KR101306169B1 - Method and apparatus for detecting direction - Google Patents

Abstract

PURPOSE: A method for detecting a direction and a method thereof are provided to maintain direction detecting accuracy even the difference of a receiving level is generated. CONSTITUTION: A direction detecting device comprises a frequency downlink converting device (210), a phase extracting part (220), a phase difference calculating part (230), an array manifold storing part (240), I/Q data sorting part (250), a standard null determining part (260), a new array manifold generating part (270), a direction detecting part (280) and a direction finding value correcting part (290). A channel having the largest receiving level is determined among channels corresponding to multiple antennas composing a circularly arranged antenna. A second array manifold based on a determined channel is generated from a first array manifold based on the predetermined first channel among channels. Direction detecting is performed using the second array manifold. The second array manifold is generated using the differences among phase difference data composing the first array manifold. [Reference numerals] (210) Frequency downlink converting device; (220) Phase extracting part; (230) Phase difference calculating part; (240) Array manifold storing part; (250) I/Q data sorting part; (260) Standard null determining part; (270) New array manifold generating part; (280) Direction detecting part; (290) Direction finding value correcting part; (AA) Direction detection result

Description

Method and apparatus for detecting direction

The present invention relates to a method and apparatus for detecting a direction, and more particularly, to a method and apparatus for detecting a direction of a signal source using a signal received through a circular array antenna.

In general, an amplitude comparison method or a phase comparison method is used to detect the direction of the signal source. In particular, in the phase comparison method, a circular array antenna in which a plurality of dipole antennas are arranged in a circle is used. 1 shows an example of such a circular array antenna.

According to the conventional direction detection method using a circular array antenna, the phase is detected for each channel corresponding to each antenna D1 to D5, and the phase difference between the reference channel corresponding to a specific reference antenna and each other channel is obtained. Based on the predetermined direction detection algorithm. As a direction detection algorithm, a multiple signal classification (MUSIC) algorithm, a maximum likelihood (ML) algorithm, or the like is used.

For example, referring to FIG. 1, direction detection is performed by using a channel corresponding to a predetermined reference antenna D1 among antennas as a reference channel, and obtaining a phase difference between the reference channel and a channel corresponding to the other antennas D2 to D5. .

However, in the circular array antenna, as shown in FIG. 1, since a plurality of antennas are arranged in a circle based on a mast 10 serving as a support in the center, the antenna may be greatly affected by the mast 10 according to a frequency. Can be. Therefore, the reception level may vary greatly from antenna to antenna, which may cause an error in the direction detection result. In particular, in the conventional direction detection technique, since the reference antenna is fixed, if the reception level of the reference antenna is significantly lower than that of other antennas, even if a signal is normally received from another antenna, serious errors may occur in the direction detection result. .

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a direction detection method and apparatus capable of maintaining direction detection accuracy even when a difference in reception level occurs for each antenna in a circular array antenna.

According to another aspect of the present invention, there is provided a direction detecting method comprising: determining a channel having a largest reception level among channels corresponding to a plurality of antennas forming a circular array antenna; Generating a second array manifold based on the determined channel from a first array manifold based on a first predetermined one of the channels; And performing direction detection using the generated second array manifold.

The generating of the second array manifold may include generating the second array manifold by using a difference between phase difference data constituting the first array manifold.

The direction detecting method may further include sorting I / Q data of the channels according to the determined channel.

The performing of the direction detection may perform the direction detection using the generated second array manifold and the aligned I / Q data.

The direction detecting method may further include correcting an azimuth value obtained by performing the direction detecting according to the determined channel.

According to an aspect of the present invention, there is provided a direction detecting apparatus comprising: a reference channel determiner configured to determine a channel having a largest reception level among channels corresponding to a plurality of antennas forming a circular array antenna; A new array manifold generator configured to generate a second array manifold based on the determined channel from a first array manifold based on a first predetermined channel among the channels; And a direction detector configured to perform direction detection using the generated second array manifold.

The new array manifold generation unit may generate the second array manifold by using a difference between phase difference data constituting the first array manifold.

The direction detecting apparatus may further include an I / Q data alignment unit for sorting I / Q data of the channels according to the determined channel.

The direction detector may perform direction detection using the generated second array manifold and the aligned I / Q data.

The direction detecting apparatus may further include a probe value correcting unit configured to correct an azimuth value obtained by performing the direction detecting according to the determined channel.

According to the present invention described above, even if a difference in reception level occurs for each antenna in the circular array antenna, the direction detection accuracy can be maintained, and the error of the direction detection result can be minimized even when the reception level of a specific antenna is significantly lowered.

1 shows an exemplary view of a circular array antenna.
2 is a block diagram of a direction detecting apparatus according to an embodiment of the present invention.
3 is a flowchart illustrating a direction detecting method according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description and the accompanying drawings, substantially the same components are denoted by the same reference numerals, and redundant description will be omitted. 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.

2 is a block diagram of a direction detecting apparatus according to an embodiment of the present invention. The direction detecting apparatus according to the present embodiment includes a frequency down converter 210, a phase extractor 220, a phase difference calculator 230, an array manifold storage 240, an I / Q data aligner 250, The reference null determiner 260, the new array manifold generator 270, the direction detector 280, and the detection value corrector 290 are included.

Signals received through the N antennas forming the circular array antenna are input to the direction detecting device, and thus the direction detecting device receives M channels corresponding to each of the N antennas (CH 1, CH 2,..., CH N). Has Hereinafter, for convenience of description, the number of channels is assumed to be 5 by assuming the circular array antenna shown in FIG. 1. However, the number of antennas, that is, the number of channels may be any plurality.

The frequency down converter 210 down-converts the signals input for each channel to generate baseband I / Q (Inphase / Quadrature) data. The I / Q data is used to determine the phase of the corresponding channel signal, while the direction detector 280, which will be described later, is used to perform the direction detection.

The phase extractor 220 extracts a phase of each channel signal from the I / Q data from the frequency down converter 210. For example, the phase extractor 220 may extract a phase of a signal by obtaining an arc tangent of I data and Q data using a coordinated rotation computer algorithm. Hereinafter, phase data obtained for CH 1, CH 2,..., And CH 5 will be represented by P1, P2,.

The phase difference calculator 230 calculates a phase difference between each channel signal and the reference channel signal using a predetermined specific channel among the channels as the reference channel. For example, when CH 1 is a reference channel, phase difference data obtained through the phase difference calculator 230 are as follows.

The set of phase difference data obtained as above is called an array manifold. As will be described later, in the embodiment of the present invention, a new array manifold having a channel other than the reference channel as a reference channel is generated from the array manifold obtained using the specific channel as the reference channel as described above. This is referred to as a new array manifold.

The existing array manifold obtained by the phase difference calculator 230 is stored in the array manifold storage 240.

The reference channel determiner 260 measures a reception level of a signal input for each channel, and determines a channel having the largest reception level. The reference channel determiner 260 determines the channel having the largest reception level as a new reference channel for the new array manifold.

The new array manifold generator 270 receives an existing array manifold from the array manifold storage 240 and based on the new reference channel determined by the reference channel determiner 260 from the existing array manifold. Create an array manifold.

In one embodiment of the present invention, the new array manifold generation unit 270 to generate a new array manifold from the existing array manifold, can be generated by using the difference between the phase difference data constituting the existing array manifold. have.

For example, when the channel having the largest reception level is determined as CH 3 by the reference channel determiner 260, the new array manifold based on CH 3, which is a new reference channel, is configured as described above based on CH 1. From the fold can be obtained as follows.

Here, C ₃₄ , C ₃₅ , C ₃₁ , and C ₃₂ are phase difference data constituting the new array manifold.

For example, when the channel having the largest reception level is determined as CH 5 in the reference channel determiner 260, the new array manifold based on CH 5, which is a new reference channel, is based on CH 1. From the array manifold can be obtained as follows.

In more general description of the creation of a new array manifold, CH 1 is an existing reference channel, the number of channels is N, and the index of the channel determined by the reference channel determiner 260 is M (2 ≦ M ≦ M A new array manifold can be obtained as

Here, C _{M (M + 1)} , C _{M (M + 2)} , ..., C _MN , C _M1 , C _M2 , C _{M (M-1)} are phase difference data constituting a new array manifold, P ₁₂ ..., P _{1 (M-1)} , P _1M , P _{1 (M + 1)} , P _{1 (M + 2)} , ..., P _1N are phase difference data constituting the existing array manifold. .

The I / Q data aligner 250 sorts the I / Q data from the frequency down converter 210 for each channel according to the new reference channel determined by the reference channel determiner 260. As described above, the I / Q data is used to detect the direction of the direction detector 280. If the reference channel is changed, the sort order of the I / Q data should also be changed. For example, when CH 1 is a reference channel, since the required sort order of I / Q data is <CH 1, CH 2, CH 3, CH 4, CH 5>, the reference channel determiner 260 uses CH 3 as a new reference. If it is determined to be a channel, the I / Q data aligner 250 changes this to align the I / Q data in the order of <CH 3, CH 4, CH 5, CH 1, and CH 2> to detect the direction 280. To provide.

The direction detector 280 receives the new array manifold from the new array manifold generator 270 and the aligned I / Q data from the I / Q data aligner 250 and performs a predetermined direction detection algorithm. To detect the direction of the signal source. As the direction detection algorithm, a known multiple signal classification (MUSIC) algorithm, a maximum likelihood (ML) algorithm, or the like may be used. For example, when the MUSIC algorithm is used, the direction detector 280 generates a covariance matrix using N channel I / Q data and a new array manifold, calculates an Eigen Vector and an Eigen Value. Calculate the bearing value using the projection matrix.

According to the exemplary embodiment of the present invention, unlike the conventional technique of generating an array manifold based on a fixed reference channel, that is, a fixed reference antenna and performing direction detection using the same, the reception is performed according to the reception level of each channel. Orientation detection is based on an adaptive array manifold based on the channel with the largest level, so that orientation detection accuracy is maintained even when there is a difference in reception levels for each antenna or when the reception level of a particular channel is significantly lowered. There is a number. In addition, the above-described adaptive array manifold can be generated through a relatively simple operation from the existing array manifold.

Meanwhile, in the present embodiment, the channel determined by the reference channel determiner 260 to have the largest reception level may be the same as the predetermined reference channel. In this case, the new array manifold generator 270 does not operate, and an existing array manifold stored in the array manifold storage 240 may be directly input to the direction detector 280 to be used for direction detection. .

The azimuth value obtained as described above in the direction detector 280 becomes an azimuth value based on a new antenna instead of the original reference antenna. Therefore, the detection value correction unit 290 detects the direction value based on the original reference antenna by correcting the direction value calculated by the direction detector 280 according to the new reference channel determined by the reference channel determiner 260. Output as a result. For example, if the direction of the original reference antenna and the new reference antenna is +144 ㅀ difference, the probe value correction unit 290 deducts the final azimuth value obtained by subtracting 144 을 from the direction value obtained by the direction detector 280. Output as a direction detection result.

3 is a flowchart illustrating a direction detecting method according to an embodiment of the present invention. The direction detecting method according to the present embodiment includes the steps performed in the direction detecting apparatus described above. Therefore, even if omitted below, the above description of the direction detecting apparatus is also applied to the direction detecting method according to the present embodiment.

In operation 310, the direction detecting apparatus determines a channel having the largest reception level among the channels corresponding to the plurality of antennas forming the circular array antenna.

In operation 320, the direction detecting apparatus arranges the I / Q data of the channels according to the channel determined through operation 310.

In operation 330, the direction detecting apparatus generates a new array manifold based on the channel determined through operation 310 from the existing array manifold based on the predetermined reference channel.

In step 340, the direction detecting apparatus performs direction detection using the new array manifold generated in step 330 and the I / Q data aligned in step 320.

In operation 350, the direction detecting apparatus corrects the orientation value obtained by performing the direction detection in operation 340 according to the channel determined in operation 310 to obtain a final orientation value.

The above-described embodiments of the present invention can be embodied in a general-purpose digital computer that can be embodied as a program that can be executed by a computer and operates the program using a computer-readable recording medium. The computer-readable recording medium includes a storage medium such as a magnetic storage medium (e.g., ROM, floppy disk, hard disk, etc.), optical reading medium (e.g., CD ROM,

So far I looked at the center of the preferred embodiment for the present invention. 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.

Claims (10)

Determining a channel having a largest reception level among channels corresponding to the plurality of antennas constituting the circular array antenna;
Generating a second array manifold based on the determined channel from a first array manifold based on a first predetermined one of the channels; And
Performing direction detection using the generated second array manifold;
The generating of the second array manifold may include generating the second array manifold using a difference between phase difference data constituting the first array manifold. delete The method of claim 1,
And aligning the I / Q data of the channels according to the determined channel. The method of claim 3,
And performing the direction detection using the generated second array manifold and the aligned I / Q data. The method of claim 1,
And correcting the azimuth value obtained by performing the direction detection according to the determined channel. A reference channel determiner configured to determine a channel having a largest reception level among channels corresponding to the plurality of antennas constituting the circular array antenna;
A new array manifold generator configured to generate a second array manifold based on the determined channel from a first array manifold based on a first predetermined channel among the channels; And
It includes a direction detection unit for performing a direction detection using the generated second array manifold,
And the new array manifold generating unit generates the second array manifold by using a difference between phase difference data constituting the first array manifold. delete The method according to claim 6,
And an I / Q data alignment unit for arranging I / Q data of the channels according to the determined channel. 9. The method of claim 8,
And the direction detecting unit performs direction detection using the generated second array manifold and the aligned I / Q data. The method according to claim 6,
And a detection value correction unit for correcting the azimuth value obtained by performing the direction detection according to the determined channel.

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