阅读说明：本技术 一种抗转发式干扰方法及装置 (Anti-forwarding interference method and device ) 是由 尹园威 赵杨 刘利民 韩壮志 马俊涛 于 2021-09-15 设计创作，主要内容包括：本发明公开了一种抗转发式干扰方法及装置,所述方法包括：根据构建的相位编码下的回波信号,构建所述回波信号的稀疏模型,并对所述稀疏模型进行压缩观测,根据获取的压缩观测结果构建压缩感知模型；计算所述相位编码下的回波信号与间歇采样干扰信号的匹配滤波结果；通过所述匹配滤波结果为所述压缩感知模型提供估计值,根据压缩感知模型对干扰样式进行识别,本发明通过匹配滤波为相位编码下的压缩感知模型提供干扰信号估计值,以使相位编码体制雷达具备对转发式干扰信号的认知能力。(The invention discloses a method and a device for resisting forwarding interference, wherein the method comprises the following steps: constructing a sparse model of the echo signal according to the constructed echo signal under the phase coding, carrying out compression observation on the sparse model, and constructing a compression sensing model according to the obtained compression observation result; calculating a matched filtering result of the echo signal and the intermittent sampling interference signal under the phase coding; according to the method, the interference signal estimation value is provided for the compressed sensing model under the phase coding through the matched filtering, so that the phase coding system radar has the cognitive ability on the forwarding interference signal.)

1. A method for mitigating interference, comprising:

constructing a sparse model of the echo signal according to the constructed echo signal under the phase coding, carrying out compression observation on the sparse model, and constructing a compression sensing model according to the obtained compression observation result;

calculating a matched filtering result of the echo signal and the intermittent sampling interference signal under the phase coding;

and providing an estimation value for the compressed sensing model according to the matched filtering result, and identifying an interference pattern according to the compressed sensing model.

2. The method according to claim 1, wherein a sparse model of the echo signal is constructed according to the constructed echo signal under the phase coding, and the sparse model is subjected to compressed observation, and constructing a compressed sensing model according to the obtained compressed observation result specifically comprises:

constructing a sparse model according to equation 1 as:

x ═ H σ + epsilon formula 1;

h is a sparse basis matrix of the echo signal, sigma is a sparse scattering vector corresponding to the time delay-frequency shift position, and epsilon is an active interference and noise signal in a coherent processing period;

carrying out compression observation on the sparse model to obtain a compression observation result shown as a formula 2:

y ═ Φ x ═ Φ (H σ + epsilon) ═ a σ + z formula 2;

phi is a Gaussian random measurement matrix with compression ratio of M/N, H is a sparse basis matrix of echo signals, sigma is a sparse scattering vector corresponding to a time delay-frequency shift position, epsilon is an active interference and noise signal in a coherent processing period, and A is MxK_τK_fA dimensional sensing matrix, wherein z is an Mx 1 dimensional interference noise measurement vector;

and constructing a compressed sensing model for the compressed observation result according to a formula 3:

where δ is a constant whose magnitude is related to the noise level.

3. The method of claim 1, wherein the intermittently sampled jammer signals include intermittently sampled direct-on jammers and intermittently sampled repeated-on jammers;

the calculating of the matched filtering result of the echo signal and the intermittent sampling interference signal under the phase encoding specifically includes:

by performing matched filtering on the echo signal under phase encoding, an output signal as shown in formula 4 is obtained:

wherein t is the time domain within the pulse width time,a phase value corresponding to the mth symbol, L_sIs the code length, tau₀The code width is the number of the code width,representing a matched filtered output envelope with an amplitude less than 1,a normalized autocorrelation function representing a waveform;

obtaining the matched filtering output of the intermittent sampling direct forwarding type interference through a formula 5;

wherein p is the code length of the intermittent sampling direct forwarding interference signal, tau₀The code width is the number of the code width,a phase value corresponding to the mth symbol, a_mRepresenting the amplitude of the corresponding mth encoded sample signal;

obtaining the matched filtering output of the intermittent sampling repeated forwarding type interference through a formula 6;

wherein the content of the first and second substances, a code sequence representing repeated retransmission interference.

4. The method according to claim 1, wherein the identifying the interference pattern according to the compressed sensing model specifically comprises:

identifying the interference pattern according to the compressed sensing model and converting the interference pattern into judgment of a formula 7;

sum (g) function represents that the absolute value of the non-zero element in the output vector sigma of the statistical matched filter is greater thanThe number of the (c) is,is an experimentally determined threshold;

H₀the established interference pattern is intermittent sampling direct forwarding type interference, and a time domain expression, H, of the intermittent sampling direct forwarding type interference is determined through a formula 8₁If the interference pattern is the intermittent sampling repeated forwarding type interference, determining a time domain expression of the intermittent sampling repeated forwarding type interference through a formula 9;

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the time delay between two peaks of the projection vector, τ_d≤T_sT is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,

wherein a () is correspondingThe magnitude of the time of day is,for polyphase coding functions, τ_dFor the number of false targets of the projection vector and the time delay between the peaks, τ_d≤T_s(b +1), T is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,k＝1:b，b≥2。

5. an anti-retransmission interference apparatus, comprising:

the compressed sensing module is used for constructing a sparse model of the echo signal according to the constructed echo signal under the phase coding, carrying out compressed observation on the sparse model and constructing a compressed sensing model according to the obtained compressed observation result;

the matched filtering module is used for calculating a matched filtering result of the echo signal and the intermittent sampling interference signal under the phase coding;

and the interference strategy estimation module provides an estimation value for the compressed sensing model through the matched filtering result and identifies an interference pattern according to the compressed sensing model.

6. The apparatus according to claim 5, wherein the compressed sensing module specifically comprises:

a sparse model is constructed according to equation 10 as:

x ═ H σ + σ equation 10;

h is a sparse basis matrix of the echo signal, sigma is a sparse scattering vector corresponding to the time delay-frequency shift position, and epsilon is an active interference and noise signal in a coherent processing period;

performing compression observation on the sparse model to obtain a compression observation result shown in a formula 11:

y ═ Φ x ═ Φ (H σ + epsilon) ═ a σ + z formula 11;

wherein phiIs a Gaussian random measurement matrix with compression ratio of M/N, H is a sparse basis matrix of echo signals, sigma is a sparse scattering vector corresponding to a time delay-frequency shift position, epsilon is an active interference and noise signal in a coherent processing period, A is MxK_τK_fA dimensional sensing matrix, wherein z is an Mx 1 dimensional interference noise measurement vector;

and constructing a compressed sensing model for the compressed observation result according to a formula 12:

where δ is a constant whose magnitude is related to the noise level.

7. The apparatus of claim 5, wherein the matched filtering module specifically comprises:

the intermittent sampling interference signal comprises intermittent sampling direct forwarding interference and intermittent sampling repeated forwarding interference;

by performing matched filtering on the echo signal under phase encoding, an output signal as shown in equation 13 is obtained:

wherein t is the time domain within the pulse width time,a phase value corresponding to the mth symbol, L_sIs the code length, tau₀The code width is the number of the code width,representing a matched filtered output envelope with an amplitude less than 1,a normalized autocorrelation function representing a waveform;

obtaining the matched filtering output of the intermittent sampling direct forwarding interference through a formula 14;

wherein p is the code length of the intermittent sampling direct forwarding interference signal, tau₀The code width is the number of the code width,a phase value corresponding to the mth symbol, a_mRepresenting the amplitude of the corresponding mth encoded sample signal;

obtaining the matched filtering output of the intermittent sampling repeated forwarding type interference through a formula 15;

wherein the content of the first and second substances, a code sequence representing repeated retransmission interference.

8. The apparatus according to claim 5, wherein the interference policy estimation module specifically includes:

identifying the interference pattern according to the compressed sensing model and converting the interference pattern into judgment of a formula 16;

sum (g) function represents that the absolute value of the non-zero element in the output vector sigma of the statistical matched filter is greater thanThe number of the (c) is,is an experimentally determined threshold;

H₀the established interference pattern is the intermittent sampling direct forwarding type interference, and the time domain expression, H, of the intermittent sampling direct forwarding type interference is determined through a formula 17₁If the interference pattern is the intermittent sampling repeated forwarding type interference, determining a time domain expression of the intermittent sampling repeated forwarding type interference through a formula 18;

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the time delay between two peaks of the projection vector, τ_d≤T_sT is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the number of false targets of the projection vector and the time delay between the peaks, τ_d≤T_s(b +1), T is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIs an intermittent sampling period，k＝1:b，b≥2。

9. An anti-retransmission interference apparatus, comprising: memory, processor and computer program stored on the memory and executable on the processor, which when executed by the processor implements the steps of the anti-forward interference method according to any of claims 1 to 4.

10. A computer-readable storage medium, on which an information transfer implementing program is stored, which, when executed by a processor, implements the steps of the anti-forward interference method according to any one of claims 1 to 4.

Technical Field

The invention relates to the technical field of radar anti-interference, in particular to a method and a device for resisting forwarding interference.

Background

The phase coding signal has been applied in some existing radar equipment, but is limited by the traditional code pattern itself and a signal processing algorithm, and the research on the coding waveform under the CSR system of the compressed sensing radar needs to be further advanced. Common traditional phase coding signals include a barker code, a Frank code and the like, but are influenced by main lobe broadening and side lobe peak level output by signal processing, the code pattern of the signals is relatively fixed, and the signal length can be restricted by code pattern definition and cannot be freely adjusted; on the basis of the code patterns, expert scholars continue to provide a Costas code pattern which is a nonlinear frequency hopping spread spectrum code pattern in essence, namely, the disadvantage of the traditional stepping frequency code pattern on the resolution is changed through nonlinear frequency hopping, so that the fuzzy function of the code pattern is approximate to an ideal pin-type fuzzy function; the expert scholars further propose LFM-Costas and NLFM-Costas code patterns on the basis of the above technical proposal, namely LFM and NLFM strategies are used in the pulse, and Costas sequence modulation strategies are used between the pulses, so as to further enhance the resolving power of the code patterns and inhibit the harmonic components of the code patterns.

Based on the optimization direction of the traditional phase coding signals, the code pattern design process can improve the target resolution performance mainly by widening the time-width bandwidth product form of the signals, and the large time-width bandwidth product signals have heavier burden on the sampling and processing process of the traditional radar; the CSR can obviously reduce the sampling requirement on the signals, more calculated amount of the CSR in the target scene reconstruction process is related to the reconstruction algorithm and the sparsity and is unrelated to the complexity of the waveform, so the calculation cost of the CSR in processing the complex waveform is similar to that of processing a simple waveform, the frequency band broadening brought by the multiphase coding is no longer a main factor influencing the signal processing process, and the increase of the fine characteristics of the signals brought by the multiphase random coding and other modes is beneficial to realizing the identification of the interference signals and improving the resolution performance of the signals.

Disclosure of Invention

The present invention provides a method and an apparatus for anti-forwarding interference, which aim to solve the above problems in the prior art.

The invention provides an anti-forwarding interference method, which comprises the following steps:

constructing a sparse model of the echo signal according to the constructed echo signal under the phase coding, carrying out compression observation on the sparse model, and constructing a compression sensing model according to the obtained compression observation result;

calculating a matched filtering result of the echo signal and the intermittent sampling interference signal under the phase coding;

and providing an estimation value for the compressed sensing model through a matched filtering result, and identifying the interference pattern according to the compressed sensing model.

Further, according to the echo signal under the constructed phase coding, constructing a sparse model of the echo signal, performing compressed observation on the sparse model, and constructing a compressed sensing model according to the obtained compressed observation result specifically includes:

constructing a sparse model according to equation 1 as:

x ═ H σ + epsilon formula 1;

h is a sparse basis matrix of the echo signal, sigma is a sparse scattering vector corresponding to the time delay-frequency shift position, and epsilon is an active interference and noise signal in a coherent processing period;

carrying out compression observation on the sparse model to obtain a compression observation result shown in a formula 2:

y ═ Φ x ═ Φ (H σ + epsilon) ═ a σ + z formula 2;

phi is a Gaussian random measurement matrix with compression ratio of M/N, H is a sparse basis matrix of echo signals, sigma is a sparse scattering vector corresponding to a time delay-frequency shift position, epsilon is an active interference and noise signal in a coherent processing period, and A is MxK_τK_fA dimensional sensing matrix, wherein z is an Mx 1 dimensional interference noise measurement vector;

and constructing a compressed sensing model for the compressed observation result according to a formula 3:

where δ is a constant whose magnitude is related to the noise level.

Further, the intermittently sampled interference signal includes intermittently sampled direct forwarding interference and intermittently sampled repeated forwarding interference;

the step of calculating the matched filtering result of the echo signal and the intermittent sampling interference signal under the phase coding specifically comprises the following steps:

by performing matched filtering on the echo signal under phase encoding, an output signal as shown in formula 4 is obtained:

wherein t is the time domain within the pulse width time,a phase value corresponding to the mth symbol, L_sIs the code length, tau₀The code width is the number of the code width,representing a matched filtered output envelope with an amplitude less than 1,a normalized autocorrelation function representing a waveform;

obtaining the matched filtering output of the intermittent sampling direct forwarding type interference through a formula 5;

wherein p is the code length of the intermittent sampling direct forwarding interference signal, tau₀The code width is the number of the code width,a phase value corresponding to the mth symbol, a_mRepresenting the amplitude of the corresponding mth encoded sample signal;

obtaining the matched filtering output of the intermittent sampling repeated forwarding type interference through a formula 6;

wherein the content of the first and second substances, a coded sequence representing intermittently sampled repetitive retransmission interference.

Further, identifying the interference pattern according to the compressed sensing model specifically includes:

identifying the interference pattern according to the compressed sensing model and converting the interference pattern into judgment of a formula 7;

sum (g) function represents that the absolute value of the non-zero element in the output vector sigma of the statistical matched filter is greater thanThe number of the (c) is,is an experimentally determined threshold;

H₀the established interference pattern is intermittent sampling direct forwarding type interference, and a time domain expression, H, of the intermittent sampling direct forwarding type interference is determined through a formula 8₁If the interference pattern is the intermittent sampling repeated forwarding type interference, determining a time domain expression of the intermittent sampling repeated forwarding type interference through a formula 9;

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the time delay between two peaks of the projection vector, τ_d≤T_sT is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the number of false targets of the projection vector and the time delay between the peaks, τ_d≤T_s(b +1), T is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,k＝1:b，b≥2。

the invention provides an anti-forwarding interference device, comprising:

the compressed sensing module is used for constructing a sparse model of the echo signal according to the constructed echo signal under the phase coding, carrying out compressed observation on the sparse model and constructing a compressed sensing model according to the obtained compressed observation result;

the matched filtering module is used for calculating a matched filtering result of the echo signal and the intermittent sampling interference signal under the phase coding;

and the interference strategy estimation module provides an estimation value for the compressed sensing model through the matched filtering result and identifies the interference pattern according to the compressed sensing model.

Further, the compressed sensing module specifically includes:

a sparse model is constructed according to equation 10 as:

x ═ H σ + epsilon formula 10;

h is a sparse basis matrix of the echo signal, sigma is a sparse scattering vector corresponding to the time delay-frequency shift position, and epsilon is an active interference and noise signal in a coherent processing period;

performing compression observation on the sparse model to obtain a compression observation result shown in formula 11:

y ═ Φ x ═ Φ (H σ + epsilon) ═ a σ + z formula 11;

phi is a Gaussian random measurement matrix with compression ratio of M/N, H is a sparse basis matrix of echo signals, sigma is a sparse scattering vector corresponding to a time delay-frequency shift position, epsilon is an active interference and noise signal in a coherent processing period, and A is MxK_τK_fA dimensional sensing matrix, wherein z is an Mx 1 dimensional interference noise measurement vector;

and constructing a compressed sensing model for the compressed observation result according to formula 12:

where δ is a constant whose magnitude is related to the noise level.

Further, the matched filtering module specifically includes:

the intermittent sampling interference signal comprises intermittent sampling direct forwarding interference and intermittent sampling repeated forwarding interference;

by performing matched filtering on the echo signal under phase encoding, an output signal as shown in equation 13 is obtained:

wherein t is the time domain within the pulse width time,a phase value corresponding to the mth symbol, L_sIs the code length, tau₀The code width is the number of the code width,representing a matched filtered output envelope with an amplitude less than 1,a normalized autocorrelation function representing a waveform;

obtaining the matched filtering output of the intermittent sampling direct forwarding interference through a formula 14;

wherein p is the code length of the intermittent sampling direct forwarding interference signal, tau₀The code width is the number of the code width,a phase value corresponding to the mth symbol, a_mRepresenting the amplitude of the corresponding mth encoded sample signal;

obtaining the matched filtering output of the intermittent sampling repeated forwarding type interference through a formula 15;

wherein the content of the first and second substances, a code sequence representing repeated retransmission interference.

Further, the interference strategy estimation module specifically includes:

identifying the interference pattern according to the compressed sensing model and converting the interference pattern into judgment of a formula 16;

sum (g) function represents that the absolute value of the non-zero element in the output vector sigma of the statistical matched filter is greater thanThe number of the (c) is,is an experimentally determined threshold;

H₀the established interference pattern is the intermittent sampling direct forwarding type interference, and the time domain expression, H, of the intermittent sampling direct forwarding type interference is determined through a formula 17₁If the interference pattern is the intermittent sampling repeated forwarding type interference, determining a time domain expression of the intermittent sampling repeated forwarding type interference through a formula 18;

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the time delay between two peaks of the projection vector, τ_d≤T_sT is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the number of false targets of the projection vector and the time delay between the peaks, τ_d≤T_s(b +1), T is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,k＝1:b，b≥2。

an embodiment of the present invention further provides an apparatus for resisting forwarding interference, including: a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program, when executed by the processor, implementing the steps of the anti-forward jamming method described above.

The embodiment of the present invention further provides a computer-readable storage medium, where an implementation program for information transfer is stored on the computer-readable storage medium, and the implementation program, when executed by a processor, implements the steps of the anti-forwarding interference method.

By adopting the embodiment of the invention, the interference strategy and the slice length are estimated by utilizing the difference of the true and false targets after the matched filtering on the time delay, so that the phase coding system radar has the cognitive capability on the forwarding interference signal.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a flow chart of an anti-forwarding interference method according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an intermittent sampling direct-forwarding interference scheme according to an embodiment of the present invention;

FIG. 3 is an intermittent sample repeat and forward interference schematic of an embodiment of the present invention;

FIG. 4 is a block diagram of an anti-forwarding interference apparatus according to an embodiment of the present invention;

FIG. 5 is a block diagram of a second embodiment of the apparatus of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. Furthermore, the terms "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Method embodiment

According to an embodiment of the present invention, a method for preventing forward interference is provided, fig. 1 is a flowchart of the method for preventing forward interference according to the embodiment of the present invention, and as shown in fig. 1, the method for preventing forward interference according to the embodiment of the present invention specifically includes:

step S101, constructing a sparse model of the echo signal according to the constructed echo signal under the phase coding, performing compressed observation on the sparse model, and constructing a compressed sensing model according to the obtained compressed observation result, wherein the step S101 specifically comprises:

constructing a sparse model according to equation 1 as:

x ═ H σ + epsilon formula 1;

h is a sparse basis matrix of the echo signal, sigma is a sparse scattering vector corresponding to the time delay-frequency shift position, and epsilon is an active interference and noise signal in a coherent processing period;

carrying out compression observation on the sparse model to obtain a compression observation result shown in a formula 2:

y ═ Φ x ═ Φ (H σ + epsilon) ═ a σ + z formula 2;

phi is a Gaussian random measurement matrix with compression ratio of M/N, H is a sparse basis matrix of echo signals, sigma is a sparse scattering vector corresponding to a time delay-frequency shift position, epsilon is an active interference and noise signal in a coherent processing period, and A is MxK_τK_fA dimensional sensing matrix, wherein z is an Mx 1 dimensional interference noise measurement vector;

and constructing a compressed sensing model for the compressed observation result according to a formula 3:

where δ is a constant, the magnitude being related to the noise level;

formula 3 is l₀And (4) converting the norm optimization problem into a convex optimization problem in the solving process.

Step S102, calculating a matched filtering result of the echo signal and the intermittent sampling interference signal under the phase encoding, wherein the step S102 specifically includes:

the intermittent sampling interference signal comprises intermittent sampling direct forwarding type interference and intermittent sampling repeated forwarding type interference, the principle of the intermittent sampling direct forwarding type interference is shown in fig. 2, the principle of the intermittent sampling repeated forwarding type interference is shown in fig. 3, and forwarding a-b in fig. 3 represents that the b-th time forwards the a-th time sampling;

the step of calculating the matched filtering result of the echo signal and the intermittent sampling interference signal under the phase coding specifically comprises the following steps:

by performing matched filtering on the echo signal under phase encoding, an output signal as shown in formula 4 is obtained:

wherein t is the time domain within the pulse width time,a phase value corresponding to the mth symbol, L_sIs the code length, tau₀The code width is the number of the code width,representing a matched filtered output envelope with an amplitude less than 1,a normalized autocorrelation function representing a waveform;

obtaining the matched filtering output of the intermittent sampling direct forwarding type interference through a formula 5;

wherein p is the code length of the intermittent sampling direct forwarding interference signal, tau₀The code width is the number of the code width,a phase value corresponding to the mth symbol, a_mRepresenting the amplitude of the corresponding mth encoded sample signal;

by comparing equation 4 with equation 5, it is found that intermittent sampling is usedThe direct forwarding interference interferes the echo signal, the interference signal generates a false target with a certain time delay after matched filtering processing after matched filtering, and the time delay is determined by tau, namely the longer the signal sampling time is, the larger the time delay is. When the interference power is not amplified, the amplitude of the false target is related to the number of coded signals in the sampled signal, and the larger the number of codes is, namely a_mThe larger the number of 1, the larger the amplitude of the decoy.

Obtaining the matched filtering output of the intermittent sampling repeated forwarding type interference through a formula 6;

wherein the content of the first and second substances, a code sequence representing repeated retransmission interference;

when the intermittent sampling repeated forwarding interference only forwards the radar signal intercepted in the current sampling signal between two sampling intervals, the interference is analyzedThe actual physical meaning of (A) is known, each forwarding slice of the repeated forwarding interference is still the cycle delay of the a-th sampling, the delay cycle is tau, the delay times are B, at this time, in the forwarding cycle based on the a-th sampling, B false targets are generated, and B (B belongs to [1, B)]) The time delay of each decoy is B tau, and the size of B is determined by the duty ratio set by the jammer. The amplitude of each decoy is still determined by the number of symbols in the sampling time, and the longer the sampling time is, the larger the amplitude is.

The intermittent sampling direct forwarding interference and the intermittent sampling repeated forwarding interference interfere the normal operation of the radar in a mode of forming one or more false targets behind a real target, however, no matter the transmission is direct or repeated, if the power of the interference signal is not adjusted, the interference signal is difficult to suppress the true target signal after the matched filtering output, so the jammer usually amplifies the pulse signal obtained by intermittent sampling to a certain extent and then transmits the pulse signal, the interference parameter estimation can not be directly carried out by comparing the false target amplitude and the real target amplitude output by the matched filtering, the interference delay caused by direct forwarding and repeated forwarding is determined by the pulse width tau of the intermittent sampling slice, the difference is the number of the false targets, and the interference strategy and the slice length are estimated by utilizing the difference of the true and false targets in time delay after the matched filtering.

Step S103, providing an estimation value for the compressed sensing model through a matched filtering result, and identifying an interference pattern according to the compressed sensing model, wherein the step S103 specifically comprises the following steps:

identifying the interference pattern according to the compressed sensing model and converting the interference pattern into judgment of a formula 7;

sum (g) function represents that the absolute value of the non-zero element in the output vector sigma of the statistical matched filter is greater thanThe number of the (c) is,is an experimentally determined threshold;

H₀the established interference pattern is intermittent sampling direct forwarding type interference, and a time domain expression, H, of the intermittent sampling direct forwarding type interference is determined through a formula 8₁If the interference pattern is the intermittent sampling repeated forwarding type interference, determining a time domain expression of the intermittent sampling repeated forwarding type interference through a formula 9;

wherein a () is pairIn response to the magnitude of the time of day,for polyphase coding functions, τ_dFor the time delay between two peaks of the projection vector, τ_d≤T_sT is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the number of false targets of the projection vector and the time delay between the peaks, τ_d≤T_s(b +1), T is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,k＝1:b，b≥2。

a simulation experiment of this method embodiment is as follows:

the phase encoded signal is set to an M sequence of 127 bits, symbol width 1 mus, pulse width 127 mus, amplitude 1. The method comprises the following steps of setting a plurality of groups of direct forwarding interference parameters as follows: firstly, intermittently sampling a pulse width tau of 10 mus, and keeping a duty ratio of 0.5; τ is 10 μ s, duty cycle 0.25; ③ 20 mus, duty ratio 0.5; r τ is 20 μ s, and the duty ratio is 0.4.

The method is obtained by directly forwarding interference matched filtering output through intermittent sampling, the amplitude of a false target is related to the duty ratio, the larger the duty ratio is, the larger the amplitude of the false target is, but interference equipment can increase the amplitude of the matched filtering output of the false target through a power modulation means, so that the radar cannot directly utilize energy parameters to identify interference signals; meanwhile, the false target delay time corresponds to the intermittent sampling pulse width one by one, the interference mode can be identified by utilizing the information, and the rough estimation of the interference power spectrum is obtained by combining the pulse pressure output amplitude.

The method comprises the following steps of setting a plurality of groups of repeated forwarding interference to be a whole-mining and whole-rotating mode, wherein the specific parameters are as follows: intermittent sampling pulse width tau is 10 mus, interference repetition period T_s＝30μs；②τ＝10μs，T_s＝40μs；③τ＝20μs，T_s＝60μs；④τ＝20μs，T_s＝80μs。

Intermittent sampling repeat-and-forward interference can increase the number of false targets through multiple slicing, but the reduction of the duty ratio can cause the pulse pressure output amplitude of the false targets to be reduced, so that the repeat-and-forward interference needs more gain compensation than direct repeat-and-forward interference. Meanwhile, the delay time of the false target relative to the true target is in one-to-one correspondence with the intermittent sampling pulse width, and after the number of the false targets is obtained, the time domain expression of repeated forwarding interference can be determined through the judgment of the delay time.

The interference signal is estimated under the current coding waveform under the CS theoretical framework, so that the phase coding system radar has the cognitive ability on the forwarding interference signal, and a foundation is laid for further improving the adaptability of CSR under the interference background.

Apparatus embodiment one

According to an embodiment of the present invention, there is provided an anti-forwarding jamming device, fig. 4 is a schematic diagram of the anti-forwarding jamming device according to the embodiment of the present invention, as shown in fig. 4, the anti-forwarding jamming device according to the embodiment of the present invention specifically includes:

the compressed sensing module 40 is configured to construct a sparse model of the echo signal according to the constructed echo signal under the phase coding, perform compressed observation on the sparse model, and construct a compressed sensing model according to the obtained compressed observation result, where the compressed sensing module 40 is specifically configured to:

a sparse model is constructed according to equation 10 as:

x ═ H σ + epsilon formula 10;

h is a sparse basis matrix of the echo signal, sigma is a sparse scattering vector corresponding to the time delay-frequency shift position, and epsilon is an active interference and noise signal in a coherent processing period;

performing compression observation on the sparse model to obtain a compression observation result shown in a formula 11:

y ═ Φ x ═ Φ (H σ + epsilon) ═ a σ + z formula 11;

phi is a Gaussian random measurement matrix with compression ratio of M/N, H is a sparse basis matrix of echo signals, sigma is a sparse scattering vector corresponding to a time delay-frequency shift position, epsilon is an active interference and noise signal in a coherent processing period, and A is MxK_τK_fA dimensional sensing matrix, wherein z is an Mx 1 dimensional interference noise measurement vector;

and constructing a compressed sensing model for the compressed observation result according to a formula 12:

where δ is a constant whose magnitude is related to the noise level.

A matched filtering module 41, configured to calculate a matched filtering result of the echo signal and the intermittent sampling interference signal under the phase encoding, where the matched filtering module 41 is specifically configured to:

the intermittent sampling interference signal comprises intermittent sampling direct forwarding interference and intermittent sampling repeated forwarding interference;

by performing matched filtering on the echo signal under phase encoding, an output signal as shown in equation 13 is obtained:

wherein t is the time domain within the pulse width time,a phase value corresponding to the mth symbol, L_sIs the code length, tau₀The code width is the number of the code width,representing a matched filtered output envelope with an amplitude less than 1,a normalized autocorrelation function representing a waveform;

obtaining the matched filtering output of the intermittent sampling direct forwarding interference through a formula 14;

wherein p is the code length of the intermittent sampling direct forwarding interference signal, tau₀The code width is the number of the code width,a phase value corresponding to the mth symbol, a_mRepresenting the amplitude of the corresponding mth encoded sample signal;

obtaining the matched filtering output of the intermittent sampling repeated forwarding type interference through a formula 15;

wherein the content of the first and second substances, a code sequence representing repeated retransmission interference.

The interference policy estimation module 42 is configured to provide an estimation value for the compressed sensing model according to the matched filtering result, and identify an interference pattern according to the compressed sensing model, where the interference policy estimation module 42 is specifically configured to:

identifying the interference pattern according to the compressed sensing model and converting the interference pattern into judgment of a formula 16;

sum (g) function represents that the absolute value of the non-zero element in the output vector sigma of the statistical matched filter is greater thanThe number of the (c) is,is an experimentally determined threshold;

H₀the established interference pattern is the intermittent sampling direct forwarding type interference, and the time domain expression, H, of the intermittent sampling direct forwarding type interference is determined through a formula 17₁If the interference pattern is the intermittent sampling repeated forwarding type interference, determining a time domain expression of the intermittent sampling repeated forwarding type interference through a formula 18;

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the time delay between two peaks of the projection vector, τ_d≤T_sT is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,

where a () is the magnitude of the corresponding time instant,for polyphase coding functions, τ_dFor the number of false targets of the projection vector and the time delay between the peaks, τ_d≤T_s(b +1), T is the time domain within the pulse width time, T is more than or equal to 0 and less than or equal to T, T_sIn order to be an intermittent sampling period,k＝1:b，b≥2。

device embodiment II

An embodiment of the present invention provides an anti-forwarding interference apparatus, as shown in fig. 5, including: a memory 50, a processor 52 and a computer program stored on the memory 50 and executable on the process 352, which computer program, when executed by the processor 52, performs the steps as described in the method embodiments.

Device embodiment III

An embodiment of the present invention provides a computer-readable storage medium, on which an implementation program for information transmission is stored, and when the program is executed by the processor 52, the steps described in the method embodiment are implemented.

The computer-readable storage medium of this embodiment includes, but is not limited to: ROM, RAM, magnetic or optical disks, and the like.

The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

In the 30 s of the 20 th century, improvements in a technology could clearly be distinguished between improvements in hardware (e.g., improvements in circuit structures such as diodes, transistors, switches, etc.) and improvements in software (improvements in process flow). However, as technology advances, many of today's process flow improvements have been seen as direct improvements in hardware circuit architecture. Designers almost always obtain the corresponding hardware circuit structure by programming an improved method flow into the hardware circuit. Thus, it cannot be said that an improvement in the process flow cannot be realized by hardware physical modules. For example, a Programmable Logic Device (PLD), such as a Field Programmable Gate Array (FPGA), is an integrated circuit whose Logic functions are determined by programming the Device by a user. A digital system is "integrated" on a PLD by the designer's own programming without requiring the chip manufacturer to design and fabricate application-specific integrated circuit chips. Furthermore, nowadays, instead of manually making an Integrated Circuit chip, such Programming is often implemented by "logic compiler" software, which is similar to a software compiler used in program development and writing, but the original code before compiling is also written by a specific Programming Language, which is called Hardware Description Language (HDL), and HDL is not only one but many, such as abel (advanced Boolean Expression Language), ahdl (alternate Hardware Description Language), traffic, pl (core universal Programming Language), HDCal (jhdware Description Language), lang, Lola, HDL, laspam, hardward Description Language (vhr Description Language), vhal (Hardware Description Language), and vhigh-Language, which are currently used in most common. It will also be apparent to those skilled in the art that hardware circuitry that implements the logical method flows can be readily obtained by merely slightly programming the method flows into an integrated circuit using the hardware description languages described above.

The controller may be implemented in any suitable manner, for example, the controller may take the form of, for example, a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro) processor, logic gates, switches, an Application Specific Integrated Circuit (ASIC), a programmable logic controller, and an embedded microcontroller, examples of which include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320, the memory controller may also be implemented as part of the control logic for the memory. Those skilled in the art will also appreciate that, in addition to implementing the controller as pure computer readable program code, the same functionality can be implemented by logically programming method steps such that the controller is in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Such a controller may thus be considered a hardware component, and the means included therein for performing the various functions may also be considered as a structure within the hardware component. Or even means for performing the functions may be regarded as being both a software module for performing the method and a structure within a hardware component.

The systems, devices, modules or units illustrated in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. One typical implementation device is a computer. In particular, the computer may be, for example, a personal computer, a laptop computer, a cellular telephone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

For convenience of description, the above devices are described as being divided into various units by function, and are described separately. Of course, the functions of the units may be implemented in the same software and/or hardware or in multiple software and/or hardware when implementing the embodiments of the present description.

One skilled in the art will recognize that one or more embodiments of the present description may be provided as a method, system, or computer program product. Accordingly, one or more embodiments of the present description may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the description may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The description has been presented with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the description. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

One or more embodiments of the present description may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. One or more embodiments of the specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The above description is only an example of this document and is not intended to limit this document. Various modifications and changes may occur to those skilled in the art from this document. Any modifications, equivalents, improvements, etc. which come within the spirit and principle of the disclosure are intended to be included within the scope of the claims of this document.