CN117148283B - Random wave radar signal generation method for complex electromagnetic environment - Google Patents
Random wave radar signal generation method for complex electromagnetic environment Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/28—Details of pulse systems
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
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- G01S7/282—Transmitters
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
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Abstract
The invention discloses a method for generating an arbitrary wave radar signal in a complex electromagnetic environment, which comprises the following steps: step 1, analyzing the communication environment of a complex electromagnetic environment, and analyzing the types and characteristics of radar signals and electronic countermeasure signals; step 2, designing a radar signal dynamic generation library simulating a complex electromagnetic environment by utilizing a digital twin technology according to the collected radar signal data, and calculating I/Q data of signals by utilizing a computer program to obtain a sample database for radar generation; step 3, simulating and generating radar signal data of different types through simulation software, and inputting the radar signal data serving as a vector signal source into a signal generator; and 4, the signal generator obtains any wave radar signals by using a time domain randomization processing method.
Description
Technical Field
The invention belongs to the technical field of electromagnetic radiology and radar signal simulation, and particularly relates to a method for generating an arbitrary wave radar signal in a complex electromagnetic environment.
Background
With development and application of information technology, in modern battlefield, weapons are in complex electromagnetic environment mainly derived from two main parts, namely a large number of various and high-power electronic devices, so that denser electromagnetic signals exist in local space; secondly, due to the influence of the change of the geographic environment and the natural condition, certain randomness, fading which cannot be estimated and the like appear in the radio wave transmission process, and a more complex wireless channel environment appears in the local environment. Under the combined action of the two factors, a dynamic electromagnetic environment with complex space domain, time domain, frequency and energy is formed.
In a complex and changeable electromagnetic environment, how to detect the performance of equipment in the complex electromagnetic environment and enhance the communication capability is a problem which needs to be solved at present.
Disclosure of Invention
Therefore, the invention provides a method for generating arbitrary wave radar signals in a complex electromagnetic environment, which can generate radar signals under complex electromagnetic environment situations of different radiation sources according to the complex electromagnetic environment simulation requirements, generate various complex electromagnetic signals of ground radars with flexibly adjustable parameters, and construct radar countermeasure signal environments.
The invention is realized by adopting the following technical scheme:
a method for generating an arbitrary wave radar signal in a complex electromagnetic environment comprises the following steps:
step 1, analyzing the communication environment of a complex electromagnetic environment, and analyzing the types and characteristics of radar signals and electronic countermeasure signals;
step 2, designing a radar signal dynamic generation library simulating a complex electromagnetic environment by utilizing a digital twin technology according to the collected radar signal data, and calculating I/Q data of signals by utilizing a computer program to obtain a sample database for radar generation;
step 3, simulating and generating radar signal data of different types through simulation software, and inputting the radar signal data serving as a vector signal source into a signal generator;
And 4, obtaining an arbitrary wave radar signal by using a time domain randomization processing method.
The arbitrary wave radar signal generation method comprises the following steps: in step 1, radar signals include continuous wave radar signals and pulse radar signals; the electronic countermeasure signals include radar interference countermeasure signals and communication interference countermeasure signals.
The method for generating the random wave radar signal comprises the following steps: encoding the collected radar signal data, representing a conventional pulsed radar signal as:
(1)
Wherein: Is the pulse repetition period in s; is the pulse width in s; is a radar transmitting signal The amplitude of the ith pulse; is the signal carrier frequency, the unit is Hz; Is the initial phase of the ith pulse in rad; Is a rectangular window function, takes value and Related to the range of (i) is
(2)
The arbitrary wave radar signal generating method, wherein step 2 includes representing the chirp signal as:
(3)
Wherein: Is the pulse repetition period in s; Is the pulse width in s; Is a rectangular window function; is the amplitude of the chirp signal; is the signal carrier frequency, the unit is Hz; is the modulation slope of B is the modulation bandwidth; is the initial phase of the signal in rad.
The arbitrary wave radar signal generating method, wherein step 2 includes the steps of representing the nonlinear frequency modulation signal as:
(4)
Wherein: Is the pulse repetition period in s; Is the pulse width in s; Is a rectangular window function; is the amplitude of the chirp signal; Is the first The nonlinear frequency modulation frequency point values are in Hz; Nonlinear frequency-tuning points.
The method for generating the random wave radar signal comprises the step 2 of modulating codeword information in carrier phase by using pseudo-random codes or random sequences as phase codes of codewords to obtain a phase coded signal.
The mathematical expression of the encoded signal is:
(5)
Wherein: Is the pulse repetition period in s; Is the pulse width in s; Is a rectangular window function; is the amplitude of the chirp signal; is the signal carrier frequency, the unit is Hz; Is a phase modulation function, the value of which is determined by the coding information, and the unit rad.
The method for generating the random wave radar signal comprises the following steps:
Different radar signals are generated through simulation, a vector signal source is obtained after resampling and filtering, a digital signal is converted into an I/Q two-baseband analog signal through a D/A module in a signal generator, the I/Q modulation module carries out quadrature carrier modulation on the I/Q two-baseband signal, the center frequency of the signal is moved to a required frequency band, and finally the signal is output.
The method for generating the random wave radar signal comprises the following steps:
let the generated signal be of length Single frame signal sequence of (a)The windowing and overlapping process is utilized as follows:
(6)
Wherein: Is the window coefficient used by the windowed overlap-add method, Is the size of the time-domain interval,Represented is the signal frame number, the window coefficients used need to satisfy:
(7)
The arbitrary wave radar signal generation method comprises the following steps:
obtaining two continuous frames of time domain signals through discrete Fourier transform AndThe frame length of the signal is。
By combining time-domain signalsFirst half of the signal and signalTime-domain interval field signal obtained by windowing and superposing the latter half part of the field signal。
Time domain signalSecond half of the signal and signalTime-domain interval other half frame signal obtained by windowing and superposing the first half part of the frame; The windowing function in this process needs to satisfy:
(8)
The arbitrary wave radar signal generation method comprises the following steps:
Introducing a correction factor Correcting the signal amplitude, combining with a hanning window function, wherein the correction coefficient is as follows:
(9)
After the correction coefficient is introduced, the output signal is processed by a hanning windowing functionMultiplying by a correction factorObtaining arbitrary wave radar signalsThe method comprises the following steps:
(equation 10).
Drawings
FIG. 1 is a schematic flow chart of a method for generating an arbitrary wave radar signal in a complex electromagnetic environment;
FIG. 2 is a radar signal classification diagram;
FIG. 3 is a diagram of specific classification of challenge signals;
FIG. 4 is a flow chart for generating a dynamic database of radar waves based on digital twin technology;
FIG. 5 is a flow chart of arbitrary wave radar vector source signal generation;
FIG. 6 is a graph of signal processing results under a half sine window function;
FIG. 7 is a graph of signal processing results under a triangular window function;
FIG. 8 is a graph of signal processing results under a Hanning window function;
FIG. 9 is a graph of signal amplitude correction coefficients;
FIG. 10 is a graph of modified arbitrary wave radar signals;
fig. 11 is a graph of a corrected arbitrary wave radar signal spectrum.
Detailed Description
The following describes embodiments of the present invention in detail with reference to FIGS. 1-11. The embodiments are exemplary only, and are not to be construed as limiting the invention. It should be apparent that the described embodiments of the invention are only some, but not all embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present invention.
Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the invention. Thus, the terms "comprising," "including," "having," and variations thereof herein mean "including but not limited to," unless expressly specified otherwise.
Fig. 1 is a schematic flow chart of a method for generating an arbitrary wave radar signal in a complex electromagnetic environment, which provides implementation steps of the method, and the steps of the method for generating the arbitrary wave radar signal in the complex electromagnetic environment include:
Step 1, analyzing a communication environment of a complex electromagnetic environment, and mainly analyzing types and characteristics of radar signals and electronic countermeasure signals;
Step 2, designing a radar signal dynamic generation library simulating a complex electromagnetic environment by utilizing a digital twin technology according to the collected domestic and foreign radar signal data, and calculating an in-phase component I and a quadrature component Q of modulation data of signals by utilizing a computer program to obtain a sample database for radar generation;
step 3, simulating and generating radar signal data of different types through simulation software, and inputting the radar signal data serving as a vector signal source into a 1465-V signal generator;
and 4, combining the existing main control computer, signal generator, signal amplifier, spectrometer and other instruments and simulation software, obtaining any wave radar signals by using a time domain randomization processing method, and correcting the time domain amplitude of the any wave radar signals by using a hanning window to reduce the frequency spectrum leakage of the radar signals.
The steps will be described in detail with reference to FIGS. 1-11
Step 1, analyzing types and characteristics of radar signals and electronic countermeasure signals
In the present battlefield, complex electromagnetic environments mainly include communication environments, radar environments, photoelectric environments, electronic countermeasure environments, civil electromagnetic environments, and natural electromagnetic environments, with radar signals and electronic countermeasure signals being the emphasis thereof.
Radar signals can be classified into continuous wave radar signals and pulse radar signals according to working waveforms, and specific classification is shown in fig. 2.
The countermeasure signals are mainly classified into radar interference countermeasure signals and communication interference countermeasure signals, and specific classifications are shown in fig. 3. Radar interference countermeasures include radar wideband noise interference countermeasures, radar narrowband noise interference countermeasures, noise amplitude modulation countermeasures, noise frequency modulation countermeasures, noise amplitude modulation-frequency modulation countermeasures decoy countermeasures; the communication interference countermeasure signal comprises a communication broadband noise interference countermeasure signal, a communication narrowband noise interference countermeasure signal, a multitone interference countermeasure signal and a single frequency point suppression interference countermeasure signal.
And 2, designing a radar signal dynamic generation library simulating a complex electromagnetic environment of a battlefield by utilizing a digital twin technology, and calculating I/Q data of signals by utilizing a computer program to obtain a sample database for radar generation.
The collected radar signal data at home and abroad are arranged, in order to reduce the dependence on radar sample data in a database, the digital twin technology is utilized to obtain the waveform parameters of the radar signals, which mainly comprise power, frequency, phase, pulse interval, pulse period, pulse width, pulse offset, antenna parameters and the like, so that fewer data samples can be utilized to obtain the radar waveform parameters.
Mapping is carried out according to the obtained radar waveform parameters to obtain the change parameters of the waveform in the space-time frequency domain, a dynamic database of the radar waveform is established by utilizing a digital twin technology, and the power, the frequency and the phase in the dynamic database are used as important data for generating the radar waveform.
The accumulation of sample data is performed by using a common radar signal, and a conventional pulse signal can be understood as a signal generated by pulse modulating a single-point frequency signal, wherein the repetition period and the pulse width of the modulated pulse are both a certain fixed value. Conventional pulse signals can be classified into high-repetition frequency signals, medium-repetition frequency signals, and low-repetition frequency signals according to repetition periods, and are mainly used in conventional radars, MTI (moving object detection radars), and pulse doppler radars.
The model of a conventional pulsed radar signal is:
(1)
In (formula 1): Is the pulse repetition period in s; is the pulse width in s; is a radar transmitting signal The amplitude of the ith pulse; is the signal carrier frequency, the unit is Hz; Is the initial phase of the ith pulse in rad; Is a rectangular window function, takes value and Related to the range of (i) is
(2)
In the implementation means, a radar waveform file with a certain duty ratio and a fixed period is generated by using matlab, then the waveform file is called by using an application development framework QT, and a conventional radar signal is generated by using a 1465 vector signal generator.
The frequency agile radar is a pulse radar, and carrier frequencies are hopped regularly or randomly in a plurality of fixed frequency points. The frequency agility is divided into two types, namely inter-pulse agility and inter-pulse group agility, namely the frequency of each pulse is different, and the inter-pulse group agility is that a group of pulses (more than or equal to 2) have the same carrier frequency, and the frequency between groups is hopped.
In order to realize the functions of anti-interference, defuzzification and the like, the pulse repetition period PRT of the modern radar may not be a fixed value, but may also be a set of values which change randomly or regularly. The carrier frequency is kept unchanged in the frequency domain, the frequency of the signal inside the pulse is single, the pulse width is unchanged in the time domain, and the radar signal with the pulse repetition period change is defined as a repetition frequency change signal and is divided into inter-pulse change and pulse group change.
The inter-pulse variation is a variation in the repetition period between each pulse according to a set parameter, while the pulse group variation is a variation in the repetition period between a group of pulses (. Gtoreq.2) while the repetition period remains unchanged within the pulse group. Different PRT change patterns are used to achieve different objectives.
The common PRT change rule is repeated frequency jitter, repeated frequency spread and repeated frequency sliding. The repeated frequency jitter signal is a signal with repeated period randomly hopped within a certain range and is mainly used for resisting the interference of the arrival time of the predicted pulse, and the repeated frequency jitter increases the difficulty of identifying the signal by the radar reconnaissance equipment, so that the interference signal cannot be synchronously transmitted before the interference machine receives the pulse.
Conventional pulse signals can be classified into high-repetition frequency signals, medium-repetition frequency signals, and low-repetition frequency signals according to repetition periods, and are mainly used in conventional radars, MTI, and pulse doppler radars. The repeated frequency spread signal is a signal with a repeated period changing according to a certain spread ratio and a certain spread number, is commonly used in an MTI system and is used for eliminating blind speed or used for high-repeated frequency radar de-blurring; the repeated frequency sliding signal is a signal with repeated period changing according to the set sliding rule (such as sawtooth increment/decrement, sine and the like) and the sliding pulse number, is used for fixed-height coverage scanning, eliminates blind pitch and is a technology of resisting asynchronous interference of the radar.
Chirped signalIs a signal that linearly modulates the carrier frequency within a pulse. The chirp signals are divided into up-frequency modulation, down-frequency modulation and bilinear frequency modulation; the expression that can be used is:
(3)
In (formula 3): is the amplitude of the chirp signal; is the signal carrier frequency, the unit is Hz; is the modulation slope of B is the modulation bandwidth; is the initial phase of the signal in rad.
Non-linear frequency modulation signalCan be expressed as:
(4)
In (formula 4): Is the first The nonlinear frequency modulation frequency point values are in Hz; Nonlinear frequency-tuning points.
The phase code using pseudo random code or random sequence as code word modulates the code word information in carrier phase to obtain phase code signal.
The phase encoded signal is a pulse compression radar signal of large bandwidth and large bandwidth with low probability of interception.
The phase coding signal has high sidelobe suppression ratio, can obtain good pulse compression processing effect, and can be flexible and changeable in waveform, so that the low interception performance of the radar is convenient to realize, but the pulse compression performance is not good for echo signals with Doppler frequency shift due to the phase coding radar, and the phase coding signal is mostly used in the field with small Doppler frequency range change. The phase encoding method can be classified into two-phase encoding and multi-phase encoding.
Coding signalThe mathematical expression of (2) is:
(5)
In (formula 5): Is a phase modulation function, the value of which is determined by the coding information, and the unit rad.
According to the calculation formula of the signals, the virtual mapping data obtained by processing the sample data by utilizing a digital twin technology is calculated and autonomously learned by a computer to obtain a radar-generated sample database.
And step 3, simulating data in the radar sample database by simulation software to generate radar signals of different types, and inputting the radar signals serving as vector signal sources into a signal generator.
Mapping is carried out according to the obtained radar waveform parameters to obtain the change parameters of the waveform in the space-time frequency domain, a dynamic database of the radar waveform is established by utilizing a digital twin technology, the power, the frequency and the phase in the dynamic database are used as important data for generating the radar waveform, and the specific implementation flow is shown in figure 4.
Different radar signals are generated by Simulink simulation, a vector signal source is obtained after resampling and filtering, a digital signal is converted into an I/Q two-baseband analog signal through a D/A module in a signal generator, the I/Q modulation module carries out quadrature carrier modulation on the I/Q two-baseband signal, the signal center frequency is moved to a required frequency band, and finally signals are output.
In the signal generation process, in order to give consideration to the universality of control software, a standardized NI-VISA function library is adopted as a driver of the system.
The main control software can call a signal source driver program, a user sets signal parameters through the main control software, and the parameters are sent to the signal source in the form of instructions for calling the I/O function library, so that the task of remotely controlling the signal source to generate radar signals is completed.
The main functions of the system software are initializing the instrument, generating and reading waveform files, and setting parameters such as parameters of phase parameters, clocks, output power, trigger sources, center frequency and the like. Among them, the waveform playback function plays a vital role in the generation of arbitrary waves, and it can play back txt or other format waveform files by calling the functions of the waveform generator driver. Therefore, the user only needs to edit the data of the waveform file, and then the required arbitrary wave can be generated through the waveform playback function, and the arbitrary wave radar vector source signal generation flow is shown in fig. 5.
And 4, using equipment such as a current main control computer, a signal generator, a signal amplifier and the like and simulation software, supporting the reading of user txt file data and radar signal simulation sample library data through the signal generator, simulating a signal source of radar equipment, setting according to set working parameters, obtaining any wave radar signals by using a windowing superposition method of time domain random signals, adopting a hanning window superposition time domain amplitude correction method, reducing spectrum leakage of the radar signals, and improving the quality of generated radar signals.
The common equipment used in the generation of the analog radar signal comprises a main control computer, a signal generator, an amplifier and the like, and common software comprises Matlab, labVIEW and other signal generation software, and can be communicated with the vector signal generator and used for data transmission.
Whether the radar signal is generated by using analog data through parameter setting or the radar signal is obtained by generating a waveform file and main parameters through user on-site recording data, smooth transition of two continuous frame signals cannot be ensured, and the continuity of two frame signal boundaries is ensured through processing.
The usual processing method is to use windowed superposition method, weighting with window function, if the signal generated is of lengthSingle frame signal sequence of (a)The windowing and overlapping process is utilized as follows:
(6)
In (formula 6): Is the window coefficient used by the windowed overlap-add method, Is the size of the time-domain interval,Represented is the signal frame number, and the window coefficient used in (equation 6) needs to satisfy (equation 7), namely:
(7)
Only the signal satisfying the condition (formula 7)Can be modulated by a periodic signal.
If two continuous frames of arbitrary signals are subjected to windowing and overlapping processing, the time domain interval needs to be ensuredObtaining two continuous frames of time domain signals through discrete Fourier transformAndThe frame length of the signal is。
If an overlap-add method is used, the time domain signal is then processedFirst half of the signal and signalTime-domain interval field signal obtained by windowing and superposing the latter half part of the field signal。
Time domain signalSecond half of the signal and signalTime-domain interval other half frame signal obtained by windowing and superposing the first half part of the frameThe process is as follows:
(8)
Wherein the method comprises the steps ofIs a given windowed window coefficient, and the windowing function needs to satisfy:
(9)
The common window functions include a half sine window function, a triangular window function and a hanning window function, and the three window functions are utilized to perform random processing, so that a frequency spectrum of a certain actual signal can be obtained, and the frequency spectrum is shown in fig. 6-8.
By using different windowing functions, the half sine window function and the triangular window function have larger frequency spectrum leakage in the processing, the signal precision is lower, the signal power spectrum obtained by the Hanning windowing function processing is more consistent with the target spectrum, the clutter attenuation can reach 120dB, and the signal power spectrum is compared with the windowing function which is the best signal processing.
In order to avoid spectrum leakage, the obtained arbitrary signal has better statistical property, and after the signal is obtained by the Hanning window function, a correction coefficient is introducedCorrecting signal amplitude and combining Hanning window functionThe correction coefficients are:
(10)
After the correction coefficient is introduced, the output signal is processed by a hanning windowing functionMultiplying by a correction factorObtaining arbitrary wave radar signalsThe method comprises the following steps:
(11)
The introduced correction factor is a discrete, periodic time domain signal, as shown in fig. 9, as known from the representation of the correction factor.
Any radar signal output after the random wave radar signal subjected to time domain randomization is overlapped by adopting a hanning window and subjected to amplitude correction is shown in fig. 10 and 11, and the periodic fluctuation is reduced after the time domain correction, the frequency spectrum leakage is smaller, and the random phase is realized.
According to the invention, 1465-V is used as a vector signal generator for generating radar signals by using simulation generated data and on-site recorded data, a user is supported to generate a waveform file and play an arbitrary wave file by using a txt format file, a signal source of simulation radar equipment can be set according to set working parameters, and the working state of the signal generator can be switched according to a designed set simulation time sequence to generate radar signals of arbitrary waves; and obtaining any wave radar signals by using a time domain randomization processing method, and reducing the frequency spectrum leakage of the radar signals by using a hanning window superposition time domain amplitude correction method. The system has complete capability of responding to the battlefield situation evolution of the battlefield on the signal level, and is suitable for training and use in institutions and troops.
The present invention is not limited to the above embodiments, but is not limited to the above embodiments, and any simple modification, equivalent changes and modification made to the above embodiments according to the technical matter of the present invention can be made by those skilled in the art without departing from the scope of the technical matter of the present invention.
Claims (7)
1. The arbitrary wave radar signal generation method of the complex electromagnetic environment is characterized by comprising the following steps of:
step 1, analyzing the communication environment of a complex electromagnetic environment, and analyzing the types and characteristics of radar signals and electronic countermeasure signals;
step 2, designing a radar signal dynamic generation library simulating a complex electromagnetic environment by utilizing a digital twin technology according to the collected radar signal data, and calculating I/Q data of signals by utilizing a computer program to obtain a sample database for radar generation;
step 3, simulating and generating radar signal data of different types through simulation software, and inputting the radar signal data serving as a vector signal source into a signal generator;
Step4, obtaining any wave radar signals by using a windowing and superposition method of the time domain random signals, and correcting the time domain amplitude of the any wave radar signals by using a hanning window to reduce the frequency spectrum leakage of the radar signals;
Wherein: step 4 includes weighting the radar signals:
Let the generated signal be a single frame signal sequence s m (N) of length N, n=1, 2, …, N, using a windowed overlap procedure:
wherein: w is a window coefficient used by a windowing and superposition method, H is a time domain interval size, m represents a signal frame number, and the used window coefficient needs to satisfy:
Obtaining two continuous frames of time domain signals s '2i (N) and s' 2i+1 (N) through discrete Fourier transform, wherein the frame length of the signals is N;
A time-domain interval half frame signal v ' 2i (n) obtained by windowing and superposing the first half part of the time-domain signal s ' 2i (n) and the second half part of the signal s ' 2i-1 (n);
The second half of the time domain signal s ' 2i (n) is windowed and superimposed with the first half of the signal s ' 2i+1 (n) to obtain a time domain interval further half frame signal v ' 2i+1 (n);
The process is as follows:
where w (n) is the window coefficient for a given windowing,
The windowing function in this process needs to satisfy:
Introducing a correction coefficient k to correct the signal amplitude, and combining with a hanning window function, wherein the correction coefficient is as follows:
After the correction coefficient is introduced, the signal v' (n) output by the hanning windowing function processing is multiplied by the correction coefficient k to obtain an arbitrary wave radar signal v (n) which is:
2. The arbitrary-wave radar signal generating method according to claim 1, characterized in that: in step 1, radar signals include continuous wave radar signals and pulse radar signals; the electronic countermeasure signals include radar interference countermeasure signals and communication interference countermeasure signals.
3. The arbitrary-wave radar signal generating method according to claim 1, wherein step 2 includes: encoding the collected radar signal data, representing a conventional pulsed radar signal as:
Wherein: t r is the pulse repetition period in s; τ is the pulse width in s; a i is the amplitude of the ith pulse in radar transmit signal S t (t); f 0 is the signal carrier frequency in Hz; Is the initial phase of the ith pulse in rad; /(I) Is a rectangular window function, the value of which is related to the range of t, namely
4. The arbitrary-wave radar signal generating method according to claim 1, wherein step 2 includes expressing the chirp signal as:
Wherein: t r is the pulse repetition period in s; τ is the pulse width in s; Is a rectangular window function; a is the chirp amplitude; f 0 is the signal carrier frequency in Hz; k is modulation slope, is + -B/tau, B is modulation bandwidth; /(I) Is the initial phase of the signal in rad.
5. The arbitrary-wave radar signal generating method according to claim 1, wherein step 2 includes expressing the nonlinear frequency-modulated signal as:
Wherein: t r is the pulse repetition period in s; τ is the pulse width in s; Is a rectangular window function; a is the chirp amplitude; f j is the j-th nonlinear frequency-regulating frequency point value, and the unit is Hz; n is the number of nonlinear frequency-modulated frequencies.
6. The arbitrary-wave radar signal generating method according to claim 1, wherein step 2 includes modulating codeword information in a carrier phase by phase encoding using a pseudo-random code or a random sequence as a codeword to obtain a phase-encoded signal;
the mathematical expression of the encoded signal is:
Wherein: t r is the pulse repetition period in s; τ is the pulse width in s; Is a rectangular window function; a is the chirp amplitude; f 0 is the signal carrier frequency in Hz; /(I) Is a phase modulation function, the value of which is determined by the coding information, and the unit rad.
7. The arbitrary-wave radar signal generating method according to claim 1, wherein step 3 includes:
different radar signals are generated through simulation, a vector signal source is obtained after resampling and filtering, a digital signal is converted into an I/Q two-baseband analog signal through a D/A module in a signal generator, the I/Q modulation module carries out quadrature carrier modulation on the I/Q two-baseband signal, the center frequency of the signal is moved to a required frequency band, and finally the signal is output.
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