Interference modulation method and system, electronic equipment and storage medium

Abstract

The invention discloses an interference modulation method and system, electronic equipment and a storage medium, and the method comprises the steps: obtaining a target signal, carrying out the parameter extraction of the target signal according to a region of interest, and obtaining a two-dimensional space coordinate of the region of interest; a two-dimensional frequency domain filter is constructed according to the two-dimensional space coordinates of the region of interest, and a target noise template is constructed according to the two-dimensional frequency domain filter; performing frequency shift modulation interference processing on the target signal on the basis of the target noise template to obtain a target interference signal; and performing retransmission conversion processing on the interference signal to obtain a retransmission signal. The embodiment of the invention can improve the interference energy utilization rate and can be widely applied to the technical field of electronic countermeasures.

Description

Technical Field

[0001] The present application relates to the field of electronic countermeasure technology, and in particular to an interference modulation method, system, electronic device and storage medium. Background Art

[0002] Synthetic aperture radar (SAR) is an active microwave imaging radar system capable of all-weather, all-day Earth observation and producing high-resolution images. Various electronic countermeasures and jamming signal generation technologies targeting SAR have attracted widespread attention. In related technologies, multi-phase segmented modulation interference can be used to generate noise interference within the main lobe through signal segmentation and random phase modulation. However, in practical applications, it has been found that these suppression interference methods can only produce fixed-shaped noise blocks, namely rectangular suppression blocks. For regions of interest with specific shapes, the fixed-shaped interference blocks will not fully utilize the interference energy, resulting in wasted interference energy and reduced interference effectiveness.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0004] The main purpose of the embodiments of the present application is to provide an interference modulation method, system, electronic device and storage medium, which can improve the utilization rate of interference energy.

[0005] To achieve the above objectives, an embodiment of the present application provides an interference modulation method, the method comprising:

[0006] Acquire a target signal, perform parameter extraction processing on the target signal according to the region of interest, and obtain the two-dimensional spatial coordinates of the region of interest;

[0007] A two-dimensional frequency domain filter is constructed according to the two-dimensional spatial coordinates of the region of interest, and a target noise template is constructed according to the two-dimensional frequency domain filter;

[0008] Performing frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal;

[0009] Perform retransmission conversion processing on the target interference signal to obtain a retransmission signal.

[0010] In some embodiments, performing parameter extraction processing on the target signal according to the region of interest to obtain the two-dimensional spatial coordinates of the region of interest includes the following steps:

[0011] Obtaining a jammer position, and establishing a first coordinate system according to the jammer position;

[0012] Perform two-dimensional spatial sampling processing on the region of interest according to the first coordinate system to obtain the two-dimensional spatial coordinates of the region of interest.

[0013] In some embodiments, constructing a two-dimensional frequency domain filter according to the two-dimensional spatial coordinates of the region of interest comprises the following steps:

[0014] Performing boundary point extraction processing on the two-dimensional spatial coordinates of the region of interest to obtain boundary point coordinates;

[0015] Performing centroid calculation processing on the region of interest according to the boundary point coordinates to obtain the region centroid;

[0016] Constructing a second coordinate system based on the region centroid, and performing coordinate transformation processing on the two-dimensional space coordinates of the region of interest based on the second coordinate system to obtain target coordinates;

[0017] Performing frequency domain conversion processing on the target coordinates to obtain two-dimensional frequency domain coordinates;

[0018] A polygon construction process is performed according to the two-dimensional frequency domain coordinates to obtain the two-dimensional frequency domain filter.

[0019] In some embodiments, constructing a target noise template according to the two-dimensional frequency domain filter comprises the following steps:

[0020] Get a two-dimensional noise template;

[0021] Performing two-dimensional random phase modulation processing on the two-dimensional noise template to obtain an initial noise template;

[0022] Performing a two-dimensional Fourier transform on the initial noise template to obtain a frequency domain template;

[0023] Performing product processing on the frequency domain template according to the two-dimensional frequency domain filter to obtain a noise frequency domain template;

[0024] Performing two-dimensional inverse Fourier transform processing on the noise frequency domain template to obtain the target noise template.

[0025] In some embodiments, performing frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal includes the following steps:

[0026] Performing time-domain multiplication processing on the target signal according to the target noise template to obtain an initial interference signal;

[0027] Obtaining an interference position, and calculating a range frequency shift and an azimuth frequency shift according to the interference position;

[0028] Frequency shift modulation processing is performed on the initial interference signal according to the range frequency shift amount and the azimuth frequency shift amount to obtain the target interference signal.

[0029] In some embodiments, performing frequency domain conversion on the target coordinates to obtain two-dimensional frequency domain coordinates includes the following steps:

[0030] Performing frequency domain coordinate conversion on the target coordinates to obtain initial frequency domain coordinates;

[0031] An interference range control process is performed on the initial frequency domain coordinates according to a preset scaling factor to obtain the two-dimensional frequency domain coordinates.

[0032] In some embodiments, acquiring the target signal comprises the following steps:

[0033] Acquire synthetic aperture radar signals;

[0034] performing gain control processing on the synthetic aperture radar signal to obtain a gain signal;

[0035] Down-conversion and analog-to-digital conversion are performed on the gain signal to obtain the target signal.

[0036] To achieve the above objectives, another aspect of the present application provides an interference modulation system, the system comprising:

[0037] The first module is used to acquire a target signal, perform parameter extraction processing on the target signal according to the region of interest, and obtain the two-dimensional spatial coordinates of the region of interest;

[0038] A second module is configured to construct a two-dimensional frequency domain filter according to the two-dimensional spatial coordinates of the region of interest, and to construct a target noise template according to the two-dimensional frequency domain filter;

[0039] A third module is configured to perform frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal;

[0040] The fourth module is configured to perform retransmission conversion processing on the interference signal to obtain a retransmission signal.

[0041] To achieve the above-mentioned purpose, another aspect of an embodiment of the present application provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the above-mentioned method when executing the computer program.

[0042] To achieve the above objectives, another aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0043] The embodiments of the present application include at least the following beneficial effects: The present application provides an interference modulation method, system, electronic device, and storage medium. This solution obtains a target signal and performs parameter extraction processing on the target signal based on the region of interest to obtain the two-dimensional spatial coordinates of the region of interest; constructs a two-dimensional frequency domain filter based on the two-dimensional spatial coordinates of the region of interest, and constructs a target noise template based on the two-dimensional frequency domain filter. The shape of the noise template can be controlled by the two-dimensional frequency domain filter, so that the interference capability is further concentrated within the region of interest, thereby improving the utilization rate of the interference energy. In addition, the solution performs frequency shift modulation interference processing on the target signal based on the target noise template to obtain a target interference signal. The interference position can be two-dimensionally controlled through frequency shift modulation, thereby improving the utilization rate of the interference energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a flow chart of an interference modulation method provided by an embodiment of the present application;

[0045] Figure 2 This is a schematic diagram of a design process for a two-dimensional filter with an arbitrary shape provided in an embodiment of the present application;

[0046] Figure 3 is a schematic diagram of a parameterized modulation process provided by an embodiment of the present application;

[0047] Figure 4 This is a schematic structural diagram of an interference modulation system provided by an embodiment of the present application;

[0048] Figure 5 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are merely examples of systems and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0050] It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various concepts, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0051] The terms "at least one", "plurality", "each", "any", etc. used in this application include "at least one", "two" or more, "plurality" or "each", "any" or "any one", "each" or "any one" as used herein.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0053] Before explaining the embodiments of the present application in detail, some of the nouns and terms involved in the embodiments of the present application are first explained. The nouns and terms involved in the embodiments of the present application are subject to the following explanations.

[0054] 1) Synthetic Aperture Radar (SAR) is an active microwave imaging radar system capable of all-weather, all-day Earth observation and generating high-resolution images. SAR uses a radar antenna mounted on a mobile platform (such as a satellite, aircraft, or drone) to transmit microwave signals to the ground and receive reflected echoes. Using synthetic aperture technology, it simulates a virtual antenna that is much larger than the actual physical antenna size, thereby achieving high-resolution imaging. The working principle of SAR mainly includes the steps of signal transmission, echo reception, data processing, and image generation. Its advantage is that it is not restricted by lighting and weather conditions and can penetrate clouds, smoke, and even shallow surfaces. It is widely used in military reconnaissance, topographic mapping, disaster monitoring, ocean observation, agricultural assessment, and other fields. The development of SAR technology has promoted the progress of remote sensing science and has become an important tool for modern Earth observation.

[0055] 2) SAR Jamming: SAR jamming is the technology that destroys or disrupts enemy SAR observations or equipment imaging. Common jamming methods include suppression jamming and deception jamming. Suppression jamming increases the noise floor of the radar receiver by transmitting high-power noise signals to cover specific targets in the SAR image. Because SAR uses two-dimensional matched filtering technology, it inherently has strong anti-interference capabilities. Therefore, in actual electronic warfare, suppression jamming usually requires high transmission power and a high cost budget. Deception jamming inserts carefully designed false targets or scenes into SAR images by transmitting false signals with echo characteristics similar to real targets, thereby misleading the enemy's judgment of the SAR image. However, deception jamming usually requires high parameter reconnaissance accuracy.

[0056] 3) Product Modulation Jamming Principle: Noise product modulation jamming is simple to implement, automatically targets the radar's center frequency, and leverages the double-sided spectrum of noise to evenly distribute jamming energy around the target echo. These characteristics make noise product modulation jamming widely used in electronic warfare. Specifically, the imaging result of noise product jamming can be viewed as a combination of countless pulse impulse functions. These pulse impulse functions are two-dimensionally incoherent, resulting in noise in the SAR image.

[0057] As an advanced active microwave detection device, SAR (Special Active Radar) offers excellent imaging capabilities in adverse weather conditions and possesses a certain degree of ground penetration. These advantages make SAR a crucial tool for space surveillance and are widely used in military fields such as battlefield situational reconnaissance, target identification and classification, terrain mapping and navigation, covert target detection, counterterrorism, and border surveillance. Furthermore, increasingly complex detection needs and technical requirements are driving the rapid development of SAR imaging technology. However, the widespread use of SAR systems and the significant improvement in their imaging capabilities have increased the risk of exposing sensitive targets. Therefore, to enhance comprehensive operational advantages in modern warfare and protect critical targets from observation and detection, various SAR-targeted electronic countermeasures and jamming signal generation technologies have garnered widespread attention.

[0058] For years, researchers have extensively studied synthetic aperture radar jamming techniques to discover effective and robust jamming methods. Generally speaking, electronic jamming techniques for synthetic aperture radars can be divided into two categories based on their effectiveness: deception jamming and suppression jamming. Deception jamming involves transmitting false signals that closely resemble target echoes, creating a highly realistic illusion and compromising the enemy SAR's information acquisition capabilities. Compared to deception jamming, suppression jamming is relatively simple to implement, does not require complex modulation precision and precise parameter requirements, and has a wider range of effects.

[0059] SAR is a pulse compression radar. Based on this characteristic, researchers have proposed a series of coherent jamming methods in recent years to replace simple incoherent noise jamming, thereby reducing the power requirements of the jammer. Noise convolution jamming methods, including one-dimensional and two-dimensional convolution, generate jamming signals by convolving a noise signal with the intercepted SAR signal. While some processing gain can be achieved, due to the limitations of the convolution principle, the resulting jamming effect always lags behind the jammer. Compared to noise convolution jamming methods, noise product jamming methods generate jamming signals by multiplying the noise signal with the SAR signal in the time domain, offering lower computational complexity. However, the jamming position of noise product jamming methods is often fixed. Delayed forwarding, including stepped delay and randomized delay forwarding, can also achieve some processing gain, but the achievable gain is limited.

[0060] In the related art, there are frequency shift interference technologies, including stepped frequency shift, random frequency shift, and segmented random frequency shift interference, which further improve the processing gain of the interference signal. However, due to the existence of the frequency shift term, most of the interference energy will be distributed in unnecessary frequency bands, thereby causing a waste of interference energy. In actual applications, it is found that these interference suppression methods can only produce noise blocks of fixed shapes, i.e., rectangular suppression blocks. For regions of interest with specific shapes, the interference blocks of fixed shapes will not make the interference energy fully utilized, and the interference energy will be wasted.

[0061] For example, multi-phase segmented modulation (MPSM) generates noise interference within the mainlobe through signal segmentation and random phase modulation. However, MPSM interference has strong sidelobes. Based on this, a cosine amplitude weighted MPSM method was proposed, which can effectively suppress the sidelobes and concentrate the energy in the mainlobe. Unfortunately, the interference range of this technology is fixed. The above method has been publicly reported to achieve control of the interference range in the downlink direction, but it is still difficult to achieve the ideal interference effect in the increasingly complex electronic countermeasure environment. Interference methods based on phase error theory have achieved azimuth expansion. However, the interference range is difficult to precisely control. Subsequently, frequency modulation error was used to achieve two-dimensional interference range and interference location control. However, the application of frequency modulation error can increase or decrease the interference signal, and the interference energy cannot be fully utilized. Related suppression interference technologies can only produce noise interference blocks with fixed shapes, which wastes interference energy in some unnecessary areas, thereby reducing the overall effectiveness of the interference. This wastes interference energy and makes it difficult to achieve two-dimensional precise control of the interference location.

[0062] In view of this, an embodiment of the present application provides an interference modulation method, system, electronic device, and storage medium. This solution obtains a target signal, performs parameter extraction processing on the target signal, and obtains the parameters of the region of interest; constructs a two-dimensional frequency domain filter based on the parameters of the region of interest, and constructs a target noise template based on the two-dimensional frequency domain filter. The shape of the noise template can be controlled by the two-dimensional frequency domain filter, so that the interference capability is further concentrated in the region of interest, thereby improving the utilization rate of the interference energy. In addition, the solution performs frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal. The interference position can be two-dimensionally controlled through frequency shift modulation, thereby improving the interference efficiency.

[0063] An interference modulation method provided in an embodiment of the present application relates to the field of electronic countermeasure technology. An interference modulation method provided in an embodiment of the present application can be applied to a terminal, can also be applied to a server, and can also be software running in a terminal or a server. In some embodiments, the terminal can be a tablet computer, a laptop computer, a desktop computer, etc., and the terminal is used as a jammer to perform interference modulation processing on the SAR signal, but is not limited to this; the server side can be configured as an independent physical server, or as a server cluster or distributed system composed of multiple physical servers, or as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network; the software can be an application that implements an interference modulation method, etc., but is not limited to the above forms.

[0064] The present application can be used in many general or special computer system environments or configurations. For example: server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and the like. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments in which tasks are performed by remote processing devices connected via a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media, including storage devices.

[0065] Figure 1 This is an optional flowchart of an interference modulation method provided in an embodiment of the present application. Figure 1The method may include but is not limited to steps S101 to S104.

[0066] Step S101, acquiring a target signal, performing parameter extraction processing on the target signal according to a region of interest, and obtaining the two-dimensional spatial coordinates of the region of interest;

[0067] Step S102, constructing a two-dimensional frequency domain filter according to the two-dimensional spatial coordinates of the region of interest, and constructing a target noise template according to the two-dimensional frequency domain filter;

[0068] Step S103, performing frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal;

[0069] Step S104: performing retransmission conversion processing on the interference signal to obtain a retransmission signal.

[0070] In the embodiment of the present application, steps S101 to S104 are performed by acquiring a target signal and performing parameter extraction processing on the target signal according to the region of interest to obtain the two-dimensional spatial coordinates of the region of interest. The target signal is a processed SAR signal, and the region of interest (ROI) is a core concept in the implementation of SAR jamming, which refers to the portion selected for key analysis or operation during the processing. Accordingly, the two-dimensional spatial coordinates of the region of interest represent the coordinates of each point in the corresponding region of interest. A two-dimensional frequency domain filter can be constructed by performing coordinate transformation, time domain to frequency domain conversion, and other processing on the two-dimensional spatial coordinates of the region of interest, so that a noise template with an arbitrary shape can be obtained based on the two-dimensional frequency domain filter. Traditional noise product modulation jamming can only produce noise blocks with a rectangular shape, which is mainly due to the fixed unilateral cutoff bandwidth of the traditional noise jamming template. The rectangular noise template seriously reduces the jamming effectiveness of the jammer in the face of complex battlefield environments, resulting in a waste of jamming energy. Fortunately, the imaging result of noise product modulation interference can be approximated as the sum of countless pulse impulse functions, and the position of each impulse function is determined by the frequency of the noise template. This means that the frequency domain design of the noise template directly determines its time domain interference effect. Based on this, a noise interference template of any shape can be constructed by generating a two-dimensional frequency domain filter of any shape, which can further concentrate the interference capability within the region of interest, thereby improving the utilization of the interference energy. The target signal is then subjected to frequency shift modulation interference processing based on the target noise template, which can two-dimensionally control the interference position and obtain the target interference signal. Finally, the target interference signal undergoes retransmission conversion processing. That is, the interference signal generated by modulation undergoes digital-to-analog conversion, up-conversion, and gain control, and is retransmitted to the SAR. Ultimately, after two-dimensional pulse compression, it produces an interference effect on the SAR image.

[0071] One of the above technical solutions has the following advantages or beneficial effects: the embodiment of the present application generates a noise interference template with an arbitrary shape by constructing a two-dimensional frequency domain filter, thereby enriching the interference pattern, and the utilization rate of the interference energy is high. The noise interference template that matches the shape of the area of interest can maximize the utilization of the interference energy, thereby improving the interference energy and interference efficiency.

[0072] In step S101 of some embodiments, acquiring the target signal includes the following steps:

[0073] Acquire synthetic aperture radar signals;

[0074] performing gain control processing on the synthetic aperture radar signal to obtain a gain signal;

[0075] Down-conversion and analog-to-digital conversion are performed on the gain signal to obtain the target signal.

[0076] In an embodiment of the present application, a synthetic aperture radar signal can be obtained by a jammer, and a gain signal can be obtained by performing gain control processing on the synthetic aperture radar signal, for example, by amplification processing. The gain signal is then down-converted and analog-to-digital converted to obtain a target signal, which is a digital baseband signal. In addition, the reconnaissance and interception of the target signal by the jammer is achieved through a closed-loop process of "detection-analysis-locking". First, a wideband receiver and spectrum analysis technology are used to scan the electromagnetic environment in the entire frequency band, and potential targets are identified through energy detection and signal feature extraction (such as frequency, modulation mode, and time domain parameters); for complex signals such as frequency hopping or spread spectrum, signal sorting and threat identification are completed by combining channelized reception and machine learning algorithms. Subsequently, the target frequency is dynamically tracked through technologies such as phase-locked loops and adaptive filtering, and the signal is demodulated and decoded in real time with the help of software-defined radio (SDR) and digital signal processing (DSP) to extract data.

[0077] One of the above technical solutions has the following advantages or beneficial effects: the embodiment of the present application provides a data basis for subsequent interference modulation by acquiring the target signal.

[0078] In step S101 of some embodiments, performing parameter extraction processing on the target signal according to the region of interest to obtain the two-dimensional spatial coordinates of the region of interest includes the following steps:

[0079] Obtaining a jammer position, and establishing a first coordinate system according to the jammer position;

[0080] Perform two-dimensional spatial sampling processing on the region of interest according to the first coordinate system to obtain the two-dimensional spatial coordinates of the region of interest.

[0081] In the embodiment of the present application, a first coordinate system can be established based on the position of the jammer, wherein the jammer is used as the coordinate origin, that is, (0, 0) is used as the origin to establish an XOY coordinate system, wherein the x-axis represents the ground distance direction and the y-axis represents the azimuth direction. The jammer takes the irregular area of interest Ω0 as the protection target. In order to obtain the coordinate position of the irregular area of interest Ω0, the azimuth resolution and the distance resolution ρ are used respectively. a ,ρ r Perform two-dimensional spatial sampling on Ω0. Thus, the coordinates of the region of interest, i.e., the parameters of the region of interest, are obtained. a ,ρ r The resolution should be high enough to preserve the geometric shape of the irregular area to the greatest extent. Finally, the coordinates of each point in the irregular Ω0 are expressed as follows:

[0082]

[0083] Where N represents the sum of all points in the irregular region of interest Ω0, p i (x i ,y i ) represents the coordinates of each point in the irregular region of interest Ω0.

[0084] One of the above technical solutions has the following advantages or beneficial effects: the embodiment of the present application obtains the two-dimensional spatial coordinates of the region of interest by extracting parameters of the target signal, providing a data basis for the subsequent construction of a two-dimensional frequency domain filter.

[0085] In some embodiments, constructing a two-dimensional frequency domain filter according to the two-dimensional spatial coordinates of the region of interest comprises the following steps:

[0086] Performing boundary point extraction processing on the two-dimensional spatial coordinates of the region of interest to obtain boundary point coordinates;

[0087] Performing centroid calculation processing on the region of interest according to the boundary point coordinates to obtain the region centroid;

[0088] Constructing a second coordinate system based on the region centroid, and performing coordinate transformation processing on the two-dimensional space coordinates of the region of interest based on the second coordinate system to obtain target coordinates;

[0089] Performing frequency domain conversion processing on the target coordinates to obtain two-dimensional frequency domain coordinates;

[0090] A polygon construction process is performed according to the two-dimensional frequency domain coordinates to obtain the two-dimensional frequency domain filter.

[0091] In the examples of this application, please refer to Figure 2The two-dimensional spatial coordinates of the region of interest include the coordinates of the points in the irregular region of interest. However, for a large region of interest, the coordinates of the points of interest are usually a huge set. This increases the storage requirements of the jammer on the one hand, and increases the computational burden of subsequent processing calculations on the other hand. For the construction of a two-dimensional irregular filter, the embodiments of the present application often pay more attention to its geometric shape. Therefore, the embodiments of the present application only need to pay attention to the boundary points of the region of interest. The alpha shapes algorithm is a simple and effective algorithm for quickly extracting boundary points, and can be used for any shape, including convex hull and concave hull. Therefore, the embodiments of the present application introduce the alpha shapes algorithm to extract the edge points of the region of interest. The boundary points of the point cloud can be determined by rolling circles to obtain the coordinates of the boundary points.

[0092] Then, according to the coordinates of the boundary points of the region of interest, the centroid of the region of interest is obtained. For two-dimensional graphics, the centroid The geometric center is the minimum sum of the squares of the distances from all points to the centroid, which is the center of the region. The calculation formula for the centroid is as follows:

[0093]

[0094] Where N represents the sum of all points in the irregular region of interest Ω0, p i (x i ,y i ) represents the coordinates of each point in the irregular region of interest Ω0.

[0095] The obtained regional centroid As the coordinate origin, the XOY coordinate system is re-established to obtain the second coordinate system. The goal of establishing the second coordinate system is to ensure that the generated noise template can be evenly distributed near the baseband frequency. Because in the subsequent coordinate transformation from the time domain to the frequency domain, the coordinate origin of the time domain corresponds to the two-dimensional zero-frequency position. At the same time, this also means that the coordinate system with the centroid as the coordinate origin can be evenly distributed near the two-dimensional zero frequency after the transformation from the time domain to the frequency domain. After the coordinate transformation, the expression of the coordinate of the i-th point in the irregular region of interest Ω0 is shown as follows:

[0096]

[0097] Where, Represents the target parameters. In order to construct the corresponding two-dimensional frequency domain filter and obtain a noise template with an arbitrary shape, it is necessary to convert the time domain coordinates in the target parameters into frequency domain coordinates, thereby obtaining the two-dimensional frequency domain parameters. Construct the minimum outer polygon in the two-dimensional frequency domain according to the two-dimensional frequency domain parameters. Specifically, by traversing the two-dimensional spectrum and performing logical judgment, the value at the frequency point position within the constructed polygon is set to 1, and vice versa. It is worth noting that in order to save time, it is not necessary to judge from the position of each frequency point in the two-dimensional frequency domain, and it can start directly from the boundary position. Finally, a filter with an arbitrary shape is generated. By simply multiplying it with the two-dimensional frequency domain of the noise template, the corresponding noise template can be generated, which lays the foundation for improving the interference effectiveness in complex battlefield situations.

[0098] One of the above technical solutions has the following advantages or beneficial effects: The embodiment of the present application constructs a two-dimensional frequency domain filter using the two-dimensional spatial parameters of the region of interest. This filter can generate a noise interference template of any shape, thereby accurately matching the target scene and saving interference energy. Furthermore, by combining different filters, various interference effects can be achieved, greatly improving the flexibility of interference implementation and enhancing the ability to cope with complex electronic countermeasures.

[0099] In some embodiments, constructing a target noise template according to the two-dimensional frequency domain filter comprises the following steps:

[0100] Get a two-dimensional noise template;

[0101] Performing two-dimensional random phase modulation processing on the two-dimensional noise template to obtain an initial noise template;

[0102] Performing a two-dimensional Fourier transform on the initial noise template to obtain a frequency domain template;

[0103] Performing product processing on the frequency domain template according to the two-dimensional frequency domain filter to obtain a noise frequency domain template;

[0104] Performing two-dimensional inverse Fourier transform processing on the noise frequency domain template to obtain the target noise template.

[0105] In the embodiment of the present application, a two-dimensional noise template n(t r ,η). Then, the generated two-dimensional noise template is subjected to two-dimensional random phase modulation. The purpose of this is to ensure that the power spectrum density energy of the noise template can cover the entire frequency band. The expression of the final generated noise template is shown as follows:

[0106] Noise(t r ,η)=n(t r,η)·exp[j2π·rand(t r )]·exp[j2π·rand(η)];

[0107] Among them, Noise(t r ,η) represents the initial noise template, n(t r ,η) represents the two-dimensional noise template, t r represents the time in range, η represents the time in azimuth, j represents the imaginary unit, and rand(·) represents the random value at different times.

[0108] It is conceivable that the above process of generating the initial noise template can be generated offline because it does not involve signal parameter information. Next, the initial noise template is transformed into the frequency domain through a two-dimensional Fourier transform and multiplied by the two-dimensional frequency domain filter. The two-dimensional frequency filter can be represented as Δ. The expression of the final target noise template is shown in the following formula:

[0109]

[0110] Where, Represents the target noise template.

[0111] One of the above technical solutions has the following advantages or beneficial effects: the embodiment of the present application controls the shape of the noise template according to the shape of the two-dimensional frequency domain filter, thereby generating a noise interference template with an arbitrary shape, which can further concentrate the interference capability in the area of interest, thereby improving the utilization rate of the interference energy.

[0112] In some embodiments, performing frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal includes the following steps:

[0113] Performing time-domain multiplication processing on the target signal according to the target noise template to obtain an initial interference signal;

[0114] Obtaining an interference position, and calculating a range frequency shift and an azimuth frequency shift according to the interference position;

[0115] Frequency shift modulation processing is performed on the initial interference signal according to the range frequency shift amount and the azimuth frequency shift amount to obtain the target interference signal.

[0116] In the embodiment of the present application, in order to make the interference template adapt to the resolution of the SAR, the resolution of the two-dimensional frequency domain filter should be close to or consistent with the resolution of the intercepted SAR signal. Since the two-dimensional spatial sampling rate is high enough, it can be consistent with the two-dimensional resolution of the SAR by downsampling. Subsequently, the filtered target noise template is transformed into a two-dimensional time domain through a two-dimensional IFFT. Finally, the noise template is multiplied by the baseband interference signal time domain to generate an interference signal with an arbitrary shape noise template, thereby obtaining the initial interference signal. The expression of the initial interference signal is shown in the following formula:

[0117]

[0118] Where, represents the initial interference signal, Indicates the target signal, Represents the target noise template.

[0119] Then the interference position is obtained, wherein the frequency shift modulation interference is used to precisely control the interference position, that is, the interference is carried out at a distance from the jammer. The interference position produces a suppression interference effect, and the frequency shift in the range and azimuth directions are calculated. The calculation formula is shown as follows:

[0120]

[0121] Where Δf r Indicates the frequency shift in the distance, Δf a Indicates the azimuth frequency shift, Indicates the distance coordinates of the preset interference position, represents the azimuth coordinate of the preset interference position, c represents the speed of light, v represents the radar flight speed, K r Indicates the frequency modulation slope of the linear modulation (LFM signal), K a Indicates the azimuth frequency modulation slope of the SAR signal.

[0122] Finally, the initial interference signal is frequency-shifted and modulated according to the frequency shift in the range and azimuth directions to obtain the target interference signal. The expression of the target interference signal is shown in the following formula:

[0123]

[0124] Where, represents the target interference signal, represents the initial interference signal, Γ a (η) and Γ r (t r ) represent the frequency shift, η represents the azimuth time, t r Represents distance to time.

[0125] One of the above technical solutions has the following advantages or beneficial effects: the embodiment of the present application can perform two-dimensional control of the interference position by performing frequency shift modulation interference processing on the target signal, and can achieve precise control of the interference position by modulating the interference signal with different frequency shift amounts.

[0126] In some embodiments, performing frequency domain conversion on the target coordinates to obtain two-dimensional frequency domain coordinates includes the following steps:

[0127] Performing frequency domain coordinate conversion on the target coordinates to obtain initial frequency domain coordinates;

[0128] An interference range control process is performed on the initial frequency domain coordinates according to a preset scaling factor to obtain the two-dimensional frequency domain coordinates.

[0129] In the embodiment of the present application, in order to construct a corresponding two-dimensional frequency domain filter and obtain a noise template with an arbitrary shape, it is necessary to convert the time domain coordinates in the set Ω0 into frequency domain coordinates. For SAR imaging technology using LFM signals, a parameterized relationship for converting from the time domain to the frequency domain is provided. Therefore, after the conversion, the frequency domain coordinates of the i-th point are converted into two-dimensional frequency domain coordinates. The expression of the two-dimensional frequency domain coordinates is shown as follows:

[0130]

[0131] Where, and Represents the different time frequency positions of point u, K r Represents the frequency modulation slope of the LFM signal, C represents the speed of light, v represents the radar flight speed, λ represents the wavelength, and R0 represents the shortest slant range from the SAR to the target point. After the conversion, the centroid corresponds to the zero frequency in the two-dimensional frequency domain, which makes the noise energy concentrated near the zero frequency and reduces the noise power loss. In addition, in order to adapt to different resolutions and achieve precise control of the interference range, the embodiment of the present application defines a scaling factor, which can proportionally expand or reduce the interference range, which further improves the controllability of the interference. Finally, the frequency domain coordinates of the i-th point after the conversion are expressed as follows:

[0132]

[0133] Where, ξ r and ξ a Represents the scaling factor.

[0134] One of the above technical solutions has the following advantages or beneficial effects: the embodiment of the present application controls the interference range of the two-dimensional frequency domain coordinates through a scaling factor, which can proportionally expand or reduce the interference range, thereby further improving the controllability of the interference.

[0135] The following is a detailed description of the embodiments of the present application with reference to specific application examples:

[0136] The embodiments of the present application can be applied to interference modulation application scenarios. Figure 3 The proposed adaptive noise jammer is deployed within a protected area and conducts reconnaissance and interception of SAR signals within the protected area. The jammer performs a series of operations on the received signal, including amplification, downconversion, and digital conversion, to obtain a digital baseband signal. Simultaneously, it extracts parameter information of interest to generate a two-dimensional noise template. This is then subjected to two-dimensional random phase modulation to generate a two-dimensional Fourier transform (FFT) result. The two-dimensional FFT result is then multiplied with a two-dimensional frequency filter to produce a two-dimensional inverse fast Fourier transform (IFFT) result. Finally, the digital baseband signal and the two-dimensional IFFT result are time-domain multiplied and frequency-shifted. The modulated result undergoes digital-to-analog conversion, upconversion, and gain control before being retransmitted. To verify the generation capabilities of the proposed adaptive noise jammer template, an aircraft multi-scatterer model was selected as the region of interest (ROI). Simulations using traditional noise product jamming only generate rectangular noise jammers, severely limiting the flexibility of jamming implementation. An elliptical noise jammer is then applied to the ROI, achieving a certain suppression jamming effect on the aircraft's multi-scatterer shape. Compared to rectangular noise jammers, the elliptical noise jammer achieves superior suppression jamming against aircraft targets, primarily due to its more concentrated jamming energy. Next, compared to the above situation, the noise interference template of the embodiment of the present application has a stronger suppression interference effect because the interference energy is more concentrated. In particular, the embodiment of the present application provides an interesting interference simulation result, which has a special shape, that is, the outside is round and the inside is square. This special filter is composed of an elliptical filter and a quadrilateral filter, thereby producing this effective phenomenon. Therefore, the embodiment of the present application can produce a noise interference template with an arbitrary shape by the design of a two-dimensional frequency domain filter, which can be accurately matched with the target scene, thereby saving interference energy. In addition, various interference effects can be achieved by combining different filters, which greatly improves the flexibility of interference implementation and enhances the ability to cope with complex electronic countermeasures.

[0137] See also Figure 4 The present application also provides an interference modulation system that can implement the above-mentioned interference modulation method. The system includes:

[0138] The first module 401 is used to acquire a target signal, perform parameter extraction processing on the target signal according to the region of interest, and obtain the two-dimensional spatial coordinates of the region of interest;

[0139] The second module 402 is configured to construct a two-dimensional frequency domain filter according to the two-dimensional spatial coordinates of the region of interest, and to construct a target noise template according to the two-dimensional frequency domain filter;

[0140] The third module 403 is configured to perform frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal;

[0141] The fourth module 404 is configured to perform retransmission conversion processing on the interference signal to obtain a retransmission signal.

[0142] It can be understood that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0143] The present application also provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the aforementioned interference modulation method when executing the computer program. The electronic device can be any smart terminal, such as a tablet computer or an in-vehicle computer.

[0144] It can be understood that the contents of the above method embodiments are applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0145] See also Figure 5 , Figure 5 The hardware structure of an electronic device according to another embodiment is shown. The electronic device includes:

[0146] The processor 501 may be implemented as a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is configured to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0147] The memory 502 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 502 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 502 and is called by the processor 501 to execute an interference modulation method of the embodiments of the present application.

[0148] Input / output interface 503, used to implement information input and output;

[0149] Communication interface 504, used to implement communication interaction between this device and other devices, which can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WiFi, Bluetooth, etc.);

[0150] Bus 505 , which transmits information between various components of the device (e.g., processor 501 , memory 502 , input / output interface 503 , and communication interface 504 );

[0151] The processor 501 , the memory 502 , the input / output interface 503 and the communication interface 504 are connected to each other in communication within the device via a bus 505 .

[0152] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned interference modulation method is implemented.

[0153] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiment, the functions specifically implemented by the present storage medium embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0154] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0155] The embodiments of the present application provide an interference modulation method, system, electronic device, and storage medium. This solution obtains a target signal, performs parameter extraction processing on the target signal, and obtains region of interest parameters. A two-dimensional frequency domain filter is constructed based on the region of interest parameters, and a target noise template is constructed based on the two-dimensional frequency domain filter. The shape of the noise template can be controlled by the two-dimensional frequency domain filter, so that the interference capability is further concentrated within the region of interest, thereby improving the utilization rate of the interference energy. In addition, the solution performs frequency shift modulation interference processing on the target signal based on the target noise template to obtain a target interference signal. The interference position can be two-dimensionally controlled through frequency shift modulation, thereby improving the accuracy of the interference.

[0156] The embodiments described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0157] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0158] The system embodiment described above is merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0159] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0160] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0161] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0162] In the several embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For example, the division of the above units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of systems or units, which can be electrical, mechanical or other forms.

[0163] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0164] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0165] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes multiple instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: various media that can store programs, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0166] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention should be within the scope of the present invention.

Claims

1. An interference modulation method, characterized in that: The method comprises the following steps: Acquire a target signal, perform parameter extraction processing on the target signal according to the region of interest, and obtain the two-dimensional spatial coordinates of the region of interest; A two-dimensional frequency domain filter is constructed according to the two-dimensional spatial coordinates of the region of interest, and a target noise template is constructed according to the two-dimensional frequency domain filter; Performing frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal; Perform retransmission conversion processing on the target interference signal to obtain a retransmission signal.

2. The method according to claim 1, characterized in that The step of performing parameter extraction processing on the target signal according to the region of interest to obtain the two-dimensional spatial coordinates of the region of interest includes the following steps: Obtaining a jammer position, and establishing a first coordinate system according to the jammer position; Perform two-dimensional spatial sampling processing on the region of interest according to the first coordinate system to obtain the two-dimensional spatial coordinates of the region of interest.

3. The method according to claim 1, characterized in that The step of constructing a two-dimensional frequency domain filter according to the two-dimensional spatial coordinates of the region of interest comprises the following steps: Performing boundary point extraction processing on the two-dimensional spatial coordinates of the region of interest to obtain boundary point coordinates; Performing centroid calculation processing on the region of interest according to the boundary point coordinates to obtain the region centroid; Constructing a second coordinate system according to the centroid of the region; Performing coordinate transformation processing on the two-dimensional space coordinates of the region of interest according to the second coordinate system to obtain target coordinates; Performing frequency domain conversion processing on the target coordinates to obtain two-dimensional frequency domain coordinates; A polygon construction process is performed according to the two-dimensional frequency domain coordinates to obtain the two-dimensional frequency domain filter.

4. The method according to claim 1, wherein The method of constructing a target noise template based on the two-dimensional frequency domain filter comprises the following steps: Get a two-dimensional noise template; Performing two-dimensional random phase modulation processing on the two-dimensional noise template to obtain an initial noise template; Performing a two-dimensional Fourier transform on the initial noise template to obtain a frequency domain template; Performing product processing on the frequency domain template according to the two-dimensional frequency domain filter to obtain a noise frequency domain template; Performing two-dimensional inverse Fourier transform processing on the noise frequency domain template to obtain the target noise template.

5. The method according to claim 1, characterized in that The step of performing frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal comprises the following steps: Performing time-domain multiplication processing on the target signal according to the target noise template to obtain an initial interference signal; Obtaining an interference position, and calculating a range frequency shift and an azimuth frequency shift according to the interference position; Frequency shift modulation processing is performed on the initial interference signal according to the range frequency shift amount and the azimuth frequency shift amount to obtain the target interference signal.

6. The method according to claim 3, characterized in that The step of performing frequency domain conversion on the target coordinates to obtain two-dimensional frequency domain coordinates includes the following steps: Performing frequency domain coordinate conversion on the target coordinates to obtain initial frequency domain coordinates; An interference range control process is performed on the initial frequency domain coordinates according to a preset scaling factor to obtain the two-dimensional frequency domain coordinates.

7. The method according to any one of claims 1 to 6, characterized in that The step of acquiring the target signal comprises the following steps: Acquire synthetic aperture radar signals; performing gain control processing on the synthetic aperture radar signal to obtain a gain signal; Down-conversion and analog-to-digital conversion are performed on the gain signal to obtain the target signal.

8. An interference modulation system, characterized in that: The system comprises: The first module is used to acquire a target signal, perform parameter extraction processing on the target signal according to the region of interest, and obtain the two-dimensional spatial coordinates of the region of interest; A second module is configured to construct a two-dimensional frequency domain filter according to the two-dimensional spatial coordinates of the region of interest, and to construct a target noise template according to the two-dimensional frequency domain filter; A third module is configured to perform frequency shift modulation interference processing on the target signal according to the target noise template to obtain a target interference signal; The fourth module is configured to perform retransmission conversion processing on the interference signal to obtain a retransmission signal.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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