Radar waveform design method based on initial phase-PRI joint modulation

Abstract

The present application relates to a radar waveform design method based on initial phase-PRI joint modulation. The method comprises: according to the actual motion state of the target, modulating based on the initial phase and pulse repetition interval to obtain a transmission signal that can be deceived as a non-cooperative dual-base radar in terms of speed and distance, so that the initial phase and pulse repetition period of the pulse train are jointly modulated based on the speed-distance deception information, and then cleverly utilizing the limitations of the matched filter constructed by the non-cooperative dual-base radar signal processing, the scattered echo of the important stealth target can be modulated into fixed clutter, and the fixed clutter can also be modulated into the echo of the moving target, so as to achieve the cover effect on the stealth target and the deception effect based on the fixed clutter, so as to achieve the purpose of resisting non-cooperative utilization.

Description

Technical Field

[0001] The present application relates to the field of radar signal processing technology, and in particular to a radar waveform design method based on initial phase-PRI joint modulation. Background Art

[0002] In the existing technology, some radars do not emit electromagnetic waves themselves, but use signals from external radiation sources to detect and track targets. They can be flexibly deployed and can be secretly deployed around radar radiation sources to steal radar intelligence and perceive the electromagnetic space situation near the radar. The operation and maintenance costs are low, and they can even detect stealth targets, posing a great threat to traditional radars and opponents.

[0003] To resist this kind of radar, waveform design is an important research idea of ​​radar system. Summary of the invention

[0004] Based on this, it is necessary to provide a radar waveform design method based on initial phase-PRI joint modulation to address the above technical problems.

[0005] A radar waveform design method based on initial phase-PRI joint modulation, the method is used for a non-cooperative bistatic radar to deceive the target motion state when intercepting a target echo signal, comprising:

[0006] Acquire radar transmission signals;

[0007] According to the actual motion state of the target, the radar transmission signal is initially phase modulated based on speed deception and pulse repetition interval modulated based on distance deception to obtain a modulated radar transmission signal;

[0008] When the modulated radar transmit signal is used for target detection, when the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary; when the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is moving.

[0009] In one embodiment, when the actual motion state of the target is motion, performing initial phase modulation based on speed deception and pulse repetition interval modulation based on distance deception on the radar transmission signal comprises:

[0010] Acquire the moving speed of the target, and convert the moving speed of the target into a dual-base equivalent speed;

[0011] Respectively representing the radar transmission signal as an initial phase modulated radar transmission signal and a pulse repetition interval modulated radar transmission signal;

[0012] Performing initial phase modulation on the initial phase modulation radar transmission signal according to the bistatic equivalent velocity;

[0013] The stepping interval of the pulse repetition interval is calculated based on the dual-base equivalent speed and the distribution law of the peak point of the target's pulse number-dual-base distance diagram to approximately meet the straight line condition that there is no distance movement, and then the pulse repetition interval modulation radar transmit signal is modulated according to the stepping interval.

[0014] In one embodiment, when the actual motion state of the target is stationary, performing initial phase modulation based on speed deception and pulse repetition interval modulation based on distance deception on the radar transmission signal includes:

[0015] Obtaining the camouflaged movement speed that the target needs to disguise, and converting the camouflaged movement speed into a dual-base equivalent speed;

[0016] Respectively representing the radar transmission signal as an initial phase modulated radar transmission signal and a pulse repetition interval modulated radar transmission signal;

[0017] Performing initial phase modulation on the initial phase modulation radar transmission signal according to the camouflaged bistatic equivalent velocity;

[0018] The stepping interval of the pulse repetition interval is calculated based on the distribution law of the peak point of the dual-base equivalent speed and the target's pulse number-dual-base distance diagram, which approximately satisfies the oblique line condition of distance movement, and then the pulse repetition interval modulation radar transmit signal is modulated according to the stepping interval.

[0019] In one embodiment, the radar transmission signal is represented as:

[0020]

[0021] In the above formula, N is the number of pulses, f c is the carrier frequency, s(t) is the baseband signal, and T1 is the pulse repetition interval; the initial phase modulated radar transmit signal is expressed as:

[0022]

[0023] In the above formula, is the initial phase modulation of the mth transmitted pulse waveform s(t-mT1) in x1(t);

[0024] The pulse repetition interval modulated radar transmission signal is expressed as:

[0025]

[0026] in,

[0027] In the above formula, PRI i is the pulse repetition interval of the i-th transmitted pulse waveform in x2(t), T0 is the initial PRI value, and ΔT is the step interval.

[0028] In one embodiment, converting the target's moving speed into a dual-base equivalent speed, or converting the camouflaged moving speed into a dual-base equivalent speed includes:

[0029]

[0030] In the above formula, v is the moving speed of the target or the camouflaged moving speed, β represents the bistatic angle, and δ represents the angle between the moving direction of the target and the bisector of the bistatic angle.

[0031] In one embodiment, when the actual motion state of the target is motion, performing initial phase modulation on the initial phase modulated radar transmission signal according to the bibasic equivalent velocity includes:

[0032]

[0033] In the above formula, λ is the wavelength, v is b is the double base equivalent velocity, is the phase modulated according to the speed information, and T1 is the pulse repetition interval.

[0034] In one embodiment, when the actual motion state of the target is stationary, performing initial phase modulation on the initial phase modulated radar transmission signal according to the bibasic equivalent velocity includes:

[0035]

[0036] In the above formula, λ is the wavelength, v is b is the double base equivalent velocity, is the phase modulated according to the speed information, and T1 is the pulse repetition interval.

[0037] In one embodiment, when the actual motion state of the target is motion, the step interval of the pulse repetition interval is:

[0038]

[0039] In the above formula, T0 is the initial PRI value, v b is the double-base equivalent velocity, N is the number of pulses, and c is the speed of light.

[0040] In one embodiment, when the actual motion state of the target is stationary, the step interval of the pulse repetition interval is:

[0041]

[0042] In the above formula, T0 is the initial PRI value, v b is the double-base equivalent velocity, N is the number of pulses, and c is the speed of light.

[0043] In one embodiment, the modulated radar transmission signal is:

[0044]

[0045] In the above formula, PRI i is the pulse repetition interval of the i-th transmitted pulse waveform in x(t), N is the number of pulses, and f c is the carrier frequency, s(t) is the baseband signal, is the waveform of the mth transmitted pulse in x(t) The initial phase modulation is received.

[0046] A radar waveform design device based on initial phase-PRI joint modulation, the device comprising:

[0047] A transmission signal acquisition module is used to acquire radar transmission signals;

[0048] A transmission signal anti-non-cooperative utilization modulation module is used to perform initial phase modulation based on speed deception and pulse repetition interval modulation based on distance deception on the radar transmission signal according to the actual motion state of the target to obtain a modulated radar transmission signal;

[0049] The modulated signal transmitting module is used to detect the target by using the modulated radar transmitting signal. When the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary. When the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is in motion.

[0050] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0051] Acquire radar transmission signals;

[0052] According to the actual motion state of the target, the radar transmission signal is initially phase modulated based on speed deception and pulse repetition interval modulated based on distance deception to obtain a modulated radar transmission signal;

[0053] When the modulated radar transmit signal is used for target detection, when the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary; when the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is moving.

[0054] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the following steps:

[0055] Acquire radar transmission signals;

[0056] According to the actual motion state of the target, the radar transmission signal is initially phase modulated based on speed deception and pulse repetition interval modulated based on distance deception to obtain a modulated radar transmission signal;

[0057] When the modulated radar transmit signal is used for target detection, when the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary; when the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is moving.

[0058] The above-mentioned radar waveform design method based on initial phase-PRI joint modulation, by modulating based on the initial phase and pulse repetition interval according to the actual motion state of the target, obtains a transmitting signal that can be deceived into a non-cooperative dual-base radar in terms of speed and distance. In this way, the initial phase and pulse repetition period of the pulse train are jointly modulated based on the speed-distance deception information, and then the limitations of the matched filter constructed by the non-cooperative dual-base radar signal processing are cleverly utilized to modulate the scattered echo of the important stealth target into fixed clutter, and the fixed clutter can also be modulated into the echo of the moving target, so as to achieve the cover effect on the stealth target and the deception effect based on the fixed clutter, so as to achieve the purpose of resisting non-cooperative utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 A schematic diagram of a flow chart of a radar waveform design method in one embodiment;

[0060] Figure 2 A schematic diagram of a signal flow based on a radar waveform design method in one embodiment;

[0061] Figure 3 1. The figure is a stroke count-distance diagram and an MTD diagram of a real moving target in one embodiment;

[0062] Figure 4 A pulse count-distance diagram and an MTD diagram of a camouflaged moving target in one embodiment;

[0063] Figure 5 1. The impulse number-distance diagram and the MTD diagram of a real stationary target in one embodiment;

[0064] Figure 6 A pulse count-distance diagram and an MTD diagram of a camouflaged stationary target in one embodiment;

[0065] Figure 7 A structural block diagram of a radar waveform design device in one embodiment;

[0066] Figure 8 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0068] To counter non-cooperative base radars, such as Figure 1 As shown, a radar waveform design method based on initial phase-PRI joint modulation is provided, comprising the following steps:

[0069] Step S100, obtaining a radar transmission signal;

[0070] Step S110, according to the actual motion state of the target, performing initial phase modulation on the radar transmission signal based on speed deception and performing pulse repetition interval modulation based on distance deception to obtain a modulated radar transmission signal;

[0071] Step S120, when the modulated radar transmit signal is used for target detection, when the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary; when the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is moving.

[0072] In this embodiment, based on the radar coherent signal processing mechanism, the initial phase and pulse repetition period of the radar transmit signal pulse bed are jointly modulated based on the speed-distance deception information, and then the limitations of the matched filter constructed by the non-cooperative dual-base radar signal processing are cleverly utilized to modulate the scattered echo of the important stealth target into fixed clutter, and the fixed clutter can also be modulated into the echo of the moving target, so as to achieve the cover effect on the stealth target and the deception effect based on the fixed clutter, thereby achieving the purpose of resisting non-cooperative utilization.

[0073] In step S100, the radar transmission signal is in a traditional waveform expression form and is expressed as:

[0074]

[0075] In formula (1), N is the number of pulses, f c is the carrier frequency, s(t) is the baseband signal, and T1 is the pulse repetition interval.

[0076] In step S110, the radar transmission signal is modulated according to the actual motion state of the target. When the actual motion state of the target is motion, the target echo signal intercepted by the non-cooperative bistatic radar needs to be modulated to have a stationary target effect, that is, it can be applied to modulate the scattered echo of the stealth moving target into fixed clutter.

[0077] The radar transmission signal is subjected to initial phase modulation based on speed deception and pulse repetition interval modulation based on distance deception, including: obtaining the moving speed of the target and converting the moving speed of the target into a dual-base equivalent speed, respectively representing the radar transmission signal as an initial phase modulated radar transmission signal and a pulse repetition interval modulated radar transmission signal, performing initial phase modulation on the initial phase modulated radar transmission signal according to the dual-base equivalent speed, calculating the step interval of the pulse repetition interval according to the dual-base equivalent speed and the distribution law of the peak point of the target's pulse number-dual-base distance diagram to approximately meet the straight line condition that there is no distance movement, and modulating the pulse repetition interval modulated radar transmission signal according to the step interval.

[0078] Specifically, the initial phase modulated radar transmit signal is expressed as:

[0079]

[0080] In formula (2), is the initial phase modulation of the mth transmitted pulse waveform s(t-mT1) in x1(t); specifically, the pulse repetition interval modulated radar transmit signal is expressed as:

[0081]

[0082] in,

[0083] In formula (3) and formula (4), PRI i is the pulse repetition interval of the i-th transmitted pulse waveform in x2(t), T0 is the initial PRI (pulse repetition interval) value, and ΔT is the step interval.

[0084] Furthermore, the target's moving speed is converted into a double-base equivalent speed, and the double-base equivalent speed is:

[0085]

[0086] In formula (5), v is the target's moving speed, β represents the bistatic angle, and δ represents the angle between the target's moving direction and the bistatic angle bisector.

[0087] When the initial phase is modulated based on speed deception, the initial phase is modulated using the dual-base speed to obtain:

[0088]

[0089] In formula (6), λ is the wavelength, v b is the double base equivalent velocity, is the phase modulated according to the speed information, and T1 is the pulse repetition interval.

[0090] Then, formula (6) is substituted into formula (2) to complete the initial phase modulation based on speed deception.

[0091] When performing pulse repetition interval modulation based on range deception, since the long-term movement of the moving target will inevitably lead to range movement, if the scattered echo of the moving target is to be modulated into a stationary clutter effect, the distribution law of the peak point of the target pulse number-dual base range diagram is approximately a straight line that satisfies the absence of range movement, so the step interval of the pulse repetition interval can be obtained as:

[0092]

[0093] In formula (7), T0 is the initial PRI value, v b is the double-base equivalent velocity, N is the number of pulses, and c is the speed of light.

[0094] Substitute formula (7) into formula (4) for modulation, and T0 = T1, and we get:

[0095]

[0096] Finally, formula (8) is substituted into formula (3) to complete the pulse repetition interval modulation based on distance deception.

[0097] In step S110, when the actual motion state of the target is stationary, the target echo signal (stationary clutter) intercepted by the non-cooperative bistatic radar needs to be modulated to have a moving target effect to achieve deception based on fixed clutter.

[0098] The radar transmission signal is subjected to initial phase modulation based on speed deception and pulse repetition interval modulation based on distance deception, including: obtaining the camouflaged movement speed that the target needs to disguise, and converting the camouflaged movement speed into a dual-base equivalent speed, respectively representing the radar transmission signal as an initial phase modulated radar transmission signal and a pulse repetition interval modulated radar transmission signal, performing initial phase modulation on the initial phase modulated radar transmission signal according to the camouflaged dual-base equivalent speed, calculating the step interval of the pulse repetition interval according to the dual-base equivalent speed and the distribution law of the peak point of the target's pulse number-dual-base distance diagram to approximately meet the oblique line condition of the existence of distance movement, and then modulating the pulse repetition interval modulated radar transmission signal according to the step interval.

[0099] Specifically, the radar transmission signal is respectively expressed as an initial phase modulated radar transmission signal and a pulse repetition interval modulated radar transmission signal, that is, expressed as formula (2) and formula (3) and (4).

[0100] Get the known speed of the moving target to be disguised, and convert it into the double-base equivalent speed, and you will get:

[0101]

[0102] Different from formula (5), v in formula (9) is the speed of the moving target to be disguised.

[0103] Similarly, the initial phase is modulated using the dual-base equivalent velocity to obtain:

[0104]

[0105] In formula (10), λ is the wavelength, v is b is the double base equivalent velocity, is the phase modulated according to the speed information, and T1 is the pulse repetition interval.

[0106] Then, formula (10) is substituted into formula (2) to complete the initial phase modulation based on speed deception.

[0107] When performing pulse repetition interval modulation based on distance deception, the target movement speed to be disguised is converted into a dual-base equivalent speed by using formula (9).

[0108] Since stationary clutter cannot simulate the distance movement caused by the long-term movement of the moving target, if the stationary clutter is modulated into the scattered echo effect of the moving target, the distribution law of the peak point of the target pulse number-dual base distance diagram is approximately a diagonal line that satisfies the existence of distance movement, so the step interval of the pulse repetition interval can be obtained as:

[0109]

[0110] In formula (11), T0 is the initial PRI value, v b is the double-base equivalent velocity, N is the number of pulses, and c is the speed of light.

[0111] Substitute formula (11) into formula (4) for modulation, and T0 = T1, and we get:

[0112]

[0113] Finally, formula (12) is substituted into formula (3) to complete the pulse repetition interval modulation based on distance deception.

[0114] In fact, the initial phase modulation based on speed deception is to perform initial phase modulation inside the pulse of the radar transmitting signal, while the pulse repetition interval modulation based on distance deception is to modulate the pulse interval of the radar transmitting signal.

[0115] Finally, the radar transmission signal modulated according to the above steps is:

[0116]

[0117] In formula (13), PRI i is the pulse repetition interval of the i-th transmitted pulse waveform in x(t), N is the number of pulses, and f c is the carrier frequency, s(t) is the baseband signal, is the waveform of the mth transmitted pulse in x(t) The initial phase modulation is received.

[0118] like Figure 2 As shown, a process step for actually modulating the radar transmission signal according to the above method is provided.

[0119] Specifically, when the radar transmission signal is modulated, it actually includes two steps: initial phase modulation based on speed deception and pulse repetition interval modulation based on distance deception.

[0120] Through the above two steps, in application one, that is, when the target is in motion, the traditional radar transmit waveform can be modulated based on formula (6) and formula (8), so that the moving target echo received by the non-cooperative dual-base radar is modulated into a stationary target effect. In application two, that is, when the target is in a stationary state, the traditional radar transmit waveform can be modulated based on formula (10) and formula (12), so that the stationary clutter received by the non-cooperative dual-base radar is modulated into a moving target effect.

[0121] In this application, data simulation is also performed based on the above method, specifically including:

[0122] For application one: modulate the moving target echo received by the non-cooperative dual-base radar into a stationary target effect. Figure 3 , Figure 4 Show.

[0123] in, Figure 3 (a) The pulse number-range processing results of the non-cooperative bistatic radar detecting real moving targets based on the traditional radar emitter signal f(t) are given. Figure 3 (b) shows the MTD (moving target detection) processing results of the non-cooperative bistatic radar for real moving targets based on the traditional radar radiation source signal f(t). Figure 3 (a) is a diagonal line with distance traveled, Figure 3 (b) The Doppler dimension is not zero.

[0124] Figure 4 (a) The pulse number-range processing results of the non-cooperative bistatic radar detecting real moving targets based on the radar emitter signal x(t) designed in this paper are given. Figure 4 (b) The MTD (moving target detection) processing results of the non-cooperative bistatic radar on the real moving target based on the radar radiation source signal x(t) designed in this paper are given.

[0125] It can be seen that the waveform designed in this paper Figure 3 (a) There is a diagonal modulation disguised as a distance travel Figure 4 (a) does not have a vertical line of distance traveled; Figure 3 (b) The position modulation camouflage of the moving target with non-zero Doppler is Figure 4 (a) The stationary clutter point with Doppler of 0. From the processing results, the radar radiator signal x(t) designed in this paper successfully achieves the effect of modulating the moving target echo received by the non-cooperative bistatic radar into a stationary target.

[0126] Application 2: Modulate the static clutter received by non-cooperative dual-base radar into a moving target effect. Figure 5 , Figure 6 shown.

[0127] Figure 5 (a) The pulse number-range processing results of the non-cooperative bistatic radar for the real stationary clutter point echo based on the traditional radar radiation source signal f(t) are given. Figure 5 (b) shows the MTD (moving target detection) processing results of the non-cooperative bistatic radar based on the traditional radar radiation source signal f(t) for the real stationary clutter point echo. It can be seen that Figure 5 (a) is a vertical line perpendicular to the range axis without any range movement, Figure 5 In (b) the Doppler dimension is zero.

[0128] Figure 6 (a) The pulse number-distance processing results of the non-cooperative bistatic radar based on the radar radiator signal x(t) designed in this paper for the real stationary clutter point echo are given. Figure 6 (b) The MTD (moving target detection) processing results of the non-cooperative bistatic radar based on the radar radiation source signal x(t) designed in this paper for the real stationary clutter point echo are given.

[0129] It can be seen that the waveform designed in this paper Figure 5 (a) There is no vertical modulation disguised as Figure 6 (a) contains a diagonal line of distance travel; Figure 5(b) The stationary clutter point with Doppler of 0 is modulated to camouflage Figure 6 (a) The position of the moving target whose Doppler is not 0. From the processing results, the radar radiation source signal x(t) designed in this paper successfully achieves the effect of modulating the stationary clutter received by the non-cooperative bistatic radar into a moving target.

[0130] In the above radar waveform design method based on initial phase-PRI joint modulation, the initial phase modulation based on speed deception and the pulse repetition interval modulation based on distance deception are performed on the traditional radar transmission signal, so that the echo of the moving target under the illumination of its modulation signal is disguised as a stationary clutter point when the non-cooperative party receives it, thereby avoiding the detection of the non-cooperative dual-base radar and achieving the effect of protecting our important targets. The stationary clutter point of the stationary target under the illumination of its modulation signal is disguised as the echo of the moving target when the non-cooperative party receives it, causing a false alarm of the non-cooperative dual-base radar and achieving the effect of misleading the non-cooperative dual-base radar. The radar transmission waveform designed by this method can effectively modulate the echo of the moving target and the stationary point clutter to achieve the purpose of deceiving the non-cooperative dual-base radar, thereby realizing the design of the radar waveform against non-cooperative utilization.

[0131] This method also makes full use of the radar coherent signal processing mechanism and adopts the method of initial phase and PRI joint modulation, so that the Doppler value and range movement phenomenon obtained by the non-cooperative party in the coherent signal processing are not real results, but the results of camouflage modulation, thereby deceiving the non-cooperative party and achieving anti-non-cooperative utilization.

[0132] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0133] In one embodiment, Figure 1 As shown, a radar waveform design device based on initial phase-PRI joint modulation is provided, including: a transmission signal acquisition module 200, a transmission signal acquisition module 200 and a modulation signal transmission module 220, wherein:

[0134] The transmission signal acquisition module 200 is used to acquire the radar transmission signal;

[0135] The transmission signal anti-non-cooperative utilization modulation module 210 is used to perform initial phase modulation based on speed deception and pulse repetition interval modulation based on distance deception on the radar transmission signal according to the actual motion state of the target to obtain a modulated radar transmission signal;

[0136] The modulated signal transmitting module 220 is used to detect the target using the modulated radar transmitting signal. When the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary. When the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is in motion.

[0137] For the specific definition of the radar waveform design device based on the initial phase-PRI joint modulation, please refer to the definition of the radar waveform design method based on the initial phase-PRI joint modulation above, which will not be repeated here. Each module in the above-mentioned radar waveform design device based on the initial phase-PRI joint modulation can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0138] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Figure 8 As shown. The computer device includes a processor, a memory, a network interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a radar waveform design method based on initial phase-PRI joint modulation is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a button, trackball or touchpad set on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0139] Those skilled in the art will understand that Figure 8The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0140] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0141] Acquire radar transmission signals;

[0142] According to the actual motion state of the target, the radar transmission signal is initially phase modulated based on speed deception and pulse repetition interval modulated based on distance deception to obtain a modulated radar transmission signal;

[0143] When the modulated radar transmit signal is used for target detection, when the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary; when the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is moving.

[0144] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0145] Acquire radar transmission signals;

[0146] According to the actual motion state of the target, the radar transmission signal is initially phase modulated based on speed deception and pulse repetition interval modulated based on distance deception to obtain a modulated radar transmission signal;

[0147] When the modulated radar transmit signal is used for target detection, when the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary; when the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is moving.

[0148] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0149] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0150] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A radar waveform design method based on initial phase-PRI joint modulation, characterized in that: The method is used for deceiving the target motion state when a non-cooperative bistatic radar intercepts a target echo signal, and comprises: A radar transmission signal is obtained, where the radar transmission signal is expressed as: In the above formula, N is the number of pulses, f c is the carrier frequency, s(t) is the baseband signal, and T1 is the pulse repetition interval; According to the actual motion state of the target, the radar transmission signal is subjected to initial phase modulation based on speed deception and pulse repetition interval modulation based on distance deception to obtain a modulated radar transmission signal, wherein when the actual motion state of the target is motion: the motion speed of the target is obtained, and the motion speed of the target is converted into a bistatic equivalent speed, the radar transmission signal is respectively represented as an initial phase modulated radar transmission signal and a pulse repetition interval modulated radar transmission signal, and the initial phase modulated radar transmission signal is subjected to initial phase modulation according to the bistatic equivalent speed, and the pulse repetition interval step interval is calculated according to the bistatic equivalent speed and the distribution law of the peak point of the target pulse number-bistatic distance diagram that approximately satisfies the straight line condition that there is no distance movement, and then the step interval of the pulse repetition interval is calculated according to the step interval The pulse repetition interval modulation radar transmission signal is modulated at intervals, wherein when the actual motion state of the target is stationary, the camouflaged motion speed that the target needs to disguise is obtained, and the camouflaged motion speed is converted into a bistatic equivalent speed, and the radar transmission signal is respectively represented as an initial phase modulation radar transmission signal and a pulse repetition interval modulation radar transmission signal, and the initial phase modulation radar transmission signal is initially phase modulated according to the bistatic equivalent speed, and the step interval of the pulse repetition interval is calculated according to the bistatic equivalent speed and the distribution law of the peak point of the target pulse number-bistatic distance diagram approximately satisfying the oblique line condition of the distance movement, and then the pulse repetition interval modulation radar transmission signal is modulated according to the step interval, and the initial phase modulation radar transmission signal is represented as: In the above formula, is the initial phase modulation of the mth transmitted pulse waveform s(t-mT1) in x1(t); The pulse repetition interval modulated radar transmission signal is expressed as: in, In the above formula, PRI i is the pulse repetition interval of the i-th transmitted pulse waveform in x2(t), T0 is the initial PRI value, and ΔT is the step interval; When the modulated radar transmit signal is used for target detection, when the actual motion state of the target is moving, the target echo signal received by the non-cooperative bistatic radar indicates that the target is stationary; when the actual motion state of the target is stationary, the target echo signal received by the non-cooperative bistatic radar indicates that the target is moving.

2. The radar waveform design method according to claim 1, characterized in that: Converting the target's moving speed into a dual-base equivalent speed, or converting the camouflaged moving speed into a dual-base equivalent speed includes: In the above formula, v is the moving speed of the target or the camouflaged moving speed, β represents the bistatic angle, and δ represents the angle between the moving direction of the target and the bisector of the bistatic angle.

3. The radar waveform design method according to claim 2, characterized in that: When the actual motion state of the target is motion, performing initial phase modulation on the initial phase modulation radar transmission signal according to the dual-base equivalent velocity includes: In the above formula, λ is the wavelength, v is b is the double base equivalent velocity, is the phase modulated according to the speed information, and T1 is the pulse repetition interval.

4. The radar waveform design method according to claim 3, characterized in that: When the actual motion state of the target is stationary, performing initial phase modulation on the initial phase modulation radar transmission signal according to the dual-base equivalent velocity includes: In the above formula, λ is the wavelength, v is b is the double base equivalent velocity, is the phase modulated according to the speed information, and T1 is the pulse repetition interval.

5. The radar waveform design method according to claim 4, characterized in that: When the actual motion state of the target is motion, the step interval of the pulse repetition interval is: In the above formula, T0 is the initial PRI value, v b is the double-base equivalent velocity, N is the number of pulses, and c is the speed of light.

6. The radar waveform design method according to claim 5, characterized in that: When the actual motion state of the target is stationary, the step interval of the pulse repetition interval is: In the above formula, T0 is the initial PRI value, v b is the double-base equivalent velocity, N is the number of pulses, and c is the speed of light.

7. The radar waveform design method according to claim 6, characterized in that: The modulated radar transmit signal is: In the above formula, PRI i is the pulse repetition interval of the i-th transmitted pulse waveform in x(t), N is the number of pulses, and f c is the carrier frequency, s(t) is the baseband signal, is the mth transmitted pulse waveform in x(t) The initial phase modulation is received.

Images