KR101020107B1 - Apparatus for trasmitting and receiving data using multi-antenna in multi-user wireless communication system and method thereof - Google Patents

Abstract

Disclosed are a data transmitting and receiving apparatus using a multiple antenna and a method thereof in a multi-user wireless communication system. A data receiving apparatus according to an embodiment of the present invention is a data receiving apparatus in a multi-user wireless communication system that receives data transmitted from multiple antennas, and the correlation between the multiple antennas is based on a signal transmitted from the multiple antennas. A correlation estimating unit for estimating; An eigenvector generator for extracting eigenvectors of the correlation matrix from the correlation matrix between the multiple antennas and calculating optimal eigenvectors among the eigenvectors to generate optimal eigenvectors corresponding to the number; A weight information generation unit generating weight information on the optimal eigenvectors based on the optimal eigenvectors and quantizing the weighted eigenvectors; And a feedback unit for returning the optimal eigenvectors and the weight information to the transmitter having the multiple antennas for calculating the weight of each of the multiple antennas.

Multi-User, Multiple Antenna, Antenna Correlation, Eigenvectors, Signal-to-Noise Ratio, Data Transmission / Reception

Description

Device for transmitting / receiving data using multi-antenna in multi-user wireless communication system and its method {APPARATUS FOR TRASMITTING AND RECEIVING DATA USING MULTI-ANTENNA IN MULTI-USER WIRELESS COMMUNICATION SYSTEM AND METHOD THEREOF}

The present invention relates to data transmission and reception using multiple antennas, and more particularly, in a multi-user wireless communication system that transmits data to an optimal receiver among a plurality of receivers using multiple antennas, a weight for each of the multiple antennas is adjusted to the receiver. An apparatus for transmitting and receiving data using multiple antennas and a method thereof in a multi-user wireless communication system capable of maximizing power of a received signal by transmitting data.

In the multi-user downlink system, a multi-antenna technique using DPC (Dirty Paper Coding) is best known as a technique for obtaining theoretical capacity when a transmitter transmits signals using multiple antennas.

However, this technique is difficult to implement due to a computational complexity and a transmission burden for feeding back channel information. Although a number of approximation techniques have been proposed to reduce this computational complexity, its utilization is limited due to the burden of transmission to feed back channel information.

The opportunistic beamforming technique operates by using only the signal-to-noise ratio (SNR) information of the user, thereby greatly reducing the transmission burden of feeding back channel information. . In particular, as the number of users increases, the multi-user diversity gain increases, thereby greatly improving the quality of the received signal.

However, this technique reduces the multiuser diversity gain in a small number of users, thereby limiting the performance of the opportunistic beamforming technique. In order to overcome this disadvantage, a method of transmitting a signal by receiving matched beam weight information additionally from a selected user has been proposed, but there is a disadvantage in that there is a transmission burden of feedback of additional channel information in order to feed back matched beam weight information.

The above-described techniques are designed assuming that there is no correlation between transmission antennas, but in a real environment, correlations exist between transmission antennas.

Opportunistic Eigenbeamforming technique is characterized by using only the inter-antenna correlation information in generating the beam weight information of the transmitter using this characteristic, since the inter-antenna correlation information does not change rapidly with time. There is an advantage in that the burden of the feedback channel can be greatly reduced, but there is a disadvantage in that performance is significantly reduced compared to using instantaneous channel information in an environment where the correlation between antennas is low.

An object of the present invention, which is designed to solve the above problems, is to adjust the transmit beam weight of each of the multiple antennas to transmit data to the receiver with the adjusted transmit beam weight, thereby maximizing the power of the received signal. The present invention provides a data transmission and reception apparatus using a multiple antenna and a method thereof in a multi-user wireless communication system.

Another object of the present invention is to select a receiver to receive data based on correlation information among multiple antennas among a plurality of receivers and to transmit data, thereby reducing a feedback burden and thereby improving the quality of a received signal. The present invention provides a data transmission / reception apparatus using a multiple antenna and a method thereof in a multi-user wireless communication system.

Another object of the present invention is to improve system performance in an environment where inter-antenna correlation exists by adaptively changing the optimal eigenvectors according to the correlation between the multiple antennas and the number of receivers. The present invention provides a data transmission / reception apparatus using a multiple antenna and a method thereof in a multi-user wireless communication system.

In order to achieve the above object, a data receiving apparatus according to an aspect of the present invention is a data receiving apparatus in a multi-user wireless communication system for receiving data transmitted from a multiple antenna, the data receiving apparatus based on the signal transmitted from the multiple antenna A correlation estimator for estimating correlations between multiple antennas; An eigenvector generator for extracting eigenvectors of the correlation matrix from the correlation matrix between the multiple antennas and calculating optimal eigenvectors among the eigenvectors to generate optimal eigenvectors corresponding to the number; A weight information generation unit generating weight information on the optimal eigenvectors based on the optimal eigenvectors and quantizing the weighted eigenvectors; And a feedback unit for returning the optimal eigenvectors and the weight information to the transmitter having the multiple antennas for calculating the weight of each of the multiple antennas.

The eigenvector generator may calculate the number of optimal eigenvectors among the eigenvectors, and output the optimal eigenvectors corresponding to the calculated number to the weight information generator and the feedback unit.

Furthermore, the apparatus may further include a signal-to-noise ratio calculator that calculates a signal-to-noise ratio based on the optimal eigenvectors, and the feedback unit may feedback the signal-to-noise ratio to the transmitter.

A data transmission apparatus according to an aspect of the present invention is a data transmission apparatus using multiple antennas in a multi-user wireless communication system, the optimal eigenvectors of the correlation matrix generated based on the correlation matrix between the multiple antennas from the receiver and the A receiver for receiving weight information of optimal eigenvectors; A weight generator configured to generate a transmission beam weight of each of the multiple antennas based on the optimal eigenvectors and the weight information; And a data transmitter configured to transmit data to the receiver through the multiple antennas whose transmission beam weights are adjusted based on the transmission beam weights.

Furthermore, the receiver may further include a receiver selector configured to select a data receiver to receive data among the plurality of receivers based on a signal-to-noise ratio of each of the plurality of receivers received through the receiver.

In this case, the receiver selector may select a receiver having a maximum signal-to-noise ratio among the signal-to-noise ratios received from each of the plurality of receivers as a data receiver.

A data reception method according to an aspect of the present invention is a data reception method in a multi-user wireless communication system for receiving data transmitted from multiple antennas, the method comprising: estimating a correlation between the multiple antennas based on a signal transmitted from the multiple antennas Making; Generating eigenvectors of the correlation matrix from the correlation matrix between the multiple antennas; Calculating the number of optimal eigenvectors among the eigenvectors; Generating weight information of the optimal eigenvectors based on the optimal eigenvectors corresponding to the calculated number and quantizing the weighted values of the eigenvectors; And returning the optimal eigenvectors and the weight information to the transmitter having the multiple antennas for calculating the weight of each of the multiple antennas.

A data transmission method according to an aspect of the present invention is a data transmission method using multiple antennas in a multi-user wireless communication system, the optimal eigenvectors of the correlation matrix generated based on the correlation matrix between the multiple antennas from the receiver and the Receiving weight information of optimal eigenvectors; Generating a transmission beam weight of each of the multiple antennas based on the optimal eigenvectors and the weight information; And transmitting data to the receiver through the multiple antennas in which transmission beam weights are adjusted based on the transmission beam weights.

Other objects and features of the present invention in addition to the above objects will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

An apparatus for transmitting and receiving data using multiple antennas and a method thereof in a multi-user wireless communication system according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7.

1 shows a system diagram for explaining the present invention.

Referring to FIG. 1, a transmitter 110 and a plurality of receivers 120 are included.

The transmitter 110 includes a multiple antenna (ANT), receives a signal-to-noise ratio (SNR) transmitted from each of the plurality of receivers, selects a receiver to receive data based on the signal-to-noise ratio, and optimally unique from the selected receiver. Receiving the weight information of the vectors and the optimal eigenvectors to generate a transmission beam weight for each of the multiple antennas, and transmits data to the receiver through the multi-antenna with the transmission beam weight is adjusted.

Here, the transmitter 110 may be fed back the index for any one of the transmission beam weight information configured in the codebook as the weight information of the optimal eigenvectors, in which case the transmitter transmits based on the optimal eigenvectors and the codebook index Beam weights may be generated.

Of course, in this case, it is preferable that both the transmitter and the receiver have a codebook including weight information.

In this case, the transmitter 110 may select a receiver having the maximum signal-to-noise ratio among the signal-to-noise ratios received from the plurality of receivers and transmit data.

The receiver 120 estimates correlations between multiple antennas based on a signal transmitted from a transmitter, for example, a pilot signal, and calculates optimal eigenvectors by generating eigenvectors based on the correlation matrix of the estimated correlation. The data may be received from the transmitter by feeding back the signal-to-noise ratio, weight information of the best eigenvectors, and the best eigenvectors calculated using the best height vectors.

In this case, the receiver 120 may return the weighted information of the optimal eigenvectors and the optimal eigenvectors to the transmitter only when receiving information indicating that the receiver has been selected as the data receiver from the transmitter, for example, its corresponding index. In order to reduce the optimal eigenvectors, it is preferable to feedback the transmitter only when the number of optimal eigenvectors or the eigenvectors change.

A detailed configuration of such a transmitter and a receiver will be described with reference to the drawings below.

Hereinafter, it is assumed that there are M multiple antennas in the transmitter and each of the K receivers has one antenna in the downlink wireless communication system.

FIG. 2 is a block diagram illustrating a data receiving apparatus according to an embodiment of the present invention, which is illustrated in FIG. 1.

Referring to FIG. 2, the receiver 120 includes a data receiver 210, an SNR calculator 220, a random beam generator 230, a weight information generator 240, an eigenvector generator 250, and a feedback unit. 260 and a correlation estimator 270.

Here, assuming that the receiver is the k-th receiver among the K receivers, the received signal received by the receiver may be represented by Equation 1 below.

Here, y _k means a received signal received by the k-th receiver, h _k = [h _k1 , ..., h _kM ] ^T means a channel vector of (M × 1) dimension, w = [w ₁ , ..., w _M ] ^T is || transmit beam weight vector of (M × 1) dimension satisfying w || = 1, || w || means Euclidian norm of the w vector, and s is E {| s | ² } = P means that the transmission signal satisfies, where n _k is E {| n _k | ² } = N means the noise component of the kth receiver satisfying N ₀ (k), * means conjugate transpose operator, T means transpose operator, and P means preset value. Means the average power of the transmitter.

The correlation estimator 270 estimates correlation between the multiple antennas based on a signal transmitted from the multiple antennas of the transmitter.

In this case, the correlation estimator 270 may estimate a correlation between the i th antenna and the j th antenna of the transmitter as shown in Equation 2 below.

Where r ^k _{i , j} denotes the correlation between the i th antenna and the j th antenna in the k th receiver, and h _ki is the i th element of h _k , between the i th transmit antenna and the receive antenna of the k th receiver The channel gain, and h _kj is the j-th element of h _k , the channel gain between the j-th transmission antenna and the receiving antenna of the k-th receiver.

The multi-antenna intercorrelation matrix R _k of the (M × M) dimension of the k th receiver configured using Equation 2 may be expressed as Equation 3 below.

The eigenvector generator 250 extracts eigenvectors of the correlation matrix based on the correlation matrix estimated by the correlation estimator 270, calculates the optimal number of eigenvectors based on the extracted eigenvectors, and calculates the number of eigenvectors. Create the corresponding optimal eigenvectors.

In this case, the eigenvector generator 250 may extract eigenvectors of the correlation matrix by singular value decomposition of R _k as shown in Equation 4 below.

Where Q _k = [ q _{k , 1} , ..., q _{k , M} ] is the size of each column ( q _{k , 1} , ..., q _{k , M} ) consisting of the eigenvectors of R _k ( M × M) unitary matrix, q is the eigenvector of the correlation matrix, Σ ² _k is the eigenvalue (σ ² _{k, 1} , ..., σ ² _{k, M} ) means a diagonal matrix whose size is (M × M), in which the sizes of the elements are arranged in descending order, such as σ ² _{k, 1} ≥ ... ≥σ ² _{k, M.}

The eigenvector generator 250 calculates the optimal number of eigenvectors based on the eigenvalue extracted through Equation 4, and the optimal eigenvectors can be calculated by Equation 5 below.

Here, L (k) denotes the number of optimal eigenvectors, and K denotes the number of receivers.

As can be seen from Equation 5, the eigenvector generator 250 calculates an index at which the calculated value of Equation 5 is the maximum among the indices of 1 to M as the optimal number of eigenvectors.

Therefore, the eigenvector generation unit 250 includes the best eigenvectors corresponding to the optimal number of eigenvectors, that is, ( q _{k , 1} , ..., q _{k , L (k)} ) _{, which are L (k)} eigenvectors. Create

The random beam generator 230 generates a random beam weight based on the optimal eigenvectors generated by the eigenvector generator 250.

In this case, the random beam generator 230 may generate a random beam weight using Equation 6 below.

를 만족하도록 임의로 생성된 수를 의미한다.Here, w _k means a random beam weight _vector having a random beam weight of (w _{k , 1} , ..., w _{k , M} ), and (v _{k , 1} , ..., v _{k , L (k )} )

It means a randomly generated number to satisfy.

The SNR calculator 220 calculates an SNR based on the random beam weight generated by the random beam generator 230.

In this case, the SNR calculator 220 may calculate the SNR using Equation 7 below.

는 k번째 수신기의 SNR을 의미하고,

=P/N₀(k)는 k번째 수신기의 평균 SNR을 의미한다.here,

Denotes the SNR of the kth receiver,

= P / N ₀ (k) means the average SNR of the k-th receiver.

The weight information generator 240 generates a quantized weight value by generating weight values of the optimal eigenvectors based on the optimal eigenvectors generated by the eigenvector generator 250 and quantizing them, and quantized optimal eigenvectors. To generate weight information.

Of course, the weight information generator 240 may generate weight information when receiving the information that the corresponding receiver is selected from the transmitter.

)가 수신되면, 수신기의 최적 고유벡터들 즉, L(

)개의 고유벡터들인 (q _k,1,...,q _k,L(

₎)을 이용하여 (M×L(

)) 차원의 행렬 Q

,_{1: L(}

₎=[q _{k ,1},...,q _{k ,L(}

₎]을 구성하고, 이를 이용하여 (L(

)×1) 차원의 가중치 값을 아래 <수학식 8>을 이용하여 생성한다.At this time, the weight information generation unit 240 is the index of the receiver selected by the transmitter (

) Is received, the optimal eigenvectors of the receiver, L (

) Eigenvectors ( q _{k, 1} , ..., q _{k, L (}

_With) ) (M × L (

)) Matrix of dimensions Q

, _{1: L (}

₎ = [ q _{k , 1} , ..., q _{k , L (}

₎ ] And use it to (L (

A weight value of) × 1) dimension is generated by using Equation 8 below.

)를 생성한다.The weight information generator 240 quantizes the weight information v generated by Equation 8 as shown in Equation 9 below to quantize the weight vector (

)

Here, F _quan ( v ) means a quantization function, and an example of a quantization technique may be a quantization technique using a codebook. The quantization technique using a codebook may be expressed as Equation 10 below.

Here, Ω = ( c ₁ , ..., c _N ) means a codebook including N weight information. As can be seen in Equation 10, the weight information generator 240 configures a codebook. Among the weighting information, an optimal index for weighting information at which the value of Equation 10 is maximized is generated.

The feedback unit 260 may generate the SNR calculated by the SNR calculator 220, the best eigenvectors generated by the eigenvector generator 250, and the peak beam weight information generated by the weight information generator 240. Feedback to the transmitter.

In this case, the feedback unit 260 reduces the amount of information fed back by not returning the optimal eigenvectors to the transmitter only when the number of optimal eigenvectors is changed or the eigenvectors information is changed. Can be.

That is, the change in the eigenvectors information may be caused by the change in the antenna correlation. In general, since the antenna correlation information has a characteristic that changes considerably slower than the fading of the channel, the eigenvectors information is rarely transmitted to the transmitter. This can reduce the additional signal feedback burden.

The data receiver 210 receives data transmitted by adjusting the transmission beam weights of the multiple antennas by the transmission beam weights calculated by the transmitter based on the information returned through the feedback unit 260.

FIG. 3 is a block diagram illustrating a data transmission apparatus according to an embodiment of the present invention, and is related to the transmitter illustrated in FIG. 1.

Referring to FIG. 3, the transmitter 110 includes a data transmitter 310, a receiver selector 320, a weight generator 330, and a receiver 340.

The receiver 340 receives SNRs fed back from the plurality of receivers, optimal eigenvectors fed back from the receiver selected by the receiver selector 320, and optimal beam weight information.

Of course, the receiver 340 may also receive optimal eigenvectors fed back from a plurality of receivers.

Here, the optimal beam weight information is a quantized optimal beam weight value, and the weight information when the transmitter and the receiver has a codebook including the weight information of the optimal eigenvectors is one of the indexes of the weight information included in the codebook. May be

That is, the receiver 340 receives the SNRs calculated by each of the plurality of receivers, outputs the SNRs to the receiver selector 320, receives the optimal eigenvectors and the optimal beam weight information fed back from the selected receiver, and receives a weight generator ( 330).

In this case, the receiver 340 preferably separates the SNR, the optimal eigenvectors, and the optimal beam weight information received by the multiple antennas, and provides them to the receiver selector 320 and the weight generator 330.

The receiver selector 320 selects a receiver to receive data based on SNRs of the plurality of receivers received by the receiver 340.

In this case, the receiver selecting unit 320 may select a receiver having the maximum SNR among the plurality of receivers in order to maximize the system capacity. The receiver may be selected by Equation 11 below.

₁ 내지

_K 중 최대값을 갖는 수신기의 인덱스(

)를 선택한다.That is, the SNR calculated by K receivers

₁ to

The index of the receiver with the highest value of _K (

Select).

In this case, when the receiver is selected by the receiver selecting unit 320, the receiver may be notified by transmitting an index of the selected receiver.

The weight generator 330 calculates a transmission beam weight of each of the multiple antennas based on information fed back from the selected receiver after the index of the selected receiver is transmitted, that is, the optimal eigenvectors and the optimal beam weight information received by the receiver 340. Create

Here, the optimal eigenvectors may be previously stored in the transmitter, and may be fed back from the receiver when the eigenvectors information is changed. That is, the transmitter does not need to receive the optimal eigenvectors from the receiver unless the eigenvectors information is changed or the number of optimal eigenvectors is changed.

In this case, the weight generator 330 may generate a transmission beam weight using Equation 12 below.

)와 L(

)개의 최적 고유벡터들인 (q _{k ,1},...,q _{k ,L(}

₎)을 이용하여 송신빔 가중치를 생성한다.That is, the weight generator 330 is a weight vector quantized by the receiver (

) And L (

) Best eigenvectors ( q _{k , 1} , ..., q _{k , L (}

₎₎ To generate a transmission beam weight using the.

The data transmitter 310 transmits data to a receiver by using a multi-antenna having a transmit beam weight adjusted, and includes a data selector 311 and a transmit beam adjuster 312.

The data selector 311 selects and outputs data to be transmitted to the receiver selected by the receiver selector 320.

The transmit beam adjuster 312 adjusts the transmit beam weight of each of the multiple antennas by using the transmit beam weight generated by the weight generator 330.

)로 송신한다. That is, the data transmitter 310 transmits data whose transmission beam weight is adjusted through a corresponding antenna (multi-antenna).

To send).

As described above, the apparatus for transmitting and receiving data according to an embodiment of the present invention can maximize the power of the received signal because the data is transmitted to the receiver with the adjusted transmit beam weight by adjusting the transmit beam weight of each of the multiple antennas. By selecting a receiver based on the correlation matrix and transmitting data, the quality of the received signal can be improved with a small amount of feedback information.

In addition, by adaptively changing the number of optimal eigenvectors according to the correlation between the multiple antennas and the number of receivers, the system performance can be adaptively improved in various environments.

4 is a flowchart illustrating a method of receiving data according to an embodiment of the present invention.

Referring to FIG. 4, the data receiving method receives a signal transmitted through multiple antennas of a transmitter, for example, a pilot signal, and estimates correlation between multiple antennas based on the received signal (S410).

In this case, the correlation between antennas may be estimated by Equation 2 described above, and the estimated multi-antenna correlation matrix may be represented by Equation 3 described above.

The eigenvectors of the correlation matrix are generated based on the estimated multi-antenna correlation matrix (S420).

Here, the eigenvectors of the correlation matrix may be obtained by singular value decomposition of the correlation matrix as shown in Equation 4 above.

The optimal number of eigenvectors is calculated based on the eigenvalues of the generated eigenvectors (S430).

In this case, the optimal number of eigenvectors may be calculated by Equation 5 described above.

The receiver should feed back the optimal eigenvectors to the transmitter, and it is desirable to reduce the amount of information fed back to the transmitter only when the information of the eigenvectors is changed or the number of optimal eigenvectors is changed.

For example, as shown in FIG. 5, when the number of optimal eigenvectors is calculated, it is determined whether the number of optimal eigenvectors or eigenvectors is changed, and thus the number of optimal eigenvectors is different from the previous number of optimal eigenvectors. If the eigenvectors information is different from the previous eigenvectors information, the optimum eigenvectors are fed back to the transmitter (S510 to S530).

That is, the receiver returns the best eigenvectors to the transmitter only when the eigenvector information or the number of best eigenvectors is changed after the best eigenvectors generated by the initial calculation are fed back to the transmitter. Of course, the timing of returning the initial optimal eigenvectors or the changed optimal eigenvectors to the transmitter may be fed back at the time of returning other information, or may be fed back at a preset time.

The receiver generates random beam weights based on the optimal eigenvectors corresponding to the calculated number of optimal eigenvectors, for example, L (k), and generates an SNR based on the generated random beam weights. The calculation returns to the transmitter (S440).

In this case, the random beam weight and the SNR may be generated and calculated by the above Equations 6 and 7 above.

After the SNR is fed back to the transmitter, when the selection signal of the corresponding receiver is selected by the transmitter, the weight value of the optimal eigenvectors is generated and quantized to generate quantized weight information of the optimal eigenvectors (S460).

In this case, the weight information may be generated by Equation 8 and Equation 9 described above.

In this case, when the selection signal is not received from the transmitter, the receiver generates the random beam weights, calculates the SNR based on the generated random beam weights, and repeats the above-described process.

Of course, when the receiver and the transmitter have a codebook including weight information, a quantization technique using a codebook, for example, an index corresponding to the optimal weight information may be calculated to generate an optimal index corresponding to the weight information, and may be fed back. .

After the generated weight information is fed back to the transmitter, data transmitted through multiple antennas of the transmitter is received (S480).

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

Referring to FIG. 6, in the data transmission method, an SNR calculated based on correlation of multiple antennas is received by each receiver from a plurality of receivers (S610).

The transmitter selects a data receiver to receive data based on the plurality of received SNRs (S620).

In this case, in order to maximize system capacity, the transmitter preferably selects a receiver having a maximum SNR among the plurality of SNRs as a data receiver.

When the receiver is selected, an index corresponding to the selected receiver is transmitted as a selection signal to recognize that the corresponding receiver is selected (S630).

When the quantized weight information of the best eigenvectors fed back by the data receiver is received after the selection signal is transmitted, the transmission beam weights of the multiple antennas are generated based on the best eigenvectors and the weight information of the data receiver (S640 and S650). .

In this case, the transmitter may generate the transmission beam weight by using Equation 12 described above.

Here, the transmitter may store the optimal eigenvectors previously fed back from the data receiver, and the optimal eigenvectors may be fed back from the receiver and updated when the eigenvectors information is changed or the number of optimal eigenvectors is changed.

For example, as shown in FIG. 7, the transmitter determines whether there are optimal eigenvectors returned from the receiver and updates the optimal eigenvectors of the data receiver when the optimal eigenvectors are returned from the selected data receiver, and updates the updated optimal eigenvectors. The transmission beam weights of the multiple antennas are generated using the vectors and the quantized weight information (S710 to S730).

Of course, when the optimal eigenvectors changed from the receiver are not fed back, the transmission beam weight is generated using the optimal eigenvectors and quantized weight information previously fed back and stored from the data receiver.

The transmitter adjusts the transmission beam weight of each of the multiple antennas using the generated transmission beam weights, and transmits data to the selected data receiver through the multiple antennas having the transmission beam weights adjusted (S660).

According to the present invention, a data transmission / reception apparatus using a multiple antenna and a method thereof in a wireless communication system can be variously modified and applied within the scope of the technical idea of the present invention, and are not limited to the above embodiments. In addition, the embodiments and drawings are merely for the purpose of describing the contents of the invention in detail, not intended to limit the scope of the technical idea of the invention, the present invention described above is common knowledge in the technical field to which the present invention belongs As those skilled in the art can have various substitutions, modifications, and changes without departing from the spirit of the present invention, it is not limited to the embodiments and the accompanying drawings. And should be judged to include equality.

1 shows a system diagram for explaining the present invention.

FIG. 2 is a block diagram illustrating a data receiving apparatus according to an embodiment of the present invention, which is illustrated in FIG. 1.

FIG. 3 is a block diagram illustrating a data transmission apparatus according to an embodiment of the present invention, and is related to the transmitter illustrated in FIG. 1.

4 is a flowchart illustrating a method of receiving data according to an embodiment of the present invention.

FIG. 5 is a flowchart of an embodiment operation of step S430 shown in FIG. 4.

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

FIG. 7 is a flowchart of an embodiment operation of step S650 illustrated in FIG. 6.

<Description of Symbols for Main Parts of Drawings>

210: data receiving unit

220: SNR calculation unit

230: random beam generation unit

240: weight information generation unit

250: eigenvector generator

260: feedback

270: correlation estimation unit

310: data transmission unit

311: data selector

312: transmission beam control unit

320: receiver selector

330: weight generation unit

340: receiving unit

Claims (14)

A data receiving apparatus in a multi-user wireless communication system for receiving data transmitted from a multi-antenna, A correlation estimator for estimating a correlation between the multiple antennas based on a signal transmitted from the multiple antennas; An eigenvector generator for extracting eigenvectors of the correlation matrix from the correlation matrix between the multiple antennas and calculating optimal eigenvectors among the eigenvectors to generate optimal eigenvectors corresponding to the number; A weight information generation unit generating weight information on the optimal eigenvectors based on the optimal eigenvectors and quantizing the weighted eigenvectors; And A feedback unit for returning the optimal eigenvectors and the weight information to the transmitter having the multiple antennas for calculating the weight of each of the multiple antennas Data receiving apparatus comprising a. The method of claim 1, The eigenvector generator A data receiving apparatus for calculating the optimal number of eigenvectors using Equation 1 below. &Quot; (1) &quot;

Where L (k) is the number of optimal eigenvectors, M is the number of multiple antennas provided in the transmitter, K is the number of receivers, and σ ² _{k, l} is the l-th eigenvalue of the k-th receiver. The method according to any one of claims 1 and 2, Signal to noise ratio calculation unit for calculating the signal to noise ratio based on the optimal eigenvectors More, The feedback part And a data receiving device for feeding back the signal-to-noise ratio to the transmitter. The method of claim 3, A random beam generator generates random beam weights based on the optimal eigenvectors and outputs the random beam weights to the signal to noise ratio calculator. More, The signal-to-noise ratio calculation unit And calculating the signal-to-noise ratio based on the random beam weight. The method according to any one of claims 1 and 2, The feedback part And the optimum eigenvectors are fed back to the transmitter when the number of the best eigenvectors is changed or the eigenvectors information is changed. A data transmission apparatus using multiple antennas in a multi-user wireless communication system, A receiver configured to receive optimal eigenvectors of the correlation matrix and weight information of the optimal eigenvectors generated based on a correlation matrix between the multiple antennas from a receiver; A weight generator configured to generate a transmission beam weight of each of the multiple antennas based on the optimal eigenvectors and the weight information; And A data transmitter for transmitting data to the receiver through the multiple antennas whose transmission beam weights are adjusted based on the transmission beam weights Data transmission device comprising a. The method of claim 6, A receiver selector configured to select a data receiver to receive data among the plurality of receivers based on a signal-to-noise ratio of each of the plurality of receivers received through the receiver; Data transmission device further comprising. The method of claim 7, wherein The receiver selector And selecting a receiver having a maximum signal-to-noise ratio among the signal-to-noise ratios received from each of the plurality of receivers as a data receiver. A data receiving method in a multi-user wireless communication system for receiving data transmitted from a multi-antenna, Estimating correlation between the multiple antennas based on the signal transmitted from the multiple antennas; Generating eigenvectors of the correlation matrix from the correlation matrix between the multiple antennas; Calculating the number of optimal eigenvectors among the eigenvectors; Generating weight information of the optimal eigenvectors based on the optimal eigenvectors corresponding to the calculated number and quantizing the weighted values of the eigenvectors; And Feeding back the optimal eigenvectors and the weight information to the transmitter having the multiple antennas for calculating the weight of each of the multiple antennas. Data receiving method comprising a. 10. The method of claim 9, The calculating step A data receiving method for calculating the optimal number of eigenvectors using Equation 1 below. &Quot; (1) &quot;

Where L (k) is the number of optimal eigenvectors, M is the number of multiple antennas provided in the transmitter, K is the number of receivers, and σ ² _{k, l} is the l-th eigenvalue of the k-th receiver. 10. The method of claim 9, Generating a random beam weight based on the optimal eigenvectors; And Calculating a signal-to-noise ratio based on the random beam weight and feeding back to the transmitter The data receiving method further comprises. A data transmission method using multiple antennas in a multi-user wireless communication system, Receiving optimal eigenvectors of the correlation matrix and weight information of the optimal eigenvectors generated based on the correlation matrix between the multiple antennas from a receiver; Generating a transmission beam weight of each of the multiple antennas based on the optimal eigenvectors and the weight information; And Transmitting data to the receiver through the multiple antennas whose transmission beam weights are adjusted based on the transmission beam weights; Data transmission method comprising a. The method of claim 12, Selecting a data receiver to receive data from among the plurality of receivers based on a signal-to-noise ratio received from each of the plurality of receivers The data transmission method further comprising. The method of claim 13, The step of selecting And selecting a receiver having a maximum signal-to-noise ratio among the signal-to-noise ratios of each of the plurality of receivers as a data receiver.

Images