阅读说明：本技术 一种基于混沌编码的探测干扰一体化波形设计方法及装置 (Chaos coding-based detection and interference integrated waveform design method and device ) 是由 汪飞 陈义源 时晨光 于 2021-07-14 设计创作，主要内容包括：本发明公开一种基于混沌编码的探测干扰一体化波形设计方法及装置,首先,基于混沌编码系统的工作原理,给出包含混沌频率编码序列生成和混沌相位编码序列,据此,进行脉内相位编码、脉间频率编码,设计混沌复合编码探干一体化波形；然后,利用模糊函数和基于Wigner谱的干扰性能表征参量分别衡量一体化波形的探测和干扰性能；最后,针对所设计波形,仿真对比单一和复合编码方式在探测性能和干扰性能上的优劣。本发明设计的混沌复合编码一体化波形的模糊函数图呈现良好“图钉状”,具有较好的距离和速度分辨力；干扰性能指标能够正确表征波形干扰性能,复合编码方式在干扰性能上优于单一编码方式。(The invention discloses a method and a device for designing a detection interference integrated waveform based on chaotic coding, which comprises the steps of firstly, based on the working principle of a chaotic coding system, generating a chaotic frequency coding sequence and a chaotic phase coding sequence, carrying out intra-pulse phase coding and inter-pulse frequency coding according to the chaotic frequency coding, and designing a chaotic composite coding probe-stem integrated waveform; then, respectively measuring the detection performance and the interference performance of the integrated waveform by using a fuzzy function and interference performance characterization parameters based on a Wigner spectrum; finally, aiming at the designed waveform, the simulation compares the advantages and disadvantages of a single and composite coding mode on the detection performance and the interference performance. The fuzzy function graph of the chaotic composite coding integrated waveform designed by the invention is in a good 'picture pin shape', and has better distance and speed resolution; the interference performance index can correctly represent the waveform interference performance, and the composite coding mode is superior to a single coding mode in interference performance.)

1. A method for designing a detection interference integrated waveform based on chaotic coding is characterized by comprising the following steps:

(1) the discrete chaotic system generates a chaotic sequence, and frequency and phase coded sequences are respectively obtained in an index value mapping and quantitative rounding mode;

(2) based on the chaos sequence, a composite coding detection interference integrated waveform is designed for a coding mode of internal phase coding of the sampling sub-pulses and frequency coding between the sub-pulses, and a time-frequency domain expression of the integrated waveform is given;

(3) the fuzzy functions, respectively noted, from a single frequency and phase encoded waveformAndwriting out a fuzzy function χ of the composite coding detection interference integrated waveform in the step (2)_v(τ,ξ)；

(4) Asymptotic spectrum accumulation distribution function P for deducing standard Wigner matrix based on Gaussian white noise set₁(x) Asymptotic spectrum accumulation distributed function of Wigner matrix constructed after noise is added to waveform sample set to be evaluatedNumber P₂(x)，P₁(x) And P₂(x) KL distance D between_KL(P₁||P₂) Recording as an interference performance characterization;

(5) and respectively analyzing the detection performance and the interference performance of the integrated waveform through the fuzzy function and the KL distance.

2. The method for designing the integrated waveform of the detection interference based on the chaotic coding according to claim 1, wherein the step (2) is realized by the following steps:

the baseband time-frequency domain of the single phase encoded waveform is represented as:

wherein the content of the first and second substances,representing an nth sub-pulse phase, each sub-pulse phase having M selectable phases;T_prepresents the sub-pulse width; p represents the length of a phase sequence generated by chaotic mapping;

the baseband time-frequency domain of a single frequency-coded waveform is represented as:

wherein the content of the first and second substances,T_frepresents the sub-pulse width; f represents the length of the chaos sequence used for coding; c. C_mΔ f denotes the frequency value of the mth sub-pulse, c_mThe value of the m-th bit of the chaotic sequence is represented, and Δ f represents the unit step size of frequency hopping, and is usually 1/T_f；

Time-frequency domain expression of integrated waveform:

wherein s is_p(t) represents the complex envelope of the chaotic phase encoded waveform, s_f(t) represents the complex envelope of the chaotic frequency encoded waveform, S_p(f) Denotes s_p(t) spectrum of S_f(f) Denotes s_f(t) spectrum.

3. The method for designing the integrated waveform of the detection interference based on the chaotic coding according to claim 1, wherein the step (3) is realized by the following steps:

ambiguity function for single frequency encoded waveformComprises the following steps:

ambiguity function for single phase encoded waveformComprises the following steps:

wherein the content of the first and second substances,represents convolving τ; { phi_mnRepresents a fuzzy function of the chaotic phase encoding sequence { exp (j phi (k)) }, and the expression is as follows:

the fuzzy function expression of the composite coding detection interference integrated waveform is as follows:

4. the chaotic-coding-based detection and interference integrated waveform design method according to claim 1, wherein the interference performance characterization D in the step (4)_KL(P₁||P₂) Comprises the following steps:

wherein, the asymptotic spectrum accumulation distribution function P of the standard Wigner matrix based on Gaussian white noise₁(x) And the asymptotic spectrum accumulation distributed function of the Wigner matrix constructed after the noise is added to the waveform sample set to be evaluated is P₂(x)；p₁(x) And p₂(x) Are respectively P₁(x) And P₂(x) Probability density function of p₂(x) Is p₁(x) An approximate probability distribution of; constructing a data set { z (n) ═ P) equivalent to { x (n), n ═ 1,2,. and l } using a probability integral transform₁(x (n)), n ═ 1,2,.., l }, fromAnd the data set { z (n) ═ P₁(x (n)), where n 1,2, 1, l } is derived from a random variable Z that obeys a uniform distribution U0, 1](ii) a Will be interval [0,1]Dividing into K parts, and recording the dividing point as u_k(K-0, 1, 2.., K), and satisfies 0-u ═ u ·₀＜u₁＜u₂＜...＜u_KWhen K → ∞ is 1,has | u_k-u_k-1I → 0, where the KL distance calculation can be transformed into the above form.

5. The method for designing the integrated waveform of the detection interference based on the chaotic coding according to claim 1, wherein the step (5) is realized by the following steps:

if the fuzzy function graph of the waveform has a narrow peak, has relatively flat side lobes which are approximate to no side lobes and are approximate to a shape of a pin, the closer to the shape, the more excellent the detection performance of the waveform is; using KL distance D_KL(P₁||P₂) Describing the distance between the integrated waveform to be evaluated and the Gaussian white noise, wherein the smaller the index value is, the closer the waveform is to the Gaussian white noise is, and the better the interference performance is.

6. A chaos coding-based detection and interference integrated waveform design device comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the computer program is loaded to the processor to realize the chaos coding-based detection and interference integrated waveform design method according to any one of claims 1-5.

Technical Field

The invention belongs to the field of wideband radar waveform design of complex coding, and particularly relates to a detection and interference integrated waveform design method and device based on chaotic coding.

Background

With the higher informatization level of modern war, the living environment of the battle platform is increasingly severe, so the development of future weaponry is more and more showing the trend of one machine with multiple functions. The design of a transmitting waveform integrating detection and interference functions is one of keys for realizing integration of a radar and a reconnaissance jammer, the shared transmitting signal can be used for carrying out concealed detection by using a strong interference signal, so that an enemy platform mistakenly regards the intercepted signal as an interference signal only, and the shared transmitting signal has excellent low interception probability performance.

The research in the aspect of random signal radar is one of basic researches on the design of a sounding-interference integrated waveform, and a large number of research achievements of domestic and foreign scholars exist. In 2014, Zhou et al proposed a random space-time coding method, which effectively suppresses the autocorrelation side lobe level of the MIMO radar waveform by modulating a specified waveform by multiplying a random permutation matrix by a random diagonal phase matrix. In 2017, Leandro et al derived a closed expression of a narrow-band fuzzy function of a stochastic frequency modulation waveform, so that the Doppler tolerance of the stochastic frequency modulation waveform can be correctly evaluated. In 2019, in order to suppress an undesired interference signal with the same modulation parameter from another FMCW radar, Yusuke et al proposed a transmitting Chirp waveform with random repetition intervals, and simulation results show that the method can effectively suppress the interference signal. In 2021, Long et al studied the fuzzy function of the random frequency and pulse repetition interval agile signal, and obtained the analytical expressions of the expectation and variance of the fuzzy function, thereby determining the direct relationship between the radio frequency identification key index and the above signal waveform parameters.

In addition, the output of the chaotic system has the characteristics of boundedness, non-periodicity, initial value sensitivity and the like, so that the chaotic waveform obtained by modulating the chaotic system has many ideal radar characteristics, and the chaotic theory is widely applied to radar systems. In 2014, Zhang et al proposed a chaos-based random step frequency radar suitable for broadband imaging, and the radar system not only can realize fast matched filtering of range profile without random noise, but also has better single-frequency interference resistance. In 2018, Hong et al propose a space-time complementary coding orthogonal chaotic phase coding waveform design framework for a MIMO radar, and simulation shows that matched filtering output of the designed waveform has a lower side lobe level and is almost insensitive to doppler phase shift. In 2020, Chandra et al propose a new method for controlling a chaotic track, which encodes a binary information track into a chaotic state by adjusting the track of the binary information, selects a state variable, and generates a controlled chaotic frequency modulation waveform for signal transmission of a joint radar communication system, aiming at the problem of waveform design of a radar communication integrated system.

The existing literature directly related to the design of the waveform integrating the interference detection is still rare, and the waveform design method only considers the detection, anti-interference and other performances of the detected waveform and does not take the interference performance of the waveform relative to a radar receiver into consideration. Therefore, it is an object of the present invention to provide a method for detecting interference in a radar system.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the radar waveform with single frequency, phase coding and composite coding, the detection performance and the interference performance are comprehensively considered, and a detection and interference integrated waveform with excellent performance is designed.

The technical scheme is as follows: the invention provides a chaotic-coding-based detection and interference integrated waveform design method, which specifically comprises the following steps of:

(1) the discrete chaotic system generates a chaotic sequence, and frequency and phase coded sequences are respectively obtained in an index value mapping and quantitative rounding mode;

(2) based on the chaos sequence, a composite coding detection interference integrated waveform is designed for a coding mode of internal phase coding of the sampling sub-pulses and frequency coding between the sub-pulses, and a time-frequency domain expression of the integrated waveform is given;

(3) according to the fuzzy functions of the single frequency and phase coding waveform, respectively noted as χ_v1(τ, ξ) and χ_v2(tau, xi), writing out a fuzzy function chi of the composite coding detection interference integrated waveform in the step (2)_v(τ,ξ)；

(4) Asymptotic spectrum accumulation distribution function P for deducing standard Wigner matrix based on Gaussian white noise set₁(x) Constructed by adding noise to a sample set of waveforms to be evaluatedThe asymptotic spectrum accumulation distributed function of the Wigner matrix is P₂(x)，P₁(x) And P₂(x) KL distance D between_KL(P₁||P₂) Recording as an interference performance characterization;

(5) and respectively analyzing the detection performance and the interference performance of the integrated waveform through the fuzzy function and the KL distance.

Further, the step (2) is realized as follows:

the baseband time-frequency domain of the single phase encoded waveform is represented as:

wherein the content of the first and second substances,representing an nth sub-pulse phase, each sub-pulse phase having M selectable phases;T_prepresents the sub-pulse width; p represents the length of a phase sequence generated by chaotic mapping;

the baseband time-frequency domain of a single frequency-coded waveform is represented as:

wherein the content of the first and second substances,T_frepresents the sub-pulse width; f represents the length of the chaos sequence used for coding; c. C_mΔ f denotes the frequency value of the mth sub-pulse, c_mThe value of the m-th bit of the chaotic sequence is represented, and Δ f represents the unit step size of frequency hopping, and is usually 1/T_f；

Time-frequency domain expression of integrated waveform:

wherein s is_p(t) represents the complex envelope of the chaotic phase encoded waveform, s_f(t) represents the complex envelope of the chaotic frequency encoded waveform, S_p(f) Denotes s_p(t) spectrum of S_f(f) Denotes s_f(t) spectrum.

Further, the step (3) is realized as follows:

ambiguity function for single frequency encoded waveformComprises the following steps:

ambiguity function χ of single phase encoded waveform_v2(τ, ξ) is:

wherein the content of the first and second substances,represents convolving τ; { phi_mnRepresents a fuzzy function of the chaotic phase encoding sequence { exp (j phi (k)) }, and the expression is as follows:

the fuzzy function expression of the composite coding detection interference integrated waveform is as follows:

further, the interference performance characterization D of step (4)_KL(P₁||P₂) Comprises the following steps:

wherein, the asymptotic spectrum accumulation distribution function P of the standard Wigner matrix based on Gaussian white noise₁(x) And the asymptotic spectrum accumulation distributed function of the Wigner matrix constructed after the noise is added to the waveform sample set to be evaluated is P₂(x)；p₁(x) And p₂(x) Are respectively P₁(x) And P₂(x) Probability density function of p₂(x) Is p₁(x) An approximate probability distribution of; constructing a data set { z (n) ═ P) equivalent to { x (n), n ═ 1,2,. and l } using a probability integral transform₁(x (n)), n ═ 1,2,. and, l }, such that dataset { z (n) ═ P }₁(x (n)), where n 1,2, 1, l } is derived from a random variable Z that obeys a uniform distribution U0, 1](ii) a Will be interval [0,1]Dividing into K parts, and recording the dividing point as u_k(K-0, 1, 2.., K), and satisfies 0-u ═ u ·₀＜u₁＜u₂＜...＜u_KWhen K → ∞ is 1,has | u_k-u_k-1I → 0, where the KL distance calculation can be transformed into the above form.

Further, the step (5) is realized as follows:

if the fuzzy function map of the waveform has narrow peak and relatively flat side lobe similar to zero, similar to "pin-shaped"The closer to the shape, the more excellent the detection performance of the waveform is; using KL distance D_KL(P₁||P₂) Describing the distance between the integrated waveform to be evaluated and the Gaussian white noise, wherein the smaller the index value is, the closer the waveform is to the Gaussian white noise is, and the better the interference performance is.

Based on the same inventive concept, the invention also provides a device for designing the detection and interference integrated waveform based on the chaotic code, which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the computer program realizes the method for designing the detection and interference integrated waveform based on the chaotic code when being loaded to the processor.

Has the advantages that: compared with the prior art, the invention has the beneficial effects that: 1. the output of the chaotic system has the characteristics of boundedness, non-periodicity, initial value sensitivity, pseudo-randomness and the like, and has ideal radar characteristics; the invention processes the output sequence of the discrete chaotic system to obtain the coded radar waveform with excellent correlation characteristic, noise-like characteristic and low interception characteristic; 2. the information theory and the probability theory are used as the mathematical theory basis of the communication field, and have a relatively perfect theoretical system; the interference performance of the sounding-trunk integrated radar waveform is creatively researched from the angles of information theory and probability theory; 3. the invention aims at finite dimension sampling signals under different signal-to-noise ratios, and more compounds practical application scenes; in addition, the chaotic system parameters and the waveform parameters are adjusted, so that the flexibility of waveform design is favorably improved.

Drawings

FIG. 1 is a flow chart of integrated waveform design for detecting interference based on chaotic coding;

FIG. 2 is a time domain plot of a frequency encoded waveform, a phase encoded waveform, and an intra-pulse phase encoded, inter-pulse frequency encoded waveform;

FIG. 3 is a frequency domain plot of frequency encoded waveforms, phase encoded waveforms and intra-pulse phase encoded, inter-pulse frequency encoded waveforms;

FIG. 4 is a three-dimensional blur function plot of different waveforms; wherein, (a) is a three-dimensional fuzzy function graph of frequency coding waveform; (b) a three-dimensional fuzzy function map of the phase encoded waveform; (c) a three-dimensional fuzzy function graph of intra-pulse phase coding and inter-pulse frequency coding waveforms;

FIG. 5 is a graph of interference performance comparison of frequency encoded waveforms, phase encoded waveforms and intra-pulse phase encoded, inter-pulse frequency encoded waveforms.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The invention provides a method for designing a detection interference integrated waveform based on chaotic coding, which comprises the steps of firstly, based on the working principle of a chaotic coding system, generating a chaotic frequency coding sequence and a chaotic phase coding sequence, carrying out intra-pulse phase coding and inter-pulse frequency coding according to the chaotic frequency coding, and designing a chaotic composite coding sounding-interference integrated waveform; then, respectively measuring the detection performance and the interference performance of the integrated waveform by using a fuzzy function and interference performance characterization parameters based on a Wigner spectrum; finally, aiming at the designed waveform, the simulation compares the advantages and disadvantages of a single and composite coding mode on the detection performance and the interference performance. As shown in fig. 1, the method specifically comprises the following steps:

step 1: the discrete chaotic system generates a chaotic sequence, and frequency and phase coded sequences are respectively obtained in an index value mapping and quantitative rounding mode.

The commonly used Tent chaotic sequence is generated by the following expression:

x(n+1)＝0.5-A|x(n)|

wherein, Tent chaos sequence initial value x (1) is [ -0.5,0.5]Sequence value x (n) epsilon (-0.5, 0.5)](ii) a A is a free parameter, approaching 2, and the free parameter A is 1.9999 in the application. In order to obtain a chaos sequence which is difficult to predict, an initial value x is supposed to be given₀Obtaining x (1) epsilon [ -0.5,0.5 [ ]]To a sequence with the length of L + F, taking the last F mapping values as a chaotic sequence { x₁,x₂,...,x_F}。

The index value mapping method comprises the following steps: chaotic sequence { x₁,x₂,...,x_FAnd ranking the sequence, wherein the index value of the minimum value is 1, and the index value of the maximum value is F, and taking the index value as a new frequency coding sequence.

The quantization rounding mapping method comprises the following steps: chaotic sequence { x₁,x₂,...,x_FThen quantization processing is carried out, and sequence values are mapped to optional phase setsM is the number of selectable phases due to Tent chaos mapping value x_p∈(-0.5,0.5]The expression for the phase map is therefore:

step 2: based on the chaos sequence, a composite coding detection interference integrated waveform is designed for a coding mode of internal phase coding of the sampling sub-pulses and frequency coding between the sub-pulses, and a time-frequency domain specific expression of the integrated waveform is given.

The baseband time-frequency domain of a single frequency-coded waveform is represented as:

wherein, T_fRepresents the sub-pulse width; f represents the length of the chaos sequence used for coding; c. C_mΔ f denotes the frequency value of the mth sub-pulse, c_mThe value of the m-th bit of the chaotic sequence is represented, and Δ f represents the unit step size of frequency hopping, and is usually 1/T_f。

The baseband time-frequency domain of the single phase encoded waveform is represented as:

wherein the content of the first and second substances,representing an nth sub-pulse phase, each sub-pulse phase having M selectable phases;T_prepresents the sub-pulse width; p represents the length of the phase sequence generated by chaotic mapping.

The time-frequency domain expression of the integrated waveform signal:

wherein s is_p(t) represents the complex envelope of the chaotic phase encoded waveform, s_f(t) represents the complex envelope of the chaotic frequency encoded waveform, S_p(f) Denotes s_p(t) spectrum of S_f(f) Denotes s_f(t) spectrum.

And step 3: the fuzzy functions, respectively noted, from a single frequency and phase encoded waveformAndwriting out a fuzzy function χ of the composite coding detection interference integrated waveform in the step 2_v(τ,ξ)。

Ambiguity function for single frequency encoded waveformExpressed as:

ambiguity function for single phase encoded waveformExpressed as:

wherein the content of the first and second substances,represents convolving τ; { phi_mnRepresents a fuzzy function of the chaotic phase encoding sequence { exp (j phi (k)) }, and the expression is as follows:

the fuzzy function expression of the integrated waveform of the intra-pulse phase coding and the inter-pulse frequency coding is as follows:

and 4, step 4: asymptotic spectrum accumulation distribution function P for deducing standard Wigner matrix based on Gaussian white noise set₁(x) And the asymptotic spectrum accumulation distributed function of the Wigner matrix constructed after the noise is added to the waveform sample set to be evaluated is P₂(x)，P₁(x) And P₂(x) KL distance D between_KL(P₁||P₂) And recording as an interference performance characterization.

From the half-circle ratio, W, of the Wigner matrix_lThe asymptotic spectral distribution of (a) is as follows:

wherein the content of the first and second substances,a representation matrix W_lIs defined as:

wherein, # Q denotes the group of set Q; lambda [ alpha ]_kK 1, 2.. and l denote a standardized Wigner matrix W_lThe characteristic value of (2). W_lThe asymptotic spectral distribution of (a) can be regarded as an essential feature of gaussian white noise.

Asymptotic spectrum accumulation distribution function P of standard Wigner matrix obtained by derivation of Gaussian white noise set₁(x) Expressed as:

wherein, for any real number P, Q > 0, Beta functionIncomplete Beta function

P₂(x) An asymptotic spectrum accumulation distributed function P of a Wigner matrix which is constructed after noise is added to a waveform sample set to be evaluated₁(x) And P₂(x) The KL distance between them is calculated by the expression:

wherein, the asymptotic spectrum accumulation distribution function P of the standard Wigner matrix based on Gaussian white noise₁(x) And the asymptotic spectrum accumulation distributed function of the Wigner matrix constructed after the noise is added to the waveform sample set to be evaluated is P₂(x)；p₁(x) And p₂(x) Are respectively P₁(x) And P₂(x) Is determined by the probability density function of (a),p₂(x) Is p₁(x) An approximate probability distribution. Constructing a data set { z (n) ═ P) equivalent to { x (n), n ═ 1,2,. and l } using a probability integral transform₁(x (n)), n ═ 1,2,. and, l }, such that dataset { z (n) ═ P }₁(x (n)), where n 1,2, 1, l } is derived from a random variable Z that obeys a uniform distribution U0, 1]. Will be interval [0,1]Dividing into K parts, and recording the dividing point as u_k(K-0, 1, 2.., K), and satisfies 0-u ═ u ·₀＜u₁＜u₂＜...＜u_K1. Based on the data set { Z (n), n ═ 1, 2.. times, l }, the empirical spectral cumulative distribution function for the random variable Z can be expressed as:

wherein I (·) represents an indicator function.

When K → ∞ is reached,has | u_k-u_k-1I → 0, where the KL distance calculation can be converted to:

and 5: and respectively analyzing the detection performance and the interference performance of the integrated waveform through the fuzzy function and the KL distance.

If the fuzzy function graph of the waveform has a narrow peak, has relatively flat side lobes which are approximate to no side lobes and are approximate to a shape of a pin, the closer to the shape, the more excellent the detection performance of the waveform is; using KL distance D_KL(P₁||P₂) Describing the distance between the integrated waveform to be evaluated and the Gaussian white noise, wherein the smaller the index value is, the closer the waveform is to the Gaussian white noise is, and the better the interference performance is.

Based on the same inventive concept, the invention also provides a device for designing the detection and interference integrated waveform based on the chaotic code, which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the computer program realizes the method for designing the detection and interference integrated waveform based on the chaotic code when being loaded to the processor.

Fig. 2 to 5 are graphs showing simulation experiments performed by the present invention. Fig. 2 and 3 show time domain contrast diagrams of frequency encoded waveforms, phase encoded waveforms and intra-pulse phase encoded, inter-pulse frequency encoded waveforms. The simulation parameters are as follows: the free parameter of Tent chaotic mapping is 1.9999, the initial value is 0.32, 5001 to 5016 of the chaotic mapping are selected as chaotic coding sequences, the index value mapping result is { 1213521486310150971411 }, the quantitative rounding mapping result is { 1100100101010001 }. pi, and the two sequences are supposed to be subjected to chaotic coding; the pulse width of the frequency coding sub-pulse is 1.6us, and the frequency hopping interval is the reciprocal of the sub-pulse width; the phase encoding code element width is 0.1 us; the sampling frequency is 5 times the bandwidth. The structural characteristics of the complex modulation integrated waveform are shown in the figure, and the total time width is equal to that of the frequency coding. The bandwidth of the composite modulation integrated waveform is equal to that of the phase coding waveform, the spectrum energy is mainly distributed in the bandwidth range of the frequency coding waveform, and the fluctuation of the spectrum in the bandwidth range is obvious, which is caused by the noise-like property of chaotic composite coding.

FIG. 4(a) shows a three-dimensional blur function plot of a frequency encoded waveform; FIG. 4(b) is a three-dimensional blur function plot of a phase encoded waveform; FIG. 4(c) is a three-dimensional fuzzy function graph of the intra-pulse phase-encoded and inter-pulse frequency-encoded waveforms. The single frequency and phase encoded code sequences respectively use the sequences used in fig. 2. As shown in the figure, the fuzzy function graph of the integrated waveform obtained by composite coding is closer to a 'drawing pin type', the distance and speed resolution performance of the integrated waveform is improved to a certain extent compared with a single coding waveform, the integrated waveform inherits the advantages of two single coding waveforms, the modulation mode of the signal is more complex, and the anti-interference capability and the interference performance of the radar signal are further improved.

Finally, the interference performance is further compared, the signal-to-noise ratio SNR is-7-3 dB, and fig. 5 shows a comparison graph of the interference performance of the frequency coding waveform, the phase coding waveform, the intra-pulse phase coding waveform and the inter-pulse frequency coding waveform. The lower the KL distance value of the waveform is, the better the interference performance is, therefore, the interference performance ranking of three waveforms can be obtained: the composite encoded integrated waveform is superior to a single frequency encoded waveform, which is superior to a single phase encoded waveform. In addition, the interference performance of the integrated waveform is related to the signal-to-noise ratio in addition to the self coding mode, and the lower the signal-to-noise ratio is, the better the interference performance of the waveform is, and the closer the waveform is to white gaussian noise.

Simulation results show that: the fuzzy function graph of the chaos composite coding integrated waveform designed by the invention is in a good 'picture pin shape', and has better distance and speed resolution; the interference performance index can correctly represent the waveform interference performance, and the composite coding mode is superior to a single coding mode in interference performance.