Multi-false target interference modulation method and system based on normalization processing

Abstract

The invention discloses a normalization-processing-based multi-false-target interference modulation method and system. The normalization-processing-based multi-false-target interference modulation method comprises the following steps: firstly, acquiring an intercepted signal; carrying out time delay modulation processing on the intercepted signal; superposing an input signal before each stage of time delay modulation and an output signal after the stage of time delay modulation to serve as an input signal for the next stage of time delay modulation, so that the number of false targets and the stage of time delay modulation are in an exponential relationship; then, performing selective superposition processing on the output signal of each stage of time delay modulation, and then outputting a bit-cut signal; and finally, performing normalization processing on the cut signal and then outputting an interference signal, thereby realizing generation of more false targets under the condition of not increasing excessive hardware resources, improving the energy of the false target signal and further improving the interference effect.

Description

Technical Field

[0001] The invention relates to the technical field of electronic countermeasures, and in particular to a multi-false target interference modulation method and system based on normalization processing. Background Art

[0002] Electronic jamming technology is an important military technology in the field of radar confrontation, and it is widely used in various combat platforms such as sea, land, and air. Nowadays, radars include a variety of new radar systems such as pulse compression radar, pulse Doppler radar, and synthetic aperture radar, which have multiple combat modes such as search, tracking, and tracking while searching; and radar false target jamming technology can generate multiple false targets at different distances on the enemy radar display screen, create false battle situations, confuse the enemy's command decisions, and cover our targets. However, the existing false target jamming modulation is implemented by delay superposition, and the number of false targets is linearly related to the number of delay units, that is, when the number of false targets required is more and the cover distance is farther, the demand for hardware resources will increase; in addition, due to the bit width limitation, the signal after each superposition needs to be truncated, and the more delay units, the more truncation times will be, which will cause the energy of the jamming signal to continue to decrease and affect the jamming effect. Summary of the invention

[0003] The purpose of the present invention is to design a multi-false target interference modulation method based on normalization processing in order to solve the above problem.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions: The multi-false target interference modulation method based on normalization processing includes the following steps: Acquire intercepted signals; The intercepted signal is subjected to delay modulation processing: the input signal before each level of delay modulation is superimposed with the output signal after the delay modulation of the level and the resultant is used as the input signal of the next level of delay modulation, so that the number of false targets is exponentially related to the level of delay modulation; The output signals of each level of time delay modulation are selectively superimposed and then output as truncated signals; The truncated signal is normalized and then an interference signal is output.

[0005] The present invention also proposes a multi-false target interference modulation system based on normalization processing, which is used to implement the multi-false target interference modulation method based on normalization processing. The multi-false target interference modulation system based on normalization processing includes: A signal acquisition module, wherein the signal acquisition module is used to acquire intercepted signals; A time delay modulation module, the time delay modulation module is connected to the signal acquisition module, and the time delay modulation module is used to perform time delay modulation processing on the intercepted signal; A selective superposition module, the selective superposition module is connected to the time delay modulation module, and the selective superposition module is used to perform selective superposition processing on the output signal of the time delay modulation module and then output a truncated signal; A normalization processing module, the normalization processing module is connected to the selective superposition module, and the normalization processing module is used to output an interference signal after performing normalization processing on the truncated signal.

[0006] The beneficial effects of the present invention are: The multi-false target interference modulation method based on normalization processing first obtains the intercepted signal; then the intercepted signal is subjected to delay modulation processing: the input signal before each level of delay modulation is superimposed with the output signal after the delay modulation of that level as the input signal of the next level of delay modulation, so that the number of false targets is exponentially related to the delay modulation level; then, the output signal of each level of delay modulation is subjected to selective superposition processing to output the truncated signal; finally, the truncated signal is subjected to normalization processing to output the interference signal, thereby achieving the generation of more false targets without increasing too many hardware resources, and increasing the energy of the false target signal, thereby improving the interference effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a flow chart of a multi-false target interference modulation method based on normalization processing of the present invention; FIG2 is a comparison diagram of simulation results of the multi-false target interference modulation method based on normalization processing of the present invention and the existing interference modulation method, wherein FIG2(a) is a simulation diagram of the existing interference modulation method, and FIG2(b) is a simulation diagram of the multi-false target interference modulation method based on normalization processing of the present invention; Figure 3 A curve diagram of the number of false targets generated by the multi-false target interference modulation method based on normalization processing of the present invention and the existing interference modulation method; Figure 4 The interference effect diagram of 11 false targets is generated by 5 delay units of the multi-false target interference modulation method based on normalization processing of the present invention. DETAILED DESCRIPTION

[0008] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0009] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0010] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0011] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0012] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0013] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0014] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0015] like Figure 1-4 As shown, the multi-false target interference modulation method based on normalization processing includes the following steps: Acquire intercepted signals; The intercepted signal is subjected to delay modulation processing: the input signal before each level of delay modulation is superimposed with the output signal after the delay modulation of the level and the resultant is used as the input signal of the next level of delay modulation, so that the number of false targets is exponentially related to the level of delay modulation; The output signals of each level of time delay modulation are selectively superimposed and then output as truncated signals; The truncated signal is normalized and then an interference signal is output.

[0016] In one embodiment, the steps of the selective superposition processing are specifically as follows: When the delay time of each level meets T n =m 0 2 n-1 When n=1,2,3,...,N-1,N, uniformly spaced dense false targets are generated, m 0 is the time interval between false targets, T n is the delay time, and n is the number of delay modulation levels.

[0017] In one embodiment, the normalization process is specifically as follows: Firstly, the phase extraction process is performed on the truncated signal by cordic operation; Then, the truncated signal is subjected to phase recovery processing through icordic transformation.

[0018] In one embodiment, the step of performing phase extraction processing on the truncated signal through cordic operation is specifically: The intercept signal is , is the signal after superposition, A is the amplitude of the signal after superposition, and M is the number of superpositions; Through the cordic operation Extract the intercept signal Phase.

[0019] In one embodiment, the step of performing phase recovery processing on the truncated signal through icordic transformation is specifically: Through the icordic transformation The phase of the truncated signal is restored.

[0020] In this embodiment, it is assumed that the number of delay units is N, and only one adder is added to each delay unit, with a total of N adders, and no additional hardware resources are added, as shown in Formula ; If the output signal of each delay unit is output separately, the number of false targets is 1, 2, 4, 8, ..., 2 N-1 ; On this basis, selective superposition can produce 1~2 N -1 The number of false targets in any combination, the maximum number of false targets is 2 N -1; the delay time is t 1 ,t 2 ,t 3 ...,t N-1 ,t N Any combination of, so the delay range is 0~t, T=t1 +t 2 +t 3 ...+t N-1 +t N In particular, when the delay per stage satisfies T n =m 0 2 n-1 When n=1,2,3,...,N-1,N, uniformly spaced dense false targets will be generated, and the time interval between false targets is m 0 .

[0021] It can be understood that the number of false targets and the number of delay units conform to the conversion law between binary numbers and decimal numbers, so by enabling the switch, the output of each delay level can be controlled to participate in the signal superposition, which can generate 1 to 2 N -1, for example: if the number of delay units is 4, if the number of false targets to be generated is 11, the binary number corresponding to the enable switch should be 1011, and then each binary digit is used as an enable signal for superposition, that is, the output signals of the first, second and fourth levels are superimposed, that is, 1+2+8=11, and 11 false target signals are obtained, so that the number of false targets is exponentially related to the number of delay units, reducing the demand for hardware resources.

[0022] In practical applications, four FIFOs (First Input First Output) are cascaded. Assume that the delay of each FIFO corresponds to t 1 , t 2 , t 3 , t 4 , take the maximum delay T(us)=t 1 +t 2 +t 3 +t 4 , a maximum of 4 false targets can be generated; the intercepted signal is converted into 8 parallel I, Q interference signals after serial-to-parallel conversion, the data rate of each signal is 150MHz, the bit width is 9bit, the clock frequency is 150MHz, and after T time, the data volume of 4 false targets is 150×T×9×8×2, that is, 22Kb×T; however, the present embodiment adopts an efficient implementation structure of 4 FIFOs to generate a maximum of 15 false targets, and the data volume in T time is 150×T×9×8×2, that is, 22Kb×T; it can be seen that under the same false target data volume and almost the same hardware resources, the present embodiment generates more false targets, and the modulation of the number and interval of false targets is more convenient and flexible.

[0023] In order to solve the problem that the signal width is limited in practical applications and truncation is required, which reduces the energy of false targets, this embodiment adopts normalization processing on the superposition result, that is, first extracting the signal phase through cordic (Coordinate Rotation Digital Computer) operation, and then using cordic transformation to restore the signal to improve the output false target energy. Specifically, without loss of generality, the signal after superposition is set to , where A is the amplitude of the signal after superposition, is the signal after superposition, so the signal after truncation As , where M is the number of superpositions; on this basis, the signal phase is extracted through cordic operation, as shown in the formula Finally, the signal is restored through icordic transformation to output the interference signal, as shown in formula , thereby realizing normalization processing to increase the energy of the interference signal and thus improve the interference effect. Compared with the existing false target interference modulation method, the multi-false target interference modulation method based on normalization processing in this embodiment is simpler and more efficient, and can generate more false targets without increasing too many hardware resources, and improve the energy of the false target signal. The simulation results are compared in Figure 2 (a) and Figure 2 (b).

[0024] The multi-false target interference modulation method based on normalization processing of the present invention first obtains the intercepted signal; then the intercepted signal is subjected to delay modulation processing: the input signal before each level of delay modulation is superimposed with the output signal after the level of delay modulation and then used as the input signal of the next level of delay modulation, so that the number of false targets is exponentially related to the level of delay modulation. Figure 3 A curve diagram of the number of false targets generated by the existing interference modulation method and the interference modulation method of this embodiment is provided; then, the output signal of each level of delay modulation is selectively superimposed and a truncated signal is output; finally, the truncated signal is normalized and an interference signal is output, thereby achieving the generation of more false targets without increasing too many hardware resources, and increasing the energy of the false target signal, thereby improving the interference effect.

[0025] The present invention also proposes a multi-false target interference modulation system based on normalization processing, which is used to implement the above-mentioned multi-false target interference modulation method based on normalization processing; the specific structure of the multi-false target interference modulation method based on normalization processing refers to the above-mentioned embodiment. Since the multi-false target interference modulation system based on normalization processing adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which are not repeated here one by one.

[0026] In one embodiment, the multi-false target interference modulation system based on normalization processing includes: A signal acquisition module, wherein the signal acquisition module is used to acquire intercepted signals; A time delay modulation module, the time delay modulation module is connected to the signal acquisition module, and the time delay modulation module is used to perform time delay modulation processing on the intercepted signal; A selective superposition module, the selective superposition module is connected to the time delay modulation module, and the selective superposition module is used to perform selective superposition processing on the output signal of the time delay modulation module and then output a truncated signal; A normalization processing module, the normalization processing module is connected to the selective superposition module, and the normalization processing module is used to output an interference signal after performing normalization processing on the truncated signal.

[0027] In one embodiment, the delay modulation module includes N delay units and N adders.

[0028] In one embodiment, the selective superposition module includes a superimposer and N enable switches, wherein the first ends of the N enable switches are connected one by one to the output ends of the N delay units, and the second ends of the N enable switches are connected to the input end of the superimposer.

[0029] In this embodiment, the signal acquisition module can be implemented by using an AD integrated circuit to obtain the intercepted signal; the delay modulation module can be implemented by using N delay units and N adders, and the adder superimposes the output signal and input signal of the delay unit connected thereto as the input signal of the next delay unit to complete the delay modulation processing; the selective superposition module can be implemented by using a superimposer and N enabling switches, and the enabling switch is connected between the N delay units and the superimposer to achieve selective superposition to generate 1~2 N -1, for example: if the number of delay units is 5, if the number of false targets to be generated is 21, the binary corresponding to the enable switch should be 10101, and then each binary digit is used as the enable signal for superposition, that is, the output signals of the first, third and fifth levels are superimposed, that is, 1+4+16=21, and 21 false target signals are obtained, so that the number of false targets is exponentially related to the number of delay units, reducing the demand for hardware resources; finally, the truncated signal is normalized by the normalization module to output the interference signal, that is, the signal phase is first extracted by cordic operation to obtain ; Then use the icordic transform to recover the signal to obtain the interference signal , thereby achieving normalization processing to increase the energy of the interference signal and thus improve the interference effect.

[0030] In summary, assuming that there are 5 delay units, the present invention can generate any number of false targets from 1 to 31; if the number of false targets is set to 11, then the enable switch corresponding to each level is 01011, and the intervals of each delay unit are 0.5us, 1us, 2us, 4us and 8us respectively, and the interference effect is as follows: Figure 4 shown.

[0031] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-false target interference modulation method based on normalization processing, characterized in that: The multi-false target interference modulation method based on normalization processing comprises the following steps: Acquire intercepted signals; The intercepted signal is subjected to delay modulation processing: the input signal before each level of delay modulation is superimposed with the output signal after the delay modulation of the level and the resultant is used as the input signal of the next level of delay modulation, so that the number of false targets is exponentially related to the level of delay modulation; The output signals of each level of time delay modulation are selectively superimposed and then output as truncated signals; The truncated signal is normalized and then an interference signal is output.

2. The multi-false target interference modulation method based on normalization processing according to claim 1 is characterized in that: The steps of the selective superposition process are specifically as follows: When the delay time of each level meets T n =m02 n-1 When n=1,2,3,...,N-1,N, uniformly spaced dense false targets are generated, m0 is the time interval between false targets, T n is the delay time, and n is the number of delay modulation levels.

3. The multi-false target interference modulation method based on normalization processing according to claim 1 is characterized in that: The steps of the normalization process are specifically as follows: Firstly, the phase extraction process is performed on the truncated signal by cordic operation; Then, the truncated signal is subjected to phase recovery processing through icordic transformation.

4. The multi-false target interference modulation method based on normalization processing according to claim 3 is characterized in that: The step of performing phase extraction processing on the intercepted signal by cordic operation is specifically as follows: The intercept signal is , is the signal after superposition, A is the amplitude of the signal after superposition, and M is the number of superpositions; Through the cordic operation Extract the intercept signal Phase.

5. The multi-false target interference modulation method based on normalization processing according to claim 4 is characterized in that: The step of performing phase recovery processing on the truncated signal by using icordic transformation is specifically as follows: Through the icordic transformation The phase of the truncated signal is restored.

6. A multi-false target interference modulation system based on normalization processing, characterized in that: The multi-false target interference modulation system based on normalization processing is used to implement the multi-false target interference modulation method based on normalization processing according to any one of claims 1 to 5, and the multi-false target interference modulation system based on normalization processing includes: A signal acquisition module, wherein the signal acquisition module is used to acquire intercepted signals; A time delay modulation module, the time delay modulation module is connected to the signal acquisition module, and the time delay modulation module is used to perform time delay modulation processing on the intercepted signal; A selective superposition module, the selective superposition module is connected to the time delay modulation module, and the selective superposition module is used to perform selective superposition processing on the output signal of the time delay modulation module and then output a truncated signal; A normalization processing module, the normalization processing module is connected to the selective superposition module, and the normalization processing module is used to output an interference signal after performing normalization processing on the truncated signal.

7. The multi-false target interference modulation system based on normalization processing according to claim 6 is characterized in that: The delay modulation module includes N delay units and N adders.

8. The multi-false target interference modulation system based on normalization processing according to claim 7 is characterized in that: The selective superposition module includes a superimposer and N enabling switches, wherein the first ends of the N enabling switches are connected one by one to the output ends of the N delay units, and the second ends of the N enabling switches are connected to the input end of the superimposer.

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