CN114487985A - Beam sharpening method and system based on difference-sum signal - Google Patents

Beam sharpening method and system based on difference-sum signal Download PDF

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CN114487985A
CN114487985A CN202210117868.4A CN202210117868A CN114487985A CN 114487985 A CN114487985 A CN 114487985A CN 202210117868 A CN202210117868 A CN 202210117868A CN 114487985 A CN114487985 A CN 114487985A
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arrival
incident
signal
signals
sum
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杨君
杜钰
曲卫
马鑫
邱磊
庞鸿锋
肖博
胡豪杰
熊帮鑫
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Peoples Liberation Army Strategic Support Force Aerospace Engineering University
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
    • G01S3/02—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using radio waves
    • G01S3/04—Details
    • G01S3/06—Means for increasing effective directivity, e.g. by combining signals having differently oriented directivity characteristics or by sharpening the envelope waveform of the signal derived from a rotating or oscillating beam antenna
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
    • G01S3/02—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using radio waves
    • G01S3/14—Systems for determining direction or deviation from predetermined direction
    • G01S3/143—Systems for determining direction or deviation from predetermined direction by vectorial combination of signals derived from differently oriented antennae

Abstract

The invention discloses a wave beam sharpening method and a wave beam sharpening system based on difference-sum signals, which relate to the technical field of signal processing and comprise the following steps: estimating initial arrival directions of K incident signals received by a target array antenna; respectively generating K sum beams and K difference beams based on a digital beam forming technology and the initial arrival directions of K incident signals, and further obtaining K sum signals and K difference signals; based on a digital signal processing technology, a sum signal, a difference signal and an initial direction of arrival corresponding to each incident signal, an iterative algorithm is adopted to determine the final direction of arrival of K incident signals, and then K sharpened beams are generated, so that the resolution, the receiving and the measurement of a plurality of echo signals in a main lobe are realized, and the method has important application values in the aspects of indistinguishable target tracking, super-resolution imaging, main lobe anti-interference and the like.

Description

Beam sharpening method and system based on difference-sum signal
Technical Field
The invention relates to the technical field of signal processing, in particular to a beam sharpening method and system based on difference-sum signals.
Background
Resolution refers to the minimum distance in space that can separate two target points. In the technical fields of radar, sonar, communication, etc., the resolution of an antenna is limited by the antenna aperture (θ)3dB0.89 λ/D, where θ3dB3dB beamwidth, λ wavelength, D antenna aperture). Conventional Beamforming (CBF) can perform signal synthesis in the direction of the angle of arrival, but the width of the main lobe of the antenna is also limited by the number of array elements; classical super-resolution algorithms, such as a subspace method, a maximum likelihood method, a compressed sensing algorithm and the like, can measure the amplitude and the angle of a plurality of signals in a main lobe, but cannot realize the separation of the signals; super beam Forming (HBF) can effectively reduce the main lobe width, but fails in the presence of multiple signals within the main lobe.
Disclosure of Invention
The invention aims to provide a wave beam sharpening method and a wave beam sharpening system based on difference-sum signals, which can accurately estimate the arrival directions of a plurality of incident signals and form a plurality of sharpened wave beams which respectively point to the arrival directions of the incident signals.
In order to achieve the purpose, the invention provides the following scheme:
in a first aspect, the present invention provides a beam sharpening method based on a difference-sum signal, including:
acquiring K incident signals received by a target array antenna;
estimating initial directions of arrival of the K incident signals;
respectively generating K sum beams and K difference beams based on a digital beam forming technology and K initial arrival directions of the incident signals; one said sum beam pointing in an initial direction of arrival of one said incident signal and a different said sum beam pointing in a different initial direction of arrival of said incident signal;
calculating the K incident signals based on the K sum beams and the K difference beams to obtain K sum signals and K difference signals;
determining final arrival directions of K incident signals by adopting an iterative algorithm based on a digital signal processing technology, and a sum signal, a difference signal and an initial arrival direction corresponding to each incident signal;
generating K sharpened beams based on the K final arrival directions of the incident signals; one of the sharpened beams points in a final direction of arrival of one of the incident signals, and a different one of the sharpened beams points in a different final direction of arrival of the incident signal.
In a second aspect, the present invention provides a beam sharpening system based on a difference-sum signal, comprising:
the incident signal acquisition module is used for acquiring K incident signals received by the target array antenna;
the initial direction-of-arrival estimation module is used for estimating initial directions of arrival of the K incident signals;
the sum beam and difference beam generating module is used for respectively generating K sum beams and K difference beams based on a digital beam forming technology and K initial arrival directions of the incident signals; one said sum beam pointing in an initial direction of arrival of one said incident signal and a different said sum beam pointing in a different initial direction of arrival of said incident signal;
the sum signal and difference signal calculation module is used for calculating K incident signals based on K sum beams and K difference beams to obtain K sum signals and K difference signals;
a final direction-of-arrival determining module, configured to determine final directions of arrival of the K incident signals by using an iterative algorithm based on a digital signal processing technique and a sum signal, a difference signal, and an initial direction of arrival corresponding to each incident signal;
a sharpened beam generation module, configured to generate K sharpened beams based on the final directions of arrival of the K incident signals; one of the sharpened beams points in a final direction of arrival of one of the incident signals, and a different one of the sharpened beams points in a different final direction of arrival of the incident signal.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention adaptively forms a plurality of sharpening beams by a Digital Beam Forming (DBF) technology to respectively point to the arrival directions of a plurality of echo signals in a main lobe, thereby realizing the resolution, the receiving and the measurement of the plurality of echo signals in the main lobe and having important application values in the aspects of indistinguishable target tracking, super-resolution imaging, main lobe anti-interference and the like.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 is a diagram of the effect of spatial spectrum spreading provided by the present invention; FIG. 1(a) is a diagram of the effect of spatial spectrum expansion in infinite observation; FIG. 1(b) is a diagram of the effect of spatial spectrum expansion in finite observation;
FIG. 2 is a schematic diagram of difference sum beam sharpening provided by the present invention;
FIG. 3 is a flowchart illustrating a beam sharpening method based on a difference-sum signal according to the present invention;
fig. 4 is a schematic structural diagram of a beam sharpening system based on a difference-sum signal according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
The core idea of the invention is as follows:
the array antenna is composed of a group of array elements with a space topological structure, each array element is used for sampling and weighting a space signal field, and compared with a single directional array element, the array antenna has higher angle resolution. The main lobe width of the array antenna can be expressed as:
Figure BDA0003497229990000031
where λ is the wavelength of an echo signal (basically, a noise-reduced received signal or an incident signal), N is the number of array elements, and d is the array element pitch. Therefore, when the number of the array elements is infinite, the optimal observation result is obtained, the spatial spectrum is a line spectrum, and the echo signals in any two different directions in the space can be distinguished. However, the number of elements of an actual array antenna is limited, and the observation of the limited elements is equivalent to adding a rectangular window to the observation of the infinite elements, as shown in fig. 1, and the directions of arrival of two echo signals are too close to each other to be resolved. In the process of estimating the angle of arrival, the rectangular window is transformed into the SINC function after Fourier transform, and the spatial spectrum spreading effect caused by limited observation is essentially the convolution result of the shock function and the SINC function.
In the array antenna, for a certain echo signal, only one phase difference exists between the echo signals received by two sub-arrays, and when the sub-array spacing is fixed, the phase difference between the echo signals received by two array elements is also fixed, and the characteristic is called the rotation invariance between the array elements. When the received echo signals are compared, the phase difference between the received signals of the two subarrays can be obtained, and then the signals received by the 3 # subarray to the infinite # subarray can be deduced, so that an approximately infinite observation result can be obtained through weighting operation, as shown in fig. 2.
The array antenna is composed of two uniform linear arrays with the same structure, and the distance between sub-arrays is delta. For each subarray, the number of array elements is N, the array element spacing is d, the array elements are all omnidirectional antennas, and the wavelength of an incident signal (i.e., an echo signal) is λ. K incident signals s exist in the main lobe1(t),…,sk(t) incident angles are each θ1,…,θK。
The matrix form of the signals received by the sub-array 1 is represented as:
Figure BDA0003497229990000041
wherein x is1(t)、x2(t)、……xKThe (t) signals are all received signals (including noise) of the sub-array 1, K received signals are total, and j represents an imaginary unit.
Ignoring noise
Figure BDA0003497229990000042
The above formula can be simplified as follows: x1(t)＝A1S(t)；
Wherein A is1＝[α(θ1)…α(αK)]，S(t)＝[s1(t)…sk(t)]TWherein α (θ)1) Is the steering vector of the 1 st incident signal, α (θ)k) For the steering vector of the kth incoming signal, T denotes transposition.
When the weight vector is W1When the array directional diagram and the output signal of the sub-array 1 are:
Figure BDA0003497229990000043
Figure BDA0003497229990000044
where H denotes a conjugate transpose.
Subarrays 2The received signal may be expressed as: x2(t)＝A2S(t)＝A1DS(t)；
Wherein the content of the first and second substances,
Figure BDA0003497229990000051
since subarray 2 is spaced from subarray 1 by Δ, the weight vector for subarray 2
Figure BDA0003497229990000052
θ0Pointing angle for the current beam.
The array pattern and output signals of the sub-array 2 are:
Figure BDA0003497229990000053
Figure BDA0003497229990000054
wherein the content of the first and second substances,
Figure BDA0003497229990000055
it can be assumed that the array pattern and output signal of the lth sub-array can be represented as:
Figure BDA0003497229990000056
Figure BDA0003497229990000057
the array directional diagram and the output signal of the array antenna are as follows:
Figure BDA0003497229990000058
Figure BDA0003497229990000059
where g is the attenuation factor introduced to converge the accumulation result.
As L approaches infinity:
Figure BDA00034972299900000510
Figure BDA00034972299900000511
after normalization:
Figure BDA00034972299900000512
Figure BDA0003497229990000061
under the adjustment of the weighting vector, when the beam pointing angle is coincident with the arrival direction of each incident signal, the incident signal of the direction can be output without attenuation. It can be seen that the choice of the weighting vector depends on the estimation of the direction of arrival.
The array antenna provided by the invention consists of two sub-arrays, and by the previous analysis, the sum beam of the two sub-arrays can be represented as follows:
Figure BDA0003497229990000062
FΣi(θi)＝2；
FΣi(θk)＝0，k≠i；k＝1，2，…，K；
for the formula
Figure BDA0003497229990000063
Comprises the following steps:
Figure BDA0003497229990000064
i denotes an identity matrix.
It can be seen that the difference between the sum signals of the two sub-arrays forms a zero point in the incident direction of all signals.
Thus constructing a poor beam is:
Figure BDA0003497229990000065
can be seen from
Figure BDA0003497229990000066
In (1)
Figure BDA0003497229990000067
Can be decomposed as the sum of K weighted vectors:
Figure BDA0003497229990000068
wherein the content of the first and second substances,
Figure BDA0003497229990000069
representing an estimate of the i-th noise-reduced incident signal,
Figure BDA00034972299900000610
representing an estimate of the noise-reduced incident signal.
In order to fully utilize the two sub-arrays, the sum signal is utilized to reform the above formula:
Figure BDA0003497229990000071
get
Figure BDA0003497229990000072
A representation sum signal;
Figure BDA0003497229990000073
to representA difference signal.
The reconstructed array directional diagram is sharper in the direction of arrival of the incident signal.
Under the condition that noise obeys Gaussian distribution, the maximum likelihood angle proves that in a single array, K sum beams which can be formed by a digital beam forming technology respectively point to the arrival direction of each incident signal, and null is formed in the arrival direction of other incident signals; the sum beam formed by the two sub-arrays also has the characteristics, the main lobe is narrower, and meanwhile, the difference beam formed by the two sub-arrays can form nulls in all echo directions. The weight of the beam sharpening expression may be decomposed into the sum of K sum beam weight vectors at this time, and thus expressed in the form of sum-difference beam ratio accumulation.
When there are multiple incident signals in the main lobe, a weight vector is also constructed based on the Bartlett weight, and b(s) represents the weight of the signal s.
Array pattern F of ith said sum beamΣi(θ) is:
Figure BDA0003497229990000074
Figure BDA0003497229990000075
array pattern F of ith said difference beamΔi(θ) is:
Figure BDA0003497229990000076
Figure BDA0003497229990000077
in the above formula, θkIndicating the k-th incident angle, and performing summation operation respectively.
The output signal of the ith said sum beam is:
Figure BDA0003497229990000078
the output signal of the ith difference beam is:
Figure BDA0003497229990000081
the ith system is pointed at thetaiFrom the previous analysis, there were:
Figure BDA0003497229990000082
Figure BDA0003497229990000083
Figure BDA0003497229990000084
for ideal conditions
Figure BDA0003497229990000085
The deviation of the ideal value from the actual value of the angular difference can be found to be:
Figure BDA0003497229990000086
the definition of f (θ) here is explained as follows:
direction of arrival theta of incident signal1In order to be a certain value of the value,
Figure BDA0003497229990000087
for measurements, the above equation can be expressed as a function of θ, given:
Figure BDA0003497229990000088
and is also provided with
Figure BDA0003497229990000089
Therefore, it is
Figure BDA00034972299900000810
Figure BDA00034972299900000811
Wherein
Figure BDA00034972299900000812
Is the inverse function of f (θ). It can also be embodied by the following function:
Figure BDA00034972299900000813
deviation of the ith system depends on whether other systems can be accurate at θiForming a null. Under the condition of multiple incident signals, the problem is a nonlinear multidimensional optimization problem, and a global multidimensional search is needed. The angle difference between the initial pointing angle of each system and the arrival direction of the incident signal cannot be obtained through one-time accurate calculation, and only the arrival direction of the incident signal is continuously approximated by updating the pointing angle of the iterative system, so that a suboptimal estimation result is obtained. At each step of the iteration, one parameter is equivalently optimized, while the other parameters remain unchanged.
For the calculation of the initial angle:
since the selection of the initial value is very important to ensure the global convergence, the selection of the initial value is a key step of the algorithm. First, an estimated value of the angle of incidence (also referred to as an estimated value of the direction of arrival) of the first incident signal is obtained:
Figure BDA0003497229990000091
s (t) represents the signal received by the target array antenna after noise reduction (i.e. reduction)Noisy incident signal), α (θ)i) A steering vector representing the i-th noise-reduced incident signal.
Then, assume that the estimated value of the direction of arrival of the first incident signal is
Figure BDA0003497229990000092
An estimate of the angle of incidence of the second incident signal is found:
Figure BDA0003497229990000093
for the nth incident signal, the initial estimate is:
Figure BDA0003497229990000094
the initial directions of arrival of the K incident signals are estimated sequentially in the above method.
When the estimated value of the incident angle of the ith incident signal is used, the estimated value of the incident angle of the first i-1 incident signals is kept, and the arrival direction of the ith incident signal is obtained, so that the K initial angles are obtained.
4. The objective function of the iteration is:
Figure BDA0003497229990000095
based on the above, the beam sharpening method based on the difference-sum signal provided in this embodiment, as shown in fig. 3, includes the following steps:
step 301: acquiring K incident signals received by a target array antenna; the target array antenna comprises a plurality of sub-arrays, and each sub-array comprises the same number of array elements.
Step 302: estimating initial directions of arrival of the K incident signals, specifically including:
carrying out noise reduction processing on the K incident signals; and estimating the initial arrival directions of the K incident signals subjected to the noise reduction processing.
Wherein, for the nth incident signal, the estimated initial direction of arrival
Figure BDA0003497229990000101
Comprises the following steps:
Figure BDA0003497229990000102
wherein the content of the first and second substances,
Figure BDA0003497229990000103
the initial direction of arrival is estimated for the ith incident signal.
Step 303: respectively generating K sum beams and K difference beams based on a digital beam forming technology and K initial arrival directions of the incident signals; one of the sum beams is directed in an initial direction of arrival of one of the incident signals and a different one of the sum beams is directed in a different initial direction of arrival of the incident signal.
Step 304: and calculating the K incident signals based on the K sum beams and the K difference beams to obtain K sum signals and K difference signals.
Wherein the ith sum signal is:
Figure BDA0003497229990000104
the ith said difference signal is:
Figure BDA0003497229990000105
in the above
Figure BDA0003497229990000106
Is the initial direction of arrival of the ith incident signal.
Step 305: and determining the final arrival directions of the K incident signals by adopting an iterative algorithm based on a digital signal processing technology, and the sum signal, the difference signal and the initial arrival direction corresponding to each incident signal.
Step 306: generating K sharpened beams based on the K final arrival directions of the incident signals; one of the sharpened beams points in a final direction of arrival of one of the incident signals, and a different one of the sharpened beams points in a different final direction of arrival of the incident signal; the method specifically comprises the following steps:
based on the final arrival directions of the K incident signals and based on a digital beam forming technology, generating K sum beams again; and sharpening the K regenerated sum beams to obtain K sharpened beams.
Wherein step 305 specifically comprises:
according to the formula
Figure BDA0003497229990000111
And calculating the estimated value of the direction of arrival of the ith incident signal at the mth time.
And judging whether the difference value between the estimated value of the direction of arrival of the ith incident signal of the mth time and the estimated value of the direction of arrival of the ith incident signal of the (m-1) th time is smaller than a set threshold value.
If yes, determining the estimated arrival direction value of the ith incident signal at the mth time as the final arrival direction of the ith incident signal; if not, adding 1 to the iteration times, and returning to the formula
Figure BDA0003497229990000112
Figure BDA0003497229990000113
And calculating the estimated value of the direction of arrival of the ith incident signal of the mth time until the final direction of arrival of the ith incident signal is determined, and further determining the final direction of arrival of each incident signal.
To achieve the above object, the present invention further provides a beam sharpening system based on a difference-sum signal, as shown in fig. 4, including:
an incident signal obtaining module 401, configured to obtain K incident signals received by the target array antenna.
An initial direction of arrival estimation module 402, configured to estimate initial directions of arrival of the K incident signals.
A sum beam and difference beam generating module 403, configured to generate K sum beams and K difference beams respectively based on a digital beam forming technique and K initial directions of arrival of the incident signals; one of the sum beams is directed in an initial direction of arrival of one of the incident signals and a different one of the sum beams is directed in a different initial direction of arrival of the incident signal.
And a sum signal and difference signal calculating module 404, configured to calculate K incident signals based on the K sum beams and the K difference beams to obtain K sum signals and K difference signals.
A final direction-of-arrival determining module 405, configured to determine final directions of arrival of the K incident signals by using an iterative algorithm based on a digital signal processing technique and a sum signal, a difference signal, and an initial direction of arrival corresponding to each incident signal.
A sharpened beam generation module 406, configured to generate K sharpened beams based on the K final directions of arrival of the incident signals; one of the sharpened beams points in a final direction of arrival of one of the incident signals, and a different one of the sharpened beams points in a different final direction of arrival of the incident signal.
The target array antenna comprises a plurality of sub-arrays, and each sub-array comprises the same number of array elements.
The initial direction of arrival estimation module 402 specifically includes:
and the noise reduction processing unit is used for carrying out noise reduction processing on the K incident signals.
And the initial direction-of-arrival estimation unit is used for estimating the initial directions of arrival of the K incident signals subjected to the noise reduction processing.
The final direction of arrival determination module 405 is further configured to:
according to the formula
Figure BDA0003497229990000121
Calculating an estimated value of the direction of arrival of the ith incident signal of the mth time;
judging whether the difference value between the direction of arrival estimation value of the ith incident signal of the mth time and the direction of arrival estimation value of the ith incident signal of the (m-1) th time is smaller than a set threshold value or not;
if yes, determining the estimated arrival direction value of the ith incident signal at the mth time as the final arrival direction of the ith incident signal; if not, adding 1 to the iteration times, and returning to the formula
Figure BDA0003497229990000122
Figure BDA0003497229990000123
And calculating the estimated value of the direction of arrival of the ith incident signal of the mth time until the final direction of arrival of the ith incident signal is determined, and further determining the final direction of arrival of each incident signal.
The sharpening beam generating module 406 specifically includes:
and a beam secondary generation unit for generating again K sum beams based on the final directions of arrival of the K incident signals and based on a digital beam forming technique; and the sharpening beam generating unit is used for sharpening the K regenerated sum beams to obtain K sharpened beams.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the description of the method part.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (10)

1. A method for beam sharpening based on a difference-sum signal, comprising:
acquiring K incident signals received by a target array antenna;
estimating initial directions of arrival of the K incident signals;
respectively generating K sum beams and K difference beams based on a digital beam forming technology and K initial arrival directions of the incident signals; one said sum beam pointing in an initial direction of arrival of one said incident signal and a different said sum beam pointing in a different initial direction of arrival of said incident signal;
calculating the K incident signals based on the K sum beams and the K difference beams to obtain K sum signals and K difference signals;
determining final arrival directions of K incident signals by adopting an iterative algorithm based on a digital signal processing technology, and a sum signal, a difference signal and an initial arrival direction corresponding to each incident signal;
generating K sharpened beams based on the K final arrival directions of the incident signals; one of the sharpened beams points in a final direction of arrival of one of the incident signals, and a different one of the sharpened beams points in a different final direction of arrival of the incident signal.
2. The method of claim 1, wherein the target array antenna comprises a plurality of sub-arrays, and each sub-array comprises the same number of elements.
3. The method according to claim 1, wherein the estimating the initial directions of arrival of the K incident signals specifically comprises:
carrying out noise reduction processing on the K incident signals;
and estimating the initial arrival directions of the K incident signals subjected to the noise reduction processing.
4. The method according to claim 1, wherein the determining final directions of arrival of the K incident signals by using an iterative algorithm based on the digital signal processing technique and the sum signal, the difference signal, and the initial direction of arrival corresponding to each incident signal specifically comprises:
calculating an estimated value of the direction of arrival of the ith incident signal of the mth time;
judging whether the difference value between the direction of arrival estimation value of the ith incident signal of the mth time and the direction of arrival estimation value of the ith incident signal of the (m-1) th time is smaller than a set threshold value or not;
if yes, determining the estimated direction of arrival of the ith incident signal at the mth time as the final direction of arrival of the ith incident signal;
and if not, adding 1 to the iteration times, returning to calculate the estimated value of the direction of arrival of the ith incident signal for the mth time until the final direction of arrival of the ith incident signal is determined, and further determining the final direction of arrival of each incident signal.
5. The method according to claim 1, wherein the generating K sharpened beams based on the K final directions of arrival of the incident signals specifically comprises:
based on the final arrival directions of the K incident signals and based on a digital beam forming technology, generating K sum beams again;
and sharpening the K regenerated sum beams to obtain K sharpened beams.
6. A beam sharpening system based on a difference-sum signal, comprising:
the incident signal acquisition module is used for acquiring K incident signals received by the target array antenna;
the initial direction-of-arrival estimation module is used for estimating initial directions of arrival of the K incident signals;
the sum beam and difference beam generating module is used for respectively generating K sum beams and K difference beams based on a digital beam forming technology and K initial arrival directions of the incident signals; one said sum beam pointing in an initial direction of arrival of one said incident signal and a different said sum beam pointing in a different initial direction of arrival of said incident signal;
the sum signal and difference signal calculation module is used for calculating K incident signals based on K sum beams and K difference beams to obtain K sum signals and K difference signals;
a final direction-of-arrival determining module, configured to determine final directions of arrival of the K incident signals by using an iterative algorithm based on a digital signal processing technique and a sum signal, a difference signal, and an initial direction of arrival corresponding to each incident signal;
a sharpened beam generation module, configured to generate K sharpened beams based on the final directions of arrival of the K incident signals; one of the sharpened beams points in a final direction of arrival of one of the incident signals, and a different one of the sharpened beams points in a different final direction of arrival of the incident signal.
7. The system of claim 6, wherein the target array antenna comprises a plurality of sub-arrays, and each sub-array comprises the same number of elements.
8. The system according to claim 6, wherein the initial direction of arrival estimation module specifically comprises:
the noise reduction processing unit is used for carrying out noise reduction processing on the K incident signals;
and the initial direction-of-arrival estimation unit is used for estimating the initial directions of arrival of the K incident signals subjected to the noise reduction processing.
9. The system according to claim 6, wherein the final direction of arrival determining module is further configured to:
calculating an estimated value of the direction of arrival of the ith incident signal of the mth time;
judging whether the difference value between the direction of arrival estimation value of the ith incident signal of the mth time and the direction of arrival estimation value of the ith incident signal of the (m-1) th time is smaller than a set threshold value or not;
if yes, determining the estimated arrival direction value of the ith incident signal at the mth time as the final arrival direction of the ith incident signal;
and if not, adding 1 to the iteration times, returning to calculate the estimated value of the direction of arrival of the ith incident signal for the mth time until the final direction of arrival of the ith incident signal is determined, and further determining the final direction of arrival of each incident signal.
10. The beam sharpening system according to claim 6, wherein the sharpened beam generating module specifically comprises:
and a beam secondary generation unit for generating again K sum beams based on the final directions of arrival of the K incident signals and based on a digital beam forming technique;
and the sharpening beam generating unit is used for sharpening the K regenerated sum beams to obtain K sharpened beams.
CN202210117868.4A 2022-02-08 2022-02-08 Beam sharpening method and system based on difference-sum signal Pending CN114487985A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114927884A (en) * 2022-05-18 2022-08-19 中国电子科技集团公司第十研究所 Dynamic compensation method for improving performance of vehicle-mounted phased array antenna

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114927884A (en) * 2022-05-18 2022-08-19 中国电子科技集团公司第十研究所 Dynamic compensation method for improving performance of vehicle-mounted phased array antenna

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