A Method for Generating Multi-Waveform Signals of Pulse Radar Based on DAC

Abstract

The present invention relates to a DAC-based pulse radar multi-waveform signal generation method, which belongs to the field of signal processing. The method can flexibly set various signal parameters, adopts a fully digital method to design and generate pulse radar signals in various relatively complex environmental scenarios, and realizes the generation of various pulse radar signal waveforms in the application environment, including frequency modulation (conventional frequency modulation, frequency diversity, frequency agility), frequency repetition rate (PRI) modulation (conventional, staggered, jitter, sliding, jumping), and intra-pulse modulation (intra-pulse single tone, linear frequency modulation, nonlinear frequency modulation, phase encoding, frequency encoding, and hybrid encoding). The method can simultaneously combine various pulse radar waveforms, dynamically adjust according to the DAC working data bit width, and generate corresponding signals according to the signal waveform output mode. The method has obvious advantages in the simulation generation of pulse radar signals in electromagnetic environments.

Description

Technical Field

[0001] The present invention relates to the field of signal processing, and in particular to a method for generating multi-waveform signals of a pulse radar based on DAC. Background Art

[0002] Radar applications are increasingly complex, facing increasingly diverse electromagnetic interference and clutter, placing higher demands on radar performance. Radars must also meet multi-task detection requirements and multi-mode functionality, requiring greater system flexibility. Therefore, using software to generate multiple pulse radar signal waveforms allows for real-time adjustment of radar parameters based on application scenarios and mission requirements, improving radar's anti-interference capabilities while making it more difficult for adversaries to detect interference.

[0003] Traditional radars are typically hardware-centric, designed to meet practical needs and address specific functions. Changing radar functionality typically requires modifications to both hardware and software, consuming significant manpower and resources. Clearly, hardware-centric traditional radars lack the flexibility and openness required, and radar performance is significantly constrained by hardware. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for generating multi-waveform signals of pulse radar based on DAC, thereby solving the shortcomings of the prior art.

[0005] The object of the present invention is achieved by the following technical solution: a method for generating multi-waveform signals of a pulse radar based on DAC, the method comprising:

[0006] Step 1: Set common parameters, frequency modulation type, repetition rate modulation type and intra-pulse modulation type, determine other repetition rate parameters according to the set repetition rate modulation type, and determine other intra-pulse modulation parameters according to the set intra-pulse modulation type;

[0007] Step 2: Initialize the pulse type and determine whether the set pulse radar parameters are correct;

[0008] Step 3: Initialize the frequency type, intra-pulse modulation type and repetition rate type respectively;

[0009] Step 4: Determine the final number of pulses and the PRI value of the pulses, determine the number of intra-pulse and extra-pulse sampling points for each pulse based on the PRI value and sampling rate, and generate corresponding intra-pulse baseband data through orthogonal modulation based on the intra-pulse modulation type;

[0010] Step 5: Output the corresponding signal according to the signal output mode. Perform corresponding frequency modulation processing on each pulse according to the frequency modulation type. Normalize the amplitude of the generated pulse radar signal according to the set signal power and the number of DAC chip bits. Finally, store the generated signal data in the data file.

[0011] The setting of common parameters, frequency modulation type, repetition frequency modulation type and intra-pulse modulation type includes:

[0012] A1. Set common parameters, including sampling rate, DAC working data bit number, PRI, radar pulse width and center frequency. PRI is the radar pulse repetition interval.

[0013] A2. Set the frequency modulation type, including normal frequency, frequency diversity, and frequency agility. Frequency diversity includes simultaneous diversity and time diversity.

[0014] A3. If the frequency modulation type is simultaneous diversity with frequency diversity, set the number of diversity channels and the frequency diversity pattern. If the frequency modulation type is time diversity with frequency diversity, set the number of diversity channels and the duration of each frequency. If the frequency modulation type is frequency agility, set the number of agility channels and the frequency agility pattern.

[0015] A4. Set the repetition frequency modulation type, including normal repetition frequency, staggered repetition frequency, sliding repetition frequency, jitter repetition frequency and jump repetition frequency;

[0016] A5. Set the intra-pulse modulation type, including intra-pulse single tone, linear frequency modulation, nonlinear frequency modulation, phase coding, frequency coding, and mixed coding.

[0017] The determining of other repetition frequency parameters according to the set repetition frequency modulation type includes: if the repetition frequency modulation type is repetition frequency slip, setting the repetition frequency slip PRI minimum value, the repetition frequency slip PRI maximum value, and the repetition frequency slip PRI increment;

[0018] If the repetition modulation type is staggered repetition, set the number of staggered repetitions and the staggered repetition sequence;

[0019] If the repetition modulation type is repetition dither, set the dither number and repetition dither amount.

[0020] The determining of other intra-pulse modulation parameters according to the set intra-pulse modulation type includes: if the intra-pulse modulation type is linear frequency modulation, setting the intra-pulse signal bandwidth and slope type;

[0021] If the intra-pulse modulation type is nonlinear frequency modulation, set the intra-pulse signal bandwidth and nonlinear frequency modulation mode, including triangle, sawtooth, sine, tangent and quadratic functions;

[0022] If the intra-pulse modulation type is phase coding, frequency coding or mixed coding, the number of code elements is set and the corresponding code element width is calculated, and the code element sequence is set.

[0023] The second step includes:

[0024] Frequency modulation parameter judgment: judge whether the number of frequency diversity is greater than or equal to 2. If so, the parameter is valid. If the frequency diversity is time diversity, judge whether the sum of the frequency duration is equal to the pulse width. If so, the parameter is valid, otherwise the parameter is invalid; judge whether the number of frequency agility is greater than or equal to 0. If so, the parameter is valid, otherwise the parameter is invalid;

[0025] Determination of some parameters of repetition modulation: Determine whether the repetition normal or repetition jitter pulse width is less than or equal to PRI. If so, the parameter is valid, otherwise the parameter is invalid; Determine whether the number of repetition staggered or repetition jump pulses is greater than or equal to 1, and whether the pulse width is less than or equal to the staggered / jump PRI. If so, the parameter is valid, otherwise the parameter is invalid; Determine whether the maximum value of the repetition slip PRI is greater than or equal to the minimum value of the slip PRI, the PRI slip increment is not 0, and the pulse width is less than or equal to the slip PRI. If so, the parameter is valid, otherwise the parameter is invalid; Determine whether the number of repetition jitter is greater than or equal to 3, and whether the jitter value range is [0,1]. If so, the parameter is valid, otherwise the parameter is invalid;

[0026] Judgment of some parameters of intra-pulse modulation: judge whether the intra-pulse bandwidth of linear frequency modulation or nonlinear frequency modulation is not 0. If so, the parameter is valid, otherwise the parameter is invalid; judge whether the number of codes of phase coding, frequency coding or mixed coding is not 0, and whether the value range of the code element sequence is [0, modulation order-1]. If so, the parameter is valid, otherwise the parameter is invalid.

[0027] The step three includes:

[0028] Frequency type initialization: When the frequency is normal, the initialization frequency number is 1 and the frequency pattern is 0; for frequency diversity or frequency agility, the initialization frequency number and pattern are both the set parameters; if the signal waveform output mode is DAC mode, the carrier frequency offset of the pulse radar signal is calculated; if the signal waveform output mode is DUC mode, the carrier frequency offset is calculated;

[0029] Initialization of intra-pulse modulation type: If the sequence length and symbol sequence are not provided for phase coding or frequency coding, the symbol sequence is randomly generated internally; if the sequence length and content are provided for hybrid coding, the corresponding symbol sequence is directly calculated; if not provided, the symbol sequence is first randomly generated internally and then the corresponding symbol sequence is calculated; set the constellation diagram;

[0030] Repetition type initialization: Calculate the number of sampling points for each PRI sequence of the corresponding type based on the number of repetition frequency deviation, repetition frequency jump, repetition frequency slip, and repetition frequency jitter.

[0031] Determining the final number of pulses and the PRI value of the pulses includes:

[0032] The final number of pulses is calculated according to the repetition type and frequency type, that is, the least common multiple of the PRI number and the frequency number, and the PRI value of each pulse is determined.

[0033] Outputting the corresponding signal according to the signal output mode includes:

[0034] When the signal output mode is set to DUC mode, the output is a baseband signal. Pulses are generated in sequence according to the number of pulses. The intra-pulse data is the intra-pulse baseband data, and the extra-pulse data is 0.

[0035] When the signal output mode is set to DAC mode, the output is an intermediate frequency signal, the baseband signal in the pulse is orthogonally up-converted, and each pulse is generated in sequence according to the number of pulses. The data in the pulse is the processed data, and the data outside the pulse is 0.

[0036] The present invention has the following advantages: a DAC-based pulse radar multi-waveform signal generation method, which utilizes software to generate signals and can reuse the same set of hardware resources. According to different functions and modes, pulse radar signals with different waveforms are generated by modifying signal parameters. The system performance is improved by upgrading and changing the signal library generated by the software or expanding the function. The method has high flexibility and strong adaptability. When a new pulse radar signal waveform is needed, only the waveform needs to be redeveloped, which can also save a lot of manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the process of the present invention;

[0038] Figure 2 Schematic diagram of frequency diversity and frequency agility;

[0039] Figure 3 It is the PSK constellation mapping diagram;

[0040] Figure 4 This is a pulse radar spectrum diagram. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided below in conjunction with the drawings is not intended to limit the scope of protection of the present application for which protection is claimed, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. The present invention is further described below in conjunction with the drawings.

[0042] The present invention specifically relates to a DAC-based pulse radar multi-waveform signal generation method. The method can flexibly set various signal parameters, adopt a fully digital method to design and generate pulse radar signals in a variety of relatively complex environmental scenarios, and realize the generation of various pulse radar signal waveforms in the application environment, including frequency modulation (conventional frequency modulation, frequency diversity, frequency agility), frequency repetition rate (PRI) modulation (conventional, staggered, jitter, sliding, jumping), intra-pulse modulation (intra-pulse single tone, linear frequency modulation, nonlinear frequency modulation, phase encoding, frequency encoding, hybrid encoding). It can simultaneously combine multiple pulse radar waveforms, and can be dynamically adjusted according to the DAC working data bit width. It can also be adjusted according to the signal waveform output mode to generate corresponding signals. It has obvious advantages in the simulation generation of pulse radar signals in electromagnetic environments.

[0043] like Figure 1 As shown, specifically including the following:

[0044] (1) Set common parameters, including sampling rate, DAC working data bit number, radar pulse repetition interval (PRI), radar pulse width, center frequency, etc.;

[0045] (2) Set the frequency modulation type, including frequency normal, frequency diversity (simultaneous diversity / time-division diversity) and frequency agility. The diagram of frequency diversity and frequency agility is as follows: Figure 2 As shown;

[0046] (3) Determine other frequency parameters based on the set frequency modulation type: If the frequency modulation type is simultaneous diversity with frequency diversity, set the number of diversity and the frequency diversity pattern; if it is time diversity, set the number of diversity and the duration of each frequency. Note that the sum of the duration of each frequency is the pulse width. If the frequency modulation type is frequency agility, set the number of agility and the frequency agility pattern;

[0047] (4) Set the repetition frequency modulation type, including normal repetition frequency, staggered repetition frequency, sliding repetition frequency, jitter repetition frequency, and jump repetition frequency;

[0048] (5) Determine other repetition parameters according to the set repetition modulation type: if the repetition modulation type is repetition slip, set the repetition slip PRI minimum value, repetition slip PRI maximum value, and repetition slip PRI increment; if the repetition modulation type is repetition stagger, set the repetition stagger number and repetition stagger sequence; if the repetition modulation type is repetition jitter, set the jitter number and repetition jitter amount;

[0049] (6) Set the intra-pulse modulation type, including intra-pulse single tone, linear frequency modulation (positive slope / negative slope), nonlinear frequency modulation (sine wave / sawtooth wave / triangle wave / inverse tangent function / quadratic function), phase coding (BPSK / QPSK / 8PSK / 16PSK), frequency coding (2FSK / 4FSK / 8FSK / 16FSK), mixed coding (2FSK-2PSK / 4FSK-4PSK / 8FSK-8PSK / 16FSK-16PSK);

[0050] (7) Set other intra-pulse modulation parameters according to the set intra-pulse modulation type. If the intra-pulse modulation type is linear frequency modulation, set the intra-pulse signal bandwidth and slope type (positive slope / negative slope); if the intra-pulse modulation type is nonlinear frequency modulation, set the intra-pulse signal bandwidth and nonlinear frequency modulation mode, including triangle (first up then down / first down then up), sawtooth, sine, tangent, and quadratic function; if the intra-pulse modulation type is phase coding, frequency coding, or mixed coding, set the number of code elements and calculate the corresponding code element width, set the code element sequence (optional, it will be randomly generated internally later). Note that the modulation frequency deviation needs to be set when frequency coding is used;

[0051] (8) Pulse radar initialization, determine whether the set pulse radar parameters are correct; specifically include the following:

[0052] 1. Frequency modulation parameter judgment:

[0053] Frequency diversity: The number of diversity must be ≥ 2, and the sum of the frequency durations of time diversity must be equal to the pulse width, otherwise the parameter is invalid;

[0054] Frequency agility: The number of agility must be ≥ 0; otherwise, the parameter is invalid.

[0055] 2. Determination of some parameters of repetition frequency modulation:

[0056] Normal repetition rate or jitter repetition rate: Pulse width must be ≤ PRI, otherwise the parameter is invalid;

[0057] Repeat frequency staggered or repeated frequency jump: the number of pulses must be ≥1, and the pulse width must be ≤ staggered / jumped PRI, otherwise the parameters are invalid;

[0058] Repetitive frequency slip: The maximum value of slip PRI must be ≥ the minimum value of slip PRI, the PRI slip increment is not equal to 0, and the pulse width must be ≤ the slip PRI, otherwise the parameters are invalid;

[0059] Repeat frequency jitter: The number of jitters must be ≥ 3, and the jitter value range is [0, 1]. Otherwise, the parameter is invalid.

[0060] 3. Judgment of some parameters of intra-pulse modulation:

[0061] Linear frequency modulation or nonlinear frequency modulation: The intra-pulse bandwidth is not 0, otherwise the parameter is invalid;

[0062] Phase / Frequency / Hybrid Coding: The number of codes is not 0, and the symbol sequence value range is [0, modulation order - 1]. Otherwise, the parameter is invalid.

[0063] (9) Initialize the frequency type, intra-pulse modulation type, and repetition rate type respectively; specifically including the following:

[0064] 1. Frequency type initialization:

[0065] When the frequency is normal, the frequency number is 1 and the frequency pattern is 0;

[0066] Frequency diversity or frequency agility: the number of frequencies and the pattern are set parameters;

[0067] If the signal waveform output mode is DAC mode, calculate the carrier frequency offset of the pulse radar signal; if the signal waveform output mode is DUC mode, then the carrier frequency offset.

[0068] 2. Initialization of intra-pulse modulation type:

[0069] Phase coding or frequency coding: If the sequence length and symbol sequence are not provided, the symbol sequence is randomly generated internally;

[0070] Hybrid coding: If the sequence length and content are provided, the corresponding FSK codeword sequence and PSK codeword sequence are directly calculated; if not provided, the codeword sequence is randomly generated internally, and then the corresponding FSK and PSK codeword sequences are calculated;

[0071] Set the constellation diagram of the corresponding PSK order: PSK constellation mapping diagram is as follows Figure 3 As shown, Figure 3 In the figure, (a) is the BPSK constellation diagram, (b) is the QSPK constellation diagram, (c) is the 8PSK constellation diagram, and (d) is the 16PSK constellation diagram.

[0072] 3. Initialization of re-frequency type:

[0073] According to the number of repetition frequency deviation, repetition frequency jump, repetition frequency slip, and repetition frequency jitter, the number of sampling points of each PRI sequence of the corresponding type is calculated respectively.

[0074] (10) Determine the final number of pulses and the PRI value of each pulse;

[0075] Calculate the final number of pulses based on the repetition rate type and frequency type, that is, the least common multiple of the PRI number and the frequency number, and determine the PRI value of each pulse;

[0076] (11) Determine the number of sampling points inside and outside the pulse of each pulse based on the pulse PRI value and sampling rate;

[0077] (12) According to the type of intra-pulse modulation, the corresponding intra-pulse baseband data is generated by orthogonal modulation. The specific generation expression is as follows:

[0078] Intra-pulse single tone: baseband data I channel is 1, Q channel is 0;

[0079] Linear frequency modulation: The most commonly used pulse compression radar intra-pulse modulation waveform, also called chirp signal, the mathematical expression is:

[0080] ,

[0081] in, is the time variable, is a linear frequency modulation signal in The signal amplitude at time , is the carrier frequency, is the frequency modulation slope of the signal, is the amplitude modulation coefficient.

[0082] Nonlinear frequency modulation, the mathematical expression is:

[0083] ,

[0084] in, It is a nonlinear frequency modulation signal in The signal amplitude at time , is the intra-pulse modulation bandwidth, is the sampling frequency, and T is the intra-pulse sampling time interval. The different types of intra-pulse modulation are set in The frequency of the moment, which mainly includes five modulation types: sine function, trigonometric function, sawtooth function, tangent function and quadratic function.

[0085] After orthogonal decomposition, we get:

[0086] ,

[0087] ;

[0088] The frequency expression of the sine function is:

[0089] ,

[0090] The frequency expression of trigonometric function is:

[0091] ,

[0092] The frequency expression of the sawtooth function is:

[0093]

[0094] The frequency expression of the tangent function is:

[0095] ,

[0096] The frequency expression of the quadratic function is:

[0097] ,

[0098] Phase coding: The symbol sequence is encoded as follows Figure 3 The mapping relationship is used to map the constellation diagram;

[0099] Frequency encoding: , , is the corresponding modulation frequency deviation;

[0100] Hybrid coding: The signal is first frequency coded and modulated, and then phase coded and modulated within each frequency value time.

[0101] (13) When the signal output mode is set to DUC mode, the output is a baseband signal, and each pulse is generated in sequence according to the number of pulses. The data within the pulse is the baseband data within the pulse, and the data outside the pulse is 0; when the signal output mode is set to DAC mode, the output is an intermediate frequency signal, and the baseband signal within the pulse is orthogonally up-converted. In essence, the received and Two in-phase and quadrature signals are modulated onto the carrier respectively, and pulses are generated in sequence according to the number of pulses. The data inside the pulse is the modulated data of the baseband signal, and the data outside the pulse is 0.

[0102] (14) According to the frequency modulation type, each pulse is subjected to corresponding frequency modulation processing. The processing formula is: ,in, It is a diversity pattern or an agile pattern.

[0103] (15) According to the set signal power and DAC chip bit number, the generated pulse radar signal is normalized. The quantization bit number after the analog interference signal is generated is determined according to the working data bit width of the DAC chip, which is dynamically adjustable: for example, when the working data bit width of the DAC chip used is 8 bits, the maximum value of the generated signal data quantization is ; When the working data bit width of the DAC chip used is 16 bits, the maximum value of the generated signal data quantization is , and so on.

[0104] (16) Store the final generated signal data in a data file.

[0105] The present invention uses the Visual Studio 2019 platform to simulate the proposed pulse radar signal generation method, uses the MATLAB 2021b platform to verify the generated signal file, and finally uses a spectrum analyzer to test it. The results show that the proposed method is feasible. Taking the sampling rate of 2.4G, DUC mode, DAC bit number of 16 bits, frequency type of frequency agility, number of agility of 3, agility patterns of -100M, 0, 100M respectively, repetition type of repetition normal, and intra-pulse modulation type of intra-pulse single tone as an example, the generated signal spectrum diagram is as follows: Figure 4 shown.

[0106] The foregoing description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Rather, the present invention is capable of various other combinations, modifications, and improvements, and is capable of modifications within the scope of the concepts described herein, through the above teachings, or through techniques or knowledge in the relevant fields. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be within the scope of the appended claims.

Claims

1. A method for generating multi-waveform signals of a pulse radar based on DAC, characterized in that: The method comprises: Step 1: Set common parameters, frequency modulation type, repetition rate modulation type and intra-pulse modulation type, determine other repetition rate parameters according to the set repetition rate modulation type, and determine other intra-pulse modulation parameters according to the set intra-pulse modulation type; Step 2: Initialize the pulse type and determine whether the set pulse radar parameters are correct; Step 3: Initialize the frequency modulation type, intra-pulse modulation type and repetition rate type respectively; Step 4: Determine the final number of pulses and the PRI value of the pulses, determine the number of intra-pulse and extra-pulse sampling points for each pulse based on the PRI value and sampling rate, and generate corresponding intra-pulse baseband data through orthogonal modulation based on the intra-pulse modulation type; Step 5: Output the corresponding signal according to the signal output mode. Perform corresponding frequency modulation processing on each pulse according to the frequency modulation type. Normalize the amplitude of the generated pulse radar signal according to the set signal power and the number of bits of the DAC chip. Finally, store the generated signal data in the data file. Outputting the corresponding signal according to the signal output mode includes: When the signal output mode is set to DUC mode, the output is a baseband signal. Pulses are generated in sequence according to the number of pulses. The intra-pulse data is the intra-pulse baseband data, and the extra-pulse data is 0. When the signal output mode is set to DAC mode, the output is an intermediate frequency signal, the baseband signal in the pulse is orthogonally up-converted, and each pulse is generated in sequence according to the number of pulses. The data in the pulse is the processed data, and the data outside the pulse is 0.

2. The method for generating multi-waveform signals of a pulse radar based on DAC according to claim 1, wherein: The setting of common parameters, frequency modulation type, repetition frequency modulation type and intra-pulse modulation type includes: A1. Set common parameters, including sampling rate, DAC working data bit number, PRI, radar pulse width and center frequency. PRI is the radar pulse repetition interval. A2. Set the frequency modulation type, including normal frequency, frequency diversity, and frequency agility. Frequency diversity includes simultaneous diversity and time diversity. A3. If the frequency modulation type is simultaneous diversity with frequency diversity, set the number of diversity channels and the frequency diversity pattern. If the frequency modulation type is time diversity with frequency diversity, set the number of diversity channels and the duration of each frequency. If the frequency modulation type is frequency agility, set the number of agility channels and the frequency agility pattern. A4. Set the repetition frequency modulation type, including normal repetition frequency, staggered repetition frequency, sliding repetition frequency, jitter repetition frequency and jump repetition frequency; A5. Set the intra-pulse modulation type, including intra-pulse single tone, linear frequency modulation, nonlinear frequency modulation, phase coding, frequency coding, and mixed coding.

3. The method for generating multi-waveform signals of a pulse radar based on DAC according to claim 2, characterized in that: The determining of other repetition frequency parameters according to the set repetition frequency modulation type includes: if the repetition frequency modulation type is repetition frequency slip, setting the repetition frequency slip PRI minimum value, the repetition frequency slip PRI maximum value, and the repetition frequency slip PRI increment; If the repetition modulation type is staggered repetition, set the number of staggered repetitions and the staggered repetition sequence; If the repetition modulation type is repetition dither, set the dither number and repetition dither amount.

4. The method for generating multi-waveform signals of a pulse radar based on DAC according to claim 2, wherein: The determining of other intra-pulse modulation parameters according to the set intra-pulse modulation type includes: if the intra-pulse modulation type is linear frequency modulation, setting the intra-pulse signal bandwidth and slope type; If the intra-pulse modulation type is nonlinear frequency modulation, set the intra-pulse signal bandwidth and nonlinear frequency modulation mode, including triangle, sawtooth, sine, tangent and quadratic functions; If the intra-pulse modulation type is phase coding, frequency coding or mixed coding, the number of code elements is set and the corresponding code element width is calculated, and the code element sequence is set.

5. The method for generating multi-waveform signals of a pulse radar based on DAC according to claim 2, wherein: The second step includes: Frequency modulation parameter judgment: judge whether the number of frequency diversity is greater than or equal to 2. If so, the parameter is valid. If the frequency diversity is time diversity, judge whether the sum of the frequency duration is equal to the pulse width. If so, the parameter is valid, otherwise the parameter is invalid; judge whether the number of frequency agility is greater than or equal to 0. If so, the parameter is valid, otherwise the parameter is invalid; Determination of some parameters of repetition modulation: Determine whether the repetition normal or repetition jitter pulse width is less than or equal to PRI. If so, the parameter is valid, otherwise the parameter is invalid; Determine whether the number of repetition staggered or repetition jump pulses is greater than or equal to 1, and whether the pulse width is less than or equal to the staggered / jump PRI. If so, the parameter is valid, otherwise the parameter is invalid; Determine whether the maximum value of the repetition slip PRI is greater than or equal to the minimum value of the slip PRI, the PRI slip increment is not 0, and the pulse width is less than or equal to the slip PRI. If so, the parameter is valid, otherwise the parameter is invalid; Determine whether the number of repetition jitter is greater than or equal to 3, and whether the jitter value range is [0,1]. If so, the parameter is valid, otherwise the parameter is invalid; Judgment of some parameters of intra-pulse modulation: judge whether the intra-pulse bandwidth of linear frequency modulation or nonlinear frequency modulation is not 0. If so, the parameter is valid, otherwise the parameter is invalid; judge whether the number of codes of phase coding, frequency coding or mixed coding is not 0, and whether the value range of the code element sequence is [0, modulation order-1]. If so, the parameter is valid, otherwise the parameter is invalid.

6. The method for generating multi-waveform signals of a pulse radar based on DAC according to claim 2, characterized in that: The step three includes: Frequency modulation type initialization: When the frequency is normal, the initialization frequency number is 1 and the frequency pattern is 0; for frequency diversity or frequency agility, the initialization frequency number and pattern are both the set parameters; if the signal waveform output mode is DAC mode, the carrier frequency offset of the pulse radar signal is calculated; if the signal waveform output mode is DUC mode, the carrier frequency offset is calculated; Initialization of intra-pulse modulation type: If the sequence length and symbol sequence are not provided for phase coding or frequency coding, the symbol sequence is randomly generated internally; if the sequence length and content are provided for hybrid coding, the corresponding symbol sequence is directly calculated; if not provided, the symbol sequence is first randomly generated internally and then the corresponding symbol sequence is calculated; set the constellation diagram; Repetition type initialization: Calculate the number of sampling points for each PRI sequence of the corresponding type based on the number of repetition frequency deviation, repetition frequency jump, repetition frequency slip, and repetition frequency jitter.

7. The method for generating multi-waveform signals of a pulse radar based on DAC according to claim 2, wherein: Determining the final number of pulses and the PRI value of the pulses includes: The final number of pulses is calculated according to the repetition type and frequency type, that is, the least common multiple of the PRI number and the frequency number, and the PRI value of each pulse is determined.

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