Anti-radar attack method and system

Abstract

The invention relates to a radar attack resisting method and system, a product and a storage medium. The method comprises the following steps: firstly, receiving an attack signal, and calculating echo flight time; secondly, adjusting the starting frequency and slope of a local-end radar to obtain an attack signal frequency range; then, adjusting a local end radar waveform parameter, and roughly estimating an attack signal duration, a Chirp number, a slope and an initial frequency parameter; the initial order is calculated, the optimal order is obtained through fixed step length searching, and fine estimation is conducted on the slope and the initial frequency through time-frequency transformation; and finally, according to the attack radar waveform parameters, adjusting the target sensing time and the attack waveform parameter estimation time of the local-end radar. According to the method, the time-frequency information of the attack signal is analyzed through waveform design and time-frequency parameter estimation, so that the local-end radar obtains a better emission parameter for avoiding the attack, the influence of the attack signal on target detection is reduced, and a guarantee is provided for distance perception of the local-end radar under the attack condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar, in particular to an anti-radar attack method and system, a product and a storage medium. BACKGROUND

[0002] With the rapid development of radar technology, its application scenarios have extended to many fields such as civil, industrial and scientific research. As the core component of modern electronic sensing system, radar realizes high-precision detection and tracking of targets by transmitting electromagnetic waves and receiving reflected signals, and provides key data support for fields such as unmanned systems, intelligent transportation, aerospace, weather monitoring, security monitoring, etc. However, when the radar system operates in a complex electromagnetic environment, its received signals are easily disturbed or attacked by malicious attacks, resulting in a decline in detection performance or even system failure. For example, an attacker can transmit interference signals in the same frequency band as the radar signal to raise the system noise floor; or simulate false target signals to induce radar to make a false judgment, thereby causing decision errors or functional failures.

[0003] To resist attacks on radar, existing methods are divided into two categories: active and passive. The active method has frequency agility and phase coding: the former divides the frequency band so that the radar works in different frequency bands, thereby avoiding the attack signal entering the radar frequency band receiving range, which can avoid significant decline in radar sensing performance; the latter modulates the phase of the transmitted signal to spread the energy of the attack signal to a wider frequency band, and uses a pseudo-random code sequence to enhance the radar's ability to resist attack signals. The passive method has signal processing and deep learning: the former reconstructs the useful signal based on the characteristics of the attack signal through time-frequency transform and other techniques to resist attacks; the latter extracts high-dimensional and nonlinear features of the attack signal based on neural network processing, separates it from the useful signal, and effectively suppresses the attack signal.

[0004] However, these methods also have some problems. For the active method: on the one hand, frequency agility requires the radar to have the ability to change frequency flexibly, which has high requirements for radio frequency devices or circuit design; on the other hand, phase coding changes the phase of the waveform, resulting in a loss of speed sensing performance, which needs to be compensated by algorithm. For the passive method: on the one hand, deep learning relies on a large amount of labeled data set for training, so it has requirements for the data set, while signal processing can effectively suppress attack signals with constant parameters, but its performance significantly decreases when dealing with complex and variable attack waveforms; on the other hand, signal processing has high computational complexity, which has certain requirements for the processing performance of the radar, and in complex scenarios with high speed, the response speed of the radar will decrease. SUMMARY

[0005] Therefore, it is necessary to provide an anti-radar attack method and system, a product and a storage medium capable of actively and adaptively changing a waveform of a radar to reduce the influence of an attack signal on target perception.

[0006] To solve the above technical problems, the technical solutions of the present application are as follows: In a first aspect, an anti-radar attack method comprises: S1, receiving an attack waveform and calculating a return flight time; S2, adjusting a starting frequency and a slope of a local radar, and calculating a starting frequency range of the attack waveform; S3, adjusting a waveform parameter of the local radar according to the starting frequency range; Receiving a return signal and an intermediate frequency signal of a single Chrip, and coarsely estimating a Chirp number of the attack waveform according to the return signal and the intermediate frequency signal; Coarsely estimating an attack waveform duration and an attack waveform slope according to the Chirp number of the attack waveform; Coarsely estimating an attack waveform starting frequency according to the waveform parameter of the local radar, the attack waveform slope and the return flight time; S4, calculating an initial rotation order according to the attack waveform slope, obtaining an optimal order through fixed step search, and finely estimating the attack waveform slope and the attack waveform starting frequency by using time-frequency transform according to the optimal order, to obtain an updated attack waveform slope and an updated attack waveform starting frequency; S5, adjusting the waveform parameter of the local radar according to the return flight time, the updated attack waveform slope and the updated attack waveform starting frequency, and adjusting a local radar target perception and attack waveform parameter estimation time according to the parameters of the attack waveform and the attack waveform duration.

[0007] In a second aspect, an anti-radar attack system comprises: A receiving module is configured to receive an attack waveform and calculate a return flight time; A preliminary identification module is configured to adjust a starting frequency and a slope of a local radar, and calculate a starting frequency range of the attack waveform; a coarse estimation module configured to adjust local radar waveform parameters according to the initial frequency range, receive echo signals and intermediate frequency signals of a single Chrip, and coarsely estimate a Chirp number of an attack waveform according to the echo signals and the intermediate frequency signals, coarsely estimate an attack waveform duration and an attack waveform slope according to the Chirp number of the attack waveform, and coarsely estimate an attack waveform initial frequency according to the local radar waveform parameters, the attack waveform slope, and the echo flight time; a fine estimation module configured to calculate an initial rotation order according to the attack waveform slope, obtain an optimal order through fixed-step search, and finely estimate the attack waveform slope and the attack waveform initial frequency according to the optimal order by using time-frequency transformation to obtain an updated attack waveform slope and an updated attack waveform initial frequency; an adaptive module configured to adjust the local radar waveform parameters according to the echo flight time, the updated attack waveform slope, and the updated attack waveform initial frequency, and adjust local radar target perception and attack waveform parameter estimation time according to the parameters of the attack waveform and the attack waveform duration.

[0008] In a third aspect, a computer program product includes a computer program or computer executable instructions, which, when executed by a processor, implement an anti-radar attack method as described above.

[0009] In a fourth aspect, a computer-readable storage medium stores at least one instruction, at least one program, a code set, or an instruction set, which are loaded and executed by a processor to implement an anti-radar attack method as described above.

[0010] Compared with the prior art, the technical scheme of the present application has the following beneficial effects: The method uses a frequency-agile continuous wave to detect an attack signal, uses the characteristic that an intermediate frequency signal is similar to a linear frequency modulation wave to preliminarily identify attack waveform parameters, and combines a step-by-step estimation method and a coarse-to-fine estimation strategy to reduce two-dimensional space search quantity and achieve accurate estimation of attack waveform parameters. The method has the following advantages: the frequency-agile continuous wave is generated without complex circuit design, which reduces the difficulty of actual deployment; the radar transmission parameters are adaptively adjusted to avoid attacks and ensure that the distance perception function is not disturbed; the full-range search is converted into a local-range search, which reduces the two-dimensional space search quantity and meets real-time processing requirements. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 FIG. 1 is a flowchart of an anti-radar attack method according to the present application; Figure 2Flowchart for peak analysis of the echo of the application and obtaining the echo time of flight; Figure 3 Flowchart for obtaining the attack waveform of the application and obtaining the initial frequency range; Figure 4 Flowchart for rough estimation of the attack waveform parameters of the application; Figure 5 Flowchart for fine estimation of the attack waveform parameters of the application; Figure 6 Flowchart for adjusting the radar transmission waveform parameters of the application according to the attack waveform parameters. DETAILED DESCRIPTION

[0012] The terms "first", "second", and the like in the description and claims of the application and the above drawings, are used for distinguishing between similar objects and not necessarily for describing a specific sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the application described herein are capable of operation in other sequences than described or illustrated herein. Furthermore, the terms "comprise", "comprising", "include", "including", and the like, as used herein, are specifically intended to be construed as open-ended terms i.e., the terms do not exclude additional, unrecited elements or method steps. The terms "by", "determining", and the like, are broadly construed to cover a wide array of actions, inactions, or processes, including obtaining, calculating, computing, processing, deriving, investigating, looking up (such as looking up in a table, a database or another data structure), ascertaining and the like, and includes receiving (such as receiving information), accessing (such as accessing data in a memory) and the like. The term "determining" encompasses the action of one or more devices or processors technically determining the result / output, and also software technically determining the result / output.

[0013] It should be noted that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or connected to the other element with intervening elements. In addition, "connected" in the following embodiments, if there is transmission of electrical signals or data between the connected objects, should be understood as "electrically connected", "communicatively connected" and the like.

[0014] It should be emphasized that the acquisition, transmission, storage, use, processing, etc. of data in the technical solutions of the embodiments of the application all comply with the relevant provisions of national laws and regulations.

[0015] In the embodiments of the application, some industry existing solutions, components, models, etc. may be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility of the implementation of the technical solutions of the application, but it does not mean that the applicant has or will necessarily use the solution.

[0016] The accompanying drawings are only intended to illustrate the present application, and should not be construed as limiting the present application; In order to better illustrate the present application, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual size of the product; It is understandable for those skilled in the art that some well-known structures and their descriptions in the drawings may be omitted.

[0017] The technical solutions of the present application will be further described below in combination with the drawings and examples.

[0018] Example 1 The present application provides an anti-radar attack method, referring to FIG. 1, comprising: S1, receiving an attack waveform and calculating the echo flight time.

[0019] S2, adjusting the starting frequency and slope of the local radar, and calculating the starting frequency range of the attack waveform.

[0020] S3, adjusting the local radar waveform parameters according to the starting frequency range; Receiving echo signals and intermediate frequency signals of a single Chrip, and coarsely estimating the Chirp number of the attack waveform according to the echo signals and the intermediate frequency signals; Coarsely estimating the attack waveform duration and the attack waveform slope according to the Chirp number of the attack waveform; Coarsely estimating the attack waveform starting frequency according to the local radar waveform parameters, the attack waveform slope and the echo flight time.

[0021] S4, calculating the initial rotation order according to the attack waveform slope, and obtaining the optimal order through fixed step search; according to the optimal order, the attack waveform slope and the attack waveform starting frequency are finely estimated by using time-frequency transform, to obtain the updated attack waveform slope and the updated attack waveform starting frequency.

[0022] S5, adjusting the local radar waveform parameters according to the echo flight time, the updated attack waveform slope and the updated attack waveform starting frequency, and adjusting the local radar target perception and attack waveform parameter estimation time according to the attack waveform parameters and the attack waveform duration.

[0023] The above method uses a frequency-agile continuous wave to detect the attack signal, uses the intermediate frequency signal with the characteristics similar to the linear frequency modulation wave, preliminarily identifies the attack waveform parameters through signal processing; at the same time, combining the step-by-step estimation method and the coarse-to-fine estimation strategy, the two-dimensional space search amount of the algorithm is reduced, and the accurate estimation of the attack waveform parameters is realized; the local radar target can also detect the target when receiving the attack.

[0024] The method described in the embodiment can be used in the fields of automatic driving, intelligent traffic, aerospace, weather monitoring, security monitoring, etc. When the embodiment is applied to an automatic driving scene, the local end is a radar-deployed car, also known as a local car.

[0025] Referring to Figure 2 In step S1, the attack waveform is received, and the echo flight time is calculated, including: S1-1, enabling the receiving antenna and the transmitting antenna of the local radar.

[0026] S1-2, judging whether is satisfied, if yes, performing S1-4, otherwise, performing S1-3, wherein, is a radar parameter initialization flag; In the embodiment, is not satisfied , S1-3 is performed.

[0027] S1-3, setting the local radar waveform parameters: , , , wherein, is the starting frequency, is the slope, is the minimum starting frequency, is the maximum slope; transmitting a single Chirp signal is :

[0028] , wherein, , is the number of Chirp sampling points, the superscript is a square operation; In the embodiment, , , , obtaining .

[0029] S1-4, receiving the echo signal of a single Chirp is , and the intermediate frequency signal is :

[0030] , wherein, , is a low-pass filtering operation, is a time-frequency transformation operation, the superscript is a conjugate inversion operation.

[0031] S1-5, judging whether the condition is met , if yes, executing S1-6, otherwise, executing S1-4, wherein, is the operation of calculating signal amplitude, is the operation of calculating signal amplitude, amplitude threshold value; In this embodiment, , when , the condition is met , executing S1-6.

[0032] S1-6, obtaining echo beat frequency index value array :

[0033] wherein, ; In this embodiment, it is assumed that , , , the condition is met and , the index value is stored in the array .

[0034] S1-7, obtaining the echo beat frequency index value with the maximum amplitude :

[0035] wherein, is the operation of taking the maximum value; In this embodiment, it is assumed that , is the maximum amplitude of the signal, then .

[0036] S1-8, calculating the echo time of flight :

[0037] wherein, is the radar sampling rate.

[0038] In this embodiment, , then .

[0039] Referring to Figure 3 , in the step S2, the starting frequency and the slope of the local radar are adjusted, and the starting frequency range of the attack waveform is calculated, including: S2-1, setting the loop threshold value :

[0040] wherein, , , is the maximum starting frequency, is the intermediate frequency bandwidth; In this embodiment, , then .

[0041] S2-2, enable the receiving antenna, close the transmitting antenna, set the local radar starting frequency and slope: ,

[0042] wherein, ; In this embodiment, .

[0043] S2-3, the received echo signal of a single Chirp is , and the intermediate frequency signal is :

[0044] wherein, .

[0045] S2-4, determine whether is satisfied, if yes, execute S2-5, otherwise, execute S2-6, wherein, is the amplitude threshold; In this embodiment, , when , satisfies , execute S2-5.

[0046] S2-5, store the index value in the array :

[0047] Calculate the frequency value and store it in the array :

[0048] wherein, is the index value, ; In this embodiment, it is assumed that is the maximum amplitude of the signal, , , , then , .

[0049] S2-6, setting , judging whether , if yes, executing S2-7, otherwise, executing S2-3, wherein, is a count value threshold; In the embodiment, , when , satisfies , executing S2-7.

[0050] S2-7, setting , .

[0051] S2-8, judging whether , if yes, executing S2-9, otherwise, executing S2-2.

[0052] S2-9, calculating the start frequency range of the attack waveform.

[0053] In the step S2-9, the start frequency range of the attack waveform is calculated, comprising: calculating the lower boundary of the start frequency of the attack waveform :

[0054] wherein, is a minimum value operation; In the embodiment, , , then .

[0055] calculating the upper boundary of the start frequency of the attack waveform : ; In the embodiment, , , then .

[0056] Referring to Figure 4 , in the step S3, the local radar waveform parameters are adjusted according to the start frequency range; the echo signal and the intermediate frequency signal of a single Chirp are received, and the Chirp number of the attack waveform is roughly estimated according to the echo signal and the intermediate frequency signal; the attack waveform duration and the attack waveform slope are roughly estimated according to the Chirp number of the attack waveform; the start frequency of the attack waveform is roughly estimated according to the local radar waveform parameters, the attack waveform slope and the echo flight time, comprising: S3-1, enable receiving antenna, close transmitting antenna, set , .

[0057] S3-2, configure local radar initial frequency array :

[0058] wherein, ; set the local radar waveform parameters: ,

[0059] In the present embodiment, , then , .

[0060] S3-3, receive echo signal of single Chirp , intermediate frequency signal :

[0061] wherein, .

[0062] S3-4, judge whether to meet , if yes, execute S3-5, otherwise, execute S3-6, wherein, is amplitude threshold value; In the present embodiment, when , meet , execute S3-5.

[0063] S3-5, store index into array :

[0064] wherein, is index value set, , is calculated data quantity; calculate quantity of second dimension data, and store it into array :

[0065] In the present embodiment, assume , , then , , , , .

[0066] S3-6, setting , whether the condition is met , if yes, performing S3-7, otherwise, performing S3-3, wherein is a count value threshold; In this embodiment, when , the condition is met, and S3-7 is performed.

[0067] S3-7, setting , .

[0068] S3-8, determining whether the condition is met , if yes, performing S3-9, otherwise, performing S3-2; In this embodiment, when , , , , the condition is met, and S3-9 is performed.

[0069] S3-9, calculating the number of Chirps of one frame of attack waveforms :

[0070] wherein, is a summation operation, is a rounding up operation, ; In this embodiment, , , then .

[0071] S3-10, obtaining the maximum number of index values :

[0072] In this embodiment, it is assumed that , then .

[0073] S3-11, calculating the duration of the attack radar transmission waveform :

[0074] wherein, is a radar sampling time, ; In the present embodiment, , , , , .

[0075] S3-12, calculating the attack waveform slope : ; In the present embodiment, , , , , .

[0076] S3-13, performing phase compensation on the signal to obtain a compensated signal : ; In the present embodiment, it is assumed that , .

[0077] S3-14, performing time-frequency transformation on the compensated signal to obtain a frequency domain signal :

[0078] wherein, .

[0079] S3-15, calculating the attack waveform starting frequency :

[0080] wherein, , ; In the present embodiment, it is assumed that , , , , , .

[0081] Referring to Figure 5 , in the above step S4, the initial rotation order is calculated according to the attack waveform slope, and the optimal order is obtained through fixed step search; according to the optimal order, the attack waveform slope and the attack waveform starting frequency are finely estimated by using time-frequency transformation, to obtain an updated attack waveform slope and an updated attack waveform starting frequency, comprising:​​ S4-1, enable the local radar receiving antenna, close the transmitting antenna, and set the local radar waveform parameters , ; In this embodiment, it is assumed that , then .

[0082] S4-2, the received echo signal of a single Chirp is , the intermediate frequency signal :

[0083] wherein .

[0084] S4-3, set the initial rotation order :

[0085] initial rotation factor :

[0086] wherein is the inverse tangent operation, and the initial search step size , is the search step size setting value.

[0087] S4-4, set the initial search space: ; In this embodiment, it is assumed that then .

[0088] S4-5, in the search space, calculate the fractional Fourier transform of with a fixed search step size , obtain the rotation factor and rotation order corresponding to the maximum amplitude of the fractional Fourier transform, wherein is the fractional Fourier transform, the superscript is the rotation factor, is the fractional Fourier transform domain, is the rotation factor corresponding to the maximum amplitude of the fractional Fourier transform, is the rotation order corresponding to the maximum amplitude of the fractional Fourier transform.

[0089] S4-6, determine whether , if yes, S4-7 is executed, otherwise, S4-10 is executed In this embodiment, When , it is satisfied that , S4-7 is executed.

[0090] S4-7, it is judged whether , if yes, S4-8 is executed, otherwise, S4-9 is executed; In this embodiment, When , it is satisfied that , S4-8 is executed.

[0091] S4-8, a new search space is set: , wherein, is a search step size scale factor; In this embodiment, it is assumed that , , , then .

[0092] S4-9, a new search space is set: ; In this embodiment, it is assumed that , , , then .

[0093] S4-10, a new search step size is set: and a rotation order: ; In this embodiment, , , , then , .

[0094] S4-11, it is judged whether , if yes, S4-12 is executed, otherwise, S4-5 is executed, wherein is a precision threshold; In this embodiment, When , it is satisfied that , S4-12 is executed.

[0095] S4-12, an optimal rotation factor: and a rotation order: .

[0096] S4-13, parameter estimation is performed using the optimal rotation factor and rotation order, and the attack waveform slope is updated and the attack waveform initial frequency : .

[0097] S4-14, the attack waveform amplitude is calculated : .

[0098] Referring to Figure 6 , in step S5, the local radar waveform parameters are adjusted according to the echo time of flight, the updated attack waveform slope, and the updated attack waveform initial frequency, and the local radar sensing target and attack waveform parameter estimation time are adjusted according to the parameters of the attack waveform and the attack waveform duration, including: S5-1, enable the local radar receiving antenna and transmitting antenna, and set the waveform parameters: .

[0099] S5-2, receive the echo signal of a single Chirp , the intermediate frequency signal :

[0100] wherein, .

[0101] S5-3, determine whether , if yes, execute S5-3, otherwise, execute S5-2.

[0102] S5-4, store the peak index in an array :

[0103] wherein, is a set of index values, ranging from ; calculate length: .

[0104] S5-5, calculate the duration of an attack waveform Chirp : ; In this embodiment, the duration of an attack waveform Chirp is one of the attack waveform parameter estimation times.

[0105] S5-6, calculating the attack waveform idle duration In this embodiment, the attack waveform idle duration is one of the attack waveform parameter estimation times.

[0106] S5-7, setting the local radar starting frequency

[0107] S5-8, setting the slope

[0108] S5-9, calculating the bandwidth

[0109] S5-10, receiving the echo signal of a single Chirp , the intermediate frequency signal

[0110] S5-11, calculating the target distance

[0111] wherein, is a set operation; In this embodiment, the target distance is one of the target distances perceived by the local radar.

[0112] S5-12, calculating the attack radar distance

[0113] wherein, is an index value, In this embodiment, the attack radar distance is one of the target distances perceived by the local radar.

[0114] The above method has the advantages that: the frequency-agile continuous wave does not require complex circuit design, reducing the difficulty of actual deployment; the radar transmission parameters are adaptively adjusted to avoid attacks and ensure that the distance perception function is not disturbed; the full-range search is converted to a local-range search, reducing the two-dimensional space search amount, and meeting the real-time processing requirements.

[0115] ​​​​​​​​​​​​​Embodiment 2 The embodiment further provides an anti-radar attack system based on the embodiment 1, comprising: A receiving module is configured to receive an attack waveform and calculate a round-trip time. The round-trip time is calculated in real time to provide a time reference for subsequent parameter estimation and ensure that the response speed of the system meets the real-time confrontation requirement. The original observation data are established by directly receiving the attack waveform to provide analysis input for the subsequent module.

[0116] A preliminary identification module is configured to adjust a starting frequency and a slope of a local radar and calculate a starting frequency range of the attack waveform. The radar parameters are dynamically adjusted to form a frequency agility characteristic and break the weakness of the traditional fixed frequency radar being easily predicted by an attack. The frequency range of the attack waveform is quickly calculated to compress the subsequent processing range from a full frequency band to a local frequency band and reduce the calculation complexity. The preliminary identification result provides a parameter constraint boundary for the subsequent module to form a processing framework from coarse to fine.

[0117] A coarse estimation module is configured to adjust a local radar waveform parameter according to the starting frequency range, receive a round-trip signal and an intermediate frequency signal of a single Chrip, and coarsely estimate a Chirp number of the attack waveform according to the round-trip signal and the intermediate frequency signal. The duration of the attack waveform and the slope of the attack waveform are coarsely estimated according to the Chirp number of the attack waveform. The starting frequency of the attack waveform is coarsely estimated according to the local radar waveform parameter, the slope of the attack waveform and the round-trip time. The coarse estimation of the starting frequency is realized in combination with the round-trip time to reduce the two-dimensional search problem to a single variable optimization problem.

[0118] A fine estimation module is configured to calculate an initial rotation order according to the slope of the attack waveform, obtain an optimal order through a fixed step search, and finely estimate the slope of the attack waveform and the starting frequency of the attack waveform according to the optimal order by using a time-frequency transform to obtain an updated slope of the attack waveform and an updated starting frequency of the attack waveform. An adaptive module is configured to adjust the local radar waveform parameter according to the round-trip time, the updated slope of the attack waveform and the updated starting frequency of the attack waveform, and adjust a local radar target and an attack waveform parameter estimation time according to the parameters of the attack waveform and the duration of the attack waveform.

[0119] The above system does not need complex circuit design and reduces the actual deployment difficulty.

[0120] It can be understood that the device of the embodiment corresponds to the method of the above-mentioned embodiment 1. The options in the above-mentioned embodiment 1 are also applicable to the embodiment, and therefore are not repeatedly described herein.

[0121] Embodiment 3 The embodiment provides a computer readable storage medium, and at least one instruction, at least one program, a code set or an instruction set are stored on the storage medium. The at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by a processor, so that the processor executes part or all steps of the method provided in the embodiment 1 of the application.

[0122] It can be understood that the storage medium can be transitory or non-transitory. Exemplarily, the storage medium includes but is not limited to a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0123] Exemplarily, the processor can be a central processing unit (CPU), a microprocessor unit (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA).

[0124] Exemplarily, the read-only memory includes but is not limited to a mask ROM, a PROM, an EPROM, an EEPROM, a flash and the like.

[0125] Exemplarily, the random access memory includes but is not limited to a DRAM, an SRAM, an SDRAM, a DDR SDRAM and the like.

[0126] In some examples, a computer program product is provided, which can be implemented in a hardware, software or combination thereof. As a non-limiting example, the computer program product can be embodied in the storage medium, and can also be embodied in a software product, such as an SDK (Software Development Kit) and the like.

[0127] As a non-limiting example, a computer program product is provided, which includes a computer program or computer executable instructions stored in a computer readable storage medium. A processor of an electronic device reads the computer program or computer executable instructions from the computer readable storage medium, and the processor executes the computer executable instructions, so that the electronic device executes part or all steps of the method provided in the embodiment of the application.

[0128] In some examples, a computer program is provided, comprising a computer-readable code. When the computer-readable code is run in a computer device, a processor in the computer device executes the code to implement part or all of the steps in the method.

[0129] This embodiment also proposes an electronic device, including a memory and a processor, wherein the memory stores at least one instruction, at least one program, code set or instruction set, and when the processor executes the at least one instruction, at least one program, code set or instruction set, it implements part or all of the steps of the method described in Example 1.

[0130] In some examples, a hardware entity of the electronic device is provided, including: a processor, a memory and a communication interface; wherein the processor generally controls the overall operation of the electronic device; the communication interface is used to enable the electronic device to communicate with other terminals or servers through a network; the memory is configured to store instructions and applications executable by the processor, and can also cache data to be processed or processed by the processor and various modules in the electronic device (including but not limited to image data, audio data, voice communication data and video communication data), and can be implemented by flash memory (FLASH), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM) or random access memory (RAM).

[0131] A processor may include one or more processing elements. Thus, a processor may include one or more integrated circuits (ICs) configured to perform the functions of the processor. Furthermore, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, and other circuits) configured to perform the functions of the processor.

[0132] Furthermore, data may be transmitted between the processor, the communication interface and the memory via a bus, which may include any number of interconnected buses and bridges, connecting various circuits of one or more processors and memories.

[0133] It can be understood that the options in the above embodiment 1 are also applicable to this embodiment, so they will not be described again here.

[0134] The same or similar reference numerals correspond to the same or similar components; The terms used in the drawings to describe positional relationships are for illustrative purposes only and are not to be construed as limiting the present application. It should be noted that the embodiments and the features in the embodiments in the present application can be combined with each other without conflict.

[0135] In different specific implementations, the methods or systems described in the present application can be implemented in software, hardware or a combination thereof. In addition, the order of the steps of the method can be changed, and various elements can be added, reordered, combined, omitted, modified, etc.

[0136] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation manners of the present application, and are not used to limit the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and each discrete structure / function module or unit can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part, and the structure and function of the discrete components can be implemented as a combined structure or component. Here, it is not necessary and also impossible to enumerate all the implementation manners. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for resisting radar attack, characterized in that: include: S1, receive the attack waveform and calculate the echo flight time; S2. Adjust the starting frequency and slope of the local radar and calculate the starting frequency range of the attack waveform; S3. Adjusting the radar waveform parameters of the local end according to the starting frequency range; Receive the echo signal and intermediate frequency signal of a single Chirp, and roughly estimate the number of Chirs in the attack waveform based on the echo signal and the intermediate frequency signal; Roughly estimating the attack waveform duration and the attack waveform slope according to the number of chirps in the attack waveform; Roughly estimating the attack waveform starting frequency based on the local radar waveform parameters, the attack waveform slope, and the echo flight time; S4. Calculating an initial rotation order based on the attack waveform slope, and obtaining an optimal order through a fixed-step search; and performing a detailed estimation of the attack waveform slope and the attack waveform starting frequency using a time-frequency transform based on the optimal order to obtain an updated attack waveform slope and an updated attack waveform starting frequency. S5. Adjust the local radar waveform parameters according to the echo flight time, the updated attack waveform slope, and the updated attack waveform starting frequency, and adjust the local radar target perception and attack waveform parameter estimation time according to the attack waveform parameters and the attack waveform duration.

2. The method for resisting radar attack according to claim 1, characterized in that: In step S1, the attack waveform is received and the echo flight time is calculated, including: S1-1. Enable the receiving antenna and transmitting antenna of the local radar; S1-2. Judgment If yes, execute S1-4, otherwise execute S1-3, where Initialize the flag for radar parameters; S1-3. Set the local radar waveform parameters: , , ,in, is the starting frequency, is the slope, is the minimum starting frequency, is the maximum slope; Transmitting a single Chirp signal is : in, , is the number of Chirp sampling points, The superscript is the square operation; S1-4, the echo signal of receiving a single Chirp is , the intermediate frequency signal is : in, , For low-pass filtering operation, is the time-frequency transform operation, superscript is the conjugate negation operation; S1-5. Judgment If yes, execute S1-6, otherwise execute S1-4, where To calculate the signal amplitude operation, for Amplitude threshold; S1-6. Get the echo beat frequency index value array : in, ; S1-7. Get the maximum amplitude echo beat frequency index value : in, To obtain the maximum value operation; S1-8, calculating the echo flight time : in, is the radar sampling rate.

3. The method for resisting radar attack according to claim 2, characterized in that: In step S2, adjusting the starting frequency and slope of the local radar and calculating the starting frequency range of the attack waveform includes: S2-1. Setting cycle threshold : in, , , is the maximum starting frequency, is the intermediate frequency bandwidth; S2-2. Enable the receiving antenna, disable the transmitting antenna, and set the starting frequency and slope of the local radar: ， in, ; S2-3, the echo signal of a single Chirp is received , the intermediate frequency signal is : in, ; S2-4. Judgment If yes, execute S2-5, otherwise, execute S2-6, where for Amplitude threshold; S2-5. Store the index value into the array : Calculate the frequency value and store it in an array : in, for Index value, ; S2-6, Setting ,judge If yes, execute S2-7, otherwise execute S2-3, where for Count value threshold; S2-7, Setting , ; S2-8, Judgment If yes, execute S2-9, otherwise execute S2-2; S2-9. Calculate the starting frequency range of the attack waveform.

4. The method for resisting radar attack according to claim 3, characterized in that: In step S2-9, calculating the starting frequency range of the attack waveform includes: Calculate the lower boundary of the attack waveform starting frequency : in, To take the minimum value operation; Calculate the upper limit of the attack waveform starting frequency : 。 5. The method for resisting radar attack according to claim 4, characterized in that: In step S3, the radar waveform parameters of the local end are adjusted according to the starting frequency range; the echo signal and the intermediate frequency signal of a single chirp are received, and the number of chirps in the attack waveform is roughly estimated based on the echo signal and the intermediate frequency signal; the attack waveform duration and the attack waveform slope are roughly estimated based on the number of chirps in the attack waveform; The method of roughly estimating the attack waveform starting frequency according to the local radar waveform parameters, the attack waveform slope, and the echo flight time includes: S3-1, enable the receiving antenna, turn off the transmitting antenna, set , ; S3-2. Configure the local radar starting frequency array : in, ; Set the local radar waveform parameters: ， S3-3, the echo signal of a single Chirp is received , the intermediate frequency signal is : in, ; S3-4. Judgment If yes, execute S3-5, otherwise execute S3-6, where for Amplitude threshold; S3-5. Store the index into the array : in, is a set of index values, , To calculate the number of data; calculate The number of second-dimensional data and store it in an array : ； S3-6, Setting ,judge If yes, execute S3-7, otherwise execute S3-3, where for Count value threshold; S3-7, Setting , ; S3-8, Judgment If yes, execute S3-9, otherwise execute S3-2; S3-9. Calculate the number of chirps in one frame of the attack waveform : in, For the sum operation, For the rounding operation, ; S3-10. Get the maximum number of index values : ； S3-11. Calculate the duration of the attack radar's transmitted waveform : in, is the radar sampling time, ; S3-12, calculating the slope of the attack waveform : ； S3-13, yes The signal is phase compensated to obtain the compensated signal : ； S3-14, yes Perform time-frequency transformation to obtain frequency domain signal : in, ; S3-15. Calculate the starting frequency of the attack waveform : in, , .

6. The method for resisting radar attack according to claim 5, characterized in that: In step S4, an initial rotation order is calculated according to the attack waveform slope, and an optimal order is obtained by fixed step search; based on the optimal order, the attack waveform slope and the attack waveform starting frequency are finely estimated using time-frequency transformation to obtain an updated attack waveform slope and an updated attack waveform starting frequency, including: S4-1. Enable the receiving antenna of the local radar, disable the transmitting antenna, and set the waveform parameters of the local radar. ， ； S4-2, the echo signal of a single Chirp is received , intermediate frequency signal : in, ; S4-3, setting the initial rotation order : Initial rotation factor : in, To calculate the inverse tangent operation, the initial search step size is , Set a value for the search step size; S4-4. Set the initial search space: ; S4-5. In the search space, With a fixed search step Compute the fractional Fourier transform, , obtain the rotation factor and rotation order corresponding to the maximum amplitude of the fractional Fourier transform, where is the fractional Fourier transform, superscript is the rotation factor, is the fractional Fourier transform domain, is the rotation factor corresponding to the maximum amplitude of the fractional Fourier transform, is the rotation order corresponding to the maximum amplitude of the fractional Fourier transform; S4-6, Judgment If yes, execute S4-7, otherwise, execute S4-10; S4-7, Judgment If yes, execute S4-8, otherwise, execute S4-9; S4-8. Set up a new search space: , in, is the search step scale factor; S4-9. Set up a new search space: ; S4-10, set a new search step: And the rotation order: ; S4-11, Judgment If yes, execute S4-12, otherwise execute S4-5, where is the accuracy threshold; S4-12, obtain the optimal rotation factor: And the rotation order: ; S4-13, using the optimal rotation factor and rotation order to perform parameter estimation and update the attack waveform slope and the attack waveform starting frequency : ； S4-14. Calculate the attack waveform amplitude : 。 7. The method for resisting radar attack according to claim 6, characterized in that: In step S5, adjusting the local radar waveform parameters according to the echo flight time, the updated attack waveform slope, and the updated attack waveform starting frequency, and adjusting the local radar target perception and attack waveform parameter estimation time according to the attack waveform parameters and the attack waveform duration, including: S5-1. Enable the local radar receiving antenna and transmitting antenna and set the waveform parameters: ； S5-2, the echo signal of receiving a single Chirp is , intermediate frequency signal : in, ; S5-3. Judgment If yes, execute S5-3, otherwise execute S5-2; S5-4. Store the peak index into the array : in, Is a set of index values, ranging from ; calculate length: ； S5-5. Calculate the duration of a chirp in the attack waveform : ； S5-6. Calculate the idle duration of the attack waveform : ； S5-7, set the starting frequency of the local radar : ； S5-8, set the slope : ； S5-9. Calculating bandwidth : ； S5-10, the echo signal of receiving a single Chirp is , intermediate frequency signal : ； S5-11. Calculate target distance : in, It is a set union operation; S5-12, calculating the attack radar distance : in, is the index value, .

8. An anti-radar attack system, characterized in that: include: The receiving module is used to receive the attack waveform and calculate the echo flight time; A preliminary identification module is used to adjust the starting frequency and slope of the local radar and calculate the starting frequency range of the attack waveform; a coarse estimation module, configured to adjust the local radar waveform parameters according to the starting frequency range; receive the echo signal and intermediate frequency signal of a single chirp, and coarsely estimate the number of chirps in the attack waveform based on the echo signal and the intermediate frequency signal; coarsely estimate the attack waveform duration and attack waveform slope based on the number of chirps in the attack waveform; and coarsely estimate the attack waveform starting frequency based on the local radar waveform parameters, the attack waveform slope, and the echo flight time; a fine estimation module, configured to calculate an initial rotation order based on the attack waveform slope and obtain an optimal order through a fixed-step search; and based on the optimal order, to perform a fine estimation of the attack waveform slope and the attack waveform starting frequency using a time-frequency transform to obtain an updated attack waveform slope and an updated attack waveform starting frequency; An adaptive module is used to adjust the local radar waveform parameters according to the echo flight time, the updated attack waveform slope, and the updated attack waveform starting frequency, and to adjust the local radar target perception and attack waveform parameter estimation time according to the attack waveform parameters and the attack waveform duration.

9. A computer program product comprising a computer program or computer executable instructions, characterized in that When the computer program or computer executable instructions are executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that The storage medium stores at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to implement the method according to any one of claims 1 to 7.

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