A method for suppressing self-excitation leakage signal of a system based on dual-polarization cancellation

Abstract

The application discloses a system self-excitation leakage signal suppression method based on dual-polarization cancellation, comprising the following steps: setting an optimal threshold, distinguishing normal signals from mixed signals possibly containing system leakage signals, calculating average power values of the normal signals and the mixed signals, and determining the mixed signals containing system leakage signals; for the mixed signals containing system leakage signals, calculating transient Stokes vectors of the mixed signals at each sampling moment, segmenting and accumulating the transient Stokes vectors, and using signal lengths of each mixed signal and average Stokes vectors to calculate an optimal polarization receiving state which makes the length of residual system leakage signals shortest; calculating an antenna effective length vector corresponding to the optimal polarization receiving state, calculating an equivalent receiving signal of a dual-polarization original echo signal under the optimal polarization receiving state, and realizing optimal polarization cancellation of system leakage signals. The application can effectively suppress system leakage signals and improve the quality of radar echo signals.

Description

Technical Field

[0001] This invention belongs to the field of radar signal processing technology, specifically relating to a method for suppressing system self-excited leakage signals based on dual-polarization cancellation. Background Technology

[0002] Self-oscillating signal leakage is a significant issue in radar systems, particularly in high-precision, high-sensitivity systems. During operation, radar systems may generate self-oscillating signals due to factors such as circuit design, signal processing algorithms, or system stability. These self-oscillating signals leak into the radar echo signal during transmission and reception, degrading the echo signal quality and consequently affecting the radar system's performance and target detection capabilities. Modern radar systems have high requirements for signal purity and stability; even minor signal leakage or interference can lead to a significant decrease in echo signal quality. The occurrence of self-oscillating signal leakage not only increases noise in the echo signal but may also introduce false target signals, leading to misjudgments or missed detections, severely impacting the reliability and accuracy of the radar system. The occurrence of self-oscillating signal leakage is usually closely related to the radar system's signal processing link, RF front-end circuit design, and system stability. For example, during radar signal transmission, circuit nonlinearity, improper filter design, or defects in the signal processing algorithm may cause some signal energy to leak into the receiving channel, forming a self-oscillating signal. These self-excited signals, when superimposed on the real echo signal at the radar receiver, significantly reduce the signal-to-noise ratio of the echo signal, leading to a decline in target detection and imaging quality. Traditional suppression methods to address this issue mainly include optimizing circuit design, improving filter performance, and enhancing the anti-interference capabilities of signal processing algorithms. However, these methods often struggle to completely eliminate the influence of self-excited signals in practical applications, especially in complex electromagnetic environments and high-dynamic target detection scenarios, where their suppression effectiveness remains limited. Therefore, effectively suppressing the impact of self-excited signal system leakage on echo signal quality has become a crucial issue in radar system design and signal processing. Summary of the Invention

[0003] The purpose of this invention is to provide a system self-excited leakage signal suppression method, computer equipment, computer-readable storage medium, and computer program product based on dual-polarization cancellation, which can effectively suppress system leakage signals and improve the quality of radar echo signals.

[0004] One aspect of the present invention provides a method for suppressing system self-excited leakage signals based on dual-polarization cancellation, comprising:

[0005] Step S1: Set an optimal threshold. In the original dual-polarized echo signal, the signal with a power value lower than the optimal threshold is regarded as a normal signal, and the signal with a power value higher than the optimal threshold is regarded as a mixed signal that may contain system leakage signal. Calculate the average power value of the normal signal and the mixed signal, and determine the mixed signal with an average power value higher than the average power value of the normal signal by a specified multiple as containing system leakage signal.

[0006] Step S2: For the mixed signal containing system leakage signal, calculate the transient Stokes vector of the mixed signal at each sampling time, accumulate the transient Stokes vector in segments, and use the signal duration of each segment of the mixed signal and the average Stokes vector to calculate the optimal polarization receiving state that minimizes the duration of the residual system leakage signal.

[0007] Step S3: Calculate the effective antenna length vector corresponding to the optimal polarization receiving state, and use the effective antenna length vector to calculate the equivalent received signal of the dual-polarized original echo signal in the optimal polarization receiving state, thereby achieving optimal polarization cancellation of the system leakage signal.

[0008] Another aspect of the present invention provides a computer device including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described above.

[0009] Another aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0010] Another aspect of the present invention provides a computer program product including a computer program that, when executed by a processor, implements the steps of the method described above.

[0011] The system self-excited leakage signal suppression method, computer device, computer-readable storage medium, and computer program product based on dual-polarization cancellation according to the above aspects of the present invention can effectively suppress system leakage signals and improve the quality of radar echo signals. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0013] Figure 1 This is a flowchart of a system self-excited leakage signal suppression method based on dual-polarization cancellation according to an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram comparing the echo signals before and after processing by a system self-excited leakage signal suppression method based on dual-polarization cancellation according to an embodiment of the present invention.

[0015] Figure 3 This is a structural diagram of a computer device according to an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0017] One embodiment of the present invention provides a method for suppressing system self-excited leakage signals based on dual-polarization cancellation, such as... Figure 1 As shown, the system self-excited leakage signal suppression method based on dual-polarization cancellation in this embodiment of the invention includes steps S1-S3.

[0018] In step S1, an optimal threshold is set. Signals with power values ​​lower than the optimal threshold in the original dual-polarized echo signal are considered normal signals, and signals with power values ​​higher than the optimal threshold are considered mixed signals that may contain system leakage signals. The average power value of the normal signal and the mixed signal is calculated, and the mixed signal with an average power value higher than a specified multiple of the average power value of the normal signal is determined to contain system leakage signals.

[0019] Assume the main polarization signal of the original echo signal received by the radar system is Orthogonal polarization signal is , The time variable is the echo signal. This signal may contain system leakage signals that leak from the radar system's self-excited signal into the receiver. In step S1, the system leakage signal is detected. The detection of the system self-excited leakage signal is achieved by utilizing the amplitude difference between the normal echo signal and the system leakage signal. Specifically, as follows.

[0020] Calculate the total dual-polarization power of the echo signal For the total power of dual polarization Discretization can be performed by setting several uniform quantization intervals to facilitate histogram statistics of the signal. To balance computational and detection performance, the number of quantization intervals can be set to 50-100. Assume a total of... There are quantization intervals, and the boundary of each quantization interval is denoted as . , For any one , Both can serve as potential detection thresholds, dividing the signal into two parts: power value and other parameters. Normal signal and power value The signal is a mixture of normal signals and system leakage signals. Calculate the inter-class variance of the two signal components. as follows:

[0021]

[0022] in and These represent the proportions of normal signals and mixed signals, respectively. and These are the average power values ​​for the normal signal and the mixed signal, respectively.

[0023] Traverse all That is, to traverse all possible detection thresholds. Find the variance between classes The highest threshold is taken as the optimal threshold. Using this threshold as the boundary, signals with power values ​​below this threshold in the echo signal are considered normal signals, while signals with power values ​​above this threshold are considered mixed signals that may contain system leakage signals.

[0024] Calculate the average power values ​​of the normal signal and the mixed signal at the optimal threshold. and If the average power of the mixed signal is higher than the average power of the normal signal... Q times, that is If the signal is positive, the mixed signal is determined to be a mixed signal containing system leakage signal, and system leakage signal suppression will be performed in subsequent steps. Otherwise, it is considered to contain no system leakage signal, and system leakage signal suppression is unnecessary. The above parameters... Q The value should not be too low or too high to avoid misjudgment during the detection process. Q The value can range from 2 to 4.

[0025] In step S2, for the mixed signal containing the system leakage signal, the transient Stokes vector of the mixed signal at each sampling time is calculated, the transient Stokes vector is accumulated in segments, and the optimal polarization reception state that minimizes the duration of the residual system leakage signal is calculated using the signal duration of each segment of the mixed signal and the average Stokes vector.

[0026] Assume that the main polarization signal of the mixed signal containing the system leakage signal detected in step S1 is Orthogonal polarization signal is , Let its time variable be denoted as . The transient Stokes vector of the signal at each sampling time can be calculated as .

[0027]

[0028] in, For the signal in t The transient Stokes vector at time t. , , , This represents the four components of the transient Stokes vector. (Symbol) This represents the conjugate transpose of a complex number.

[0029] Furthermore, the transient Stokes vectors mentioned above are accumulated piecewise, dividing the time-domain support set of the mixed signal into... Segment, let the signal duration of each segment be denoted as . And calculate the average Stokes vector for each segment of the mixed signal. ,in Divided into The purpose of processing this segment is to prevent outliers caused by other interference or anomalous signals in the mixed signal from resulting in incorrect polarization parameter estimation results. The value of should be able to accommodate the non-stationarity that may exist in the signal, and also ensure that there are a sufficient number of sampling points in each segment. Therefore The value should not be too large or too small; a value between 5 and 10 is recommended.

[0030] Furthermore, the optimal polarization receiving state of the mixed signal that achieves optimal system leakage signal suppression is estimated. Using... and Calculate the optimal polarization reception state that minimizes the percentage of affected signals. Solve the following optimization problem:

[0031]

[0032] The variable to be solved is the optimal antenna polarization. , For the Poincaré sphere, it contains all possible polarization receiving states. For characteristic functions, i.e., when Meet the conditions The value is 1 when it is active and 0 otherwise. for , for When the conditions are met hour, The value is 1 if it is not found, and 0 otherwise. The matrix... for:

[0033]

[0034] The above optimization problem seeks the optimal This minimizes the duration of the residual system leakage signal, thus satisfying the condition. The total time is shortest. The solution space is discretized, and each possible solution is traversed to approximate the solution. First, on the Poincaré sphere... The above is obtained through Fibonacci sampling of the sphere. candidate antenna polarization ,get:

[0035]

[0036] in Indicates all Each spherical sampling point can correspond to On candidate antenna polarization ,in This represents the polarization vector of each candidate antenna in the Poincaré sphere. Three components in space. Polarization for each candidate antenna. The duration of its residual leakage signal can be calculated. ,in This represents the threshold for judgment. It is determined by iterating through... To achieve polarization of candidate antennas The parameters are searched, and the one that minimizes the remaining interference duration is selected. This allows for an approximate solution to the aforementioned optimization problem, yielding the optimal polarization receiving state. By polarizing the original signal under this optimal polarization reception state, the minimum system leakage signal duty cycle can be obtained, thus achieving optimal system leakage signal polarization cancellation suppression.

[0037] In step S3, the effective length vector of the antenna corresponding to the optimal polarization receiving state is calculated. The equivalent received signal of the dual-polarized original echo signal under the optimal polarization receiving state is obtained by using the effective length vector of the antenna, thereby realizing the optimal polarization cancellation of the system leakage signal.

[0038] The optimal polarization receiving state is used to achieve orthogonal polarization reception processing of the dual-polarized raw echo signal. The optimal polarization receiving state is calculated. The corresponding antenna effective length vector ,in and These represent the horizontal and vertical polarization components of the antenna's effective length vector, respectively. (The effective length vector of the antenna...) With the original echo signal main polarization signal Orthogonal polarization signal is By performing the calculations, the optimal polarization reception state of the original echo signal corresponding to the effective length of the antenna can be obtained. Equivalent received signal This achieves optimal polarization cancellation of the system leakage signal. The specific calculation formula is as follows:

[0039]

[0040] Taking actual radar data as an example, the beneficial effects of the system self-excited leakage signal suppression method based on dual polarization cancellation in this embodiment of the invention are explained.

[0041] In this example, such as Figure 2 As shown, the original echo signal received by the radar system exhibits system self-excitation signal leakage within a time range of approximately -1000µs to approximately -700µs, with its signal strength significantly higher than at other times. After processing using the system self-excitation leakage signal suppression method based on dual-polarization cancellation according to the embodiments of the present invention, the signal strength of the canceled signal is significantly reduced within the range of approximately -1000µs to approximately -700µs, consistent with the signal strength at other times, indicating that the system self-excitation leakage signal has achieved good polarization cancellation suppression.

[0042] Furthermore, in this example, the time-frequency plot of the original echo signal received by the radar system shows a significant spectral line caused by system leakage signal, occupying the range from -1000µs to approximately -700µs in the time domain, consistent with the time range of the self-excited leakage signal in the time domain, while appearing as a narrowband leakage signal in the frequency domain. After processing by the system self-excited leakage signal suppression method based on dual-polarization cancellation according to this embodiment of the invention, this spectral line is significantly suppressed in the time-frequency plot, indicating a significant suppression effect on the system self-excited leakage signal.

[0043] The system self-excited leakage signal suppression method based on dual-polarization cancellation in this invention has the following beneficial effects:

[0044] The method of this invention takes as input a dual-polarized echo signal from a radar system exhibiting self-excited leakage. By detecting the system self-excited leakage signal, the system leakage signal is extracted from the input signal. Based on the system self-excited leakage signal, its optimal polarization reception state is estimated. Based on the optimal polarization reception state of the system self-excited leakage signal, a dual-polarization cancellation method is used to suppress the system leakage signal, thereby enhancing the echo signal. This method of the present invention solves the problem of the deteriorating effect of system self-excited signal leakage on echo quality through dual-polarization signal processing, achieving system echo signal enhancement, solving the problem of suppressing system self-excited signal leakage, and improving the echo signal quality of dual-polarized radars with system leakage. This method of the present invention does not require changes to the radar system's RF front-end design, is simple to implement, has low computational load, and robust performance, showing good prospects for engineering applications.

[0045] Embodiments of the present invention also provide a computer device, which may be a server, and its internal structure diagram may be as follows: Figure 3 As shown. The computer device includes a processor, memory, and a network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores operating parameter data for various components. The network interface communicates with external terminals via a network connection. When executed by the processor, the computer program implements the steps of the method according to embodiments of the present invention.

[0046] Those skilled in the art will understand that Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0047] Embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method of the embodiments of the present invention.

[0048] Embodiments of the present invention also provide a computer program product, including a computer program that, when executed by a processor, implements the steps of the method of the embodiments of the present invention.

[0049] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for suppressing system self-excited leakage signals based on dual-polarization cancellation, characterized in that, include: Step S1: Set an optimal threshold. In the original dual-polarized echo signal, the signal with a power value lower than the optimal threshold is regarded as a normal signal, and the signal with a power value higher than the optimal threshold is regarded as a mixed signal that may contain system leakage signal. Calculate the average power value of the normal signal and the mixed signal, and determine the mixed signal with an average power value higher than the average power value of the normal signal by a specified multiple as containing system leakage signal. Step S2: For the mixed signal containing system leakage signal, calculate the transient Stokes vector of the mixed signal at each sampling time, accumulate the transient Stokes vector in segments, and use the signal duration of each segment of the mixed signal and the average Stokes vector to calculate the optimal polarization receiving state that minimizes the duration of the residual system leakage signal. Step S3: Calculate the effective length vector of the antenna corresponding to the optimal polarization receiving state, and use the effective length vector of the antenna to calculate the equivalent received signal of the dual-polarization original echo signal in the optimal polarization receiving state, so as to realize the optimal polarization cancellation of the system leakage signal. In step S1, the total dual-polarization power of the echo signal is discretized, and the following settings are made: A uniform quantization interval, with the boundary of each quantization interval as the boundary. As a detection threshold Calculate the inter-class variance of the normal signal and the mixed signal that may contain system leakage signals in each quantization interval. : in, and These represent the proportions of normal signals and mixed signals, respectively. and These are the average power values ​​for the normal signal and the mixed signal, respectively. Traverse all detection thresholds Find the variance between classes The highest detection threshold is taken as the optimal threshold.

2. The method according to claim 1, characterized in that, The following calculates the total dual-polarization power of the echo signal. : in, The dominant polarization signal of the echo signal. The orthogonal polarization signal of the echo signal, It is a time variable; Power value The echo signal is taken as a normal signal, and the power value is... The echo signal is a mixed signal that may contain system leakage signals.

3. The method according to claim 2, characterized in that, In step S2, the transient Stokes vector of the mixed signal containing the system leakage signal is calculated at each sampling time, and the time-domain support set of the mixed signal is divided into... Segment, let the first The signal duration of the segment is , Calculate the first Average Stokes vector of segment mixed signal ; Solve the following optimization problem to obtain the optimal polarization receiver state: The variable to be solved is the optimal antenna polarization. , For Poincaré's ball, The average power value of a normal signal, when the condition is met. hour, The value is 1 if it is not 1, and 0 otherwise. (Matrix) for: 。 4. The method according to claim 3, characterized in that, wherein... The dominant polarization signal of the mixed signal is Orthogonal polarization signal is Then the transient Stokes vector of the mixed signal at each sampling time is: in, For mixed signals in t The transient Stokes vector at time t. , , , The four components represent the transient Stokes vector. This represents the conjugate transpose of a complex number.

5. The method according to claim 4, characterized in that, The optimization problem is solved as follows: First, Fibonacci sampling was performed on the Poincaré sphere. Candidate antenna polarization vectors: in Indicates all Each spherical sampling point corresponds to a Poincaré sphere. On candidate antenna polarization ,in This represents the polarization vector of each candidate antenna in the Poincaré sphere. The three components in space polarize each candidate antenna. The duration of the residual leakage signal is calculated, and the candidate antenna polarization with the smallest residual leakage signal duration is selected as the optimal polarization receiving state.

6. The method according to claim 5, characterized in that, In step S3, the equivalent received signal of the dual-polarized original echo signal under the optimal polarization receiving state is obtained. for: in, The effective length vector of the antenna. and These represent the horizontal and vertical polarization components of the effective length vector of the antenna, respectively.

7. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1-6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1-6.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1-6.

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