KR20110057966A - Antenna arrays with antenna switching and method for wireless communication - Google Patents

Abstract

PURPOSE: A method for performing wireless communication using plane and linear antenna arrays is provided to estimate a moving parameter of a moving object at the same time. CONSTITUTION: A receiver(14) creates a mixed signal by mixing a received reflection signal through a reception antenna selecting unit and a transmitting signal. The receiver coverts the mixed signal into a digital signal. A controller(17) forms beam about the converted mixed signal. The controller estimates a moving parameter about the moving object.

Description

Technical Field [0001] The present invention relates to a linear antenna array device, a flat antenna array device, and a wireless communication method using the antenna array device.

[0001] One aspect of the present invention relates to wireless communication technology, and more particularly, to a wireless communication technique that uses an antenna array for direction detection.

The present invention is derived from research carried out as part of the Ministry of Knowledge Economy. [Project Assignment Number: 2008-S-002-02, Title: Development of IT Growth Driving Technology].

Direction detection of moving objects is recognized as an important research field in many wireless applications such as mobile wireless sensor network, intelligent traffic system (ITS), distributed sensor network, and radar control system. Antenna arrays are a must in the development of high performance wireless systems for accurate direction detection of targets.

In a conventional system structure using a linear or planar antenna array, the number of receiving antennas is equal to the number of receivers, so that the system configuration is complicated, bulky, and expensive. Also, gain and phase differences between receive channels may degrade system performance.

On the other hand, in order to detect a high-precision direction, a transmitting and receiving method capable of simultaneously estimating a moving parameter including a target moving angle (azimuth and elevation angle), distance, and speed information is required.

According to one aspect, an antenna array technology is proposed in which the system configuration is simple and motion parameters of a moving object can be simultaneously estimated.

According to an aspect of the present invention, there is provided a linear antenna array device including: a plurality of reception antennas for receiving reflection signals from a moving object, respectively, with respect to transmission signals transmitted to a moving object, A receiver for mixing the reflection signal received from the reception antenna selected through the reception antenna selection unit with the transmission signal to generate a mixed signal and digitally converting the mixed signal, and a receiver for digitally converting the mixed signal, And estimates a movement parameter for the moving object.

According to another aspect of the present invention, there is provided a planar antenna array device comprising: a receiving antenna in the form of an N ₁ × N ₂ matrix for receiving a reflected signal from a moving object with respect to a transmitting signal transmitted to a moving object, A reception antenna selector for selecting a reception antenna to receive a reflection signal for each antenna; and a receiver for mixing the reflection signal received from the reception antenna selected through the reception antenna selector with a transmission signal to generate a mixed signal and digitally converting the mixed signal forming a beam for the N _one linear antenna array, and the converted digital mixing signal N by _one linear antenna array, and a control unit for estimating the movement parameters for the mobile.

According to another aspect of the present invention, there is provided a wireless communication method using an antenna array, including the steps of: transmitting a signal to a moving object, which is a target to be detected, and receiving a plurality of reflected signals from the mobile object via a plurality of receiving antennas, Generating a mixed signal by mixing a reflection signal received through the selected reception antenna with a transmission signal, and performing digital conversion on the mixed signal to generate a mixed signal; And estimating a moving parameter for the moving object.

According to one embodiment, since the antenna array apparatus of the present invention includes one transmitter, one transmission antenna, a plurality of reception antennas, one reception antenna selection unit, and one receiver, the number of receivers can be greatly reduced , A simple, compact and inexpensive linear antenna array or a planar antenna array structure can be realized.

According to another embodiment, it is possible to simultaneously estimate not only the azimuth and altitude angles of the moving object, but also the distance and velocity information.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying 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. In addition, the terms described below are defined in consideration of the functions of the present invention, and these may vary depending on the intention or custom of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

1 is a configuration diagram of a linear antenna array device 1 according to an embodiment of the present invention.

1, a linear antenna array 1 includes one transmitter 11, one transmission antenna 10, n reception antennas 12, one reception antenna selection unit 13 ) And one receiver (14).

The n reception antennas 12 receive echo signals from the moving object with respect to the transmission signal _xo (t) transmitted to the target, which is the target to detect the direction.

The reception antenna selector 13 selects a reception antenna to receive the reflection signal for each of the n reception antennas 12. The reception antenna selection unit 13 may be implemented with a switch. At this time, the receiving antenna selector 13 can sequentially select the receiving antennas so as to receive the reflected signals for each of the receiving antennas.

The receiver 14 includes a mixer 15 and an analog-to-digital converter 16. The mixer 15 mixes the reflection signal received via the reception antenna selected by the reception antenna selector 13 with the transmission signal, And generates a mixed signal. Then, the analog-to-digital converter 16 converts the mixed signal into a digital signal.

According to one embodiment, the receiver 14 may adjust the mixing signal using a time-variant steering vector, which may include azimuth angle, velocity, range, And time information. Specifically, the adjustment vector of n receive antennas (12) in which is received through the first receiving time delay from the antenna to the n-th receiving antenna, the first reception propagation time and the n th receiving antenna of the reflection signal received through an antenna Is the value calculated by using the propagation time of the reflected signal.

The controller 17 forms a beam for the digital-converted mixed signal and estimates a moving parameter for the moving object. The movement parameters include the azimuth, velocity, distance and time information of the moving object.

The controller 17 may use a wideband capon ' s beamforming model in beamforming and motion parameter estimation. Specifically, the controller 17 calculates an estimate of the covariance matrix, which is a multiplication of the Hermitian transpose of the digitally converted mixed signal and the digitally converted mixed signal. Next, a beamforming weight vector is generated that allows the beam to be generated using an estimated value of the covariance matrix and a time-variant steering vector for adjusting the mixed signal. Then, a signal estimate, which is a multiplication of the weight vector and the erimit transposed value of the digitally converted mixed signal, is obtained. Then, a power function is obtained using the signal estimation value, and a movement parameter for the moving object is estimated using the power function. The controller 17 may use a Fourier transform method in calculating the power function.

2 is a configuration diagram of a planar antenna array device 2 according to an embodiment of the present invention.

2, a planar phased array antenna 2 includes a transmitter 21, N ₁ × N ₂ receive antennas 22, N ₁ linear antenna arrays 23, (27).

The transmit antennas share one of the receive antennas, and the N ₁ linear antenna arrays 23 each comprise one receive antenna selector 23 and one receiver 24. One receiver 24 includes a mixer 25 and an analog to digital converter 24.

The receiving antenna 22 in the form of an N ₁ × N ₂ matrix receives a reflected signal from a moving object with respect to a transmitting signal transmitted to a moving object, which is a target for detecting a direction.

The N ₁ linear antenna array 23 includes a reception antenna selector 23 for selecting a reception antenna so that the reception antenna 22 in the form of an N ₁ × N ₂ matrix receives a reflection signal for each reception antenna, And a receiver 24 for mixing the reflection signal received from the selected reception antenna with the transmission signal to generate a mixed signal and converting the mixed signal into a digital signal.

The reception antenna selection unit 23 may be implemented with a switch. At this time, the receiving antenna selector 23 can sequentially select the receiving antennas so as to receive the reflected signals for each of the receiving antennas. The receiver 24 may adjust the mixed signal using the steering vector, which may include azimuth angle, elevation angle, velocity, range, and time information of the mobile object . The adjustment vector is a time delay from the (1,1) th reception antenna of the first period to the (n ₁ , n ₂ ) -th reception antenna of the u-th period in the reception antenna 22 of the N ₁ × N ₂ matrix, the second is a value calculated by using the propagation time of the signal received through the (1,1) th receiving the propagation time of the signal received through the antenna and the (n _1, n ₂₎ th receive antenna of the u-th period of the cycle.

The controller 27 forms a beam for the mixed signal digitally converted for each of the N ₁ linear antenna arrays 23 and estimates a moving parameter for the moving object.

The control unit 27 can use a wideband K-beam beam forming method in beam formation and movement parameter estimation. Specifically, the control unit 27 calculates a covariance matrix estimate, which is a multiplication of the Hermitian transpose of the digitally converted mixed signal and the digitally converted mixed signal. Then, a weight vector is generated that allows the beam to be generated using the estimation value of the covariance matrix and the adjustment vector for adjusting the mixed signal. Then, a signal estimation value, which is a multiplication of the weight vector and the erimit transposed value of the digitally converted mixed signal, is obtained, and a power function is obtained using the signal estimation value. Then, a movement parameter for the moving object is estimated using the power function.

Referring to FIG. 3, an antenna array using one switch of the present invention can be used to obtain angle information such as an azimuth angle and an elevation angle of a moving object, velocity) information at the same time.

Hereinafter, a method of estimating the movement parameter using the antenna array of the present invention will be described in detail. Here, the antenna array may be a linear antenna array or a planar antenna array, but a method of estimating a moving parameter around the plane antenna array will be described in detail later.

이다. 여기서 T는 펄스시간, f ₀는 초기 주파수, f ₁은 처프율(chirp rate)로서 f ₁ = F/T로 주어지며, F는 대역폭이다. Each antenna of the planar antenna array is denoted ( n ₁ , n ₂ ), and the ranges of n ₁ and n ₂ are ₁ ≤ n ₁ ≤ N ₁ and ₁ ≤ n ₂ ≤ N ₂ . The transmitted signal, a linear frequency-modulated (FM) signal,

to be. Where T is the pulse time, f ₀ is the initial frequency, f ₁ is the chirp rate, and f ₁ = F / T , where F is the bandwidth.

As shown in FIG. 4, the plurality of pulses have a time [( u -1) N ₂ + n ₂ -1] T , u = 1, 2, ..., U , n ₂ = , which it is transmitted starting in N _2. U is the number of cycles, and is switched once from the receiving antennas ( n ₁ , 1) to ( n ₁ , N ₂ ) in one cycle.

는 송신신호의 켤레 복소수

와 혼합되며, 벡터 형태로의 수신 신호는 수학식 1과 같이 표현된다.echo signal from the moving target received by the receiving antenna ( n ₁ , n ₂ ) in the u th period,

Is the complex conjugate of the transmitted signal

And the received signal in the form of a vector is expressed by Equation (1).

은 각각 원하는 신호(desired signal)와 그에 상응하는 조정 벡터(time-variant steering vector)이며, q는 방위각(azimuth angle), j는 고도각(elevation angle), v는 속도(velocity), r는 거리(range)이고, m(t)는 다른 신호와 잡음이 합쳐진 벡터(other-signals-plus-noise)이다. 수학식 1에서 s(t)와

은 수학식 2와 수학식 3과 같이 표현된다.Here, s ( t ) and

Where q is the azimuth angle, j is the elevation angle, v is the velocity, r is the distance, (range), and m ( t ) is the other-signals-plus-noise vector. In Equation (1), s ( t ) and

Is expressed by Equations (2) and (3).

는 감쇄된 신호 크기(attenuated amplitude)이고,

이다.here,

Is the attenuated amplitude,

to be.

이고

이다. 여기서,

은 (1,1)번 째 수신 안테나로부터 (n ₁,n ₂)번째 수신 안테나까지의 시간 지연이고, d는 안테나간 간격이며, c는 전파속도이다.

ego

to be. here,

Is the time delay from the (1,1) th receive antenna to the ( n ₁ , n ₂ ) th receive antenna, d is the spacing between the antennas, and c is the propagation velocity.

Hereinafter, a method of acquiring the azimuth angle, elevation angle, velocity, and distance information from the received signal will be described. Various beam forming algorithms can be applied, but in the present description, a method of forming a K-beam beam is used. The signal estimate of the signal by the K-PON method can be obtained by the following equation (4).

는 빔형성 가중치 벡터(beamforming weight vector)로서 수학식 5와 같다.Here, (·) ^H is a Hermitian transpose,

(5) as a beamforming weight vector.

는 공분산 행렬의 추정치(estimate of covariance matrix)이며 수학식 6과 같이 표현된다.here,

Is an estimate of the covariance matrix and is expressed as Equation (6).

Here, W is the number of measurements.

The power function of the K-Phen method can be expressed as Equation (7) using Equation (4).

As a result, the azimuth, elevation angle, velocity, and distance information of the moving target can be obtained as shown in Equation (8).

Meanwhile, according to another embodiment of the present invention, a power function can be obtained by using a Fourier transform, unlike Equation (7).

를 삽입하면, s(t)는 수학식 9와 같이 표현된다. T in place of _1,1,1 of s (t) of equation (2)

, S ( t ) is expressed by Equation (9).

The third element in Equation (9) can be neglected because it is significantly smaller than the other elements, and Equation (9) can be simplified as shown in Equation (10).

The Fourier transform of s ( t ) in Equation (10) is expressed as Equation (11).

를 삽입하면 수학식 7과는 다른 새로운 전력함수를 수학식 12와 같이 얻는다.Instead of s ( t ) in Equation (11), Equation

A new power function different from Equation (7) is obtained as in Equation (12).

The azimuth angle, elevation angle, velocity, and distance information of the moving target can be obtained using Equation (8) using the power function of Equation (12).

5 is a flowchart illustrating a wireless communication method using an antenna array according to an embodiment of the present invention.

Referring to FIG. 5, the antenna array apparatus of the present invention transmits a signal to a moving object, which is a target to detect a direction, and receives a plurality of reflected signals from a moving object with respect to the transmitted signal (500). The antenna array may be either a linear antenna array or a planar antenna array.

Then, the antenna array apparatus selects one of the plurality of received reflected signals (510). Then, the mixed signal is generated (520) by mixing the selected reflection signal with the transmission signal and converted into a digital signal (530).

Then, the antenna array apparatus forms a beam for the digitally converted mixed signal and estimates a moving parameter for the moving object (540). The movement parameter includes information about at least one of the azimuth, elevation angle, velocity, distance and time with respect to the moving object.

The embodiments of the present invention have been described above. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

1 is a block diagram of a linear antenna array apparatus according to an embodiment of the present invention;

FIG. 2 is a configuration diagram of a planar antenna array device according to an embodiment of the present invention,

FIG. 3 is a view for explaining a moving object parameter estimated using an antenna array according to an embodiment of the present invention; FIG.

4 is a data acquisition cycle structure diagram according to an embodiment of the present invention;

5 is a flowchart illustrating a wireless communication method using an antenna array according to an embodiment of the present invention.

Description of the Related Art

1: Linear antenna array device 2: Planar antenna array device

Claims (20)

A plurality of reception antennas for respectively receiving reflection signals from the moving object, with respect to transmission signals transmitted to a moving object, which is a target for detecting a direction; A reception antenna selector for selecting a reception antenna so that the plurality of reception antennas receive the reflection signal for each reception antenna; A receiver for mixing a reflection signal received from the reception antenna selected through the reception antenna selector with the transmission signal to generate a mixed signal and digitally converting the mixed signal; And And a control unit for forming a beam on the digital-converted mixed signal and estimating a moving parameter for the moving object. 2. The receiver of claim 1, And selects the reception antennas in order to receive the reflection signals for each of the reception antennas according to a preset cycle. 2. The receiver of claim 1, Adjusting the mixed signal using a steering vector, Wherein the adjustment vector includes azimuth angle, velocity, distance and time information of the moving object. The method of claim 3, The adjustment vector may be a time delay from a first reception antenna to an nth reception antenna of the plurality of reception antennas, a propagation time of a reflection signal received through a first reception antenna, a propagation time of a reflection signal received through an nth reception antenna And a value calculated using a time. The apparatus of claim 1, Wherein a wideband K-beam beamforming scheme is used in the beamforming and motion parameter estimation. 6. The apparatus of claim 5, A beamformer may be used to calculate a covariance matrix estimate that is a form of a multiplication of the Hermitian transpose of the digitally converted mixed signal and the digitally converted mixed signal and to generate a beam using an adjustment vector that adjusts the estimate of the covariance matrix and the mixed signal. And a signal estimation value which is a product of the weight vector and the erimit transposed value of the digitally converted mixed signal is obtained and a power function is obtained using the signal estimation value, And estimates a moving parameter for the linear antenna array. 7. The apparatus of claim 6, Wherein the Fourier transform method is used in calculating the power function. A receiving antenna in the form of an N ₁ x N ₂ matrix for receiving a reflection signal from the moving object with respect to a transmission signal transmitted to a moving object as a target to be detected in a direction; And A reception antenna selector for selecting a reception antenna so that the plurality of reception antennas receive the reflection signal for each reception antenna; and a mixer for mixing the reflection signal received from the reception antenna selected through the reception antenna selector with the transmission signal, An N ₁ linear antenna array including a receiver for generating and digitally converting a received signal; And And a control unit for forming a beam for the digital-converted mixed signal for each of the N ₁ linear antenna arrays and estimating a moving parameter for the moving object. 9. The receiver of claim 8, And selects a receiving antenna in order to receive the reflected signals for each of the receiving antennas according to a predetermined period. 9. The receiver of claim 8, Adjusting the mixed signal using a steering vector, Wherein the adjustment vector includes azimuth angle, elevation angle, velocity, distance, and time information of the moving object. 11. The method of claim 10, The adjustment vector is a time delay from the (1,1) th reception antenna of the first period to the (n ₁ , n ₂ ) -th reception antenna of the u-th period among the reception antennas of the N ₁ × N ₂ matrix type, of (1, 1) th receiving antenna of the propagation time and the u-th cycle of the signal received on (n _1, n _2), characterized in that the value calculated by the propagation time of the signal received through the second receive antenna Plane antenna array device. 9. The apparatus according to claim 8, Wherein a wideband K-beam beamforming scheme is used for the beamforming and motion parameter estimation. 13. The apparatus according to claim 12, A beamformer may be used to calculate a covariance matrix estimate that is a form of a multiplication of the Hermitian transpose of the digitally converted mixed signal and the digitally converted mixed signal and to generate a beam using an adjustment vector that adjusts the estimate of the covariance matrix and the mixed signal. And a signal estimation value which is a product of the weight vector and the erimit transposed value of the digitally converted mixed signal is obtained and a power function is obtained using the signal estimation value, And estimates a moving parameter for the antenna array. 14. The apparatus of claim 13, Wherein the Fourier transform method is used in calculating the power function. A wireless communication method using an antenna array, Transmitting a signal to a moving object which is a target to detect a direction and receiving a reflection signal from the moving object via a plurality of reception antennas with respect to the transmission signal; Selecting a receive antenna to receive the reflected signal for each receive antenna; Mixing the reflection signal received through the selected reception antenna with the transmission signal to generate a mixed signal and digitally converting the mixed signal; And And forming a beam for the digital-converted mixed signal and estimating a movement parameter for the moving object. 16. The method of claim 15, And information on at least one of azimuth, elevation angle, speed, distance and time with respect to the moving object. 16. The method of claim 15, Wherein the antenna array is one of a linear antenna array or a planar antenna array. 16. The method of claim 15, wherein estimating the movement parameter for the moving object comprises: Calculating a covariance matrix estimate that is a form of a multiplication of the Hermit transposition value of the digitally converted mixed signal and the digitally converted mixed signal; Obtaining a weight vector for generating a beam using an estimation value of the covariance matrix and an adjustment vector for adjusting a mixed signal; Obtaining a signal estimate value which is a multiplication of the weight vector and the erimit transposed value of the digitally converted mixed signal; Obtaining a power function using the signal estimate; And And estimating a movement parameter for the moving object using the power function. 19. The method of claim 18, Wherein the adjustment vector includes azimuth angle, velocity, distance and time information of the moving object. 19. The method of claim 18, The adjustment vector is a time delay from the (1,1) th reception antenna of the first period to the (n ₁ , n ₂ ) -th reception antenna of the u-th period among the reception antennas of the N ₁ × N ₂ matrix type, of (1, 1) th receiving antenna of the propagation time and the u-th cycle of the signal received on (n _1, n _2), characterized in that the value calculated by the propagation time of the signal received through the second receive antenna Wireless communication method.

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