CN107356943B - Digital beam forming and phase fitting method - Google Patents
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Abstract
The invention provides a digital beam forming and phase fitting method, and aims to provide a method capable of suppressing interference, improving a signal-to-interference-and-noise ratio and accurately controlling a beam forming signal phase. The invention is realized by the following technical scheme: the guiding vector model obtains accurate array absolute guiding vectors by using relative guiding vectors obtained by online calibration and combining absolute phase response measured by a reference array element darkroom, and combines the existing absolute guiding vectors to fit model parameters of the guiding vectors so as to obtain accurate standby guiding vectors of the antenna array in any direction. Iterative computation of second-order statistics of the array signals is carried out through an array signal statistics hardware computation module, the second-order statistics of the array signals are sent to an array signal position algorithm module together with the antenna array guide vectors and channel responses, and optimal beam weights are computed; and finally, the array signal processing algorithm module puts the optimal beam weight value into a digital beam forming module to perform real-time digital beam forming and phase fitting, and process multi-channel array data and beam output in real time.
Description
Technical Field
The invention relates to a digital beam forming method in the fields of radar, radio astronomy, sonar, communication, navigation, direction finding, seismology, medical diagnosis and treatment, which needs signal separation and precise phase control application. In particular to a digital beam forming and phase fitting method of an antenna array steering vector model.
Background
Array signal processing techniques have been widely used in many signal processing systems over the last several decades. It is composed of a plurality of sensors arranged at different positions in space to form a sensor array, and the sensor array is used to receive space signals and then perform specific processing on the received signals, so as to enhance interesting useful signals, suppress useless interference and noise or uninteresting information, extract useful signal characteristics and interpret the information contained in the signals. The array antenna is an important means for improving the anti-interference performance and the survival performance of the signal receiving system. In practical application, error factors such as position errors of array elements, amplitude-phase inconsistency of channels, mutual coupling effect of the array elements and the like exist in a sensor and an electronic circuit, so that actual array steering vectors are inconsistent with ideal array steering vectors, the performance of beam forming processing is seriously influenced, and in the worst case, nulls are formed in the direction of expected signals, namely, the expected signals are mistakenly taken as interference signals and are greatly restrained.
Aiming at array error factors such as array element errors, channel consistency, array element mutual coupling and the like, experts and scholars at home and abroad make a great deal of research, which can be mainly divided into the following two research directions: an array correction method and a robust adaptive beamforming algorithm. The array correction method mainly obtains array errors through a known source signal or an array self-correction method, and then corrects the antenna array according to the obtained array errors. This approach may improve the performance of the system to some extent, but after all it is not a real-time correction and eventually fails as the antenna array changes over time. The robust adaptive beam forming algorithm is insensitive to errors in the array system, and a better system output signal-to-interference-and-noise ratio can be obtained even if the antenna array errors exist. However, the robust adaptive beamforming algorithm cannot control the phase response of the beamformed signal, making it unusable in phase critical applications.
A multi-channel array signal processing system for receiving a navigation satellite signal by an antenna array is a multi-channel array signal processing system for improving the signal-to-noise ratio and the anti-interference capability of the navigation satellite signal by means of space-time domain filtering. The conventional processing method mainly adopts a conventional beam forming method. For a limited array aperture, the resolving power of conventional beamforming is limited by the rayleigh limit: that is, for a certain array of finite elements, the minimum beam width is constant, and when multiple signals are in the same beam width, conventional beamforming cannot resolve the signals. When the interference and the signal are within the same beam width in the incident direction of the space, the signal cannot be received. The adaptive beam forming technology in the array signal processing can break through the limitation of Rayleigh limit, realize effective inhibition to interference signals and effectively improve the signal-to-interference-and-noise ratio of the signals. The basic principle of the method is that the weight design of synthesizing multi-channel data into one path of data is described as an optimization problem, the energy of the synthesized signal is minimized, and the self-adaptive attenuation of an interference signal is realized. Different places are constraints of the optimization problem, such as Minimum Variance Distortion-free Response (MVDR), which constrains the signal passing in the signal incidence direction without Distortion, Linear Constrained Minimum Variance (LCMV) which adds a set of Linear Response constraints, and Power Inversion (PI), which simply minimizes the output Power after beamforming. Unlike robust adaptive beamforming algorithms, these adaptive algorithms require accurate array steering vectors in order to obtain optimal weight vectors. The navigation satellite signal has the characteristics that the power reaching the antenna is lower than the thermal noise power, the phase information is closely related to the position relation, and the like, the non-omnidirectional characteristic of the antenna and the inconsistency of the channels can cause damage to the phase information of the navigation satellite signal, and the inaccurate antenna array response vector can cause that the optimal weight vector and the signal-to-noise ratio cannot be obtained; on the other hand, it is more serious that the differential satellite navigation relative positioning algorithm based on the carrier phase measurement is disabled. At present, an antenna array receiving and processing system based on traditional self-adaptive beam forming can obtain certain anti-interference capacity, but the relative phase relation of a navigation satellite signal reaching an antenna is damaged, so that landing/carrier landing/battle guidance application with high-precision relative positioning requirements cannot benefit.
When the array beam forming algorithm is realized, the real-time estimation of the covariance matrix of the second-order statistics of the array signals and the inverse matrix of the covariance matrix is involved, and when the number of channels is large and the signal bandwidth is large, the real-time processing capability of a digital processing module is greatly required. The conventional method adopts block processing, and transmits a block of continuous sampling data to a microprocessor for covariance matrix calculation and inversion, so that the real-time performance of array processing is reduced, and the weight vector formed by beam forming cannot be rapidly converged to the optimal weight vector.
Disclosure of Invention
The invention aims at the defects in the prior art and provides a digital beam forming and phase fitting method of an antenna array steering vector model, which can inhibit interference, improve the signal-to-interference-and-noise ratio, accurately control the phase of a beam forming signal, improve the real-time performance of an array processing system and realize the stability of an equivalent phase center of an antenna array.
The above object of the present invention can be achieved by a digital beamforming phase fitting method, characterized by comprising the steps of: in a multi-channel array signal processing beam forming system, a guide vector model is constructed by utilizing a polynomial or spherical harmonic series expansion theory, the guide vector model utilizes a relative guide vector obtained by online calibration, an accurate and absolute array guide vector is obtained by combining absolute phase response measured by a reference array element darkroom, and model parameters of the guide vector are fitted by combining the existing absolute guide vector, so that a standby accurate guide vector of an antenna array in any incident direction of space is obtained. The array signal statistic hardware calculation module calculates the inverse matrix of a sample covariance matrix of the current array signal in real time or equivalent array signal second-order statistic and sends the inverse matrix or equivalent array signal second-order statistic into the array signal processing algorithm module, and the array signal processing algorithm module extracts the absolute guide vector of the antenna array according to the relative position of the attitude of the target satellite and the incident direction of the received satellite signal, extracts channel response and calculates the optimal weight vector of the satellite signal in the incident direction; and finally, a beam forming algorithm module is adopted to place the beam weight into a digital beam forming module DBF for digital beam forming and phase fitting, and multi-channel array data and beam output are processed in real time.
Compared with the prior art, the invention has the following beneficial effects:
1. interference can be suppressed. The method comprises the steps of constructing a guide vector model by utilizing a polynomial or spherical harmonic series expansion theory, and calculating a guide vector of a signal direction by applying the model according to attitude input and estimation of the current satellite direction; the method comprises the steps of utilizing a relative guide vector obtained by online calibration, combining absolute phase response measured by a reference array element darkroom, combining to obtain an accurate absolute guide vector of an array, combining the existing absolute guide vector to fit a model parameter of the guide vector, obtaining the guide vector of an antenna array in any incident direction in space by means of a calibration technology, effectively calculating second-order statistical data of a current incident signal by an iterative calculation method, namely an inverse matrix of a covariance matrix or equivalent second-order statistics, adding a constraint that a phase center is unchanged, calculating an optimal weight, and setting the optimal weight to a hardware digital beam forming module to perform beam synthesis of the array signal; when a plurality of groups of guide vector models exist, the guide vector models are fused, interference is inhibited, the signal to interference noise ratio is improved, and the precise differential relative positioning and anti-interference target based on the navigation satellite signals is realized. The accurate guide vector of the current satellite target signal is obtained by using the guide vector model, and after channel response compensation, the phase of the signal after beam forming can be accurately controlled, so that the stability of the equivalent phase center of the antenna array is realized.
2. The signal-to-interference-and-noise ratio is improved, and the phase of a beam forming signal is accurately controlled. The invention obtains the incident direction of a target satellite signal according to the posture and the relative position relation, substitutes the incident direction into the model of the array guide vector, calculates the guide vector of the incident direction, is used for a beam forming algorithm after channel response compensation, the array signal statistical meter hardware calculation module provides the second order statistic of the array signal to the beam forming algorithm module in real time, the antenna guide vector model is constructed according to the channel response provided by calibration, the absolute antenna response of darkroom calibration and the relative antenna response of on-line calibration, the beam forming algorithm module provides the accurate guide vector required by the beam forming algorithm in real time, the phase response of a plurality of beams is maintained to be equal, the equivalent phase center of the antenna array is controlled to be stable, and the phase of the beam forming signal is accurately controlled while the signal-to-interference-noise ratio is improved.
3. The self-adaptive capacity of the array processing system is improved. When the beam forming algorithm is realized, a plurality of groups of antenna guide vector models are selectively used or fused for use, the method is suitable for application of various scenes, the second-order statistic of array signals is irrelevant to incident signals, the signal statistic information is calculated through the iterative algorithm, the operation of directly calculating the covariance matrix and the inversion of the covariance matrix is avoided, multiplexing can be performed during calculation of a plurality of beam weights, the partial calculation can be realized on hardware in real time, and the self-adaptive capacity of the array processing system is greatly improved.
4. The antenna array equivalent phase center is stable. According to the invention, the incident direction of the target satellite is obtained according to the satellite attitude and the relative position relationship, and then the incident direction is substituted into the model of the array steering vector, so that the beam forming algorithm module can calculate the steering vector of the incident direction, and after channel response compensation, the equivalent phase center stability of the antenna array is realized. And the usability of the carrier phase measurement after the navigation satellite signal is received and processed by the antenna array is ensured.
The antenna array steering vector model and the statistical data calculation method are particularly suitable for being applied to a navigation satellite signal antenna array receiving and processing system which needs precise relative application of carrier phase measurement and has strong anti-jamming capability and a high maneuvering carrier platform.
The invention can be applied to a system for receiving and processing navigation satellite signals by adopting an array, and is a beam forming method for inhibiting interference, improving the signal-to-interference-and-noise ratio and stabilizing the phase center of the array.
Drawings
Fig. 1 is a schematic diagram of a multi-channel array signal processing beamforming system.
Fig. 2 is a data processing flow diagram of beamforming and fine phase fitting of the antenna array steering vector model of fig. 1.
The invention is further illustrated in the following description with reference to the figures and examples, but the invention is not limited thereby within the scope of the examples described.
Detailed Description
See fig. 1. According to the invention, the digital beam forming and precise phase fitting of the antenna steering vector model are divided into a steering vector model, an array signal processing algorithm module, a digital beam forming module DBF and an array signal statistic hardware calculation module to form four mutually-crosslinked multi-channel array signal processing beam forming systems. In a multi-channel array signal processing beam forming system, a guide vector model module receives absolute reference antenna phase response and relative antenna guide vector training guide vector models, and an array signal processing algorithm module outputs satellite signal incidence directions to the guide vector models according to input multiple groups of array antenna attitudes and satellite signals to obtain corresponding satellite signal absolute guide vector outputs. And the array signal statistic hardware calculation module iteratively calculates the array signal statistic according to the input multi-channel array complex baseband signal. The array signal processing algorithm module combines the satellite signal direction absolute steering vector, the input channel response and the array signal statistics to calculate a plurality of groups of beam weights, and inputs the beam weights into the digital beam forming module DBF. And the digital beam forming module DBF carries out real-time beam synthesis on the input multi-channel array complex baseband signals to complete the output of a plurality of groups of beams.
In a multi-channel array signal processing beam forming system, a guide vector model is constructed by utilizing a polynomial or spherical harmonic series expansion theory, the guide vector model utilizes a relative guide vector obtained by online calibration, combines absolute phase response measured by a reference array element darkroom with an accurate absolute guide vector of an array, combines the existing absolute guide vectors to fit a model parameter of the guide vector, and accordingly obtains a standby accurate guide vector of an antenna array in any incident direction of a space. Calculating an inverse matrix or equivalent second-order statistic of a covariance matrix of the current array signal in real time by adopting an array signal statistic hardware calculation module; sending array signal second-order statistics to a digital beam forming module DBF through an array signal statistics hardware calculation module, extracting a guide vector of an antenna array and an inverse covariance matrix of a current array signal of the array signal statistics hardware calculation module according to a multi-path beam weight output by an array antenna attitude and a satellite number of an algorithm module at the array signal and a satellite signal received by a target satellite attitude relative position and an incidence direction by the digital beam forming module DBF, extracting a channel response, and calculating an optimal weight vector of the satellite signal in the incidence direction; and finally, the beam weight is placed into a digital beam forming module DBF by adopting a beam forming algorithm module to form digital beams, and the multi-channel array data and beam output are processed in real time. The specific processing manner and principle of each module are described in detail below.
1. The method comprises the steps of establishing a response model of an array to incident signals in an antenna guide vector model, when the response model is established, firstly establishing an antenna coordinate system, a reference array element located at the origin of coordinates, and the central frequency and normal incident signals of the reference array element, normalizing to unit gain and zero phase by taking the response of the central frequency and normal incident signals as the reference of the whole array guide vector model, receiving signals incident in the directions of a specific azimuth angle theta and a specific pitch angle phi in the antenna coordinate system by an antenna array, and obtaining vectors formed by the amplitude and phase gain of each array element, namely the array guide vector model. Wherein the steering vector model can be mathematically expressed as:
in the formula, ai(theta, phi) is the amplitude gain of the ith array element in the signal direction,
the phase gain of the ith array element in the signal direction is shown, and N is the number of the array elements. Assuming that the array element 1 is a reference array element, in the present invention, the input of the steering vector model is the absolute phase response ψ of the array element 11(theta, phi) (without loss of generality, array element 1 is chosen as the reference array element here), and a partial relative steering vector ar(θi,φi)：
In the formula
Representing the set of incident directions of all relative steering vectors.
The steering vector is divided into an absolute phase response directional diagram of a reference array element and a relative steering vector of the array, wherein the absolute phase response directional diagram of the reference array element is measured in a darkroom, and the relative array steering vector can be measured in the darkroom or in an open environment. The latter can be carried out periodically in a working environment, and the processing method solves the problems that the integral correction data obtained by the traditional array correction method in a darkroom does not conform to the actual environment and fails along with the change of time.
In order to obtain the guide vector of any incident direction from a group of discrete guide vector measurement values, the invention adopts a series expansion theory, such as polynomial or spherical harmonic series expansion, and the like, to construct a complete array guide vector model.
Polynomial representation the array steering vector model represented as a polynomial representation is represented as:
where g (θ, φ) represents the amplitude phase response of a single array element to a signal of a particular incident direction, αikThe model coefficient is an array steering vector representation under a polynomial model, when the coefficient is known, the array steering vector in any direction can be calculated according to the model, theta and phi respectively represent a pitch angle and an azimuth angle of an incident signal, and m is the order of the polynomial model.
The guiding vector model using spherical harmonics is:
where g (theta, phi) represents the amplitude phase response of a single array element to a signal of a particular direction of incidence,
is a model coefficient, is an array guide vector representation under a spherical harmonic series expansion model,
the order of the spherical harmonic function is represented by l and m, which are the integral orthogonal spherical harmonic functions on the unit circle, and when the coefficient is known, the array steering vector in any direction can be calculated according to the model. When the incident angle parameters theta and phi are given, the function value of any order can be calculated according to the spherical harmonic function definition in the complex function theory
In order to train and obtain a steering vector model of the array antenna, a relative steering vector set obtained by a navigation satellite array antenna receiving system through calibration or darkroom measurement can be used
In the incident direction of (1) to (m) in order, according to
The value g (theta) of the middle relative steering vectori,φi) I 1, …, m, the following system of linear equations is constructed:
with the aid of the least squares method, the estimated steering vector model coefficients are:
in the formula, + represents a pseudo-inverse, and T represents a matrix transpose. The fitting principle of the guide vector model based on the spherical harmonic function is completely the same.
With the model coefficient, the incident direction angle theta and phi of the appointed satellite is provided according to the signal incident direction input of the array signal processing algorithm module, and the corresponding absolute steering vector can be calculated. During implementation, grid point data of two dimensions of azimuth and pitch angles in all possible incident directions in a three-dimensional space are calculated according to the above embodiment, a guide vector model table is made, and when a guide vector of a specific satellite signal incident direction angle theta and phi in a specific antenna attitude is extracted, the guide vector can be obtained by linear interpolation according to the guide vector near the incident direction, so that the implementation real-time performance is improved.
The relative guide vector sets obtained by the navigation satellite array antenna receiving system through calibration or darkroom measurement in different scenes are different, and different guide vector models can be trained by the guide vector model module. In different steering vector models, the navigation satellite array antenna receiving system can select one of the different steering vector models to use or fuse different model weights together according to a scene. Under the same scene, by saving the vector, the invention supports retraining the whole model when adding new measurement.
2. The array signal statistic hardware calculation module is the second core part of the invention and is the key for improving the real-time performance of the digital beam forming adaptive processing. The array signal sample covariance matrix is a good estimation of the second-order statistics of the array signal, and the adaptive capacity of the array processing is derived from the real-time covariance estimation. In order to avoid direct calculation of covariance matrix and inversion of covariance matrix, the invention provides two methods to calculate second-order statistics of array signals for use by an array processing algorithm part:
the first is a calculation method suitable for microprocessor hardware, which includes counting a matrix p (k) as first intermediate variable data and calculating a vector g (k) as second intermediate variable data:
in the formula (I), the compound is shown in the specification,Hthe method comprises the steps of representing the conjugate transposition of a complex vector or a matrix, wherein X (K) is array sampling complex baseband sampling data at the moment K, mu is a forgetting factor, and 0 & ltmu & lt 1, wherein the vector g (K) and the matrix P (K) are both intermediate variables containing incident signal statistical information, and are used for a beam forming algorithm to update an optimal weight vector.
The second method is a calculation method suitable for realizing field programmable gate array FPGA, and the inverse matrix R of the covariance matrix of the array signal is calculated in an iterative way according to the following formulainv(K)：
Wherein b is (1-mu)/mu, mu is a forgetting factor, and R isinv(K) An inverse of the sample covariance matrix for the beamforming algorithm to compute the optimal weight vector.
3. The array signal processing algorithm module is a third part, and calculates the optimal weight vector formed by the digital beam according to the steering vector and the array signal statistic provided by the first two parts and the incident direction of the satellite signal under the antenna attitude provided by the outside (such as inertial navigation).
When the array signal statistics is vector g (K) and matrix P (K), the optimal weight vector calculation formula corresponding to the satellite m is iteratively updated by:
in the formula, a is a steering vector corresponding to the satellite m calculated by the steering vector model, h is a channel response vector, x is an operation of multiplying corresponding elements, and w' (K) is an optimal beam weight vector corresponding to the moment K. The last step in the above equation is the key to keep the phase center of the signal unchanged after array processing.
When the array signal statistic is Rinv(K) And then, iteratively updating an optimal weight vector calculation formula corresponding to the satellite m:
wherein the variables are defined as in the first method.
4. The fourth part is a beam forming module, each beam has corresponding optimal weight input, and the input array digital signals are weighted and synthesized according to the weight:
yi,n＝wi(K)HX(n), (14)
in the formula, yi,nDigital beam-forming output at time n, w, for the ith beami(K) For the optimal weight of the ith beam updated K times, x (n) is the array sample at time n, where K is not necessarily equal to n, and the update rate of the weight vector is usually lower than the digital sampling rate of the array signal.
See fig. 2. In the data processing flow, the processing procedures of all the steps from top to bottom correspond to the processing procedures in the above sub-module description one by one.
The first step is in the calibration data fitting steering vector model, the calibration data are absolute reference antenna phase response directional diagram and relative antenna steering vector, and the fitting method is the processing of the antenna steering vector model part in fig. 1.
And secondly, extracting the azimuth angle and the pitch angle of the satellite signal incidence direction under the current array antenna attitude through input data (such as an inertial navigation module) of an external module.
And thirdly, calculating a signal guide vector by the guide vector model module according to the guide vector model and the incidence direction, substituting the azimuth angle and the pitch angle of the satellite signal extracted by the calibration data fitting guide vector model under the current posture into a polynomial model or a spherical harmonic model of the guide vector model in the figure 1, or interpolating in a grid point data table of the guide vector model according to nearby values, and calculating the incidence guide vector of the satellite signal.
And the fourth step, namely calculating a real guide vector according to the channel response by the array signal processing algorithm module, performing the first step of equations (12) and (13), and multiplying the guide vector obtained by calculation of the guide vector model by the channel response vector.
The fifth step, the array signal processing algorithm module iteratively calculates a weight vector corresponding to the current satellite signal by combining the array signal statistical intermediate variable, which is part 3 in fig. 1.
And a sixth step of phase center stable compensation, which is the last step in the formulas (12) and (X13), wherein the accurate guide vector of the current satellite target signal is obtained by using a guide vector model, the phase of the weight vector is corrected to compensate the channel response according to the guide vector and the weight vector, the phase of the signal after beam forming is accurately controlled, the stability of the equivalent phase center of the antenna array is realized, and the phase of the weight vector is corrected according to the guide vector and the weight vector.
The seventh step, the array signal processing algorithm module puts the beam weights into the digital beam forming module for beam forming, which is part 4 of fig. 1, and enters the next update period, and so on.
Claims (10)
1. A method of digital beamforming phase fitting, comprising the steps of: in a multi-channel array signal processing beam forming system, a guide vector model is constructed by utilizing a polynomial or spherical harmonic series expansion theory, the guide vector model utilizes a relative guide vector obtained by online calibration, an accurate absolute array guide vector is obtained by combining absolute phase response measured by a reference array element darkroom, and the model parameters of the guide vector are fitted by combining the existing absolute guide vector so as to obtain a standby accurate guide vector of an antenna array in any incident direction; the array signal statistic hardware calculation module calculates the inverse matrix of a sample covariance matrix of the current array signal in real time or equivalent array signal second-order statistic and sends the inverse matrix or equivalent array signal second-order statistic into the array signal processing algorithm module, and the array signal processing algorithm module extracts the absolute guide vector of the antenna array according to the relative position of the attitude of the target satellite and the incident direction of the received satellite signal, extracts channel response and calculates the optimal weight vector of the satellite signal in the incident direction; and finally, a beam forming algorithm module is adopted to place the beam weight into a digital beam forming module DBF for digital beam forming and phase fitting, and multi-channel array data and beam output are processed in real time.
2. The digital beamforming phase fitting method of claim 1, wherein: the antenna steering vector model is divided into a steering vector model, an array signal processing algorithm module, a digital beam forming module DBF and an array signal statistic hardware calculation module through digital beam forming and precise phase fitting, so that four mutually-crosslinked multi-channel array signal processing beam forming systems are formed.
3. The digital beamforming phase fitting method of claim 2, wherein: in a multi-channel array signal processing beam forming system, a steering vector model module receives absolute reference antenna phase response and relative antenna steering vector training steering vector models; and the array signal processing algorithm module outputs a pitch angle and an azimuth angle corresponding to the incident direction of the satellite signal to the steering vector model according to the input multiple groups of array antenna attitudes and satellite numbers to obtain corresponding satellite signal absolute steering vector output.
4. The digital beamforming phase fitting method of claim 2, wherein: the array signal statistics hardware calculation module iteratively calculates array signal statistics according to an input multi-channel array complex baseband signal of a multi-channel array signal processing beam forming system after a preceding stage AD sampling digital signal enters a digital down-conversion DDC, the array signal processing algorithm module calculates a plurality of groups of beam weights by combining a satellite signal direction absolute steering vector, an input channel response and the array signal statistics, the beam weights are input into a digital beam forming module DBF, and the digital beam forming module DBF carries out real-time beam synthesis on the multi-channel array complex baseband signal input by the preceding stage to complete multi-group beam output.
5. The digital beamforming phase fitting method of claim 1, wherein: establishing a guide vector model of the array to incident signals in an antenna guide vector model module, and when establishing the guide vector model, firstly establishing an antenna coordinate system, a reference array element positioned at a coordinate origin, and a central frequency and a normal incident signal of the reference array element, and normalizing the central frequency and the normal incident signal as a reference of the whole array guide vector model to unity gain and zero phase; after signals incident in a specific azimuth angle and a pitch angle direction under an antenna coordinate system are received by the antenna array, a vector formed by the amplitude and phase gain of each array element is an array steering vector.
6. The digital beamforming phase fitting method of claim 1, wherein: the guide vector model module divides the guide vector into an absolute phase response directional diagram of the reference array element and a relative guide vector of the array, wherein the absolute phase response directional diagram of the reference array element is measured in a darkroom, and the relative array guide vector is measured in the darkroom or in an open environment.
7. The digital beamforming phase fitting method of claim 1, wherein: and the array signal processing algorithm module calculates the optimal weight vector formed by the digital wave beam according to the guiding vector, the array signal statistic and the incident direction of the satellite signal under the antenna attitude provided by external inertial navigation.
8. The digital beamforming phase fitting method of claim 1, wherein: the guide vector model module calculates an array guide vector of the satellite signal according to the guide vector model obtained by training and the incidence direction of the navigation satellite signal input by the array signal processing algorithm module; specifically, the array signal processing algorithm module extracts an azimuth angle and a pitch angle of the satellite signal under the current attitude, and brings the azimuth angle and the pitch angle into a polynomial model or a spherical harmonic model in a steering vector model to calculate an array steering vector of the satellite signal, or brings the azimuth angle and the pitch angle of the satellite signal into a steering vector table pre-calculated according to the steering vector model, and obtains the array steering vector of the satellite signal according to the array steering vector interpolation near the satellite signal incidence direction.
9. The digital beamforming phase fitting method of claim 1, wherein: and the array signal processing algorithm module calculates a real guide vector according to the channel response, and multiplies the guide vector calculated by the guide vector model by the channel response vector.
10. The digital beamforming phase fitting method of claim 1, wherein: the steering vector model obtains an accurate steering vector of the current target satellite signal, corrects the phase of the weight vector according to the steering vector and the weight vector, compensates the phase error introduced by a channel response and array processing algorithm, accurately controls the phase of the signal after beam forming, and realizes the stability of the equivalent phase center of the antenna array.
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| CN109283555A (en) * | 2018-09-28 | 2019-01-29 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | A Method of Suppressing Interference by Satellite Beamforming |
| CN109507698B (en) * | 2018-09-28 | 2022-07-08 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Automatic correction system for anti-interference guide vector of satellite navigation |
| CN109239741B (en) * | 2018-09-30 | 2023-03-28 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Automatic calibration test system for multi-array element antenna of navigation satellite |
| CN109633692B (en) * | 2018-11-26 | 2022-07-08 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | GNSS navigation satellite signal anti-interference processing method |
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| CN111817766B (en) * | 2020-06-29 | 2023-05-26 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Beam forming method of combined array antenna unit directional diagram |
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