CN101826900B - Antenna array direction-finding method for searching minimum amplitude vector angle - Google Patents

Abstract

An antenna array direction-finding method for searching the minimum amplitude vector angle belongs to the antenna array direction-finding category. An antenna array database is established, and an arrival direction which corresponds to an amplitude vector in a database making a minimum included angle with the amplitude vector of a real-timely received signal is searched and used as an estimated arrival direction value for the real-timely received signal. An arrival direction/amplitude vector database for an antenna array is first established; the amplitude vector of the real-timely received signal is then measured, and the included angles between the amplitude vector and all the amplitude vectors in the database of the antenna array are determined; finally, the amplitude vector in the database, which makes the minimum included angle with the amplitude vector of the signal real-timely received by the antenna array, is searched, and the arrival direction corresponding to the amplitude vector is the estimated arrival direction of the signal. The method does not need additional hardware and software to real-timely carry out phase correction, amplitude correction, mutual coupling correction and antenna position error correction on the antenna array, the direction-finding precision is high, the direction-finding error of the circular array comprising five whip antennas is probably less than 1 degree for signals with a frequency equal to 293MHz within the ultrashort wave frequency band, and the probability is larger than 97 percent.

Description

A kind of antenna array direction-finding method of searching minimum amplitude vector angle

Affiliated technical field

The invention belongs to the wireless receiving category; The antenna array direction-finding method that relates to wireless signal receiving system, the vectorial minimum angle of database amplitude vector that carries with aerial array of signal amplitude that relates in particular to the reception in real time of a kind of search antenna array is estimated the method for single direction of arrival of signal.

Background technology

Utilize aerial array that the technology of wireless signal direction finding has been widely used in fields such as radio monitoring, astronomy, sonar, geology detecting, earthquake, radar, radio communication.According to aerial array interferometer direction finding principle commonly used; Need carry out phasing, mutual coupling calibration and aerial position error correction to the antenna in the aerial array; Signal receiver to each antenna rear end carries out the correction of real-time phase consistency; Could make that the phase difference of the signal that each antenna receives is only relevant with the relative position of arrival direction, signal frequency or the wavelength of signal, each antenna; Owing to can confirm the relative position of signal frequency or wavelength, each antenna in advance, so just can be by the anti-arrival direction that pushes away signal of phase difference of the reception signal of each antenna.If the mutual coupling between the antenna, passage is inconsistent and the direction finding requirement is not satisfied in the correction of aerial array site error, all can directly cause the aerial array interferometer direction finding decreased performance of using always.

Yet this correction of aerial array often need be paid additional hardware and software cost, seriously has influence on complexity and the data volume and the processing speed of signal processing of system cost, controller and the signal processing apparatus of antenna array direction-finding.Therefore, how to reduce in addition avoid to aerial array carry out the required hardware and software cost of real-time phase correction, amplitude correction and mutual coupling calibration to realize low cost, low complex degree, antenna array direction-finding has great importance fast.

To above-mentioned defective, the applicant is 200710049079 at application number, denomination of invention discloses a kind of method that does not receive the array df of part phasing error effect in the patent documentation of " array synthetic direction-finding method of wireless signal receiving system ".This method is at first utilized the mould vector that does not receive the array received signal that phase place influences not exclusively synchronously; The direction difference that obtains other signal and reference signal is estimated; Utilize the complex vector of phase place subarray reception fully synchronously signal and complete subspace orthogonal property again; Obtain the direction of reference signal, thereby the direction of arrival of accomplishing all signals is estimated.This method has overcome considerable part phasing error array direction finding Effect on Performance; Improved direction finding precision; But need utilize the fully synchronous subarray of a phase place to estimate the direction of reference signal, and still receive mutual coupling effect and the influence of aerial position error between the antenna.Thereby, be not suitable for existing between the antenna mutual coupling effect and aerial position to have the aerial array of error.

Summary of the invention

The objective of the invention is deficiency to above-mentioned prior art; A kind of direction-finding method of aerial array is provided; This method is particularly suitable for existing between each signal receive path the aerial array of phase place and amplitude response disparity error, mutual coupling effect and aerial position error, does not receive mutual coupling effect and the influence of aerial position error between the antenna.Simultaneously, neither need pay additional hardware and software cost need not utilize the synchronous fully subarray of a phase place to estimate the direction of reference signal again.

The objective of the invention is to reach like this:

A kind of antenna array direction-finding method of searching minimum amplitude vector angle; It is characterized in that: set up the aerial array database; Amplitude vector in the signal amplitude vector angle minimal data storehouse of search and reception in real time, the direction of this amplitude vector correspondence is as the real-time arrival direction estimated value that receives signal.At first, the aerial array foundation for each signal receive path carries database on turntable; Then, at the signal amplitude vector of using the reception in real time of place measurement aerial array, and the angle between all amplitude vectors in the aerial array database of the signal amplitude vector of definite aerial array reception in real time and foundation; At last, the amplitude vector in the signal amplitude vector angle minimal data storehouse that search and aerial array receive in real time, the arrival direction that this amplitude vector is corresponding promptly is the estimated signals arrival direction.The said data of setting up in the aerial array database comprise and are established to the data that reach direction and amplitude vector.

Concrete steps are:

A. confirm arrival direction, the amplitude vector database of aerial array: aerial array is placed on the turntable; With the far field that constantly is placed on aerial array in setting up of the transmitting signal source that aerial array carries database; Turntable rotates by a direction, moving 1 time of revolution, and the arrival direction of signal just changes 1 time; Aerial array is just measured the signal amplitude vector of a reception, in database, preserves the record of an arrival direction, amplitude vector after amplitude vector is handled through normalization.

B. measure the signal amplitude vector that aerial array receives in real time: will accomplish the aerial array of setting up database and be positioned over the application place, and measure the signal amplitude vector that aerial array receives in real time, and normalization is handled to the amplitude vector process.

C. confirm the signal amplitude vector of aerial array reception in real time and the angle between all amplitude vectors in the aerial array database.

D. the amplitude vector in the aerial array database of the signal amplitude vector angle minimum of search and aerial array reception in real time confirms that direction of arrival of signal is the corresponding arrival direction of this amplitude vector.

Said turntable rotates by a direction, and the arrival direction of moving 1 signal of revolution just changes 1 time, is meant that the arrival direction of moving 1 signal of revolution just changes 1 degree, and omnidirectional's 360 degree always have the record of 360 arrival directions, amplitude vector.

If the antenna number of aerial array is M, the direction that the space has a narrow band signal s (t) to arrive this array is θ, and the t received signal vector of array constantly is:

$x\left(t\right)=\left[\begin{array}{c}{x}_1\left(t\right)\\ x_2\left(t\right)\\ .\\ .\\ .\\ x_M\left(t\right)\end{array}\right]=a\left(\mathrm{\θ}\right)s\left(t\right)+v\left(t\right)---\left(1\right)$

Wherein, a (θ) be with direction of arrival of signal θ, aerial position, antenna between mutual coupling, the amplitude direction vector relevant of signal receive path with phase response, v (t) is a noise,

The amplitude vector that above-mentioned aerial array measurement is set up data field signal or received signal in real time is:

$y_k\left(t\right)=\left[\begin{array}{c}\left|x_1\left(t\right)\right|\\ \left|x_2\left(t\right)\right|\\ .\\ .\\ .\\ \left|x_M\left(t\right)\right|\end{array}\right]---\left(2\right)$

Wherein, || expression absolute value, y during k=0 ₀(t) expression receives the amplitude vector of signal in real time, k=1, and 2 ..., 360 o'clock y _k(t) the corresponding amplitude vector of setting up data field signal of the per 1 degree arrival direction of expression, omnidirectional has 360 degree.

The normalization result that said aerial array is set up the amplitude vector of data field signal or reception signal is:

$z\left(k\right)=\frac{y_k\left(t\right)}{\sqrt{y_k^T\left(t\right)y_k\left(t\right)}}---\left(3\right)$

Wherein, [] ^TThe transposition of expression vector, z during k=0 (0) expression receives the normalization amplitude vector of signal in real time, k=1,2 ..., the corresponding normalization amplitude vector of building the storehouse signal of the per 1 degree arrival direction of 360 o'clock z (k) expression, omnidirectional has 360 degree.

An arrival direction in the said database, being recorded as of amplitude vector: (k, z (k)), and wherein, k=1,2 ..., 360.

The arrival direction that signal amplitude vector and the aerial array that said aerial array receives in real time carries, the angle between the amplitude vector in the amplitude vector database is cos ^-1(φ (k)), wherein, φ (k) is:

φ (k)=z ^T(k) z (0) (4) wherein, k=1,2 ..., 360.

Amplitude vector in the signal amplitude vector angle minimal data storehouse that said search and aerial array receive in real time is at k=1,2 ..., the maximum of search φ (k) in 360 scopes, that is:

$\hat{k}=\underset{1\≤k\≤360}{\max }\mathrm{\φ}\left(k\right)---\left(5\right)$

Max

corresponds to the amplitude of the database vector

corresponding to the direction of arrival

that is a signal arrival direction estimation.

Advantage of the present invention is:

1, adopt the present invention to estimate that the arrival direction of individual signals need not pay additional hardware and software cost aerial array is carried out real-time phase correction, amplitude correction, mutual coupling calibration and aerial position error correction.Direction finding precision is high: it is example that the signal that the circular array of forming with 5 whip antennas equals 293MHz to the frequency in the ultrashort wave frequency range carries out direction finding; Each antenna horizontal direction is an omnidirectional; Polarization mode is a perpendicular polarization, and vertical the placement is evenly distributed on the horizontal circle of 1.646 meters of diameters.Adopt direction finding error of the present invention less than 1 the degree probability greater than 97%; And the aerial array interferometer direction finding method of proofreading and correct without real-time phase in the employing background technology lost efficacy, through complicated aerial array interferometer direction finding error of proofreading and correct greater than the probability of 1 degree greater than 1%.

2, this method is easy to use and reliable, and is applied widely, is specially adapted to exist between the antenna mutual coupling effect and aerial position to have the aerial array of error.

Description of drawings

Fig. 1 is the inventive method schematic flow sheet.

The arrival direction of Fig. 2 for using in the inventive method embodiment, amplitude vector database, z among the figure _mWhen (k) the expression turntable forwards k to and spends, the value of m the element of the amplitude vector z (k) of record.

Embodiment

Concrete mode is carried out with the aerial array that has phase place and amplitude response disparity error, mutual coupling effect and aerial position error between each signal receive path.The circular array that this example is formed with 5 whip antennas carries out direction finding to the signal that the frequency in the ultrashort wave frequency range equals 293MHz, and each antenna horizontal direction is an omnidirectional, and polarization mode is a perpendicular polarization, and vertical the placement is evenly distributed on the horizontal circle of 1.646 meters of diameters.

A. confirm arrival direction, the amplitude vector database of aerial array.

At first; Aerial array is placed on the turntable, and in the far field that the storehouse signal source is placed on aerial array of building that transmits, turntable rotates by a direction with constantly; The arrival direction of moving 1 signal of revolution just changes 1 degree, and aerial array is just measured the signal amplitude vector of a reception:

$y_k\left(t\right)=\left[\begin{array}{c}\left|x_1\left(t\right)\right|\\ \left|x_2\left(t\right)\right|\\ .\\ .\\ .\\ \left|x_M\left(t\right)\right|\end{array}\right]---\left(6\right)$

Wherein, || the expression absolute value, k=1,2 ..., 360 o'clock y _k(t) the corresponding amplitude vector of building the storehouse signal of the per 1 degree arrival direction of expression, omnidirectional has 360 degree.Here,

$x\left(t\right)=\left[\begin{array}{c}{x}_1\left(t\right)\\ x_2\left(t\right)\\ .\\ .\\ .\\ x_M\left(t\right)\end{array}\right]---\left(7\right)$

Be t constantly array received build the storehouse signal vector.

Then, amplitude vector being carried out normalization handles:

$z\left(k\right)=\frac{y_k\left(t\right)}{\sqrt{y_k^T\left(t\right)y_k\left(t\right)}}---\left(8\right)$

Wherein, k=1,2 ..., the corresponding normalization amplitude vector of building the storehouse signal of the per 1 degree arrival direction of 360 o'clock z (k) expression, omnidirectional has 360 degree.

At last, after turntable rotated 360 times, omnidirectional's 360 degree had been preserved 360 arrival directions altogether in database, the record of amplitude vector, that is: (k, z (k)), and wherein, k=1,2 ..., 360.

Fig. 2 has provided the arrival direction that uses in the inventive method embodiment, amplitude vector database, z among the figure _mWhen (k) the expression turntable forwards k to and spends, the value of m the element of the amplitude vector z (k) of record.

B. measure the signal amplitude vector that aerial array receives in real time.

The aerial array of completion being built the storehouse is positioned over the application place, measures the signal amplitude vector that aerial array receives in real time:

$y_0\left(t\right)=\left[\begin{array}{c}\left|x_1\left(t\right)\right|\\ \left|x_2\left(t\right)\right|\\ .\\ .\\ .\\ \left|x_M\left(t\right)\right|\end{array}\right]---\left(9\right)$

And amplitude vector is passed through normalization handles:

$z\left(0\right)=\frac{y_0\left(t\right)}{\sqrt{y_0^T\left(t\right)y_0\left(t\right)}}---\left(10\right)$

Here,

$x\left(t\right)=\left[\begin{array}{c}{x}_1\left(t\right)\\ x_2\left(t\right)\\ .\\ .\\ .\\ x_M\left(t\right)\end{array}\right]---\left(11\right)$

It is the t real-time signal vector that receives of array constantly.

C. confirm the vectorial arrival direction that carries with aerial array of signal amplitude that aerial array receives in real time, the angle between all amplitude vectors in the amplitude vector database is cos ^-1(φ (k)), wherein, φ (k) is:

φ(k)＝z ^T(k)z(0) (12)

Wherein, k=1,2 ..., 360.

D. search for the amplitude vector in the signal amplitude vector angle minimal data storehouse that receives in real time with aerial array: at k=1,2 ..., the maximum of searching for φ (k) in 360 scopes, the arrival direction that this amplitude vector is corresponding promptly is the estimated signals arrival direction, that is:

$\hat{k}=\underset{1\≤k\≤360}{\max }\mathrm{\φ}\left(k\right)---\left(13\right)$

Adopt direction finding error of the present invention less than 1 the degree probability greater than 97%.

Though antenna array direction-finding method of the present invention is described with way of example with reference to accompanying drawing, the present invention is not limited only to above-mentioned these details, and the application contains the various modification or the change of covering within the claim scope.

Claims (6)

1. the antenna array direction-finding method of a searching minimum amplitude vector angle; It is characterized in that: set up the aerial array database; Amplitude vector in the signal amplitude vector angle minimal data storehouse of search and reception in real time; The direction conduct of this amplitude vector correspondence receives the arrival direction estimated value of signal in real time: at first, the aerial array foundation for each signal receive path on turntable carries database; Then, at the signal amplitude vector of using the reception in real time of place measurement aerial array, and the angle between all amplitude vectors in the aerial array database of the signal amplitude vector of definite aerial array reception in real time and foundation; At last, the amplitude vector in the signal amplitude vector angle minimal data storehouse that search and aerial array receive in real time, the arrival direction that this amplitude vector is corresponding promptly is the estimated signals arrival direction; The said aerial array of setting up carries database and is meant and sets up arrival direction, amplitude vector database;

Concrete steps are:

A. confirm arrival direction, the amplitude vector database of aerial array: aerial array is placed on the turntable; With the far field that constantly is placed on aerial array in setting up of the transmitting signal source that aerial array carries database; Turntable rotates by a direction, moving 1 time of revolution, and the arrival direction of signal just changes 1 time; Aerial array is just measured the signal amplitude vector of a reception, in database, preserves the record of an arrival direction, amplitude vector after amplitude vector is handled through normalization;

B. measure the signal amplitude vector that aerial array receives in real time: will accomplish the aerial array of setting up database and be positioned over the application place, and measure the signal amplitude vector that aerial array receives in real time, and normalization is handled to the amplitude vector process;

C. confirm the signal amplitude vector of aerial array reception in real time and the angle between all amplitude vectors in the aerial array database;

D. the amplitude vector in the aerial array database of the signal amplitude vector angle minimum of search and aerial array reception in real time confirms that direction of arrival of signal is the corresponding arrival direction of this amplitude vector.

2. the antenna array direction-finding method of searching minimum amplitude vector angle as claimed in claim 1; It is characterized in that: said turntable rotates by a direction; The arrival direction of moving 1 signal of revolution just changes 1 time; The arrival direction that is meant moving 1 signal of revolution just changes 1 degree, and omnidirectional's 360 degree always have the record of 360 arrival directions, amplitude vector.

3. the antenna array direction-finding method of searching minimum amplitude vector angle as claimed in claim 1; It is characterized in that: the antenna number of establishing aerial array is M; The direction that the space has a narrow band signal s (t) to arrive this array is θ, and the t received signal vector of array constantly is:

$x\left(t\right)=\left[\begin{array}{c}{x}_1\left(t\right)\\ x_2\left(t\right)\\ .\\ .\\ .\\ x_M\left(t\right)\end{array}\right]=a\left(\mathrm{\θ}\right)s\left(t\right)+v\left(t\right)$

Wherein, a (θ) be with direction of arrival of signal θ, aerial position, antenna between mutual lotus root, the amplitude direction vector relevant of signal receive path with phase response, v (t) is a noise,

The amplitude vector that above-mentioned aerial array measurement is set up data field signal or received signal in real time is:

$y_k\left(t\right)=\left[\begin{array}{c}\left|x_1\left(t\right)\right|\\ \left|x_2\left(t\right)\right|\\ .\\ .\\ .\\ \left|x_M\left(t\right)\right|\end{array}\right]$

Wherein, | | expression absolute value, y during k=0 ₀(t) expression receives the amplitude vector of signal in real time, k=1, and 2 ..., 360 o'clock y _k(t) the corresponding amplitude vector of setting up data field signal of the per 1 degree arrival direction of expression, omnidirectional has 360 degree.

4. the antenna array direction-finding method of searching minimum amplitude vector angle as claimed in claim 3 is characterized in that: antenna database signal that said aerial array is measured or the normalization result that receives the amplitude vector of signal are:

$z\left(k\right)=\frac{y_k\left(t\right)}{\sqrt{y_k^T\left(t\right)y_k\left(t\right)}}$

Wherein, [] ^TThe transposition of expression vector, z during k=0 (0) expression receives the normalization amplitude vector of signal in real time, k=1,2 ..., the corresponding normalization amplitude vector of building the storehouse signal of the per 1 degree arrival direction of 360 o'clock z (k) expression, omnidirectional has 360 degree.

5. the antenna array direction-finding method of searching minimum amplitude vector angle as claimed in claim 1 is characterized in that: being recorded as an of arrival direction in the said database, amplitude vector: (k, z (k)), wherein, k=1,2 ..., 360,

Signal amplitude vector that said aerial array receives in real time and the angle between the amplitude vector in the aerial array database are cos ^-1(φ (k)), wherein, φ (k) is:

$\mathrm{\φ}\left(k\right)=z^T\left(k\right)z\left(0\right)$ Wherein, k=1,2 ..., 360.

6. the antenna array direction-finding method of searching minimum amplitude vector angle as claimed in claim 5; It is characterized in that: the amplitude vector in the signal amplitude vector angle minimal data storehouse that said search and aerial array receive in real time; Be at k=1,2 ... The maximum of search φ (k) in 360 scopes, that is:

$\hat{k}=\underset{1\≤k\≤360}{\max }\mathrm{\φ}\left(k\right)$

Amplitude vector in maximum

correspondence database, corresponding arrival direction

promptly is the estimated signals arrival direction.

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