KR101072021B1 - Sequential transmit multi-beamforming method with low complexity using hadamard matrix - Google Patents

Abstract

An apparatus and method for low complexity sequential transmit multi-beam forming using a Hadamard matrix are disclosed. Hadamard matrices can be used to generate codebooks with a simple configuration, and simple codebooks can be generated out of the complex codebook form, thus reducing the number of weight vectors and hardware complexity. Diversity gain can be maximized using the spatial diversity processor, and the beamforming weight vector can be systematically generated.

Description

Low Complexity Sequential Transmission Multiple Beam Forming Method Using HADAMAMRAD Matrix {SEQUENTIAL TRANSMIT MULTI-BEAMFORMING METHOD WITH LOW COMPLEXITY USING HADAMARD MATRIX}

The present invention relates to a transmit / receive beamforming technique using multiple transmit / receive antennas, and more particularly, to a transmit / receive multiple beamforming technique using a codebook.

The present invention is derived from the research conducted as part of the IT source technology development project of the Ministry of Knowledge Economy and the Korea Institute of Industrial Technology Evaluation and Management [Task Management No .: 2009-F-047-01, Task name: Development of open mmWave air interface platform technology] .

The present invention relates to a transmit / receive beamforming technique using multiple transmit / receive antennas, and more particularly, to a transmit / receive multiple beamforming technique using a codebook.

The beamforming technique uses multiple antennas to directionally transmit and receive radio waves according to spatial distribution of users, thereby improving communication quality by reducing power efficiency and unnecessary interference. Multiple antennas for beam forming use linear antenna arrays, planar antenna arrays, and the like.

In multiple antennas, the beamformer applies appropriate weights to each transmit and receive antenna and performs beamforming using the weights. A signal is generated by multiplying the signal by a weight, and then beamforming is performed by using the sum of the signals as an output signal.

The multi-antenna beamforming technique is applicable to the transmitter and the receiver, respectively, and may use weights for beamforming according to the position and environment of the transmitter and the receiver.

The beamforming technique using a codebook refers to a method of defining weight vectors for beamforming in advance, and selecting an optimal beamforming vector according to a transmission / reception environment to improve communication quality.

The weights used in the multi-beam former include a weight vector used in a one-dimensional array such as a linear antenna array and a weight matrix used in a two-dimensional array such as a planar antenna array according to the antenna array. The weight matrix used for the two-dimensional array is calculated from Equation 1 from the weight vector used for the one-dimensional array.

[Equation 1]

는 전치행렬이다.
Where w ^k and w ^l are the k th and l th weight vectors,

Is a transpose matrix.

번째 송신 빔과

번째 수신 빔 간의 복소 채널 이득을 추정하고, 복소 채널 이득 및 추정된 복소 채널 이득을 송신 빔 가중치 행렬과 곱하고 이 값을 송신단에 전송하여 송신 다중 빔 형성기에 적용한다. 이때 공간 다이버시티의 이득은 [수학식 2]와 같다.
In order to improve the quality of the received signal, a spatial diversity processor may be applied to the receiving end. Each sequentially for N transmit beams

The first transmission beam

The complex channel gain between the first receive beam is estimated, the complex channel gain and the estimated complex channel gain are multiplied by the transmit beam weight matrix, and the value is transmitted to the transmitter to apply to the transmit multiple beam former. In this case, the gain of spatial diversity is shown in Equation 2.

[Equation 2]

는

번째 송신 빔과

번째 수신 빔 간의 복소 채널 이득이다.Where the channel is a single input single output (SISO) for each transmit and receive beam,

Is

The first transmission beam

Is the complex channel gain between the first receive beam.

Hadamard matrices can be used to create a simple codebook, which not only reduces the number of weight vectors, but also reduces hardware complexity through simple antenna gain.

According to an embodiment of the present invention, a codebook storage unit for storing a transmission codebook generated using a Hadamard matrix and a transmission beam forming unit for forming a transmission beam using weight vector or channel information of the transmission codebook A transmit beamformer is provided that includes.

According to an aspect of the present invention, the transmission codebook is a matrix that performs permutation of log ₂ R-1 times with respect to the R x R Hadamard matrix according to the number R of antennas of the transmission beamformer. Can be generated based on the product of _{(R / 2 + 1) xR} , and Φ _{(R / 2 + 1) xR} may be defined as follows.

According to an aspect of the present invention, the channel information includes a weight vector reflecting a channel state, and the transmission beam forming unit may form a transmit beam using the weight vector reflecting the channel state.

In this case, the weight vector reflecting the channel state estimates the channel gain through the sequential transmission beam change of the transmission beam former using the transmission codebook and the sequential reception beam change of the reception beam former using the reception codebook of the reception beam former. Can be calculated using the estimated channel gain for the receive beam and the transmission codebook of the transmit beamformer to maximize the channel size calculated through the estimated channel gain.

In this case, the weight vector reflecting the channel state estimates the channel gain through the sequential transmission beam change of the transmission beam former using the transmission codebook and the sequential reception beam change of the reception beam former using the reception codebook of the reception beam former. , For each of the received beams, may be calculated using the channel gain and the transmit codebook of the transmit beamformer, wherein the transmit beamformer uses the weight vector reflecting the channel state to each of the receive beams. By forming a transmission beam for the data can be repeatedly transmitted as many as the number of the reception beam.

According to an embodiment of the present invention, a codebook storage unit for storing a reception codebook generated using a Hadamard matrix, a reception beam forming unit for forming a reception beam using a weight vector of the reception codebook, and the reception beam forming unit A receive beamformer is provided that includes a spatial diversity processor that is connected to transmit channel information to the transmit beamformer.

According to one aspect of the invention, the reception codebook is a log for an R x R Hadamard matrix according to the number of antennas (R) of the reception beamformer.₂Matrices with R-1 permutation and Φ_{(R / 2 + 1) xR}Can be generated based on the product of_{(R / 2 + 1) xR}Can be defined as follows.

According to an aspect of the present invention, the channel information may include at least one of a channel gain, a channel size, and a weight vector reflecting a channel state.

In this case, the weight vector reflecting the channel state estimates the channel gain through the sequential transmission beam change of the transmission beam former using the transmission codebook of the transmission beam former and the sequential reception beam change of the reception beam former using the reception codebook. Can be calculated using the estimated channel gain for the receive beam and the transmission codebook of the transmit beamformer to maximize the channel size calculated through the estimated channel gain.

In this case, the weight vector reflecting the channel state estimates the channel gain through the sequential transmission beam change of the transmission beam former using the transmission codebook of the transmission beam former and the sequential reception beam change of the reception beam former using the reception codebook. For each of the received beams can be calculated using the channel gain and the transmission codebook of the transmission beam former, the transmission beam forming unit, for each of the received beams using a weight vector reflecting the channel state A transmission beam may be formed and data may be repeatedly transmitted as many as the number of the reception beams.

According to an embodiment of the present invention, a transmission beamformer for forming a transmission beam using a transmission codebook generated using a Hadamard matrix, and a reception for forming a reception beam using a reception codebook generated using a Hadamard matrix A transmit / receive beamforming wireless communication system is provided that includes a spatial diversity processor coupled to a beamformer and the receive beamformer to transmit channel information to a transmit beamformer.

According to an aspect of the present invention, the transmit codebook and the receive codebook are log ₂ R-1 times for an R x R Hadamard matrix according to the number R of antennas of each of the transmit beamformer and the receive beamformer. It can be generated based on the product of the permutation matrix and Φ _{(R / 2 + 1) x R} , the Φ _{(R / 2 + 1) x R} can be defined as follows.

According to an aspect of the present invention, the channel information includes a weight vector reflecting a channel state, and the transmission beam former may form a transmit beam using the weight vector reflecting the channel state.

In this case, the weight vector reflecting the channel state estimates a channel gain through a sequential transmission beam change of the transmission beam former using the transmission codebook and a sequential reception beam change of the reception beam former using the reception codebook, and the estimation The estimated channel gain for the receive beam and the transmit codebook of the transmit beam former may be calculated to maximize the channel size calculated through the channel gain.

In this case, the weight vector reflecting the channel state may estimate a channel gain through a sequential transmission beam change of the transmission beam former using the transmission codebook and a sequential reception beam change of the reception beam former using the reception codebook. For the receive beam, the channel gain and the transmit codebook of the transmit beamformer are calculated, and the transmit beamformer uses the weight vector reflecting the channel condition to determine the transmit beam for each receive beam. The data may be repeatedly transmitted as many as the number of the reception beams.

According to an embodiment of the present invention, for a specific beam of a reception beam former using a reception codebook of a reception beam former, the reception beam former is sequentially changed beams in the transmission beam former using a transmission codebook of a transmission beam former. Transmitting the sequence to the; Receiving the sequence and estimating a channel gain at the receive beamformer; Performing the channel gain estimation sequentially on all beams of the receive beamformer; Calculating a weight vector reflecting a channel state using the estimated channel gain for the received beam and the transmission codebook of the transmit beam former to maximize the channel size calculated through the estimated channel gain; And forming a transmission beam by using the weight vector reflecting the channel state.

According to an embodiment of the present invention, for a specific beam of a reception beam former using a reception codebook of a reception beam former, the reception beam former is sequentially changed beams in the transmission beam former using a transmission codebook of a transmission beam former. Transmitting the sequence to the; Receiving the sequence and estimating a channel gain at the receive beamformer; Performing the channel gain estimation sequentially on all beams of the receive beamformer; Calculating a weight vector reflecting a channel state by using the estimated channel gain for each of the received beams through the estimated channel gains and the transmission codebook of the transmission beam former; And forming the transmission beams for each of the reception beams by using the weight vector reflecting the channel state, and repeatedly transmitting data as many as the number of the reception beams.

According to an embodiment of the present invention, in the method of generating a codebook, permutation of log ₂ R-1 times with respect to the R x R Hadamard matrix according to the number R of antennas of a transmitting or receiving beamformer A codebook generation method of a transmit or receive beamformer is provided based on a product of matrices performed by π _{(R / 2 + 1) xR} , and φ _{(R / 2 + 1) xR} may be defined as follows.

According to an embodiment of the present invention, in the antenna implementation for generating multiple beams, it is possible to provide a method and apparatus for generating a codebook that can reduce the complexity of hardware by using multiple transmit / receive antennas and weights for each antenna, and an equal interval. It is possible to generate multiple beams of.

In addition, according to an embodiment of the present invention, the diversity gain may be maximized using a spatial diversity processor, and the beamforming weight vector may be systematically generated.

1 is a diagram illustrating a transceiver structure of a multiple antenna system according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an equivalent structure of a transmission beam former for generating a transmission beam using the estimated channel gain and the directional single beam of the transmission codebook according to an embodiment of the present invention.
3 is a simplified flowchart of a beam forming method according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating channel gain estimation using sequential beam change using a codebook and a beamforming method using the same, when only transmission diversity is used.
FIG. 5 is a flowchart illustrating channel gain estimation through sequential beam change using a codebook and beam forming method using the same when both transmit and receive diversity are used.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In describing the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terminology used herein is a term used to properly express a preferred embodiment of the present invention, which may vary according to a user, an operator's intention, or a custom in the field to which the present invention belongs. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

1 is a diagram illustrating a transceiver structure of a multiple antenna system according to the present invention.

Referring to FIG. 1, the communication system to which the beam former is applied is briefly represented because the present invention focuses on channel gain estimation according to a codebook of a single beam and multiple beam generation through the estimated channel gain. The transmitter includes a transmit beamformer 110 and a transmit antenna 140 applying a code and a modulator and a codebook generated according to an embodiment of the present invention. The transmission beam former 110 may include a codebook storage unit 120 and a transmission beam former 130. The receiving end may include a receiving antenna 150, a receiving beamformer 160 to which a codebook generated according to an embodiment of the present invention is applied, and a demodulator and decoder. The reception beamformer 160 includes a transmit / receive codebook storage unit 170, a reception beamformer 180 applying a codebook generated according to an embodiment of the present invention, and a spatial diversity processor 190 to maximize antenna gain. ) May be included.

번째 빔을 적용한 송신 빔 형성기에 사용된 가중치 벡터는 w ^Tx,i=[w₁ ^Tx,i, w₂ ^Tx,i,…, w_N ^Tx,i] 이고, 본 발명에 따른 코드북의

번째 빔을 적용한 수신 빔 형성기에 사용된 가중치 벡터는 w ^Rx,j=[w₁ ^Rx,i, w₂ ^Rx,j,…, w_N ^Rx,j] 이며, 각각 송신 빔 형성기와 수신 빔 형성기에 사용된 안테나의 개수는

개와

개이다. Herein of the codebook according to an embodiment of the present invention

The weight vector used in the transmission beamformer applying the first beam is w ^{Tx, i} = [w ₁ ^{Tx, i} , w ₂ ^{Tx, i} ,... , w _N ^{Tx, i} ] and the codebook of the present invention

The weight vector used in the reception beamformer to which the second beam is applied is w ^{Rx, j} = [w ₁ ^{Rx, i} , w ₂ ^{Rx, j} ,... , w _N ^{Rx, j} ] and the number of antennas used in the transmit beamformer and the receive beamformer

Dog

Dog.

Referring to FIG. 1, a spatial diversity processor of a receiver may have a reverse transmission path for estimating a channel gain and transmitting an estimated channel gain to a transmitter in order to generate a transmission beam using the estimated channel gain. Here, the transmission beam formed through the present invention may have the form of multiple beams, and the reception beam may have the form of a single beam.

2 is a diagram illustrating an equivalent structure of a transmission beam former that generates a transmission beam using the estimated channel gain and the directional single beam of the codebook.

Referring to FIG. 2, the transmit beamformer places a directional transmit single beam weight vector 210 after a multiplier 220 that multiplies the conjugate value of the estimated channel gain, and transmits the weighted signals of the same antenna. The sum is transmitted to the antenna.

3 is a simplified flowchart of a multi-beam generation method according to an embodiment of the present invention.

Referring to FIG. 3, a method of generating and storing a codebook of a directional single beam having the same spacing between beams in a simple manner through one embodiment of the present invention (310), one embodiment of the present invention in a transmit beam former and a receive beam former In operation 320, the channel gain between the transmitter and the receiver is estimated while sequentially changing the single beams of the transmission codebook and the reception codebook. The estimated channel gain may be transmitted to the transmitter and used to form the transmission beam (330).

According to an embodiment of the present invention, a method for generating a codebook using a Hadamard matrix is as follows.

개의 가중치 종류를 갖는 지향성 단일 빔의 코드북 생성을 위해서

Hadamard 행렬은 안테나의 수

에 따라 log₂R-1 번의 퍼뮤테이션(permutation)을 수행한다. Hadamard 행렬은 [수학식 3]과 같다.
The same spacing between the beams

Codebook Generation of Directional Single Beams

Hadamard matrix is the number of antennas

According to the log ₂ R-1 permutation (permutation) is performed. Hadamard matrix is shown in [Equation 3].

&Quot; (3) "

에 따라

인 행렬로 표현되며 퍼뮤테이션(permutation)을 수행하기 위해서 [수학식 4]와 같이 정의된 행렬을 생성할 수 있다.
Since the Hadamard matrix is of the form 2 ⁿ , the number of antennas

Depending on the

In order to perform permutation, a matrix defined as [Equation 4] may be generated.

&Quot; (4) "

에 관계없이 첫 번째 퍼뮤테이션(permutation) 행렬을 구성하게 된다. 만약

이 4인 경우 한 번의 퍼뮤테이션을 거치게 되며, 이 때 퍼뮤테이션 행렬은 [수학식 5]와 같은 형태가 될 수 있다.
This matrix is the number of antennas

Regardless of this, the first permutation matrix is formed. if

In the case of 4, one permutation is performed, and the permutation matrix may be in the form of [Equation 5].

[Equation 5]

는 모두

행렬이고,

은 영행렬을 의미한다.When R is 8 and 16, the first permutation is in the form of Equation 5. At this time,

Are all

Matrix,

Means zero matrix.

The first permutation according to R can be generated by the matrix and zero matrix defined in Equation 6.

&Quot; (6) "

이 4인 경우 첫 번째로 구한 P₁ ⁴를 이용하여 [수학식 7]과 같이 구할 수 있다.
If R is 8 then the second permutation is

In the case of 4, P ₁ ⁴ can be obtained as shown in [Equation 7].

[Equation 7]

는 단위 행렬 I_(R/2)*(R/2)의 열 혹은 행의 순서를 바꾼 형태의 행렬이다.

이 16인 경우의 두 번째와 세 번째 퍼뮤테이션은 각각 [수학식 8]과 같이 나타낼 수 있다.
In Equation 7, matrix

Is a matrix of the order of the columns or rows of the unitary matrix I _{(R / 2) * (R / 2)} .

In the case of 16, the second and third permutations may be expressed as Equation 8, respectively.

[Equation 8]

이 2의 승수로 증가할 때 이전의 퍼뮤테이션 행렬을 이용하여 구할 수 있다. [수학식 9]는 하다마드 행렬을 log₂R-1개의 퍼뮤테이션 행렬들을 사용하여 변환한 후 최종적으로 얻게 되는 지향성 단일 빔의 가중치 벡터 모임인 코드북을 구하는 식이다.
After all, the number of antennas

When increasing to a power of 2, it can be found using the previous permutation matrix. Equation (9) obtains a codebook, which is a weighted vector collection of directional single beams obtained after converting a Hadamard matrix using log ₂ R-1 permutation matrices.

[Equation 9]

Here, Φ _{(R / 2 + 1) xR} is expressed as [Equation 10].

[Equation 10]

In the matrix shown in Equation 9, the kth column is used as the kth weight vector of the codebook in the sequential beam change process of the directional single beam, and the weight vectors w ^k = [w ₁ ^k , w ₂ ^k ,... , w _N ^k ], which is represented by Equation 11 below.

[Equation 11]

는 행렬

의

번째 열 벡터를 의미한다. In Equation 11

Is a matrix

of

Second column vector.

According to the above method, which is an embodiment of the present invention, the codebook when the number of antennas R = 8 and R / 2 + 1 is 5 may be expressed as Equation 12 below.

[Equation 12]

FIG. 4 is a flowchart illustrating channel gain estimation using sequential beam change using a codebook and a beamforming method using the same, when only transmission diversity is used.

Referring to FIG. 4, the beam of the receiver 160 is fixed by using the reception codebook of the directional single beam generated by the embodiment of the present invention, and the transmitter 110 is generated by the embodiment of the present invention. The sequence may be transmitted while sequentially changing the beam using the transmission codebook of the directional single beam (410 and 420).

()에 따라 R x R 하다마드 행렬에 대해 log₂R-1 번의 퍼뮤테이션을 수행함으로써 생성되는 [수학식 9]의 송신/수신 코드북일 수 있다.In this case, as described above, the transmit / receive codebook includes the number of antennas (

It can be a transmit / receive codebook of [Equation 9] generated by performing log ₂ R-1 permutation on the R × R Hadamard matrix according to ().

)을 추정하고 이를 공간 다이버시티 처리기(190)에 저장할 수 있다(430). 순차적으로 송신 빔을 변경하면서 모든 송신 빔에 대한 채널 이득(

)을 추정한 이후(435) 수신 빔에 대한 채널 크기 값을 계산한다(440). 여기서

번째 수신 빔에 대한 채널 크기 값은 [수학식 13]로 정의된다.
The spatial diversity processor 190 of the receive beamformer 160 can determine the channel gain (a) through the received sequence.

) May be estimated and stored in the spatial diversity processor 190 (430). Channel gains for all transmit beams (sequentially changing transmit beams)

), The channel size value for the received beam is calculated (440). here

The channel size value for the first received beam is defined by Equation 13.

[Equation 13]

은 송신 빔의 개수를 의미한다.here

Means the number of transmission beams.

The estimated channel gain and the calculated channel size value may be transmitted to the transmit beamformer 110 through the reverse transmission path (450). The estimated channel gain and channel size values may be stored in the codebook storage unit 120 of the transmission beam former 110. This process is applied to all receive beams (455).

번째 수신 빔에 대응하는 채널 이득을 이용하여 송신 빔 형성기(110)의 채널 상태가 반영된 가중치 벡터

를 [수학식 14]과 같이 계산할 수 있다(470).
Through the above process, the reception beam corresponding to the maximum value among the channel size values for all the reception beams is selected (460), and the selected

A weight vector reflecting the channel state of the transmission beam former 110 using the channel gain corresponding to the first reception beam

May be calculated as shown in Equation 14 (470).

[Equation 14]

The spatial diversity processor 190 may transmit the weight vector reflecting the channel state to the transmission beamformer 110 (480). The weight vector reflecting the channel state may be stored in the codebook storage unit 120 of the transmission beam former 110.

The transmit beam former 140 of the transmit beam former 110 forms a transmit beam using a weight vector reflecting the channel state, and the receive beam former 180 of the receive beam former 160 has a maximum channel size value. A depth beam having a shape is formed (490).

FIG. 5 is a flowchart illustrating channel gain estimation through sequential beam change using a codebook and beam forming method using the same when both transmit and receive diversity are used.

Referring to FIG. 5, since both transmit beams for each receive beam are formed to use both transmit and receive diversity, data is retransmitted by the number of receive beams.

Referring to FIG. 5, the receiving beam of the receiving end is fixed using the receiving codebook of the directional single beam generated by the embodiment of the present invention, and the transmitting of the directional single beam generated by the embodiment of the present invention of the transmitting end. A sequence may be transmitted while sequentially changing the transmission beam using the codebook (510, 520).

)에 따라

*

* 하다마드 행렬에 대해 log₂R-1 번의 퍼뮤테이션(permutation)을 수행한 행렬과 [수학식 10]에 나타낸 행렬의 곱을 기초로 생성되는 [수학식 9]의 송신/수신 코드북일 수 있다.In this case, as described above, the transmit / receive codebook includes the number of antennas (

)Depending on the

*

* It may be a transmit / receive codebook of [Equation 9] generated based on the product of a matrix performing log ₂ R-1 permutation on the Hadamard matrix and the matrix shown in Equation 10.

를 역방향 전송로를 통해 송신 빔 형성기(110)로 전송할 수 있다(540). 이와 같은 채널 정보는 송신 빔 형성기(110)의 코드북 저장부(120)에 저장될 수 있다. 이러한 과정을 모든 수신 빔에 대하여 적용한다(545).The spatial diversity processor 190 of the receive beamformer 160 may estimate and store the channel gain through the received sequence (530). In this way, the channel gain h _{i, j} is estimated for all transmission beams (535), and the channel gain h _{i, j} or channel state vector.

May be transmitted to the transmission beamformer 110 through the reverse transmission path (540). Such channel information may be stored in the codebook storage unit 120 of the transmission beam former 110. This process is applied to all received beams (545).

The spatial diversity processor 190 calculates the weight vector w ₁ ^Tx reflecting the channel state of the transmission beam former 110 by using the channel gain obtained through the corresponding process for the first reception beam [Equation 14] It can be calculated as (550). The spatial diversity processor 190 may transmit the weight vector reflecting the channel state to the transmission beamformer 110 (560). The weight vector reflecting the channel state may be stored in the codebook storage unit 120 of the transmission beam former 110. The transmission beam former 140 of the transmission beam former 110 may form a transmission beam using the weight vector reflecting the channel state (570) and transmit data (580). This process is sequentially processed for all receive beams in the same manner (585) to obtain a receive diversity effect.

번째 수신 빔 가중치 벡터(570)는 [수학식 9]에서 얻게 되는 열 벡터 자체를 사용하여 [수학식 15]로 정의할 수 있다.
At this time,

The first received beam weight vector 570 may be defined by Equation 15 using the column vector itself obtained from Equation 9.

[Equation 15]

The transmission and reception beam weight vectors of Equations 14 and 15 correspond to a one-dimensional antenna array, and a weight matrix suitable for the two-dimensional antenna array may be calculated using Equation 1.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

110: transmission beam former

Claims (18)

In the transmission beam former for forming a transmission beam using a codebook,
A codebook storage unit for storing a transmission codebook generated using a Hadamard matrix;
Transmission beam forming unit for forming a transmission beam using the weight vector or channel information of the transmission codebook
Including,
The channel information includes a weight vector reflecting a channel state.
The transmission beam forming unit forms a transmission beam using a weight vector reflecting the channel state,
The weight vector reflecting the channel state is
A channel gain is estimated through the sequential transmission beam change of the transmission beamformer using the transmission codebook and the sequential reception beam change of the reception beamformer using the reception codebook of the reception beamformer, and a channel calculated through the estimated channel gain. A transmit beamformer calculated using the estimated channel gain for the receive beam to maximize in magnitude and the transmit codebook of the transmit beamformer. delete delete In the transmission beam former for forming a transmission beam using a codebook,
A codebook storage unit for storing a transmission codebook generated using a Hadamard matrix;
Transmission beam forming unit for forming a transmission beam using the weight vector or channel information of the transmission codebook
Including,
The channel information includes a weight vector reflecting a channel state.
The transmission beam forming unit forms a transmission beam using a weight vector reflecting the channel state,
The weight vector reflecting the channel state is
Estimating a channel gain through the sequential transmit beam change of the transmit beamformer using the transmit codebook and the sequential receive beam change of the receive beamformer using the receive codebook of the receive beamformer, for each of the receive beams Gain and calculated using the transmission codebook of the transmission beamformer,
The transmission beam forming unit,
And a transmission beam for each of the reception beams using the weight vector reflecting the channel state, and repeatedly transmitting data as many as the number of the reception beams. In the transmission beam former for forming a transmission beam using a codebook,
A codebook storage unit for storing a transmission codebook generated using a Hadamard matrix;
Transmission beam forming unit for forming a transmission beam using the weight vector or channel information of the transmission codebook
Including,
The transmission codebook is a matrix that performs permutation of log ₂ R-1 times with respect to the R x R Hadamard matrix according to the number R of antennas of the transmission beam former, and Φ _{(R / 2 + 1) xR.} Is based on the product of
The Φ _{(R / 2 + 1) x R} is defined by the following equation.
[Equation]

delete In a receive beam former for forming a receive beam using a codebook,
A codebook storage unit for storing a received codebook generated using a Hadamard matrix;
A reception beam forming unit for forming a reception beam using the weight vector of the reception codebook; And
A spatial diversity processor connected to the receiving beam former and transmitting channel information to a transmission beam former
Including,
The reception codebook is a matrix that performs permutation of log ₂ R-1 times with respect to the R x R Hadamard matrix according to the number R of antennas of the reception beamformer, and Φ _{(R / 2 + 1) xR.} Is based on the product of
The Φ _{(R / 2 + 1) x R} is defined by the following equation.
[Equation]

delete In a receive beam former for forming a receive beam using a codebook,
A codebook storage unit for storing a received codebook generated using a Hadamard matrix;
A reception beam forming unit for forming a reception beam using the weight vector of the reception codebook; And
A spatial diversity processor coupled to the receive beamformer to transmit channel information to a transmit beamformer
Including,
The channel information includes at least one of a channel gain, a channel size, and a weight vector reflecting a channel state.
The weight vector reflecting the channel state is
A channel gain is estimated through a sequential transmission beam change of the transmission beam former using a transmission codebook of a transmission beam former and a sequential reception beam change of the reception beam former using the reception codebook, and a channel calculated through the estimated channel gain. A receive beamformer calculated using the estimated channel gain for the receive beam to maximize its magnitude and the transmit codebook of the transmit beamformer. In a receive beam former for forming a receive beam using a codebook,
A codebook storage unit for storing a received codebook generated using a Hadamard matrix;
A reception beam forming unit for forming a reception beam using the weight vector of the reception codebook; And
A spatial diversity processor coupled to the receive beamformer to transmit channel information to a transmit beamformer
Including,
The channel information includes at least one of a channel gain, a channel size, and a weight vector reflecting a channel state.
The weight vector reflecting the channel state is
The channel gain is estimated through the sequential transmission beam change of the transmission beam former using the transmission codebook of the transmission beam former and the sequential reception beam change of the reception beam former using the reception codebook, and the channel gain for each of the received beams. And a receive beamformer calculated using the transmit codebook of the transmit beamformer.
delete delete delete delete delete In the method of forming a transmission beam using a codebook,
For a particular beam of the receive beamformer using the receive codebook of the receive beamformer, using the transmit codebook of the transmit beamformer, transmitting a sequence to the receive beamformer while sequentially changing beams in the transmit beamformer;
Receiving the sequence and estimating a channel gain at the receive beamformer;
Performing the channel gain estimation sequentially on all beams of the receive beamformer;
Calculating a weight vector reflecting a channel state using the estimated channel gain for the received beam and the transmission codebook of the transmit beam former to maximize the channel size calculated through the estimated channel gain; And
Forming a transmission beam using a weight vector reflecting the channel state
Transmission beam forming method comprising a.

In the method of forming a transmission beam using a codebook,
For a particular beam of the receive beamformer using the receive codebook of the receive beamformer, using the transmit codebook of the transmit beamformer, transmitting a sequence to the receive beamformer while sequentially changing beams in the transmit beamformer;
Receiving the sequence and estimating a channel gain at the receive beamformer;
Performing the channel gain estimation sequentially on all beams of the receive beamformer;
Calculating a weight vector reflecting a channel state by using the estimated channel gain for each of the received beams through the estimated channel gains and the transmission codebook of the transmission beam former; And
Forming the transmission beams for each of the reception beams by using the weight vector reflecting the channel state, and repeatedly transmitting data as many as the number of the reception beams.
Transmission beam forming method comprising a.

In the method for generating a codebook,
Based on the product of Φ _{(R / 2 + 1) xR} and a matrix that performs log ₂ R-1 permutations for the R x R Hadamard matrix, depending on the number of antennas (R) of the transmit or receive beamformer. Generating a codebook of a transmit or receive beamformer.
Here, Φ _{(R / 2 + 1) xR} is defined through the following equation.
[Equation]

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