KR101073918B1 - method of performing TxAA in multicarrier system having plural antennas - Google Patents

Abstract

The present invention relates to a transmission diversity scheme, and more particularly, to a method of applying a transmit antenna array (TxAA) in an OFDM / OFDMA system using a plurality of transmission antennas. A method of applying TxAA in a multi-carrier system using a plurality of transmit / receive antennas according to the present invention includes: receiving weights according to grouped carriers for each of the transmit antennas from a receiver; And multiplying a weight corresponding to a data stream allocated to each of the transmit antennas.

OFDM, OFDMA, TxAA, Weighted, Diversity

Description

Method of performing TxAA in multicarrier system having plural antennas

1 is a view showing the concept of the STTD according to the prior art.

2 is a diagram illustrating the concept of TxAA according to the prior art.

3 is a diagram illustrating a method of applying TxAA in a multi-carrier system using a plurality of transmit and receive antennas according to the present invention.

4 is a diagram illustrating another method of applying TxAA in a multi-carrier system using multiple transmit / receive antennas.

The present invention relates to a transmission diversity scheme, and more particularly, to a method of applying a transmit antenna array (TxAA) in an OFDM / OFDMA system using a plurality of transmission antennas.

Hereinafter, a transmission diversity scheme according to the prior art will be described. Currently, 3D mobile communication systems use STTD (Space Time Transmit Diversity) and TxAA modes 1 and 2 as transmission diversity schemes.

The STTD according to the prior art is an open loop technique, which uses two antennas and provides spatial diversity gain as well as temporal diversity through time and space simple coding between symbols transmitted from the two antennas. There is also a purpose to get. The prior art configuration requires two antennas and a space time coding block for coding between symbols transmitted by the two antennas.

TxAA mode 1 and 2 according to the prior art is a closed loop technology, which uses two transmitting antennas and multiplies the weight value transmitted from the receiving end to the transmitting end to transmit the performance. There is a purpose.

Hereinafter, the operation of the Space Time Transmit Diversity (STTD) according to the prior art will be described. The STTD is a technique for obtaining a diversity effect through space-time coding in which a channel coding technique, which is mainly applied on a time axis, is extended in space. This scheme is applicable to all downlink physical channels except SCH of WCDMA. The STTD scheme is an open loop technology, and since a feedback signal is not required, there is no performance degradation due to a feedback signal delay depending on a speed. The operation principle of the STTD may be represented as shown in Table 1 below. Table 1 below shows the STTD encoding and transmission order of two antennas, and T represents a symbol period.

Time

Time

Antenna 1

Antenna 2

에서의 채널과

에서의 채널이 같다고 가정할 경우 수신 안테나 단에서는 다음과 같이 수신된다.As shown in Table 1, the symbol to be transmitted is STTD-encoded and transmitted to transmit antennas 1 and 2 in chronological order, respectively. The signal transmitted to each antenna goes through different independent channels and time

Channel in

Assuming that the channels at are the same, the receiving antenna stage is received as follows.

은 t 시간에 수신 단에서의 수신 신호이고, 상기

는 t+T 시간에 수신 단에서 수신 신호를 의미한다. 또한,

는 각각 송신 안테나 1, 2와 수신 안테나 간의 채널을 의미하며,

은 수신 단에서의 복소 잡음을 의미한다. 각각의 채널은 파일럿 신호로 추정(channel estimation)이 가능하며, 수신신호를 하기 수학식 2와 같이 결합을 하게 되면 수신 다이버시티의 MRC(Maximum Ratio Combining)방식과 같은 값을 얻을 수 있고 이를 바탕으로 송신된 심볼을 추정할 수 있게 된다. remind

Is the received signal at the receiving end at time t, and

Denotes a received signal at the receiver at t + T time. Also,

Denote channels between transmit antennas 1 and 2 and receive antennas, respectively.

Denotes complex noise at the receiving end. Each channel can be estimated as a pilot signal, and when the received signals are combined as shown in Equation 2 below, values such as MRC (Maximum Ratio Combining) method of reception diversity can be obtained. It is possible to estimate the transmitted symbol.

1 is a diagram illustrating a transmitting end and a receiving end of an open loop D-STTD (Double Space Time Transmit Diversity). The open-loop D-STTD is a system for transmitting two diversity data streams through a STTD encoder and performing diversity by using space-time channels. Each stream to be transmitted can be transmitted by changing the data rate independently according to its state through channel information sent from the receiving end.

Hereinafter, the closed loop TxAA modes 1 and 2 will be described. TxAA modes 1 and 2 are diversity systems for multiplying and transmitting data to be transmitted with weights fed back from the receiving end. 2 is a view showing the structure of the TxAA according to the prior art. In the TxAA modes 1 and 2, the receiver obtains a weight to maximize the power of the received signal and transmits the weight to the transmitter. In FIG. 2, a weight generator obtains a weight from the weight generator included in the receiver. The transmitting end receives the weight and multiplies the transmission signal transmitted to the receiving end. Assuming two receive antennas, the received signal in each antenna of the receive end can be expressed as follows.

,

,

,

는 송신 안테나 1, 2와 수신 안테나 1, 2 간의 채널을 나타내는 값이다. 또한, 상기 s 는 데이터 심볼이고, n ₁, n ₂ 는 AWGN(Additive White Gaussian Noise)이다. The r ₁ is a reception signal received by the reception antenna ₁ of FIG. 2, the r2 is a signal received by the reception antenna 2,

,

,

,

Is a value representing a channel between transmit antennas 1 and 2 and receive antennas 1 and 2. In addition, s is a data symbol, n ₁ , n ₂ is AWGN (Additive White Gaussian Noise).

Recovery of data symbols of TxAA mode 1 and 2 is performed by the following equation.

The weight is to maximize the power of the received signal at the receiving end. One method of obtaining the weight may be defined as an eigenvector for the maximum eigenvalue of the covariance matrix of the channel. This can be obtained by the following equation.

는 eigenvalue를 의미한다. R is a covariance matrix of channels represented by a product of a matrix H representing a channel between each transmitting / receiving antenna and an H 'matrix that performs a hermit operation on the matrix H. Also, w is a weight vector,

Means eigenvalue.

Differences between Mode 1 and Mode 2 of the TxAA are distinguished according to differences in a method of actually implementing a weight vector. That is, in mode 1, the weight vector is represented by 1 bit to feed back, whereas in mode 2, 3 bit information including information about phase and information about amplitude are provided. It feeds back the included 1 bit information.

Hereinafter, OFDM / OFDMA according to the prior art will be described. OFDM or OFDMA, which is a multi-carrier transmission method, is a method suitable for high-speed data transmission in a wired / wireless channel and is recently actively researched and communication technology. In the OFDM scheme, since a plurality of subcarriers having mutual orthogonality are used, frequency utilization efficiency is increased, and a process of modulating and demodulating the plurality of carriers at a transmitting and receiving end is performed by an Inverse Discrete Fourier Transform (IDFT) and a Discrete Fourier Transform (DFT), respectively. Inverse Fast Fourier Transform (IFFT) and Fast Fourier Transform (FFT) can be implemented at high speed.

The principle of OFDM divides a high speed data stream into a plurality of low speed data streams and transmits them simultaneously using a plurality of subcarriers, thereby increasing symbol duration to multi-path delay spread. It is to reduce relative dispersion in the time domain. Transmission of data by the OFDM scheme is based on transmission symbols.

In the OFDMA physical layer, active carriers are divided into groups and transmitted to different receivers for each group. The group of carriers transmitted to the receiver is called a sub-channel. Carriers constituting each subchannel may be adjacent to each other or spaced at equal intervals. In this way, by allowing multiple access in subchannel units, implementation complexity increases, but there is an advantage in that frequency diversity gain, power concentration gain, and forward power control can be efficiently performed.

In order to apply TxAA to the multicarrier system according to the related art described above, the receiver obtains a weight and transmits the weight to the transmitter, which makes it difficult to obtain a weight in the time domain. Therefore, there is a problem that a new system design is required to use multiple antennas in a multi-carrier system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to limit a method of applying TxAA in an OFDM / OFDMA system using a plurality of transmit / receive antennas.

Another object of the present invention is to provide a method of applying TxAA providing independent weights according to respective subcarriers.

Another object of the present invention is to provide a method of applying TxAA that can provide a weight independent of a specific subcarrier and prevent performance degradation due to feedback.

The present invention proposes a method of applying TxAA in an OFDM / OFDMA system using a plurality of transmit and receive antennas. There is no limit to the number of antennas, but the embodiment of the present invention described below describes the TxAA operation for four transmit antennas and two receive antennas. As described below, TxAA operation for a plurality of transmit antennas and a plurality of receive antennas is described. The present invention can be extended to four or more receive antennas.

A method of applying TxAA in a multi-carrier system using a plurality of transmit / receive antennas according to the present invention includes: receiving weights according to grouped carriers for each of the transmit antennas from a receiver; And multiplying a weight corresponding to a data stream allocated to each of the transmit antennas.

In addition, the method of applying TxAA in a multi-carrier system using a plurality of transmit and receive antennas according to the present invention includes grouping each transmit antenna on a transmitting side in order to maximize power of a received signal received through the receive antenna. Calculating a weight according to the carrier; Transmitting the calculated weight to a transmitting side; And receiving the signal in which the weight is reflected from the transmitting side.

In addition, in a multi-carrier system using a plurality of transmit and receive antennas according to the present invention, a transmission and reception apparatus using TxAA includes: a weight receiver configured to receive weights according to grouped carriers for each transmit antenna from a receiver; A weight multiplier that multiplies the data streams allocated to the respective transmit antennas by the weights; And a wireless transmitter for transmitting a data stream input from the weight multiplier using a multicarrier and the transmit antenna.

In addition, in a multi-carrier system using a plurality of transmission and reception antennas according to the present invention, a transmission and reception apparatus using TxAA is a multi-input and output multi-carrier system having a plurality of reception antennas, the power of the received signal received through the reception antenna A weight calculator configured to calculate weights according to the grouped carriers for each of the transmitting antennas on the receiving side for maximization; And a plurality of receiving antennas for receiving the signal reflecting the weight from the transmitting side.

In addition, the present invention has a feature that data streams transmitted to a plurality of transmit and receive antennas are independent of each other. The data stream may be simultaneously input to a plurality of transmit antennas belonging to a specific group among a plurality of grouped transmit antennas. The weight calculated by the receiver has a characteristic of being multiplied by a data stream transmitted through the transmission antenna.

Further, in the present invention, the weight is characterized by maximizing the power of the received signal on the receiving side at all times. In addition, the receiving side of the present invention can generate the channel quality indicator (CQI) information according to the state of the received signal to enable the transmitting side MCS control.

In addition, the plurality of transmitting antennas may be variably grouped, and the receiving side may change the antenna group according to a changing channel state.

The weight may be determined separately for each subcarrier, grouped into a specific group, and may be determined identically within each group.

3 is a diagram illustrating a transmitting and receiving end of an OFDM / OFDMA system using four transmitting antennas and two receiving antennas according to an embodiment of the present invention. The transmission data is encoded and interleaved in the interleaver, and then each of the two independent data streams is operated by a serial-to-parallel operation. Each of the data streams is separate data and multiplies each independent data stream by a weight obtained in the frequency domain, and then performs an Inverse Fast Fourier Transform (IFFT). Then, the weight is multiplied and the IFFT signal is transmitted to a plurality of transmit antennas. In the present embodiment, the receiving end having two receiving antennas recovers data transmitted through a serial to parallel (Ferial to Parallel) transform, a Fast Fourier Transform (FFT) and a detection, and performs a parallel / parallel conversion. The original data is restored by being input to a decoder by a to-serial operation. Independent data streams transmitted to each transmit antenna have a data rate adjusted according to channel conditions. To this end, the receiving end transmits channel state information and channel quality indicator (CQI).

Hereinafter, the operation of the transmitter / receiver according to the present invention will be described in detail.

The first embodiment of the present invention described below describes a method in which weights are independently determined for each subcarrier.

The transmit antennas are grouped and operate. Hereinafter, the transmit antennas are operated in groups of two. Two transmit antennas can be combined to perform TxAA operation. Since the data stream 1 and the data stream 2 classified by the S / P converter of FIG. 3 are transmitted through the transmit antennas 1 and 2 and the transmit antennas 3 and 4, respectively, two transmit antennas are combined. (I.e., transmit antennas 1 and 2 form one group and transmit antennas 3 and 4 form another group) to perform TxAA. The weight used for each antenna combination is determined in the following way.

,

는 주파수 영역에서 A(n), B(n)에 대한 가중치 벡터이다. 시간 영역에서 채널은 주파수 선택적 페이딩 채널(frequency selective fading channel)로 가정한다. 상기 직병렬 변환부(S/P)에 의해 구분되어 두 개씩 조합된 송신 안테나로 전송되는 A(n), B(n)은, 수신 단으로부터 수신된 가중치 벡터에 곱해져서 IFFT 단으로 전송된다. 상기 가중치 벡터에 곱해지는 A(n), B(n) 데이터 스트림은 다음과 같이 표시된다. A (n) and B (n) are data streams transmitted to an nth subcarrier, and A (n) is transmitted through a first antenna combination, that is, transmit antennas 1 and 2, and B (n) Is transmitted through the second antenna combination, i.e., transmit antennas 3 and 4.

,

Is a weight vector for A (n) and B (n) in the frequency domain. In the time domain, the channel is assumed to be a frequency selective fading channel. A (n) and B (n), which are divided by the serial-to-parallel converter S / P and transmitted to the combined antennas, are multiplied by the weight vector received from the receiver to be transmitted to the IFFT stage. The A (n) and B (n) data streams multiplied by the weight vector are represented as follows.

C (n), D (n), E (n), and F (n) define output data after the IFFT stage as c (n), d (n), e (n), and f (n). . Data passing through a frequency selective fading channel in each transmit antenna may be expressed as follows.

The r ₁ (n) represents a signal received by the receiving antenna 1, the r ₂ (n) represents a signal received by the receiving antenna 2. K denotes the number of multipaths of a channel.

After performing the FFT on the received signal, data can be expressed as follows.

Since the received signal has a weight and a channel value in the data stream, multiplying the weighted signal with respect to the received signal leaves only the data component including the channel value, and the channel is a training symbol or pilot. Since the channel estimation is performed by the signal, the transmission data streams A (n) and B (n) can be obtained at the receiving end according to the first embodiment of the present invention.

A weight vector generated by the weight calculator of the receiver and transmitted to the transmitter is obtained by the following equation.

이고,

이며,

이다. 또한, 상기 H 연산자는 허미션 연산자이다. 상기 수식에 따라

을 최대화하는 가중치 벡터를 구하여 채널의 covariance matrix의 최대 eigenvalue에 대한 eigenvector를 구하여 수신 단의 수신전력을 최대화할 수 있다.In the above formula

ego,

,

to be. Also, the H operator is a hermition operator. According to the above formula

By obtaining the weight vector maximizing the eigenvector for the maximum eigenvalue of the covariance matrix of the channel can be maximized the receiving power of the receiver.

The receiving end may transmit a Channel Qualification Indicator (CQI) indicating a channel state of the transmitting end and the receiving end to the transmitting end, and the transmitting end may perform MCS (Modulation and Coding Set) control using the CQI. The receiver may transmit the SINR of the channel through the CQI or transmit a frame error rate (FER) value required by the receiver based on the SINR information, and the transmitter receives the CQI based on the CQI. The side modulation method or the channel coding method can be controlled. The control is performed by an MCS controller, and the MCS controller controls a modulation method and a coding method of a transmitter according to channel quality. The CQI for data rate adjustment according to the channel state is represented by the following equation. Can be obtained by SINR. The SINR value is calculated according to the type of receiver of the receiver. If the receiver of the receiver is a minimum mean squared error (MMSE) receiver, the SINR of the received signal is calculated by the following equation.

는, 상기 수식과 같다. 상기

은 기지국에서 전송되는 전체 전력을 의미하고, 상기

는 특정 수신 단을 위한 신호의 전력이며,

은 서빙 셀에서의 간섭(interference)이며,

는 다른 셀로부터의 간섭(interference)이다. 상기 수식에 의해

가 결정되고, 상기

와 g1(n), g2(n)에 의해 SINR이 산출되고, 이러한 SINR에 의해 CQI가 생성된다. In the above equation, g ₁ (n) and g ₂ (n) are defined in Equation 8, and are used to prevent noise from being amplified by deep fading of a channel in the MMSE receiver.

Is the same as the above formula. remind

Means total power transmitted from the base station, and

Is the power of the signal for a particular receive end,

Is the interference in the serving cell,

Is interference from another cell. By the above formula

Is determined and said

And SI1 are calculated by g1 (n) and g2 (n), and CQI is generated by such SINR.

Hereinafter, a second embodiment of the present invention will be described. In the case of the first embodiment, a weight is determined independently for each subcarrier. Since it is assumed that channels are independent for each subcarrier, weights are individually determined for each subcarrier. However, in the second embodiment described below, independent weights are not determined for every subcarrier, but independent weights are determined for a specific subcarrier group to which a plurality of subcarriers belong. Therefore, the same weight is applied to subcarriers belonging to the same subcarrier group.

When independent weights are determined for all subcarriers, the amount of information on weights fed back from the receiving end to the transmitting end is increased, which may cause a performance degradation due to a feedback signal delay. In addition, in a channel for each subcarrier, determining weight values that are different from each other for channels having a high correlation between channels does not significantly improve performance. For subcarriers belonging to a particular subcarrier group, It is preferable that the same weight is applied.

The subcarrier group is determined by a subcarrier group determiner located inside or outside the detector of the receiver. In addition, the subcarrier group may be adaptively determined based on the channel correlation between the subcarriers calculated by the receiver, or may be the same as a preset criterion (for example, a subcarrier having a predetermined interval). Belonging to a subcarrier group).

)는 동일한 가중치를 갖는다. 본 실시예에 따라 그룹화된 가중치가 곱해진 송신 신호는 다음과 같이 정의된다A (n) and B (n) are data streams transmitted to an nth subcarrier, and A (n) is transmitted through a first antenna group, that is, transmit antennas 1 and 2, and B (n) Is transmitted through the second antenna group, i.e., transmit antennas 3 and 4. W ₁ = [W ₁₁ W ₁₂ ] ^T , W ₂ = [W ₂₁ W ₂₂ ] ^T is a weight vector for A (n) and B (n) in the frequency domain. In this embodiment, the n th carrier belonging to a specific subcarrier group (

) Have the same weight. According to the present embodiment, a transmission signal multiplied by a grouped weight is defined as follows.

In addition, the results of FFT of the received signal through the frequency selective fading channel of C (n), D (n), E (n), and F (n) according to Equations 7 to 8 are as follows. .

In the above equation, since the received signal is multiplied by the channel value and the weight of the data stream, multiplying the weighted value for the received signal leaves only the data stream component containing the channel value, and the channel is a training symbol or pilot. Since the channel estimation is performed by the signal, transmission data A (n) and B (n) can be obtained at the receiving end according to the second embodiment of the present invention.

Weights for the grouped subcarriers can be obtained as follows.

이고,

이며,

이다. 또한, 상기 H 연산자는 허미션 연산자이다. 상기 수식에 따라

을 최대화하는 가중치 벡터 를 구하여 채널의 covariance matrix의 최대 eigenvalue에 대한 eigenvector를 구하여 수신 단의 수신전력을 최대화할 수 있다. 상기 수식에서의 covariance matrix는, 특정한 부 반송파 n(

, 즉 동일한 부 반송파 그룹에 속하는 부 반송파 n)에 대한 채널(channel)의 covariance matrix의 합이므로, 특정 그룹에 속하는 부 반송파들에 대한 채널의 covariance matrix 합에 대한 최대 eigenvalue에 대한 eigenvector를 구하여 수신 단의 수신전력을 최대화할 수 있다. In the above formula

ego,

,

to be. Also, the H operator is a hermition operator. According to the above formula

By obtaining the weight vector maximizing the eigenvector for the maximum eigenvalue of the covariance matrix of the channel can be maximized the receiving power of the receiver. The covariance matrix in the above formula is a specific subcarrier n (

That is, since the sum of the covariance matrix of channels for subcarriers n) belonging to the same subcarrier group, the eigenvector for the maximum eigenvalue for the sum of the covariance matrix of channels for subcarriers belonging to a specific group is obtained. It is possible to maximize the reception power of.

W ₁ and W ₂ determined by the above equation are the same for subcarriers belonging to a specific subcarrier group. Accordingly, information indicating a specific subcarrier group and weights W ₁ and W ₂ for the subcarrier group are fed back to the transmitting end, and the transmitting end can obtain the weight for each subcarrier. According to this embodiment, it is not necessary to transmit weight information about all subcarriers. However, if information indicating a specific subcarrier group and weight information for each group are transmitted, a weight can be obtained from a transmitting end. It can prevent performance degradation.

Even in the present embodiment, the receiving end may transmit a channel qualification indicator (CQI) indicating the channel status of the transmitting end and the receiving end to the transmitting end, and the transmitting end controls the modulation and coding set (MCS) using the CQI. You can do The receiving end may transmit the SINR of the channel through the CQI or transmit the FER value required by the receiving end based on the SINR information, and the receiving end may modulate the data stream based on the CQI. The method or the channel coding method can be controlled. The control is performed by the MCS control unit, and the MCS control unit controls the modulation method and the coding method of the transmitter according to the quality of the channel. According to the channel state, the CQI for data rate adjustment can be obtained by SINR according to the following equation. The SINR value changes according to the type of receiver of the receiver. If the receiver of the receiver is an MMSE receiver, the SINR of each data stream is expressed by the following equation.

4 is a diagram illustrating another method of applying TxAA in a multi-carrier system using multiple transmit / receive antennas. Hereinafter, a third embodiment of the present invention will be described with reference to FIG. In the first and second embodiments, data stream 1 is provided to transmit antenna 1 and transmit antenna 2 of FIG. 3, and data stream 2 is provided to transmit antenna 3 and transmit antenna 4. Therefore, it can be said that the four transmit antennas are grouped into two groups. As described above, antennas transmitting the same data stream may belong to the same antenna group, and the information about the antenna group may be referred to as antenna grouping information. The transmitting antenna 1 and the transmitting antenna 2 belong to a specific antenna group, and the transmission antenna 3 and the transmitting antenna 4 belong to a different antenna group. That is, two transmit antennas belong to one antenna group and operate TxAA.

In the case of changing the antenna combination, a diversity effect can be obtained by the difference of each antenna characteristic. That is, the data stream 1 may be transmitted to the transmit antenna 1 and the transmit antenna 3, and the data stream 1 may be transmitted to the transmit antenna 2 and the transmit antenna 4. As shown in FIG. 3, when using four transmit antennas, each antenna combination is three. The antenna grouping determination unit located inside or outside the detector of the receiving end may determine an optimal antenna combination by determining a channel condition that varies depending on the antenna combination of each antenna group. For example, the optimal antenna combination may be determined by calculating and comparing the SNR values of the received signals that vary with each antenna combination. As described above, the antenna grouping information indicating the antenna combination is three antenna combinations in the case of four transmitting antennas, so two bits of information are sufficient. Therefore, it is preferable to feed back the antenna grouping information determined by the antenna grouping determining unit of the receiving end to the transmitting end so that the transmitting end changes the antenna combination. The transmitting end receiving the antenna grouping information transmits each data stream to a transmitting antenna belonging to a specific antenna group by using a data stream input control unit. For example, when transmitting antennas 1 and 3 are in one group and transmitting antennas 2 and 4 are in another group, data stream 1 is controlled by controlling the data stream input control unit according to the antenna grouping information as described above. Input to transmit antennas 1 and 3 and data stream 2 to transmit antennas 2 and 4.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the protection scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be based on the description of the claims.

The receiving end of the communication system according to the present invention may calculate the weight in the frequency domain and implement DTxAA (Dobule TxAA) operation in the OFDM / OFDMA system. If the channel changes slowly, it can operate with a relatively high throughput. In addition, according to the present invention, a weight and a CQI are defined for each subcarrier and a specific subcarrier group, thereby increasing the flexibility of the operation. In addition, the diversity effect and the spatial multiplexing may be appropriately combined to have an optimum throughput.

Claims (35)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete In a multiple input and output multi-carrier system having a plurality of transmit antennas, Receiving weights according to grouped carriers for each of the transmitting antennas from a receiving side; Multiplying a weight corresponding to a data stream assigned to each of the transmit antennas, Weights according to the grouped carriers are determined individually for each carrier or the same for carriers belonging to a specific group, The data stream is a method of applying a transmit antenna array (TxAA) in a multi-carrier system using a plurality of transmit and receive antennas are transmitted simultaneously through a plurality of transmit antennas belonging to a specific group of the plurality of transmit antennas that are variably grouped. 32. The method of claim 31, When weights according to the grouped carriers are individually determined for each carrier, The weights W1 (n) and W2 (n) according to a carrier grouped to each of the transmission antennas transmitting the first data stream and the second data stream included in the data stream,

ego, here,

Is a channel for the first data stream,

Is a channel for the second data stream, n denotes each carrier, and a TxAA (Transmit Antenna Array) in a multi-carrier system using a plurality of transmit and receive antennas. 32. The method of claim 31, When weights according to the grouped carriers are equally determined for carriers belonging to a specific group, The weights W1 (n) and W2 (n) according to a carrier grouped to each of the transmission antennas transmitting the first data stream and the second data stream included in the data stream,

ego, here,

Is a channel for the first data stream,

Is a channel for the second data stream, n denotes each carrier, and a TxAA (Transmit Antenna Array) in a multi-carrier system using a plurality of transmit and receive antennas. In the transmission apparatus of a multi-carrier system, A weight receiver configured to receive weights according to grouped carriers for each of the transmit antennas from the receiver; A weight multiplier that multiplies the data streams allocated to the respective transmit antennas by the weights; And It includes a wireless transmitter for transmitting a data stream input from the weight multiplier using a multi-carrier and the transmission antenna, The weights according to the grouped carriers are determined individually for each carrier or the same for carriers belonging to a specific group, The data stream is simultaneously transmitted through a wireless transmitter using a plurality of transmit antennas belonging to a specific group among the plurality of transmit antennas that are variably grouped. Applied transmitter. The method of claim 34, When weights according to the grouped carriers are individually determined for each carrier, The weights W1 (n) and W2 (n) according to a carrier grouped to each of the transmission antennas transmitting the first data stream and the second data stream included in the data stream,

ego, When weights according to the grouped carriers are equally determined for carriers belonging to a specific group, The weights W1 (n) and W2 (n) according to a carrier grouped to each of the transmission antennas transmitting the first data stream and the second data stream included in the data stream,

ego, here,

Is a channel for the first data stream,

Is a channel for the second data stream, and n is a transmission apparatus using a transmit antenna array (TxAA) in a multi-carrier system using a plurality of transmit antennas, each of which represents a carrier.

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