KR102240369B1 - Measuring device for angle of arrival and measuring methdo for angle of arrival - Google Patents

Abstract

The embodiment relates to a device and method for measuring an angle of arrival. The device for measuring an angle of arrival iteratively calculates the spatial spectrum of an input signal to generate a histogram using accumulated peak values, uses the number of bins and the average value of elements having a count number exceeding a preset threshold value, and measures the number of the input signals and the angle of arrival of the input signals.

Description

Apparatus and method for measuring the angle of arrival {MEASURING DEVICE FOR ANGLE OF ARRIVAL AND MEASURING METHDO FOR ANGLE OF ARRIVAL}

The embodiment relates to an apparatus and method for measuring an angle of arrival, and more particularly, to an apparatus and method for measuring the number of received signals and an angle of arrival of a received signal.

In areas such as airports and borders, various radio wave detection systems are operated to protect communication systems, and finding the location of a radio wave transmission source is one of the important roles of the radio wave detection system. The location of the radio wave transmission source can be calculated by using the triangulation technique or information on the angle of arrival (angle at which the signal is received by the antenna) measured by the monitoring system for multiple radio waves. It arrives through signal processing for the radio waves received by the array antenna. Each measurement is possible.

Multiple Signal Classification (MUSIC) is a representative angle of arrival measurement algorithm, but in order to measure the angle of arrival of a signal, the number of input signals must be known in advance. Also, in the conventional method of measuring the angle of arrival, the number of signals is measured using the eigenvalues of the covariance matrix. However, such a conventional method of measuring the angle of arrival has a problem that the accuracy is greatly deteriorated when the input signal has a high correlation characteristic. Therefore, there is a problem in that the dimension of the noise subspace is calculated differently from the actual one, and thus the accuracy of measuring the angle of arrival of the signal is lowered.

The apparatus and method for measuring the angle of arrival according to the embodiment do not use the eigenvalue when measuring the angle of arrival of the signal using the MUSIC algorithm, so that even when a plurality of signals having high correlation characteristics are received, the number of input signals and the angle of arrival are It is to provide an apparatus and a method capable of accurately measuring a value.

The technical problems to be achieved by the embodiment are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those of ordinary skill in the art from the description of the present invention.

An embodiment is an angle of arrival measuring apparatus, comprising: an array antenna including a plurality of antenna elements, a receiver for converting an input signal received from the array antenna into a digital signal, and a spatial spectrum using the digital signal, and the space The histogram is generated by using the peak-to-peak value of the spectrum, and the number of the received input signals and the arrival of the received input signal are performed using a bin having a count number equal to or greater than a preset threshold. It includes a signal processing unit that measures the angle.

In addition, the signal processor of the apparatus for measuring an angle of arrival according to an embodiment may repeatedly calculate a spatial spectrum of the digital signal to accumulate a peak-to-peak value, and generate the histogram using the accumulated peak-to-peak value.

In addition, the signal processor of the apparatus for measuring an angle of arrival according to an embodiment may measure the number of received signals by using the number of bins of the histogram having a count exceeding the threshold value.

In addition, the signal processing unit of the apparatus for measuring the angle of arrival according to the embodiment may measure the angle of arrival by obtaining an average value of the elements of the bin exceeding the threshold value.

In addition, the method of measuring the angle of arrival according to the embodiment includes receiving a signal using an array antenna including a plurality of antenna elements, converting the received signal into a digital signal at a receiving unit, and a signal processing unit converting the digital signal. Generating a spatial spectrum by using, the signal processing unit generating a histogram using the peak-to-peak value of the spatial spectrum, and the signal processing unit having the number of counts equal to or greater than a preset threshold and measuring the number of the received input signals and the angle of arrival of the received input signals using (bin).

In addition, generating the histogram of the method for measuring the angle of arrival according to the embodiment includes accumulating peak-to-peak values by repeatedly calculating the spatial spectrum of the digital signal, and generating the histogram using the accumulated peak-to-peak values. Include more.

In addition, the method of measuring an angle of arrival according to an embodiment further includes the step of measuring, by the signal processing unit, the number of received signals by using the number of bins of the histogram having a count number exceeding the threshold value.

In addition, the method of measuring the angle of arrival according to the embodiment further includes the step of measuring the angle of arrival by obtaining, by the signal processing unit, an average value of the elements of the bin exceeding the threshold value.

The apparatus and method for measuring the angle of arrival according to the embodiment do not use the eigenvalue when measuring the angle of arrival of the signal using the MUSIC algorithm, so that even when a plurality of signals having high correlation characteristics are received, the number of input signals and the angle of arrival are There is an effect that can be accurately measured.

1 is a block diagram showing a schematic configuration of an apparatus for measuring an angle of arrival according to an embodiment.
2 is a graph showing a spatial spectrum indicating a power magnitude according to a direction of an array antenna according to an embodiment.
3 is an example of a graph showing a histogram showing the number of counts of peak-to-peak values of a spatial spectrum according to a measurement angle of arrival according to an embodiment.
4 is a flowchart illustrating a flow of a method for measuring an angle of arrival according to an embodiment.

Hereinafter, exemplary embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar reference numerals are assigned to the same or similar elements, and redundant descriptions thereof will be omitted. The suffixes "module" and "unit" for constituent elements used in the following description are given or used interchangeably in consideration of only the ease of preparation of the specification, and do not have meanings or roles that are distinguished from each other by themselves. In addition, in describing the embodiments disclosed in the present specification, when it is determined that a detailed description of related known technologies may obscure the subject matter of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are for easy understanding of the embodiments disclosed in the present specification, and the technical idea disclosed in the present specification is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention It should be understood to include equivalents or substitutes.

Terms including ordinal numbers such as first and second may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component.

When a component is referred to as being "connected" or "connected" to another component, it is understood that it may be directly connected or connected to the other component, but other components may exist in the middle. It should be. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in the middle.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, terms such as "comprises" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

Hereinafter, an apparatus for measuring an angle of arrival according to an embodiment will be described with reference to FIG. 1.

1 is a block diagram showing a schematic configuration of an apparatus for measuring an angle of arrival according to an embodiment.

Referring to FIG. 1, an apparatus for measuring an angle of arrival 1 according to an embodiment includes an array antenna 110, a receiving unit 120, and a signal processing unit 130.

The array antenna 110 includes a plurality of antenna elements 101a to 101e. For the convenience of explanation, FIG. 1 shows that the array antenna 110 includes five antenna elements 101a to 101e, but the embodiment is not limited thereto, and the array antenna 110 includes five or more antenna elements. Can include.

Each of the plurality of antenna elements 101a to 101e receives an input signal S, and the received input signal S may be an analog signal.

The receiving unit 120 generates a digital signal Sd by converting the frequency of the input signal S. Accordingly, the receiving unit 120 is configured with a plurality of channels corresponding to the number of the plurality of antenna elements 101a to 101e in order to receive the input signal S from each of the plurality of antenna elements 101a to 101e.

The signal processing unit 130 generates a spatial spectrum and a histogram using the digital signal Sd generated by the receiving unit 120, and the number of input signals S received using the histogram and the received input signal S Calculate the angle of arrival of

Hereinafter, a specific method of calculating the number and angle of arrival of the input signals S by the signal processing unit 130 will be described.

First, the signal processing unit 130 converts the digital signal Sd generated by the receiving unit 120 into a vector form. Then, the signal processing unit 130 calculates the covariance matrix R using the vector. The covariance matrix R calculated by the signal processing unit 130 is shown in Equation 1 below.

[Equation 1]

Here, x(i) is the vector of the digital signal, and N is the number of samples.

The signal processing unit 130 eigenly decomposes the covariance matrix R calculated using a vector. This eigen decomposition is shown in Equation 2 below.

[Equation 2]

Here, λ is an eigenvalue and v is an eigenvector.

The signal processing unit 130 may calculate _{a noise subspace (v N} ) and a signal subspace (v _S ) when the number of input signals (S) is D using the eigenvector (v), and the following equation It can be calculated using 3.

[Equation 3]

Here, D is the number of input signals S, and M is the number of antenna elements.

_{The signal processing unit 130 may calculate noise subspaces (v k} ) of all dimensions from a case where the number of input signals S is 1 to M-1. The noise subspace (v _k ) of all the calculated dimensions is shown in Equation 4 below.

[Equation 4]

Here, v _k is the noise subspace when the number of input signals (S) is k, M is the number of antenna elements, and k is the number of input signals (k=1, 2,……, M-1). do.

The signal processing unit 130 may calculate a spatial spectrum using _{noise subspaces (v k) of all dimensions.} The spatial spectrum represents the power magnitude according to the direction of the array antenna 110. Therefore, the peak value on the spectrum means that the input signal S is present.

The spatial spectrum (P _k (θ)) is as shown in Equation 5 below.

[Equation 5]

Here, a(θ) denotes a steering vector of the array antenna 110, and the steering vector of the array antenna 110 is determined by physical characteristics of the array antenna.

The signal processing unit 130 generates a histogram using the peak-to-peak value of the spatial spectrum, and accumulates the peak-to-peak value by repeatedly calculating the spatial spectrum. The signal processing unit 130 may generate a histogram using the accumulated peak-to-peak values.

The accumulated peak value is a result obtained in the spatial spectrum when the number of input signals S is 1 to M-1. In the angular range of the array antenna 110 corresponding to the direction of the actual input signal S, the peak-to-peak position is repeated.

Therefore, when a histogram is constructed with the number of counts of the peak-to-peak values repeatedly collected, the number of counts in the angular range in which the actual input signal S exists is high. Therefore, the signal processing unit 130 may measure the number of input signals S by using the number of bins in which the number of peak-to-peak counts exceeds a preset threshold value.

Also, the signal processing unit 130 may measure the angle of arrival by obtaining an average value of the elements included in the bin exceeding the threshold value. A detailed method of measuring the angle of arrival by the signal processing unit 130 will be described later.

Hereinafter, a method of counting the number of input signals S using a spatial spectrum by the signal processing unit 130 according to an exemplary embodiment will be described with reference to FIG. 2.

2 is a graph showing a spatial spectrum indicating a power magnitude according to a direction of an array antenna according to an embodiment.

Referring to FIG. 2, the x-axis represents the angle of the array antenna 110, and the y-axis represents the amount of power according to the direction of the array antenna 110. In the direction in which the input signal S is present, the power intensity of the spatial spectrum is large. Therefore, it means that there is a high possibility that the input signal S exists at the angle at which the peak values P1 and P2 of the spatial spectrum are measured.

The signal processing unit 130 may count the input signals S as two according to the measured two peak-to-peak values. For example, the signal processing unit 130 measures a first peak value P1 at a first angle (-52°) and a second peak value P2 at a second angle (42°). The signal processing unit 130 may count as two input signals S according to the number of the measured first peak value P1 and the measured second peak value P2.

In addition, the signal processing unit 130 may repeatedly calculate the spatial spectrum, accumulate and store the peak-to-peak value and the angle at which the peak-to-peak value is measured, and generate a histogram using the number of stored peak values.

Hereinafter, a method of measuring the number of input signals S by accumulating the number of peak-to-peak counts and measuring the angle of arrival by the signal processing unit 130 according to an exemplary embodiment will be described with reference to FIG. 3.

3 is an example of a graph showing a histogram showing the number of counts of peak-to-peak values of a spatial spectrum according to a measurement angle of arrival according to an embodiment.

Referring to FIG. 3, the x-axis represents a measurement angle of arrival, and the measurement angle of arrival may correspond to an angle of the array antenna 110. Bins can be set at intervals of 10°.

The y-axis represents the cumulative count of the peak-to-peak value of the spatial spectrum.

The signal processing unit 130 accumulates the number of peak-to-peak counts included in a predetermined bin and compares the accumulated count with the threshold value th. The signal processing unit 130 measures the number of bins corresponding to the accumulated count exceeding the threshold value th as the number of input signals S.

For example, the signal processing unit 130 accumulates the number of peak-to-peak counts included in the first bin B1. _{Specifically, the number of accumulated counts of 1} included in the interval of -50° to -40° and the threshold value (th) are compared. Since the _{number of 1} accumulated count exceeds the threshold value th, the signal processing unit 130 counts the number of input signals S corresponding to the first bin B1.

In addition, the signal processing unit 130 accumulates the number of peak-to-peak counts included in the second bin B2. _{Specifically, the number of accumulated counts of l 2} included in the interval of -20° to -10° and the threshold value (th) are compared. l ₂ can of cumulative count exceeds the threshold value so (th), the signal processor 130 counts the number of the input signal (S) corresponding to the second blank (B2).

In this way, the signal processing unit 130 counts the number of input signals S as 2 according to the first bin B1 and the second bin B2.

In addition, the signal processing unit 130 may measure the angle of arrival by using the average value of the elements included in the bin having the number of counts exceeding the threshold value th. These elements correspond to the measurement angle of the peak-to-peak value of the spatial spectrum described with reference to FIG. 2. The average value of the element is defined as in Equation 6 below.

[Equation 6]

Here, θ ₁ and θ ₂ are the angles of arrival, y ₁ (i), y ₂ (i) are the elements of the bin, and l ₁ and l ₂ are the number of elements.

For example, it is possible to measure a first arrival angle (θ ₁₎ to the average value of l ₁ of elements (y ₁ (i)) contained in the first bin (B1) using the equation (6).

In addition, the second angle of arrival θ ₂ may be measured _{as an average value of l 2} elements y ₂ (i) included in the second bin B2 using Equation 6.

In this way, the signal processing unit 130 may measure the _{first angle of arrival θ 1} and the second angle of arrival θ 2 of the two input signals S.

For convenience of explanation, only two signals are displayed in the histogram of FIG. 3, but embodiments are not limited thereto, and the number of two or more input signals exceeding a threshold value and an angle of arrival of the input signals may be measured.

For convenience of explanation, it has been described that the signal processing unit 130 counts two input signals S and measures the angles of arrival of the two input signals S, but the embodiment is not limited thereto.

In addition, although it has been described that the bin has an interval of 10°, the embodiment is not limited thereto.

Hereinafter, a method of measuring an angle of arrival according to an embodiment will be described with reference to FIG. 4.

4 is a flowchart illustrating a flow of a method for measuring an angle of arrival according to an exemplary embodiment.

Referring to FIG. 4, in step S210, an input signal S is received using an array antenna 110. The array antenna 110 includes a plurality of antenna elements 101a to 101e, and each of the plurality of antenna elements 101a to 101e receives an input signal S. The input signal S may be an analog signal.

In step S220, the receiving unit 120 converts the frequency of the received input signal S using the array antenna 110 to generate a digital signal Sd.

In step S230, the signal processing unit 130 generates a spatial spectrum by using the digital signal Sd generated by the receiving unit 120.

First, the signal processing unit 130 converts the digital signal Sd generated by the receiving unit 120 into a vector form. Then, the signal processing unit 130 calculates the covariance matrix R using the vector using Equation 1.

The signal processing unit 130 eigenizes the covariance matrix R calculated using a vector using Equation 2.

_{The signal processing unit 130 can calculate the noise subspace (v N} ) and the signal subspace (v _S ) when the number of input signals (S) is D using the eigenvector (v) using Equation 3. have.

_{In addition, the signal processing unit 130 may calculate noise subspaces (v k} ) of all dimensions from a case where the number of input signals S is 1 to a case of M-1 using Equation (4). The signal processing unit 130 may calculate a spatial spectrum P _k (θ) _{using the calculated noise subspace v k and Equation 5 of all dimensions.}

The spatial spectrum represents the power magnitude according to the direction of the array antenna 110. Therefore, the peak value on the spatial spectrum means that there is a high possibility that the input signal S is present. Accordingly, the signal processing unit 130 may accumulate peak-to-peak values of the spatial spectrum and generate a histogram using the accumulated peak-to-peak values.

In step S240, the signal processing unit 130 generates a histogram using the peak-to-peak value obtained using the spatial spectrum, and may generate a histogram using the accumulated peak-to-peak value by repeatedly calculating the spatial spectrum.

The accumulated peak value is a result obtained in the spatial spectrum when the number of input signals S is 1 to M-1. In the angular range of the array antenna 110 corresponding to the direction of the actual input signal S, the peak-to-peak position is repeated.

Accordingly, when a histogram is constructed with the number of counts of the peak-to-peak values repeatedly collected, the number of counts appears high in the angular range in which the input signal S exists. Therefore, the signal processing unit 130 measures the number of input signals S and the angle of arrival of the input signals S by using the number of bins and the elements of the bins exceeding a preset threshold. can do.

In step S250, the signal processing unit 130 accumulates the number of peak-to-peak counts included in a predetermined bin of the histogram and compares the accumulated count with a threshold value. The signal processing unit 130 measures the number of bins corresponding to the accumulated count exceeding the threshold value as the number of input signals S.

In addition, the signal processing unit 130 may measure the angle of arrival by using the average value of the elements included in the bin having the count number exceeding the threshold value, and the average value of the element is calculated using Equation 6.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims are also provided. It belongs to the scope of rights. Therefore, the above detailed description should not be construed as restrictive in all respects, but should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

1: angle of arrival measuring device S: input signal
SD: digital signal th: threshold
101a, 101b, 101c, 101d, 101e: antenna element 110: array antenna
120: receiving unit 130: signal processing unit

Claims (8)

Array antenna including a plurality of antenna elements,
A receiver for converting the input signal received by the array antenna into a digital signal, and
Generate a spatial spectrum using the digital signal, generate a histogram using the peak-to-peak value of the spatial spectrum, and use a bin having a count number equal to or greater than a preset threshold Signal processing unit for measuring the number of received input signals and the angle of arrival of the received input signals
Containing, the angle of arrival measuring device. The method of claim 1,
The signal processing unit,
An angle of arrival measuring apparatus for accumulating a peak-to-peak value by repeatedly calculating the spatial spectrum of the digital signal, and generating the histogram using the accumulated peak-to-peak value. The method of claim 2,
The signal processing unit,
An angle of arrival measuring apparatus for measuring the number of received signals by using the number of bins of the histogram having a count exceeding the threshold value. The method of claim 3,
The signal processing unit measures the angle of arrival by obtaining an average value of the elements of the bin exceeding the threshold value. Receiving a signal using an array antenna including a plurality of antenna elements,
Converting the received signal into a digital signal in a receiving unit,
Generating a spatial spectrum using the digital signal by a signal processing unit,
Generating a histogram using the peak-to-peak value of the spatial spectrum by the signal processing unit, and
The signal processing unit measuring the number of the received input signals and the angle of arrival of the received input signals using bins having the number of counts of the peak-to-peak value of the spatial spectrum using a bin having a count number equal to or greater than a preset threshold value.
Containing, the angle of arrival measurement method. The method of claim 5,
Generating the histogram,
Accumulating peak-to-peak values by iteratively calculating the spatial spectrum of the digital signal, and
Generating the histogram using the accumulated peak-to-peak values
The method of measuring the angle of arrival further comprising. The method of claim 6,
Measuring, by the signal processing unit, the number of received signals using the number of bins of the histogram having a count number exceeding the threshold value
The method of measuring the angle of arrival further comprising. The method of claim 7,
The signal processing unit measuring the angle of arrival by obtaining an average value of the elements of the bin exceeding the threshold
The method of measuring the angle of arrival further comprising.

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