Electromagnetic signal parameter estimation system and method based on vector antenna

Abstract

The invention discloses an electromagnetic signal parameter estimation system and method based on a vector antenna. The electromagnetic signal parameter estimation system based on the vector antenna comprises the vector antenna, a radio frequency unit, a signal preprocessing unit, a data storage unit, a correlation matching unit and a data processing unit, the vector antenna receives incident electromagnetic waves, converts the incident electromagnetic waves into radio-frequency signals and outputs the radio-frequency signals; and the radio frequency unit is electrically connected with the feed output end of the vector antenna and is used for processing the received radio frequency signal according to a preset radio frequency processing step so as to obtain an analog signal. The electromagnetic signal parameter estimation system and method based on the vector antenna, disclosed by the invention, have the beneficial effects that space, time, frequency and polarization domain joint estimation is realized based on the vector antenna, the system architecture is simplified, the method is clear, and the system and method are particularly suitable for the fields of frequency spectrum monitoring and signal direction finding.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic signal parameter estimation, specifically relating to an electromagnetic signal parameter estimation system based on a vector antenna and an electromagnetic signal parameter estimation method based on a vector antenna. Background Technology

[0002] A vector antenna is a device capable of receiving electric field vectors and / or magnetic field vectors. A classic co-located vector antenna can receive the field components of incident electromagnetic waves in six dimensions (defined as Ex, Ey, Ez, Hx, Hy, and Hz in Cartesian coordinates). The increased degrees of freedom in vector antenna measurement make joint detection in the space-time-frequency-polarization domain possible, providing support for accurate estimation of signal parameters (not limited to angle of arrival estimation, but also including polarization parameter estimation, etc.).

[0003] In the existing technology, the use of vector antennas for multidimensional signal parameter estimation has the following main characteristics.

[0004] 1. Polarization-spatial domain coherent reception of signals forms an effective aperture, which has a certain resistance to multipath propagation.

[0005] 2. It can realize three-dimensional spatial grating-free beamforming.

[0006] 3. Parameters can be extracted simultaneously in the polarization and spatial domains. By making reasonable use of their statistical properties, the robustness of parameter extraction can be improved.

[0007] In other words, related research mainly focuses on theoretical fields and sensor design. In practical applications, further improvements are needed on how to build a reasonable and efficient system based on vector antennas, and what methods can be used to conveniently estimate signal parameters. Summary of the Invention

[0008] In view of the current situation of the prior art and to overcome the above-mentioned defects, the present invention provides an electromagnetic signal parameter estimation system and a method for electromagnetic signal parameter estimation based on a vector antenna.

[0009] This invention employs the following technical solution: an electromagnetic signal parameter estimation system based on a vector antenna, comprising a vector antenna, a radio frequency unit, a signal preprocessing unit, a data storage unit, a correlation matching unit, and a data processing unit, wherein:

[0010] A vector antenna receives incident electromagnetic waves and converts them into radio frequency signals for output.

[0011] The radio frequency unit is electrically connected to the feed output terminal of the vector antenna and processes the received radio frequency signal according to preset radio frequency processing steps to obtain an analog signal.

[0012] The signal preprocessing unit processes the digitized time series signal according to a preset steering vector solution step to obtain the receiving steering vector X;

[0013] Data storage unit, storing the reference dataset REF;

[0014] The relevant matching unit sequentially compares the receive steering vector X, which serves as the measurement result, with the reference data table DS. i And calculate the matching degree BF. i Preliminary matching result CS is generated based on threshold conditions. i ;

[0015] The data processing unit processes the initial matching results CS. i Further filtering and selection are performed to generate the final result.

[0016] As a preferred technical solution to the above technical solutions, the signal preprocessing unit includes a digital sampling subunit, a preliminary processing subunit, and a steering vector solving subunit. The digital sampling subunit receives the analog signal transmitted by the radio frequency unit and processes it to obtain a digital signal. The preliminary processing subunit receives the digital signal transmitted by the digital sampling subunit and processes it to obtain a digital time series signal. The steering vector solving subunit receives the digital time series signal transmitted by the preliminary processing subunit and processes it to obtain a receiving steering vector X.

[0017] As a preferred technical solution to the above technical solutions, refer to data table DS i Including address index S i and reference guide vector A i Address index S i Let it be S i =[φ i θ i γ i η i f i ], φ i θ represents the incident azimuth angle. i Represents the incident elevation angle, γ i Represents the polarization auxiliary angle, η i f represents the polarization phase difference. i Represents frequency; reference steering vector A i Let it be A i =[E xi E yi E zi H xi H yi H zi ], representing the response values ​​of the vector antenna in the three dimensions of electric and magnetic fields when receiving electromagnetic waves; all reference data tables DS iThe set is defined as the reference dataset REF, denoted as REF = {DS} i}={[S i A i ]}.

[0018] As a preferred technical solution to the above technical solutions, the relevant matching unit includes a data table traversal subunit, a matching degree calculation subunit, a threshold setting subunit, and a matching analysis subunit; the data table traversal subunit receives the reference dataset REF transmitted by the data storage unit and generates a corresponding strategy; the matching degree calculation subunit receives the receiving guide vector X transmitted by the guide vector solving subunit and the reference data table DS transmitted by the data table traversal subunit. ii To calculate and generate the receiving guidance vector X and the reference data table DS i Matching degree BF i The threshold setting subunit generates the threshold condition TH; the matching analysis subunit receives the matching degree BF transmitted by the matching degree calculation subunit. i and address index S i It also receives the threshold condition TH passed by the threshold setting subunit to compare and generate a preliminary matching result CS. i .

[0019] As a preferred embodiment of the above technical solutions, the data processing unit includes an interferometric estimation subunit, a repeated measurement decision subunit, and a statistical output subunit; the interferometric estimation subunit receives the preliminary matching result CS transmitted by the matching analysis subunit. i Based on the preliminary matching results CS i The polarization prior information, for the preliminary matching result CS i Filtering is performed to obtain a filtering result; if no filtering result is generated in this filtering, the repeated measurement decision subunit repeats the measurement in one or more additional time periods; if a filtering result is generated after the repeated measurement decision subunit makes a decision, the statistical output subunit receives the filtering result transmitted by the repeated measurement decision subunit, evaluates the stability of the multiple filtering results, and generates the final result.

[0020] This invention employs the following technical solution: an electromagnetic signal parameter estimation method based on a vector antenna, comprising the following steps:

[0021] S1: Receive the incident electromagnetic wave signal, preprocess it, and characterize the receiving steering vector X in a parameterized manner; S2: Transmit a reference signal and obtain the reference steering vector A. i Generate a reference dataset REF;

[0022] S3: Match degree calculation, generating preliminary matching results CS i ;

[0023] S4: Analyze the initial matching results (CS) i After screening and filtering, evaluation, and fusion, the final result is generated.

[0024] As the preferred technical solution above, step S1 is specifically implemented as follows:

[0025] S11: Acquire digitized time series signals;

[0026] S12: Perform frequency domain conversion on the digitized time series signal;

[0027] S13: Calculate the covariance matrix and extract eigenvalues;

[0028] S14: Normalize the data and obtain the receiving guide vector X.

[0029] As the preferred technical solution above, step S2 is specifically implemented as follows:

[0030] S21: Construct a reference signal;

[0031] S22: Obtain the reference dataset DS i .

[0032] As the preferred technical solution above, step S3 is specifically implemented as follows:

[0033] S31: Use a strategy to traverse the reference data table DS i ;

[0034] S32: Calculate the receiving guidance vector X and the reference guidance vector A i Matching degree BF i ;

[0035] S33: Set threshold condition TH;

[0036] S34: Generate preliminary matching results CS i .

[0037] As the preferred technical solution above, step S4 is specifically implemented as follows:

[0038] S41: Polarization filtration;

[0039] S42: Evaluate the validity of this measurement and adopt appropriate strategies;

[0040] S43: Statistical fusion, submit the final results.

[0041] The electromagnetic signal parameter estimation system and method based on vector antenna disclosed in this invention have the following advantages:

[0042] 1. Based on vector antennas, it realizes joint estimation of space, time, frequency and polarization domains. The system architecture is simplified and the method is clear, making it particularly suitable for spectrum monitoring and signal direction finding.

[0043] 2. By introducing steps such as polarization filtering, the confidence level of signal parameter extraction is guaranteed, and it has certain anti-interference and multipath performance.

[0044] 3. It can simultaneously estimate parameters such as the angle of arrival, polarization parameters, and frequency of the incident electromagnetic wave. Attached Figure Description

[0045] Figure 1 This is a block diagram of the electromagnetic signal parameter estimation system based on a vector antenna according to the present invention.

[0046] Figure 2 This is a schematic diagram of the signal receiving model of the co-located six-dimensional vector antenna of the present invention.

[0047] Figure 2 In the diagram, the red lines represent the components of the electric and magnetic fields along the X-axis; the green lines represent the components of the electric and magnetic fields along the Y-axis; and the blue lines represent the components of the electric and magnetic fields along the Z-axis.

[0048] Figure 3 This is a flowchart of the electromagnetic signal parameter estimation method based on a vector antenna according to the present invention.

[0049] The reference numerals in the attached figures include: 11-Vector antenna; 12-RF unit; 13-Signal preprocessing unit; 131-Digital sampling subunit; 132-Preliminary processing subunit; 133-Guided vector solution subunit; 14-Data storage unit; 15-Correlation matching unit; 151-Data table traversal subunit; 152-Matching degree calculation subunit; 153-Threshold setting subunit; 154-Matching analysis subunit; 16-Data processing unit; 161-Interference estimation subunit; 162-Repeated measurement decision subunit; 163-Statistical output subunit. Detailed Implementation

[0050] This invention discloses an electromagnetic signal parameter estimation system and a method based on a vector antenna. The following description, in conjunction with a preferred embodiment (Embodiment 1), is shown in the accompanying drawings. Figures 1 to 3 The specific embodiments of the present invention will be further described below.

[0051] Example 1.

[0052] Preferably, the electromagnetic signal parameter estimation system based on a vector antenna includes a vector antenna 11, a radio frequency unit 12, a signal preprocessing unit 13, a data storage unit 14, a correlation matching unit 15, and a data processing unit 16, wherein:

[0053] Vector antenna 11 receives incident electromagnetic waves and converts them into radio frequency signals for output.

[0054] The radio frequency unit 12 is electrically connected to the feed output terminal of the vector antenna 11, and processes the received radio frequency signal according to the preset radio frequency processing steps to obtain an analog signal.

[0055] The signal preprocessing unit 13 processes the digitized time series signal according to the preset steering vector solution steps to obtain the receiving steering vector X;

[0056] Data storage unit 14 stores the reference dataset REF;

[0057] The relevant matching unit 15 sequentially compares the receiving guide vector X, which serves as the measurement result, with the reference data table DS. i And calculate the matching degree BF. i Preliminary matching result CS is generated based on threshold conditions. i ;

[0058] Data processing unit 16 processes the preliminary matching results CS i Further filtering and selection are performed to generate the final result.

[0059] The signal preprocessing unit 13 includes a digitization sampling subunit 131, a preliminary processing subunit 132, and a steering vector solving subunit 133. The digitization sampling subunit 131 receives the analog signal transmitted by the radio frequency unit 12 and processes it to obtain a digital signal. The preliminary processing subunit 132 receives the digital signal transmitted by the digitization sampling subunit 131 and processes it to obtain a digitized time series signal. The steering vector solving subunit 133 receives the digitized time series signal transmitted by the preliminary processing subunit 132 and processes it to obtain a receiving steering vector X.

[0060] Among them, reference data table DS i Including address index S i and reference guide vector A i Address index S i Let it be S i =[φ i θ i γ i η i f i ], φ i θ represents the incident azimuth angle. i Represents the incident elevation angle, γ i Represents the polarization auxiliary angle, η i f represents the polarization phase difference. i Represents frequency; reference steering vector A i Let it be A i=[E xi E yi E zi H xi H yi H zi ], representing the response values ​​of the vector antenna in the three dimensions of electric and magnetic fields when receiving electromagnetic waves; all reference data tables DS i The set is defined as the reference dataset REF, denoted as REF = {DS} i}={[S i A i ]}.

[0061] The relevant matching unit 15 includes a data table traversal subunit 151, a matching degree calculation subunit 152, a threshold setting subunit 153, and a matching analysis subunit 154. The data table traversal subunit 151 receives the reference dataset REF transmitted by the data storage unit 14 and generates a corresponding strategy. The matching degree calculation subunit 152 receives the receiving guide vector X transmitted by the guide vector solving subunit 133 and the reference data table DS transmitted by the data table traversal subunit 151. ii To calculate and generate the receiving guidance vector X and the reference data table DS i Matching degree BF i The threshold setting subunit 153 generates a (suitable) threshold condition TH, the specific method of which will be described in detail later; the matching analysis subunit 154 receives the matching degree BF transmitted by the matching degree calculation subunit 152. i and address index S i It also receives the threshold condition TH passed by the threshold setting subunit 153 to compare and generate a preliminary matching result CS. i .

[0062] The data processing unit 16 includes an interferometric estimation subunit 161, a repeated measurement decision subunit 162, and a statistical output subunit 163; the interferometric estimation subunit 161 receives the preliminary matching result CS transmitted by the matching analysis subunit 154. i Based on the preliminary matching results CS i The polarization prior information, for the preliminary matching result CS i Filtering is performed to (potentially) obtain a filtering result. If no filtering result is generated for this filtering (measurement), it means that the filtering (measurement) process did not achieve the expected result. The repeated measurement decision subunit 162 repeats the measurement over one or more additional time periods to minimize the impact of multipath / electromagnetic interference. If a filtering result is generated after the repeated measurement decision subunit 162 makes its decision, the statistical output subunit 163 receives the filtering result transmitted by the repeated measurement decision subunit 162, evaluates the stability of the multiple filtering results, and generates the final result.

[0063] The working principle of the electromagnetic signal parameter estimation system based on a vector antenna disclosed in this embodiment is explained below.

[0064] Specifically, the electromagnetic signal parameter estimation system based on a vector antenna includes a vector antenna 11, a radio frequency unit 12, a signal preprocessing unit 13, a data storage unit 14, a correlation matching unit 15, and a data processing unit 16.

[0065] Vector antenna 11 receives the field components (E) of the incident electromagnetic wave in six dimensions. x E y E z H x H y H z ), and convert it into a radio frequency signal output.

[0066] The radio frequency unit 12 is electrically connected to the feed output terminal of the vector antenna 11. It processes the received radio frequency signal according to preset radio frequency processing steps to obtain an analog signal. The preset radio frequency processing steps include, but are not limited to, gain control steps, path selection steps, filtering steps, notch filtering steps, and frequency conversion steps. In this way, a distortion-free analog signal that is easy to digitize is obtained. The radio frequency unit 12 is well known to those skilled in the art, and will not be described in detail in this embodiment.

[0067] The signal preprocessing unit 13 performs digital sampling on the analog signal to obtain a digital signal, and processes the digital signal according to preset digital signal preliminary processing steps to obtain a digital time series signal. The preset digital signal preliminary processing steps include, but are not limited to, resampling steps, digital filtering steps, and digital down-conversion steps. The combination of the above steps may have subtle differences in specific applications.

[0068] The signal preprocessing unit 13 processes the digitized time series signal according to the preset steering vector solution steps to obtain the receiving steering vector X. The physical meaning of the receiving steering vector X is the array response of the vector antenna 11 to the incident signal. The preset steering vector solution steps include, but are not limited to, framing steps, short-time Fourier transform steps, and feature value extraction steps (the specific steps will be elaborated later).

[0069] For those skilled in the art, the combination of digital sampling and preliminary processing is a prerequisite for implementing various types of signal processing, and this embodiment is no exception.

[0070] The signal preprocessing unit 13 includes a digital sampling subunit 131, a preliminary processing subunit 132, and a guide vector solving subunit 133.

[0071] The digital sampling subunit 131 receives the analog signal transmitted by the radio frequency unit 12 and processes it to obtain a digital signal; the preliminary processing subunit 132 receives the digital signal transmitted by the digital sampling subunit 131 and processes it to obtain a digital time series signal; the steering vector solving subunit 133 receives the digital time series signal transmitted by the preliminary processing subunit 132 and processes it to obtain a receiving steering vector X.

[0072] Data storage unit 14 stores the reference dataset REF.

[0073] It should be noted that the array response and signal parameters of single-carrier signals with different azimuths, polarizations, and frequencies when they arrive at the vector antenna 11 are defined as those in the reference data table DS. i Reference data table DS i It consists of two parts. The first part is called the address index S. i denoted as S i =[φ i θ i γ i η i f i ], φ i θ represents the incident azimuth angle. i Represents the incident elevation angle, γ i Represents the polarization auxiliary angle, η i f represents the polarization phase difference. i The representative frequency; the second part is called the reference steering vector A. i , denoted as A i =[E xi E yi E zi H xi H yi H zi ], representing the response values ​​of the vector antenna in the electric and magnetic fields when receiving electromagnetic waves, respectively. All reference data sheets DS i The set is defined as the reference dataset REF, denoted as REF = {DS} i}={[S i A i ]}.

[0074] The relevant matching unit 15 sequentially compares the receiving guide vector X, which serves as the measurement result, with the reference data table DS. i And calculate the matching degree BF. i Preliminary matching result CS is generated based on threshold conditions. i .

[0075] It should be noted that, depending on the application, a global traversal or a local traversal search strategy can be adopted (e.g., only for a specified frequency range, specified polarization characteristics, etc.).

[0076] The relevant matching unit 15 includes a data table traversal subunit 151, a matching degree calculation subunit 152, a threshold setting subunit 153, and a matching analysis subunit 154.

[0077] The data table traversal subunit 151 receives the reference dataset REF passed by the data storage unit 14 and generates the corresponding strategy.

[0078] Matching degree calculation subunit 152 receives the received guide vector X transmitted by the guide vector solving subunit 133 and the reference data table DS transmitted by the data table traversal subunit 151. ii To calculate and generate the receiving guidance vector X and the reference data table DS i Matching degree BF i .

[0079] The threshold setting subunit 153 generates (suitable) threshold conditions TH, and the specific method will be explained in detail later.

[0080] Matching analysis subunit 154 receives the matching degree BF transmitted by matching degree calculation subunit 152. i and address index S i It also receives the threshold condition TH passed by the threshold setting subunit 153 to compare and generate a preliminary matching result CS. i .

[0081] It should be noted that the preliminary matching result CS i It's the match degree BF i The set of address indices that meet the threshold condition TH may contain more than one address index.

[0082] Data processing unit 16 processes the preliminary matching results CS i Further filtering and selection are performed to generate the final result.

[0083] The data processing unit 16 includes an interferometric estimation subunit 161, a repeated measurement decision subunit 162, and a statistical output subunit 163.

[0084] Interference estimation subunit 161 receives the preliminary matching result CS transmitted by matching analysis subunit 154. i Based on the preliminary matching results CS i The polarization prior information, for the preliminary matching result CS iFiltering is performed to (potentially) obtain a filtering result. If no filtering result is generated for this filtering (measurement), it means that the filtering (measurement) process did not achieve the expected result. The repeated measurement decision subunit 162 repeats the measurement in one or more additional time periods to minimize the impact of multipath and electromagnetic interference. If a filtering result is generated after the repeated measurement decision subunit 162 makes its decision, the statistical output subunit 163 receives the filtering result transmitted by the repeated measurement decision subunit 162, evaluates the stability of the multiple filtering results, and generates the final result.

[0085] It is worth mentioning that this embodiment is logically divided in the manner described above. However, in practical applications, the logical functions may be recombined (for example, the relevant matching unit 15 and the data processing unit 16 may be merged into the same hardware module entity), or they may be separated and run in different hardware entities (for example, the signal preprocessing unit 13 may be split into two independent hardware module entities).

[0086] When describing the function of the electromagnetic signal parameter estimation system based on vector antenna, for ease of understanding, some functional units (second level) such as the signal preprocessing unit 13 are decomposed into sub-units (third level) such as the digital sampling sub-unit 131, and their functions and roles are briefly described.

[0087] Example 2.

[0088] Preferably, the electromagnetic signal parameter estimation method based on a vector antenna includes the following steps:

[0089] S1: Receive the incident electromagnetic wave signal, preprocess it, and characterize the receiving steering vector X in a parameterized manner; S2: Transmit a reference signal and obtain the reference steering vector A. i Generate a reference dataset REF;

[0090] S3: Match degree calculation, generating preliminary matching results CS i ;

[0091] S4: Analyze the initial matching results (CS) i After screening and filtering, evaluation, and fusion, the final result is generated.

[0092] Specifically, step S1 is implemented as follows:

[0093] S11: Acquire digitized time series signals;

[0094] S12: Perform frequency domain conversion on the digitized time series signal;

[0095] S13: Calculate the covariance matrix and extract eigenvalues;

[0096] S14: Normalize the data and obtain the receiving guide vector X.

[0097] Specifically, step S2 is implemented as follows:

[0098] S21: Construct a reference signal;

[0099] S22: Obtain the reference dataset DS i .

[0100] Specifically, step S3 is implemented as follows:

[0101] S31: Use a strategy to traverse the reference data table DS i ;

[0102] S32: Calculate the receiving guidance vector X and the reference guidance vector A i Matching degree BF i ;

[0103] S33: Set threshold condition TH;

[0104] S34: Generate preliminary matching results CS i .

[0105] Specifically, step S4 is implemented as follows:

[0106] S41: Polarization filtration;

[0107] S42: Evaluate the validity of this measurement and adopt appropriate strategies;

[0108] S43: Statistical fusion, submit the final results.

[0109] The working principle of the electromagnetic signal parameter estimation method based on vector antenna disclosed in this embodiment is explained below.

[0110] First, we will briefly introduce the receiving model of the electromagnetic signal parameter estimation system based on vector antennas to help those skilled in the art to understand its principle more easily.

[0111] For a co-located six-dimensional vector antenna, its signal reception model is as follows: Figure 2 As shown, when a signal propagates in free space, the electric field, magnetic field, and wave vector are all orthogonal to each other. When the signal arrives at the co-located six-dimensional vector antenna, the projections of the electric field along the X, Y, and Z axes are converted into electrical signals and transmitted to the receiver processor.

[0112] Similarly, the projections of the magnetic field along the X, Y, and Z axes are converted into electrical signals and transmitted to the receiver processor. The received signals in the above six dimensions are called the receiving steering vector X, and the expression for the receiving steering vector X is shown in Equation (1). Here, φ and θ are the azimuth and elevation angles of the incident signal, respectively; γ and η are the polarization auxiliary angle and polarization phase difference of the incident signal, respectively. D is the correction matrix, which includes factors such as wave impedance, normalization, and mutual coupling, and can be obtained through simulation or measurement.

[0113]

[0114] Receive guide vector X and reference guide vector A i All follow Equation 1) and are 6-element vectors. The core idea of ​​this invention is to compare the receiving guidance vector X and the reference guidance vector A. i Relevance, A with the highest relevance i The corresponding address index S i This means that there is a high probability that the parameter is the incident electromagnetic wave.

[0115] like Figure 3 As shown, the electromagnetic signal parameter estimation method based on vector antennas includes the following steps.

[0116] S1: Receives the signal of the incident electromagnetic wave, preprocesses it, and characterizes the receive steering vector X (array response) in a (suitable) parameterized manner.

[0117] Furthermore, S1 can be decomposed into the following sub-steps.

[0118] S11: Acquire digitized time series signals.

[0119] Vector antenna 11 receives the field components (E) of the incident electromagnetic wave in six dimensions. x E y E z H x H y H z The analog signal is then converted into a radio frequency (RF) signal and output. Through the RF unit 12, a distortion-free analog signal suitable for digitization is obtained. The analog signal is then digitally sampled, and preliminary processing is performed on the digital signal to obtain a digitized time series signal, expressed as x(t) = [E]. x (t), E y (t), E z (t), H x (t), H y (t), H z (t)].

[0120] S12: Perform frequency domain conversion on the digitized time series signal.

[0121] Those skilled in the art will readily understand that frequency domain processing of digital signals is a common approach for feature analysis and parameter extraction, and that frequency domain analysis methods can be used to focus on the frequency components of the signal of interest.

[0122] Digital time series signals are time-domain representations of signals and require appropriate frequency-domain transformation. Combining N time series samples forms a time frame x. frame = [x(t0), x(t1), ..., x(t)] N-1 Performing a short-time Fourier transform on the time frame yields the frequency domain representation of the signal, x(w0), where w0 represents the frequency of interest. Furthermore, the frequency domain representation of multi-frame samples is actually related to the frequency w0 and the frame number fn, and can be written as x(w0). fn .

[0123] S13: Calculate the covariance matrix and extract eigenvalues.

[0124] For the frequency w0 of interest, the covariance matrix of the multi-frame samples can be solved according to equation (2).

[0125] Q = ∑ fn x(w0) fn ·x(w0) fn H (2);

[0126] After eigenvalue extraction, the unnormalized guide vector X′ is obtained according to equation (3).

[0127] X′=EigenVector(Q)| λmax (3);

[0128] S14: Normalize the data and obtain the receiving guide vector X.

[0129] The unnormalized steering vector X′ is normalized. Note that this value is a 6-element vector, representing the three dimensions of the electric field and the three dimensions of the magnetic field. During normalization, the measured values ​​of the electric field and magnetic field need to be normalized separately (the first three elements are grouped together for normalization; the last three elements are grouped together for normalization) to obtain the receiving steering vector X.

[0130] S2: Transmit a (suitable) reference signal to obtain the reference steering vector A. i Generate a reference dataset REF.

[0131] Furthermore, S2 can be decomposed into the following steps.

[0132] S21: Construct a reference signal.

[0133] The following three requirements must be met:

[0134] 1) The transmitted signal waveform should be a stable, narrowband, single-carrier signal. One possible waveform is a CW signal.

[0135] 2) The test needs to be conducted in an environment free from interference and multipath interference. One recommended testing environment is an anechoic chamber.

[0136] 2) The transmitted signal has five degrees of freedom: spatial characteristics (azimuth and elevation angles of the incident signal); polarization characteristics (polarization auxiliary angle and polarization phase difference of the incident signal); and frequency characteristics (carrier frequency of the incident signal). Each time a transmission occurs, these five parameters must be recorded as the address index S. i =[φ i θ i γ i η i f i ].

[0137] Optionally, if the polarization parameters are known a priori in certain applications, or if only a certain polarization (such as vertical polarization) is of interest, the parameter space can be compressed into three dimensions.

[0138] S22: Obtain the reference dataset DS i .

[0139] Similar to step S1, for each reference signal, a reference steering vector is obtained after receiving and processing, denoted as A. i .

[0140] Each reference signal corresponds to a reference data table DS i DS i =[S i A i The reference data table DS is obtained by traversing the spatial domain, polarization, and frequency of the reference signal. i Create a reference dataset, REF = {DS} i}

[0141] Reference dataset DS i Characterizing the ideal response of the reference signal in the five-dimensional parameter space is the basis for parameter solving.

[0142] Similarly, if the polarization parameters are known a priori in certain applications, or if only a certain polarization is of interest (such as vertical polarization), the parameter space can be compressed into three dimensions.

[0143] S3: Match degree calculation, generating preliminary matching results CS i .

[0144] Furthermore, S3 can be decomposed into the following sub-steps.

[0145] S31: Traverse the reference data table DS using a (suitable) strategy. i .

[0146] The most typical traversal strategy is to traverse the entire parameter space. However, in some applications, we may only be interested in signals in certain spatial domains or signals with certain polarizations. In these scenarios, we can set a local traversal strategy to improve search efficiency.

[0147] S32: Calculate the receiving guidance vector X and the reference guidance vector A i Matching degree BF i .

[0148] One of the most typical ways to calculate the matching degree is to calculate the generalized inner product of the two, as shown in equation (4).

[0149] BF i =||A i H ·X·X H ·A i || (4).

[0150] Alternatively, the matching degree between the two can be calculated using the direct inner product, as shown in equation (5).

[0151] BF i =||A i H ·X|| (5).

[0152] S33: Set threshold condition TH.

[0153] The threshold condition TH can be set according to the application scenario.

[0154] The matching degree BF calculated according to equation (4) or equation (5) i It will only be in the

[01] interval. When the two are completely matched, BF i =1; when the two are orthogonal, BF i =0.

[0155] Generally, a suitable value needs to be set statically or dynamically, taking into account both the false alarm rate and the false negative rate, based on the statistical characteristics of the reference signal. Alternatively, it can be set to report a limited number of results (e.g., search matching degree BF). i (The result corresponding to the maximum).

[0156] S34: Generate preliminary matching results CS i .

[0157] When the matching degree is BF iWhen the threshold condition TH is met, the corresponding address index is the preliminary matching result CS. i It can be written as equation (6).

[0158]

[0159] S4: Analyze the initial matching results (CS) i After screening and filtering, evaluation, and fusion, the final result is generated.

[0160] Furthermore, S4 can be decomposed into the following sub-steps.

[0161] S41: Polarization Filtering.

[0162] Step S41 is optional. In some applications, the initial matching results can be filtered based on prior knowledge (e.g., the polarization characteristics of the incident wave have a defined range) or polarization statistics (e.g., when the signal is stationary, the polarization characteristics should be stable within a range).

[0163] S42: Evaluate the validity of the measurement and adopt appropriate strategies.

[0164] If no data is input at this step, it means that the measurement value cannot be matched with a single plane wave. In this case, there may be severe interference or multipath conditions, and the measurement needs to be performed again. The number of remeasurements and the termination conditions are determined by the repeated measurement decision subunit 162.

[0165] If at this step there is input data, it means that the measurement is relatively accurate and the spatial parameters, polarization parameters and frequency of the incident wave have been calculated, which is a reliable result.

[0166] If multiple input data points are found at this step, it indicates that the accuracy of the measurement needs improvement. One possible approach is to repeat the measurement and tighten the threshold condition TH until only one data result remains. The number of remeasurements and the termination condition are determined by the repeated measurement decision subunit 162.

[0167] S43: Statistical fusion, submit the final results.

[0168] Those skilled in the art will understand that most interference and multipath effects are sporadic (not constant in the time or spatial domains). Especially when this equipment is mounted on a mobile platform for parameter estimation, severe multipath effects can occur as the position changes and measurement time progresses, potentially degrading the measurement accuracy, although the duration is often short. Therefore, it is necessary to fuse multiple measurement results to further improve accuracy and eliminate outliers. The specific methods for statistical fusion of signal parameters are well known to those skilled in the art and will not be elaborated upon in this embodiment.

[0169] It is worth mentioning that the specific methods of statistical fusion of signal parameters involved in this patent application should be regarded as prior art. The specific structure, working principle and possible control methods and spatial arrangement methods of these technical features can be conventionally selected in the field and should not be regarded as the inventive point of this patent. This patent will not be further elaborated in detail.

[0170] For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. An electromagnetic signal parameter estimation system based on a vector antenna, characterized in that, It includes a vector antenna, a radio frequency unit, a signal preprocessing unit, a data storage unit, a correlation matching unit, and a data processing unit, wherein: A vector antenna receives incident electromagnetic waves and converts them into radio frequency signals for output. The radio frequency unit is electrically connected to the feed output terminal of the vector antenna and processes the received radio frequency signal according to preset radio frequency processing steps to obtain an analog signal. The signal preprocessing unit processes the digitized time series signal according to a preset steering vector solution step to obtain the receiving steering vector X; Data storage unit, storing the reference dataset REF; The relevant matching unit sequentially compares the receive steering vector X, which serves as the measurement result, with the reference data table DS. i And calculate the matching degree BF. i Preliminary matching result CS is generated based on threshold conditions. i ; The data processing unit processes the initial matching results CS. i Further filtering and selection are performed to generate the final result.

2. The electromagnetic signal parameter estimation system based on a vector antenna according to claim 1, characterized in that, The signal preprocessing unit includes a digitization sampling subunit, a preliminary processing subunit, and a steering vector solving subunit. The digitization sampling subunit receives the analog signal transmitted by the radio frequency unit and processes it to obtain a digital signal. The preliminary processing subunit receives the digital signal transmitted by the digitization sampling subunit and processes it to obtain a digitized time-series signal. The steering vector solving subunit receives the digitized time-series signal transmitted by the preliminary processing subunit and processes it to obtain the receiving steering vector X.

3. The electromagnetic signal parameter estimation system based on a vector antenna according to claim 1, characterized in that, Reference Data Table DS i Including address index S i and reference guide vector A i Address index S i Let it be S i =[φ i θ i γ i η i f i ], φ i θ represents the incident azimuth angle. i Represents the incident elevation angle, γ i Represents the polarization auxiliary angle, η i f represents the polarization phase difference. i Represents frequency; reference steering vector A i Let it be A i =[E xi E yi E zi H xi H yi H zi ], representing the response values ​​of the vector antenna in the three dimensions of electric and magnetic fields when receiving electromagnetic waves; all reference data tables DS i The set is defined as the reference dataset REF, denoted as REF = {DS} i }={[S i A i ]}.

4. The electromagnetic signal parameter estimation system based on a vector antenna according to claim 2, characterized in that, The relevant matching unit includes a data table traversal subunit, a matching degree calculation subunit, a threshold setting subunit, and a matching analysis subunit; The data table traversal subunit receives the reference dataset REF passed by the data storage unit and generates the corresponding strategy; the matching degree calculation subunit receives the receiving guidance vector X passed by the guidance vector solving subunit and the reference data table DS passed by the data table traversal subunit. ii To calculate and generate the receiving guidance vector X and the reference data table DS i Matching degree BF i Threshold condition TH is generated by the threshold setting subunit; The matching analysis subunit receives the matching degree BF transmitted by the matching degree calculation subunit. i and address index S i It also receives the threshold condition TH passed by the threshold setting subunit to compare and generate a preliminary matching result CS. i .

5. The electromagnetic signal parameter estimation system based on a vector antenna according to claim 4, characterized in that, The data processing unit includes an interferometric estimation subunit, a repeated measurement decision subunit, and a statistical output subunit; interferometric The estimation subunit receives the preliminary matching result CS transmitted by the matching analysis subunit. i Based on the preliminary matching results CS i The polarization prior information, for the preliminary matching result CS i Filtering is performed to obtain the filtering results; if no filtering results are generated in this filtering, the repeated measurement decision subunit repeats the measurement in one or more additional time periods. After the repeated measurement decision subunit makes a decision and a filtering result is generated, the statistical output subunit receives the filtering result transmitted by the repeated measurement decision subunit, evaluates the stability of the filtering results multiple times, and generates the final result.

6. A method for estimating electromagnetic signal parameters based on a vector antenna, characterized in that, Includes the following steps: S1: The signal of the incident electromagnetic wave is received, preprocessed, and the receiving guide vector X is characterized in a parameterized manner; S2: Transmit a reference signal and acquire the reference steering vector A. i Generate a reference dataset REF; S3: Match degree calculation, generating preliminary matching results CS i ; S4: Analyze the initial matching results (CS) i After screening and filtering, evaluation, and fusion, the final result is generated.

7. The electromagnetic signal parameter estimation method based on a vector antenna according to claim 6, characterized in that, Step S1 is specifically implemented as follows: S11: Acquire digitized time series signals; S12: Perform frequency domain conversion on the digitized time series signal; S13: Calculate the covariance matrix and extract eigenvalues; S14: Normalize the data and obtain the receiving guide vector X.

8. The electromagnetic signal parameter estimation method based on a vector antenna according to claim 7, characterized in that, Step S2 is specifically implemented as follows: S21: Construct a reference signal; S22: Obtain the reference dataset DS i .

9. The electromagnetic signal parameter estimation method based on a vector antenna according to claim 8, characterized in that, Step S3 is specifically implemented as follows: S31: Use a strategy to traverse the reference data table DS i ; S32: Calculate the receiving guidance vector X and the reference guidance vector A i Matching degree BF i ; S33: Set threshold condition TH; S34: Generate preliminary matching results CS i .

10. The electromagnetic signal parameter estimation method based on a vector antenna according to claim 9, characterized in that, Step S4 is specifically implemented as follows: S41: Polarization filtration; S42: Evaluate the validity of this measurement and adopt appropriate strategies; S43: Statistical fusion, submit the final results.

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