner based on the channel state information generated by the channel estimator, and feeding back a first index for the selected precoding matrix to the transmitter. It includes a precoding matrix selector.

A transmitter supporting the MIMO mode operating method using a multimode codebook according to still another aspect of the present invention for achieving the above object feeds back a first index for a precoding matrix and a second index for a codebook from a receiver. Receiving feedback receiving unit; Selecting a precoding matrix corresponding to the first index from a codebook corresponding to the value of the second index among the first and second codebooks, and precoding transmission data to be transmitted to a receiving apparatus using the selected precoding matrix Precoding performing unit; And a data transmitter for transmitting the precoded transmission data by the precoding performer to the receiver through a plurality of antennas.

As described above, according to the present invention, it is possible to determine various MIMO mode types applicable to a wireless communication system, and under such various MIMO mode types, a receiver uses a codebook having a different size for each MIMO mode type, thereby allowing the receiver to precode the matrix. In addition to reducing the complexity incurred in searching the index for, the feedback overhead to the transmitting apparatus can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, before describing the present invention, various wireless communication system environments to which the MIMO mode operating method according to the present invention can be applied will be briefly described. In the wireless communication system environment described below, a base station includes four transmit / receive antennas and each terminal includes a maximum of two transmit / receive antennas in order to obtain high frequency efficiency and high data rate. However, the present invention is not limited thereto, and the number of transmit / receive antennas of the base station and the terminal may vary in consideration of channel conditions.

First, a wireless communication system environment to which a 2x2 MIMO mode is applied will be described with reference to FIGS. 1A and 1B. FIG. 1A illustrates a single user (SU) MIMO based communication system. In the case of the SU-MIMO based communication system as shown in FIG. 1A, a base station 100 having two transmit / receive antennas and two It can be seen that it consists of one terminal 110 having a transmission and reception antenna.

Meanwhile, FIG. 1B is a diagram illustrating a communication system based on a multi-user Multi User MIMO Collaborator Spatial Multiplexing (CSM). As illustrated in FIG. 1B, two transmission / reception are performed in the case of a MU-MIMO CSM-based communication system. It can be seen that the base station 100 having an antenna and two terminals 120 and 130 having one transmitting and receiving antenna. In this case, in the MU-MIMO CSM-based wireless communication system illustrated in FIG. 2, two terminals may transmit data using the same frequency.

Next, a wireless communication system environment of a 4x4 MIMO mode will be described with reference to FIGS. 2A and 2B. FIG. 2A illustrates a SISO-MIMO CSM-based communication system. As shown in FIG. 3, in the SISO-MIMO CSM-based communication system, a base station 200 having four transmit / receive antennas and one antenna are illustrated. It can be seen that it consists of two terminals 210 and 220 and one terminal 230 having two antennas (SU-MIMO). In this case, three terminals transmit data using the same frequency.

Meanwhile, FIG. 2B illustrates a communication system based on the SU-MU-MIMO CSM. As illustrated in FIG. 2B, the base station 200 having four transmit / receive antennas in the case of the SU-MU-MIMO CSM-based communication system is illustrated. And it can be seen that consists of two terminals 240, 250 having two transmit and receive antennas. In this case, the two terminals transmit data using the same frequency.

In FIG. 2B, although it may be referred to as SU-MIMO from the viewpoint of each terminal, from the system-wide perspective, two terminals become MU-MIMO because they are paired as CSM.

Among the various communication system environments described above, in the wireless communication system environment shown in FIGS. 1A, 1B, and 2A, since there is no terminal or only one terminal that is SU-MIMO, STTD (Space Time Transmit Diversity) and SM ( Spatial Multiplexing) may be selectively applied. However, in the wireless communication system environment illustrated in FIG. 2B, since there are two terminals that are SU-MIMO, the various systems as illustrated in FIGS. 3A to 3C are different from each other. There may be a MIMO mode type.

First, in the MIMO mode type illustrated in FIG. 3A, when the channel conditions of the two terminals, which are SU-MIMO, are not good, for example, when the two terminals, which are SU-MIMO, have a low signal-to-interference noise ratio (SINR) As shown as a MIMO mode applicable to, both SU-MIMO terminals may use STTD as a MIMO mode.

As described above, the STTD is a method of repeatedly transmitting two different symbols by repeatedly changing the phase of each symbol and an antenna to transmit each symbol, and is relatively stable and improved by alleviating fading according to space. The advantage is that the transmission rate can be guaranteed.

Next, the MIMO mode type illustrated in FIG. 3B shows a MIMO mode applicable to a case where channel conditions of two terminals, which are SU-MIMO, are good, for example, when both terminals, which are SU-MIMO, have a high SINR. As shown, both SU-MIMO terminals can use the SM as the MIMO mode. As described above, the SM can increase the data rate by transmitting and receiving a plurality of different symbols simultaneously through a plurality of antennas.

Lastly, the MIMO mode type illustrated in FIG. 3C is a mixture of STTD and SM, in which one of two terminals SU-MIMO has a poor channel condition and the other has a good channel condition. One of two terminals, which is SU-MIMO, shows a MIMO mode applicable to a case in which one terminal has a low SINR and the other terminal has a high SINR. As shown, a terminal having a poor channel situation may use STTD as a MIMO mode, and a terminal having a good channel condition may use an SM as a MIMO mode.

Meanwhile, the MIMO mode includes an open loop MIMO method and a closed loop MIMO method according to whether channel information is required. In the MIMO mode of each UE shown in FIGS. 3A to 3C, STTD is open. The loop MIMO scheme and the SM may be an open loop MIMO scheme or a closed loop MIMO scheme. Specifically, the SM MIMO mode of the open loop method is used for the Partial Usage Subchannel (PUSC) mode, and the SM MIMO mode of the closed loop method is used for the Adaptive Modulation Coding (AMC) mode.

Here, the closed loop scheme is a precoding matrix that is fed back from the receiving apparatus when the transmitting apparatus (for example, the terminal or the base station) receives feedback information from the receiving apparatus (for example, the base station or the terminal) with respect to the forward data transmitted. A method of precoding the forward data by using a precoding matrix corresponding to the index for.

Hereinafter, a description will be given on the assumption that the terminal is a transmitter and the base station is a receiver for uplink data transmission. In the case of downlink data transmission, the roles may be interchanged.

In one embodiment, in the MIMO mode type (hereinafter referred to as 'first MIMO mode type') shown in Figure 3b and the MIMO mode type (hereinafter referred to as 'second MIMO mode type') shown in Figure 3c When the system is in the Band AMC mode, the SM uses a closed loop scheme. At this time, the precoding matrix to be used for the precoding of the forward data is selected from the codebook of each terminal, so that the precoding matrix for the entire system is one. It may be determined by a combination of precoding matrices of each terminal in pairs.

In this case, since the terminal using the STTD does not need a codebook in the second MIMO mode type, only the codebook of the second terminal using the SM as the MIMO mode of the two terminals may be considered in order to determine a precoding matrix for the entire system. In the first MIMO mode type, since both terminals use the SM in the MIMO mode, the codebooks of both terminals should be considered to determine the precoding matrix for the entire system.

Specifically, first, in the case of the second MIMO mode type, the precoding matrix of the entire system is determined in consideration of only the codebook of the second terminal using the SM in the MIMO mode, so that the precoding matrix of the entire system is represented by Equation 1 below. It can be defined as

Here, V denotes a precoding matrix of the second terminal in FIG. 3B, I denotes a unit matrix, and O denotes a zero matrix. In this case, V, I, and O may be a 2ⅹ2 matrix.

Meanwhile, in the first MIMO mode type, since the precoding matrix of the entire system is determined in consideration of the codebooks of both terminals using the SM in the MIMO mode, the precoding matrix of the entire system may be defined as in Equation 2 below. Can be.

Here, V1 represents a precoding matrix of the first terminal using the SM in the MIMO mode, V2 represents a precoding matrix of the second terminal using the SM in the MIMO mode, and O represents a zero matrix. However, in the case of the first MIMO mode type, as shown in Equation 2, when the size of the codebook used by each terminal is 64 (6 bits), the size of the codebook of the entire system is 4096, which is the codebook of the entire system. The problem may arise that the size of the can be too large.

Accordingly, the size of the codebook of the entire system of the first MIMO mode type and the second MIMO mode type may vary according to the size of the codebook of each terminal, and the performance of the MIMO of the system may vary according to the size of the codebook of the entire system. As such, the present invention provides a method by which the system can efficiently operate both of these MIMO mode types.

That is, in the present invention, a MIMO mode using a multi-mode codebook capable of efficiently operating a MIMO mode by allowing a terminal using an SM as a MIMO mode in a first MIMO mode type and a second MIMO mode type to use codebooks having different sizes. Present the operation method.

Hereinafter, a method of operating a MIMO mode using a multi-mode codebook and a base station and a terminal for supporting the method will be described in detail with reference to FIGS. 4 to 7. As described above, hereinafter, for convenience of description, the base station serves as a receiving apparatus and the terminal assumes a case of uplink data transmission in which the role of a transmitting apparatus. However, this is merely exemplary. It will be readily understood that the roles of the base station and the terminal for the transmitting device or the receiving device can be switched with each other.

First, FIG. 4 is a diagram illustrating a configuration of a base station supporting a MIMO mode operating method using a multi-mode codebook according to an embodiment of the present invention. As shown, the base station 400 uses the codebook determiner 410, the channel estimator 420, the precoding matrix selector 430, the transmission data detector 440, and the P / S converter 450. Include.

The codebook determiner 410 determines one of the first and second codebooks according to the MIMO mode type of the entire system determined by the base station 400. Here, the first and second codebooks may be separate codebooks having different sizes, and in the modified embodiment, the first and second codebooks are not stored separately, but a subset of the first codebook is used. To generate a second codebook. That is, the base station has only the first codebook and generates a second codebook using a subset of the first codebook according to the type of the MIMO mode.

In one embodiment, the first codebook may include 64 precoding matrices and the second codebook may include eight precoding matrices. The first codebook including the 64 precoding matrices and the second codebook including the eight precoding matrices are represented by Equations 3 and 4 below.

Looking at the process of determining the codebook by the codebook determiner 410 in more detail, the codebook determiner 410 is the first MIMO mode type of the entire system, that is, all of the terminals using the SM in the MIMO mode In this case, the codebook determiner 410 may determine a second codebook having a smaller size among the first codebook and the second codebook as the codebook to which the precoding matrix is to be selected.

In addition, when the MIMO mode type of the entire system is the second MIMO mode type, that is, when one of the terminals uses the STTD in the MIMO mode and the other uses the SM in the MIMO mode, the codebook determiner 410 determines the first codebook. And a first codebook having a larger size among the second codebooks as a codebook in which the precoding matrix is to be selected.

As described above, in the case of the codebook determining unit 410 according to an embodiment of the present invention, when all terminals use the SM in the MIMO mode, a small codebook, for example, a codebook having eight precoding matrices is determined. The complexity of selecting the precoding matrix by the precoding matrix selector 430 and searching the indices for the selected precoding matrix can be reduced, and the size of the index for the precoding matrix can be reduced to provide feedback. It is possible to reduce the overhead.

Thereafter, the codebook determiner 410 determines the index value for the selected codebook and provides it to the precoding matrix selector 430 which will be described later. In one embodiment, the index for the codebook may be represented by using 1 bit. For example, when the codebook determiner 410 selects the first codebook, it assigns 1 to the value and selects the second codebook. The value is assigned to 0.

Next, the channel estimator 420 generates channel state information by estimating characteristics of a channel by using a transmission signal of a terminal received through the transmit / receive antenna 405, and precodes a matrix to be described later. Provided to the selection unit 430.

The precoding matrix selector 430 selects a precoding matrix from the codebook determined by the codebook determiner 410 based on the channel state information provided from the channel estimator 420. According to an embodiment, the precoding matrix selector 430 may select a precoding matrix having the highest signal to interference noise ratio (SINR) among the precoding matrices included in the codebook.

Thereafter, the precoding matrix selector 430 feeds back the index for the selected precoding matrix and the index for the codebook determined by the codebook determiner 430 to the terminal.

Meanwhile, the transmission data detector 440 is configured by the precoding matrix and the channel state estimator 420 selected by the precoding matrix selector 430 described above with respect to the transmission data received from the terminal through the transmission / reception antenna 405. The generated channel state information is sensed and the detected transmission data are provided to the P / S converter 450 to be described later using a plurality of different virtual antennas.

The P / S converter 450 converts and transmits the parallel transmission data sensed by the transmission data detection unit 440 into one serial data stream.

5 is a diagram illustrating a configuration of a terminal supporting a MIMO mode operating method using a multi-mode codebook according to an embodiment of the present invention. As shown, the terminal 500 includes an S / P converter 510, a precoding performer 520, a data transmitter 530, and a feedback receiver 550.

The S / P converter 510 converts the transmission data into a plurality of parallel transmission data and provides them to the precoding performing unit 520 which will be described later using a plurality of different virtual antennas. At this time, the number of parallel transmission data may be equal to the number of virtual antennas. For example, in the present invention, since each terminal may have up to two transmit / receive antennas, the S / P converter 510 may convert the transmission data into two parallel transmission data.

The precoding performer 520 selects a precoding matrix using an index for the precoding matrix and an index for the codebook selected by the base station received through the feedback receiver 550, which will be described later. In detail, the precoding performer 520 first determines an index value for the codebook to determine a codebook corresponding to the index value. For example, when the index value is 1, the first codebook is determined as the codebook to select the precoding matrix, and when the index value is 0, the second codebook is determined as the codebook to select the precoding matrix.

In this case, the first and second codebooks may be the same as those of the above-described base station. That is, the first and second codebooks are codebooks having different sizes, and the terminal 500 stores two codebooks having different sizes or, in a modified embodiment, stores two codebooks. Instead, only the first codebook is stored, and if necessary, a second codebook may be generated using a subset of the first codebook. In one embodiment, the first codebook may include 64 precoding matrices and the second codebook may include eight precoding matrices.

Subsequently, the precoding performer 520 selects a precoding matrix corresponding to the index of the precoding matrix from the determined codebook, and transmits the parallel data to the selected precoding matrix from the S / P converter 510 described above. Multiply by to perform precoding on the transmitted data.

Finally, the data transmitter 530 transmits the plurality of parallel transmission data precoded by the precoding performer 520 to the base station through the plurality of transmit / receive antennas 540. In this case, the plurality of parallel transmission data may be transmitted through different transmission / reception antennas.

FIG. 6 is a flowchart illustrating a method of operating a MIMO mode using a multi-mode codebook according to an embodiment of the present invention performed at the base station shown in FIG. 4.

As shown, first, the MIMO mode type to be applied to the entire system is determined (S600). In one embodiment, the MIMO mode type includes a first MIMO mode type in which all terminals use the SM in the MIMO mode, and one of the terminals uses the STTD in the MIMO mode, and the second MIMO mode type uses the SM in the MIMO mode. It may include.

When the MIMO mode type of the entire system is determined as the second MIMO mode type, the first codebook is determined as a codebook to select a precoding matrix from among the first and second codebooks (S610). In one embodiment, the first and second codebooks are codebooks having different sizes, and the first codebook may include 64 precoding matrices and the second codebook may include eight precoding matrices. And the second codebook may be separate codebooks having different sizes, or the base station may have only the first codebook and, if necessary, generate the second codebook using a subset of the first codebook.

That is, when the MIMO mode type of the entire system is the second MIMO mode type, the first codebook having a larger size is selected among the first and second codebooks.

Thereafter, after selecting a precoding matrix from the first codebook based on the estimated channel state information (S620), an index corresponding to the selected precoding matrix and an index corresponding to the first codebook are transmitted to the terminal (S630). In one embodiment, the index for the codebook may be 1 bit, in which case the value of the index corresponding to the first codebook may be 1.

In S600, when the MIMO mode type of the entire system is determined as the first MIMO mode type, the second codebook is determined as a codebook to select a precoding matrix from among the first and second codebooks (S640). That is, when the MIMO mode type of the entire system is the first MIMO mode type, the second codebook having a smaller size is selected among the first and second codebooks.

Thereafter, after selecting a precoding matrix from the second codebook based on the estimated channel state information (S650), an index corresponding to the selected precoding matrix and an index corresponding to the second codebook are transmitted to the terminal. In one embodiment, the index for the codebook may be 1 bit, in which case the value of the index corresponding to the second codebook may be zero.

Finally, the transmission data transmitted from the terminal is sensed using the precoding matrix and channel state information selected through the above-described process (S670), and the detected transmission data are converted into a serial data stream and provided (S680). ).

FIG. 7 is a flowchart illustrating a method of operating a MIMO mode using a multi-mode codebook according to an embodiment of the present invention performed in the terminal shown in FIG. 5.

As shown, first, feedback information is received from the base station (S700). In one embodiment, the feedback information fed back from the base station includes a first index for the precoding matrix selected by the base station and a second index for the codebook determined by the base station.

Thereafter, the value of the second index, which is an index for the codebook, is checked (S705). As a result of the check, when the value of the second index is the first value, for example, 1, the precoding matrix corresponding to the first index, which is the index for the precoding matrix, is selected from the first codebook (S710), and the value of the second index. If the second value is 0, for example, a precoding matrix corresponding to the first index, which is an index of the precoding matrix, is selected from the second codebook (S720).

In one embodiment, the first and second codebooks may be identical to those of the base station described above. That is, the first and second codebooks are codebooks having different sizes, and the terminal stores two codebooks having different sizes or, in a modified embodiment, does not store two codebooks but the first codebook. Only the codebook is stored, and if necessary, a second codebook may be generated using a subset of the first codebook.

Next, the transmission data is precoded using the precoding matrix selected in S710 or S720 (S730). In one embodiment, the transmission data may be precoded by multiplying the transmission data and the precoding matrix. Here, the transmission data to be precoded may be one transmission data is converted into a plurality of parallel transmission data.

Finally, the precoded transmission data is transmitted to the base station using the plurality of transmission and reception antennas (S740).

The MIMO mode operating method using the above-described multi-mode codebook can be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer-readable recording medium. In this case, the computer-readable recording medium may include program instructions, data files, data structures, and the like, alone or in combination. Meanwhile, the program instructions recorded on the recording medium may be those specially designed and configured for the present invention, or may be known and available to those skilled in computer software.

Computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks such as floppy disks. Magnetic-Optical Media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. The recording medium may be a transmission medium such as an optical or metal wire, a waveguide, or the like including a carrier wave for transmitting a signal specifying a program command, a data structure, or the like.

In addition, program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

On the other hand, those skilled in the art will understand that the present invention described above can be implemented in other specific forms without changing the technical spirit or essential features.

Therefore, it is to be understood that the embodiments described above are exemplary in all respects and not restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

1A and 1B illustrate a wireless communication system environment to which a 2x2 MIMO mode is applied.

2A and 2B are diagrams illustrating a wireless communication system environment to which a 4x4 MIMO mode is applied.

3A-3C illustrate MIMO mode types applicable in the wireless communication system environment shown in FIG. 2B.

4 is a schematic block diagram of a base station supporting a method of operating a MIMO mode using a multi-mode codebook according to an embodiment of the present invention.

5 is a schematic block diagram of a terminal supporting a MIMO mode operating method using a multi-mode codebook according to an embodiment of the present invention.

FIG. 6 is a flowchart illustrating a method of operating a MIMO mode using a multi-mode codebook according to an embodiment of the present invention performed at the base station shown in FIG. 4.

FIG. 7 is a flowchart illustrating a method of operating a MIMO mode using a multi-mode codebook according to an embodiment of the present invention performed in a terminal shown in FIG. 5.

Claims (23)

Determining one of the first and second codebooks according to the Multi Input Multi Output (MIMO) mode type of the entire system; Selecting a precoding matrix from the determined codebook based on estimated channel state information; And And feeding back a first index for the selected precoding matrix to a transmitting device. The method of claim 1, The MIMO mode type of the entire system includes a first MIMO mode type in which all the MIMO modes of the transmitters are spatial multiplexing (SM), the MIMO mode of one of the transmitters is SM, and the other MIMO mode is STTD (Space). MIMO mode operating method using a multi-mode codebook, characterized in that it comprises a second MIMO type (Time Transmit Diversity). The method of claim 1, wherein in the codebook determination step, When the MIMO mode type of the entire system is a first MIMO mode type, a codebook having a smaller size is determined among the first and second codebooks, and when the MIMO mode type of the premise system is a second MIMO type, the first MIMO mode type is determined. And selecting a codebook having a larger size from among the second codebooks. The method of claim 1, Any one of the first and second codebooks is generated using a different subset of the MIMO mode using a multi-mode codebook. The method of claim 1, Determining a second index representing the selected codebook, And in the first index feedback step, feeding the second index together with the first index to a transmitting device. The method of claim 1, The second index is a size of 1 bit (Bit) MIMO mode operating method using a multi-mode codebook. The method of claim 1, The first codebook includes 64 precoding matrices, and the second codebook includes eight precoding matrices. The method of claim 1, In the precoding matrix selection step, MIMO mode operating method using a multi-mode codebook, characterized in that for selecting the precoding matrix having the highest SINR from the determined codebook. The method of claim 1, And detecting transmission data transmitted from at least one transmitting apparatus based on the selected precoding matrix and the estimated channel state information. Receiving a feedback from the receiving apparatus, the first index for the precoding matrix and the second index for the codebook; Selecting a precoding matrix corresponding to the first index from a codebook corresponding to the value of the second index among first and second codebooks; Precoding the transmission data to be transmitted to the receiver by using the selected precoding matrix; And  And transmitting the precoded transmission data through a plurality of transmission antennas. The method of claim 10, The first and second codebooks are codebooks having different sizes, and any one of the first and second codebooks is a codebook generated using a different subset. Way. The method of claim 10, The first codebook includes 64 precoding matrices, and the second codebook includes eight precoding matrices. A codebook determiner which determines one of the first and second codebooks according to the MIMO mode type of the entire system; A channel estimator for generating channel state information by analyzing channel characteristics from a signal transmitted from a transmitter; And A precoding matrix is selected from a codebook determined by the codebook determiner based on the channel state information generated by the channel estimator, and fed back to a transmitting apparatus with a first index for the selected precoding matrix; Receiving apparatus for supporting the MIMO mode operation method using a multiple codebook, characterized in that it comprises a coding matrix selector. The method of claim 13, The MIMO mode type of the entire system includes a first MIMO mode type in which all the MIMO modes of the transmitters are spatial multiplexing (SM), the MIMO mode of one of the transmitters is SM, and the other MIMO mode is STTD (Space). A receiver supporting the MIMO mode operation method using a multi-mode codebook, characterized in that it comprises a second MIMO type (Time Transmit Diversity). The method of claim 14, The codebook determiner may determine a codebook having a smaller size among the first and second codebooks when the MIMO mode type of the entire system is the first MIMO mode type, and wherein the MIMO mode of the entire system is the second MIMO mode type. And a receiver supporting the MIMO mode operating method using the multi-mode codebook, wherein the codebook having a larger size is determined among the first and second codebooks. The method of claim 13, Any one of the first and the second codebook is generated using a different subset of the receiver supporting the MIMO mode operation method using a multi-mode codebook. The method of claim 13, The codebook determiner determines a second index representing the selected codebook and provides the codebook to the precoding matrix selector. And the precoding matrix selector feeds back the second index along with the first index to a transmitter. The method of claim 13, And the first codebook includes 64 precoding matrices and the second codebook includes eight precoding matrices. The method of claim 13, The precoding matrix selection unit supports a MIMO mode operation method using a multi-mode codebook, characterized in that for selecting the precoding matrix having the highest SINR from the determined codebook. The method of claim 13, And a transmission data detector for detecting transmission data transmitted from at least one transmission device based on the selected precoding matrix and channel state information. . A feedback receiver for receiving a feedback from the receiver on the first index of the precoding matrix and the second index of the codebook; Selecting a precoding matrix corresponding to the first index from a codebook corresponding to the value of the second index among the first and second codebooks, and precoding transmission data to be transmitted to a receiving apparatus using the selected precoding matrix Precoding performing unit; And  And a data transmitter for transmitting the precoded transmission data by the precoding performer to the receiving apparatus through a plurality of antennas. The method of claim 21, The first and second codebooks are codebooks having different sizes, and any one of the first and second codebooks is a codebook generated using a different subset. Transmitters that support the method. The method of claim 21, And the first codebook includes 64 precoding matrices and the second codebook includes eight precoding matrices.

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