CN106100695A - A kind of pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code - Google Patents

Abstract

The invention discloses a kind of pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code, the described pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code combines chaotic secret communication and pattern modulation, corresponding pseudo-code is generated to Constructing Chaotic Code XOR after real information is extended, being controlled whether corresponding hop period sends carrier frequency by pseudo-code, the positional information whether sending carrier frequency in the cycle forms different modulation pattern；The rule whether being sent by carrier frequency transmits information, and real information is hidden in modulation pattern, and the randomness of chaos sequence enhanced modulation pattern.The rule whether present invention is sent by carrier frequency transmits information, real information is hidden in modulation pattern, and chaos sequence enhances the randomness of modulation pattern, it is difficult to find its rule, the information that ensure that is difficult to disturbed in the communications and intercepts and captures, and improves the safety and reliability of information.

Description

A kind of pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code

Technical field

The invention belongs to TTC&T Technology field, particularly relate to a kind of pattern modulation frequency hopping Anti TBIgG based on Constructing Chaotic Code Method.

Background technology

The confidentiality of the critical datas such as space telemetry, remote control, outer survey, target range experiment, reliability and counter steal for state Family's safety is most important.Enemy's information is detected all kinds of for serious threat Spacecraft Launchs and flight safety.And space flight Anti TBIgG skill Art primarily to the safety of guarantee information, even if non-partner know we in communication, but the composition that we can not be communicated Lethal challenge.Therefore, the importance of telemetry communication signal reliability requirement and communication security in space mission so that observing and controlling is led to Communication system has to possess the ability well resisting intercepting and capturing.Modern test and control communication system generally uses jump spread spectrum mode to resist and cuts Obtain and anti-interference, with the raising of interception capability and signal identifying processing algorithm ability, basic jump spread spectrum Anti TBIgG and interference Ability seems day by day weak.The current ability improving Anti TBIgG, mainly based on spread spectrum and frequency hopping, on the one hand improves hop rate With the bandwidth of frequency set, on the one hand use the frequency-hopping mode that differential jumping frequency and AFH etc. are new.There is hardware in these methods The problems such as expense is relatively big, networking planning is relatively difficult, real-time is very poor.Although conventional frequency hopping, Technology of differential frequency hopping and from Adapt to frequency hopping and all can resist most intercepting and capturing and conflicting mode, but resist growing acquisition techniques During with perturbation technique, its performance still can not meet the needs of telemetry communication.

As growing electronic warfare threatens, the risk of Space TT&C and being vulnerable to intercept and capture and interference degree also Increasing therewith, in order to ensure the security and the reliability of TT&C system communication, exigence proposes new simple and practical anti-section Obtain method.

Content of the invention

It is an object of the invention to provide a kind of modulation frequency hopping Anti TBIgG method of the pattern based on Constructing Chaotic Code, it is intended to solve with Growing demand for security, the risk of Space TT&C and the degree being vulnerable to intercept and capture and disturb are consequently increased, and survey The security and the reliability problem in urgent need of strengthening of Ore-controlling Role communication.

The present invention is achieved in that a kind of modulation frequency hopping Anti TBIgG method of the pattern based on Constructing Chaotic Code, described based on mixed The pattern modulation frequency hopping Anti TBIgG method of ignorant code combines chaotic secret communication and pattern modulation, with chaos after extending real information Code XOR generates corresponding pseudo-code, is controlled whether corresponding hop period sends carrier frequency by pseudo-code, whether sends the position of carrier frequency in the cycle Confidence breath forms different modulation pattern；The rule whether being sent by carrier frequency transmits information, and real information is hidden in tune In drawing sample, and the randomness of chaos sequence enhanced modulation pattern.

Further, the described pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code comprises the following steps:

Step one, by real information i.e. the 1 of code word and 0 sequence after N times extends, mixed with corresponding time sequencing respectively Ignorant sequence carries out XOR, obtains the corresponding pseudo-code of information code word；

Step 2, every for the frequency hop sequences being generated by pseudo-code generator N number of point is divided into one group by information transmitting terminal, each code word Corresponding N number of pseudo-code element is corresponding to the frequency in frequency hop sequences N number of cycle, and 1 and the 0 of pseudo-code represents corresponding hop period respectively On whether send carrier frequency, form modulation pattern, pseudo-code sequence carried out unconventional modulation by modulation pattern, then with by frequency synthesis The frequency hopping pattern that device generates is mixed, and is transmitted；

Step 3, after information receiving end receives signal, estimates to the transmission rule of transmitting terminal carrier frequency, then with Known Hopping frequencies sequence compares, equal with corresponding temporal carrier frequency, is designated as 1, with corresponding temporal carrier wave Frequency is unequal is designated as 0；

Step 4, the chaos sequence XOR identical with transmitting terminal by comparing the sequence obtaining, compresses through N times and can obtain very Real information.

Described step one farther includes:

The first step, is F by bit rate_{b_real}N=5 times extending transversely of authentic and valid information x [1:1000] of=25kbps, I.e. 1 expands to 11111, and 0 expands to 00000, obtains sequence x₁[1:5000], sample rate is F_{s_real}=5MHz；

Second step, produces Chebyshev-Map chaos sequence y [1:5000], and mapping equation is:

y_n+1=T_k(y_n)=cos (k cos^-1y_n),y_n∈[-1,1]；

Wherein k is that Chebyshev mapping parameters takes 4, y_nFor current state, y_n+1For next state, from initial value y₀Open Beginning iteration, uses thresholding to quantify to obtain sequences y={ y by the sequence two-value obtaining₀,y₁,y₂,…,y_i... }, initial value y₀Take 0.6；

3rd step, by sequence x₁Obtain pseudo-random sequence z [1:5000] with chaos sequence y XOR:

$z=x_1\⊕y.$

Described step 2 farther includes:

(1) being generated modulation pattern by 1 and 0 control of pseudo-code sequence z [1:5000], pseudo-code sequence z carries out unconventional BPSK Modulation, is 1, then in the corresponding time, baseband signal is cos (2 π f_{c_bpsk}T), be 0, then in the corresponding time, baseband signal is all 0, life Become baseband modulation signal f_bpsk[1:100000]；

(2) being produced pseudo-random sequence by pseudo-noise code generator, by command decoder, control frequency synthesizer generates jumps Frequently pattern X；

(3) by baseband modulation signal f_bpskWith frequency hopping pattern X after frequency mixer mixing, obtain sending signal rs and carry out again sending out Send.

Further, the method that described synthesizer generates frequency hopping pattern X is: be 1-8 by pseudo-noise code generator formation range Frequency hop sequences x_hop[1:5000], with random number x_hop(i), i=1...5000 corresponding frequency-hopping carrier frequency f_c(x_hop(i)) For:

f_c(x_hop(i))=f_L+(x_hop(i)-1)*f_I；

f_send(i)=f_c(x_hop(i))；

Wherein low-limit frequency f_L=30M, stepped-frequency interval is f_I=0.25M, thus obtains frequency-hopping carrier frequency set f_send[1: 5000], the i.e. frequency hopping pattern X of regeneration frequency-hopping carrier [1:100000].

Described step 3 farther includes:

The first step, by Short Time Fourier Transform spectrogram method to the process of receipt signal r, first carries out Fu in short-term to signal In leaf transformation, carry out delivery to result and square operation obtain signal spectrogram, then take time domain maximum to spectrogram and obtain signal Rough estimate time-frequency crestal line r₁；

Second step, the time-frequency crestal line r to the rough estimate obtaining₁Make first-order difference, highlight the jump position of signal, differentiated Signal is r₂；

3rd step, chooses some peaks, utilizes least square method to make linear fit in the signal after first-order difference Obtain straight line；

4th step, after estimating hop rate R, estimates jumping moment α T further_h, wherein T_h=1/R is hop period, and α is then Drawn by following formula:

$\mathrm{\α}=\frac{(s\·\[\underset{i=1}{\overset{M}{\Σ}}p(i)\])\%\left(\frac{F_{s\_real}}{R}\right)}{\left(\frac{F_{s\_real}}{R}\right)};$

5th step, estimates hop rate R and jumping moment α T_hAfter, carry out to the simple signal in each hop period estimating frequency, The simple signal receiving is appointed and takes data r that a segment length is 10_t, t=0,1,2 ..., 9, according to following formula:

$f=\frac{F_{s\_real}}{2\mathrm{\π}}\underset{t=0}{\overset{l-2}{\Σ}}{w}_t\∠r_t*r_{t+1};$

Wherein:Meeting * to represent and take conjugation, ∠ represents and seeks signal r_tAnd signal r_t+1Phase difference, estimate signal(-) carrier frequency f [1:5000], and the time-frequency crestal line of signal；

6th step, carrier frequency f [1:5000] and known Hopping frequencies sequence f that will estimate_send[1:5000] is carried out Comparison, is designated as 1 with carrier frequency is equal on the corresponding time, and above carrier frequency is unequal with the corresponding time is designated as 0, obtains sequence rz [1:5000]。

Described further utilize least square method to obtain straight line concrete grammar as linear fit to include:

At r₂In choose=250 peaks p (i), i=1,2,3 ..., M, number and be converted to (i, p (i)) coordinate Form, wherein, i represents time-gap number, i.e. which frequency hop time slot, and p (i) represents frame number, i.e. jumping moment；M choosing Coordinate points substitution least-squares algorithm formula:

$k=\frac{M\underset{i=1}{\overset{M}{\Σ}}ip\left(i\right)-\underset{i=1}{\overset{M}{\Σ}}i\underset{i=1}{\overset{M}{\Σ}}p\left(i\right)}{M\underset{i=1}{\overset{M}{\Σ}}{i}^2-{\left(\underset{i=1}{\overset{M}{\Σ}}i\right)}^2};$

$b=\frac{1}{M}(\underset{i=1}{\overset{M}{\Σ}}p\left(i\right)-k\underset{i=1}{\overset{M}{\Σ}}i);$

P=ki+b；

The slope k of straight line p is the number of the Frame that frequency hopping point averagely occupies, and is multiplied by Short Time Fourier Transform with frame number k Sliding window step-length s=256 is frequency hop time slot, represents frequency hop time slot with the data c that counts, it may be assumed that

C=k × s；

Further according to sample rate F_{s_real}Draw calculating following formula with the intrinsic relation of single frequency point duration:

$R=\frac{F_{s\_real}}{c};$

Estimate hop rate R；

Described step 4 farther includes:

(1) utilize the chaos sequence y identical with signal sending end and pseudo-random sequence rz to carry out XOR and obtain rx:

$rx=rz\⊕y;$

(2) rx [1:5000] is carried out 5 times of compressions, every 5 code words one group, 11111 boil down to 1,00000 boil down tos 0, To sequence rx [1:1000], the authentic and valid information i.e. receiving.

The pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code that the present invention provides, anti-based on existing frequency hopping system cuts Obtain performance, and pattern modulation frequency-hopping method theoretical in conjunction with chaotic secret communication, propose a kind of pattern modulation based on Constructing Chaotic Code and jump Frequently Anti TBIgG method, represents information by the transmission position rule of system carrier, and the transmission rule that only need to detect frequency solves Information, whether transmitting terminal sends carrier wave in being controlled hop period by pseudo-code " 1 " and " 0 ", real information is hidden in modulation pattern In, simultaneously because the aperiodicity of chaos sequence, misconvergence and irreversible character, the transmitting terminal being applied to this method can The randomness of enhanced modulation pattern, therefore compared with the Anti TBIgG technology based on frequency hopping of existing routine, the present invention is in signal to noise ratio The Anti TBIgG performance almost up to 100% is can reach when being 10.

Pattern modulation frequency hopping Anti TBIgG Enhancement Method based on Constructing Chaotic Code proposed by the invention can be additionally used in space flight measurement and control Anti-tracking interference and electronic countermeasure electronics investigation field.

Brief description

Fig. 1 is the pattern modulation frequency hopping Anti TBIgG method flow diagram based on Constructing Chaotic Code that the embodiment of the present invention provides.

Fig. 2 is the theory diagram of the embodiment that the embodiment of the present invention provides.

Fig. 3 is the time-frequency figure of the pattern modulating system based on Constructing Chaotic Code that the embodiment of the present invention provides.

Fig. 4 is that the signal receiving end that the embodiment of the present invention provides obtains after carrying out Short Time Fourier Transform spectrogram conversion The signal time-frequency crestal line of rough estimate.

Fig. 5 is to be jumped after the time-frequency crestal line of rough estimate is carried out first-order difference by the signal receiving end that the embodiment of the present invention provides Frequently time chart.

Fig. 6 is that the signal receiving end that the embodiment of the present invention provides accurately is estimated after frequency through simple signal Frequency Estimation method Signal accurate time-frequency crestal line figure.

Detailed description of the invention

In order to make the purpose of the present invention, technical scheme and advantage clearer, below in conjunction with embodiment, to the present invention It is further elaborated.It should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not used to Limit the present invention.

Below in conjunction with the accompanying drawings the application principle of the present invention is explained in detail.

As it is shown in figure 1, the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code of the embodiment of the present invention includes following step Rapid:

S101: by " 1 " and " 0 " sequence of the i.e. code word of real information after N times extends, respectively with corresponding time sequencing Chaos sequence carries out XOR, i.e. can get the corresponding pseudo-code of information code word；

Every for the frequency hop sequences being generated by pseudo-code generator N number of point is divided into one group by S102: information transmitting terminal, each code word phase The N number of pseudo-code element answered corresponding to the frequency in frequency hop sequences N number of cycle, and pseudo-code ' " 1 " and " 0 " represents its corresponding jump respectively Frequently whether send carrier frequency on the cycle, form modulation pattern, pseudo-code sequence is carried out unconventional modulation by this modulation pattern, then with by The frequency hopping pattern that frequency synthesizer generates is mixed, and is then transmitted；

S103: after information receiving end receives signal, estimates to the transmission rule of transmitting terminal carrier frequency, then with Know that Hopping frequencies sequence compares, if equal with corresponding temporal carrier frequency, be designated as " 1 ", be otherwise designated as " 0 "；

S104: the chaos sequence XOR identical with transmitting terminal by comparing the sequence obtaining in S103, after compress i.e. through N times Can get real information.

It is further described below in conjunction with the application principle to the present invention for the specific embodiment.

The pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code of the embodiment of the present invention comprises the following steps:

1st, by " 1 " and " 0 " sequence of the i.e. code word of real information after N times extends, mixed with corresponding time sequencing respectively Ignorant sequence carries out XOR, i.e. can get the corresponding pseudo-code of information code word, comprising:

1.1) it is F by bit rate_{b_real}Authentic and valid information x [1:1000 (the data length)] N extending transversely of=25kbps =5 times, i.e. " 1 " expand to " 11111 ", " 0 " expands to " 00000 ", obtains sequence x₁[1:5000], its sample rate is F_{s_real} =5MHz；

1.2) producing Chebyshev-Map chaos sequence y [1:5000 (data length)], its mapping equation is:

y_n+1=T_k(y_n)=cos (k cos^-1y_n),y_n∈[-1,1]；

Wherein k is that Chebyshev mapping parameters takes 4, y_nFor current state, y_n+1For next state, from initial value y₀Open Beginning iteration, uses thresholding to quantify to can be obtained by sequences y={ y by the sequence two-value obtaining₀,y₁,y₂,…,y_i,…}.At the beginning of herein Initial value y₀Take 0.6.

1.3) by sequence x₁Obtain pseudo-random sequence z [1:5000] with chaos sequence y XOR:

$z=x_1\⊕y;$

2nd, information transmitting terminal is by frequency hop sequences x_hopEvery 5 points are divided into one group, and corresponding 5 the pseudo-code elements of each code word are corresponding Frequency within 5 cycles of frequency hop sequences, and pseudo-code ' " 1 " and " 0 " represents whether send load on its corresponding hop period respectively Frequently, modulation pattern is formed.Pseudo-code sequence is carried out unconventional modulation by this modulation pattern, then is mixed with frequency hopping pattern, so After be transmitted, comprising:

2.1) " 1 " and " 0 " control of pseudo-code sequence z [1:5000] is generated modulation pattern, pseudo-code sequence z is carried out very Rule BPSK modulation, if " 1 ", then in the corresponding time, baseband signal is cos (2 π f_{c_bpsk}T), if " 0 ", then base in the corresponding time Band signal is all 0, thus generates baseband modulation signal f_bpsk[1:100000]；

2.2) being produced pseudo-random sequence by pseudo-noise code generator, by command decoder, control frequency synthesizer generates Frequency hopping pattern X, specifically comprises the following steps that by the frequency hop sequences x that pseudo-noise code generator formation range is 1-8_hop[1:5000], with Random number x_hop(i), i=1...5000 corresponding frequency-hopping carrier frequency f_c(x_hop(i)) be:

f_c(x_hop(i))=f_L+(x_hop(i)-1)*f_I；

f_send(i)=f_c(x_hop(i))；

Wherein low-limit frequency f_L=30M, stepped-frequency interval is f_I=0.25M, thus obtains frequency-hopping carrier frequency set f_send[1: 5000], the i.e. frequency hopping pattern X of regeneration frequency-hopping carrier [1:100000]；

2.3) by baseband modulation signal f_bpskWith frequency hopping pattern X after frequency mixer mixing, obtain sending signal rs and carry out again Send.

3rd, estimating carrier frequency saltus step rule comparing with known frequency hopping pattern.Use Short Time Fourier Transform Spectrogram and least square fitting combination method estimate hop rate and jumping moment, then use simple signal Frequency Estimation method to come to often Signal in individual hop period carries out single-frequency estimation, thus estimates carrier frequency saltus step rule.Again with known Hopping frequencies sequence Row compare, if carrier frequency equal be designated as " 1 " upper with the corresponding time is otherwise designated as " 0 ", concretely comprise the following steps:

3.1) by Short Time Fourier Transform spectrogram method to the process of receipt signal r, the rough estimate time-frequency of signal is obtained Crestal line r₁；As shown in Figure 4；

3.2) the time-frequency crestal line r to the rough estimate obtaining₁Make first-order difference, highlight the jump position of signal, difference with this After signal be r₂；As shown in Figure 5；

3.3) signal after first-order difference chooses some peaks, utilize least square method (LS) to make linear fit Obtain straight line；Concrete grammar is:

At r₂In choose=250 peaks p (i), i=1,2,3 ..., M, they are numbered and are converted to (i, p (i)) coordinate form, wherein, i represents time-gap number, i.e. which frequency hop time slot, and p (i) represents frame number, i.e. jumping moment, two The difference of frame number is exactly a lasting frame number of frequency hop time slot；M the coordinate points substitution least-squares algorithm formula that will choose:

$k=\frac{M\underset{i=1}{\overset{M}{\Σ}}ip\left(i\right)-\underset{i=1}{\overset{M}{\Σ}}i\underset{i=1}{\overset{M}{\Σ}}p\left(i\right)}{M\underset{i=1}{\overset{M}{\Σ}}{i}^2-{\left(\underset{i=1}{\overset{M}{\Σ}}i\right)}^2};$

$b=\frac{1}{M}(\underset{i=1}{\overset{M}{\Σ}}p\left(i\right)-k\underset{i=1}{\overset{M}{\Σ}}i);$

P=ki+b；

The slope k of this straight line p is exactly the number of the Frame that frequency hopping point averagely occupies, and is multiplied by Fourier in short-term with frame number k Conversion sliding window step-length s=256 is exactly frequency hop time slot, represents frequency hop time slot at this with the data c that counts, it may be assumed that

C=k × s；

Further according to sample rate F_{s_real}Draw calculating following formula with the intrinsic relation of single frequency point duration:

$R=\frac{F_{s\_real}}{c};$

Hop rate R can be estimated；

3.4), after estimating hop rate R, jumping moment α T is estimated further_h, wherein T_h=1/R is hop period, α then by Following formula draws:

$\mathrm{\α}=\frac{(s\·\[\underset{i=1}{\overset{M}{\Σ}}p(i)\])\%\left(\frac{F_{s\_real}}{R}\right)}{\left(\frac{F_{s\_real}}{R}\right)};$

3.5) hop rate R and jumping moment α T are estimated_hAfter, use Kay to propose the simple signal in each hop period Quick high accuracy simple signal Frequency Estimation method accurately estimate frequency, appoint in the simple signal receiving and take a segment length and be Data r of 10_t, t=0,1,2 ..., 9, according to following formula:

$f=\frac{F_{s\_real}}{2\mathrm{\π}}\underset{t=0}{\overset{l-2}{\Σ}}{w}_t\∠r_t*r_{t+1};$

Wherein:Meeting * to represent and take conjugation, ∠ represents and seeks signal r_tAnd signal r_t+1Phase difference.Thus signal(-) carrier frequency f [1:5000] can be estimated exactly, and the time-frequency crestal line of signal, such as Fig. 6 Shown in.

3.6) by carrier frequency f [1:5000] estimating and known Hopping frequencies sequence f_send[1:5000] compares Relatively, if carrier frequency equal be designated as " 1 " upper with the corresponding time is otherwise designated as " 0 ".Obtain sequence rz [1:5000].

4th, by sequence rz, then through and chaos XOR, N times compress after obtain real information, concretely comprise the following steps:

4.1) utilize the chaos sequence y identical with signal sending end and pseudo-random sequence rz to carry out XOR and obtain rx:

$rx=rz\⊕y;$

4.2) rx [1:5000] carrying out 5 times of compressions, every 5 code words one group, " 11111 " boil down to " 1 ", " 00000 " presses It is condensed to " 0 ", obtain sequence rx [1:1000], the authentic and valid information i.e. receiving.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all essences in the present invention Any modification, equivalent and the improvement etc. made within god and principle, should be included within the scope of the present invention.

Claims (9)

1. the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code, it is characterised in that the described pattern based on Constructing Chaotic Code Modulation frequency hopping Anti TBIgG method combines chaotic secret communication and pattern modulation, generates with Constructing Chaotic Code XOR after extending real information By pseudo-code, corresponding pseudo-code, controls whether corresponding hop period sends carrier frequency, the positional information whether sending carrier frequency in the cycle is formed Different modulation pattern；The rule whether being sent by carrier frequency transmits information, and real information is hidden in modulation pattern, and And the randomness of chaos sequence enhanced modulation pattern.

2. the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code as claimed in claim 1, it is characterised in that described based on The pattern modulation frequency hopping Anti TBIgG method of Constructing Chaotic Code comprises the following steps:

Step one, by real information i.e. the 1 of code word and 0 sequence after N times extends, the chaos sequence with corresponding time sequencing respectively Row carry out XOR, obtain the corresponding pseudo-code of information code word；

Step 2, every for the frequency hop sequences being generated by pseudo-code generator N number of point is divided into one group by information transmitting terminal, and each code word is corresponding N number of pseudo-code element corresponding to the frequency in frequency hop sequences N number of cycle, and 1 and the 0 of pseudo-code represents respectively and on corresponding hop period is No transmission carrier frequency, forms modulation pattern, by modulation pattern, pseudo-code sequence is carried out unconventional modulation, then gives birth to by frequency synthesizer The frequency hopping pattern becoming is mixed, and is transmitted；

Step 3, after information receiving end receives signal, estimates to the transmission rule of transmitting terminal carrier frequency, then with known Hopping frequencies sequence compares, equal with corresponding temporal carrier frequency, is designated as 1, with corresponding temporal carrier frequency It unequal is designated as 0；

Step 4, the chaos sequence XOR identical with transmitting terminal by comparing the sequence obtaining, compresses through N times and can obtain really Information.

3. the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code as claimed in claim 2, it is characterised in that described step One farther includes:

The first step, is F by bit rate_{b_real}N=5 times extending transversely of authentic and valid information x [1:1000] of=25kbps, i.e. 1 expands Exhibition is 11111, and 0 expands to 00000, obtains sequence x₁[1:5000], sample rate is F_{s_real}=5MHz；

Second step, produces Chebyshev-Map chaos sequence y [1:5000], and mapping equation is:

y_n+1=T_k(y_n)=cos (k cos^-1y_n),y_n∈[-1,1]；

Wherein k is that Chebyshev mapping parameters takes 4, y_nFor current state, y_n+1For next state, from initial value y₀Start repeatedly In generation, thresholding is used to quantify to obtain sequences y={ y by the sequence two-value obtaining₀,y₁,y₂,…,y_i... }, initial value y₀Take 0.6；

3rd step, by sequence x₁Obtain pseudo-random sequence z [1:5000] with chaos sequence y XOR:

$z=x_1\⊕y.$

4. the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code as claimed in claim 2, it is characterised in that described step Two farther include:

(1) being generated modulation pattern by 1 and 0 control of pseudo-code sequence z [1:5000], pseudo-code sequence z carries out unconventional BPSK modulation, Be 1, then in the corresponding time, baseband signal is cos (2 π f_{c_bpsk}T), be 0, then in the corresponding time, baseband signal is all 0, generates base Band modulated signal f_bpsk[1:100000]；

(2) being produced pseudo-random sequence by pseudo-noise code generator, by command decoder, control frequency synthesizer generates hopping pattern Case X；

(3) by baseband modulation signal f_bpskWith frequency hopping pattern X after frequency mixer mixing, obtain sending signal rs and be transmitted again.

5. the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code as claimed in claim 4, it is characterised in that described synthesis The method that device generates frequency hopping pattern X is: by the frequency hop sequences x that pseudo-noise code generator formation range is 1-8_hop[1:5000], with Random number x_hop(i), i=1...5000 corresponding frequency-hopping carrier frequency f_c(x_hop(i)) be:

f_c(x_hop(i))=f_L+(x_hop(i)-1)*f_I；

f_send(i)=f_c(x_hop(i))；

Wherein low-limit frequency f_L=30M, stepped-frequency interval is f_I=0.25M, thus obtains frequency-hopping carrier frequency set f_send[1: 5000], the i.e. frequency hopping pattern X of regeneration frequency-hopping carrier [1:100000].

6. the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code as claimed in claim 2, it is characterised in that described step Three farther include:

The first step, by Short Time Fourier Transform spectrogram method to the process of receipt signal r, obtains the rough estimate time-frequency ridge of signal Line r₁；

Second step, the time-frequency crestal line r to the rough estimate obtaining₁Make first-order difference, highlight the jump position of signal, differentiated signal For r₂；

3rd step, chooses some peaks, utilizes least square method to obtain one as linear fit in the signal after first-order difference Bar straight line；

4th step, after estimating hop rate R, estimates jumping moment α T further_h, wherein T_h=1/R is hop period, α then by under Formula draws:

$\mathrm{\α}=\frac{(s\·\[\underset{i=1}{\overset{M}{\mathrm{\Σ}}}p(i)\])\%\left(\frac{F_{s\_real}}{R}\right)}{\left(\frac{F_{s\_real}}{R}\right)};$

5th step, estimates hop rate R and jumping moment α T_hAfter, carry out to the simple signal in each hop period estimating frequency, connecing The simple signal receiving is appointed and takes data r that a segment length is 10_t, t=0,1,2 ..., 9, according to following formula:

$f=\frac{F_{s\_real}}{2\mathrm{\π}}\underset{t=0}{\overset{l-2}{\Σ}}{w}_t\∠r_t*r_{t+1};$

Wherein:Meeting * to represent and take conjugation, ∠ represents and seeks signal r_tWith signal r_t+1Phase Potential difference, estimates signal(-) carrier frequency f [1:5000], and the time-frequency crestal line of signal；

6th step, carrier frequency f [1:5000] and known Hopping frequencies sequence f that will estimate_send[1:5000] compares, Upper with the corresponding time carrier frequency is equal is designated as 1, and upper with the corresponding time carrier frequency is unequal is designated as 0, obtain sequence rz [1: 5000]。

7. the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code as claimed in claim 6, it is characterised in that described utilization Least square method obtains straight line concrete grammar as linear fit and includes:

At r₂In choose=250 peaks p (i), i=1,2,3 ..., M, number and be converted to (i, p (i)) coordinate form, Wherein, i represents time-gap number, i.e. which frequency hop time slot, and p (i) represents frame number, i.e. jumping moment；M the coordinate points that will choose Substitution least-squares algorithm formula:

$k=\frac{M\underset{i=1}{\overset{M}{\Σ}}ip\left(i\right)-\underset{i=1}{\overset{M}{\Σ}}i\underset{i=1}{\overset{M}{\Σ}}p\left(i\right)}{M\underset{i=1}{\overset{M}{\Σ}}{i}^2-{\left(\underset{i=1}{\overset{M}{\Σ}}i\right)}^2};$

$b=\frac{1}{M}\left(\underset{i=1}{\overset{M}{\mathrm{\Σ}}}p\right(i)-k\underset{i=1}{\overset{M}{\mathrm{\Σ}}}i);$

P=ki+b；

The slope k of straight line p is the number of the Frame that frequency hopping point averagely occupies, and is multiplied by Short Time Fourier Transform sliding window with frame number k Step-length s=256 is frequency hop time slot, represents frequency hop time slot with the data c that counts, it may be assumed that

C=k × s；

Further according to sample rate F_{s_real}Draw calculating following formula with the intrinsic relation of single frequency point duration:

$R=\frac{F_{s\_real}}{c};$

Estimate hop rate R.

8. the pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code as claimed in claim 2, it is characterised in that described step Four farther include:

(1) utilize the chaos sequence y identical with signal sending end and pseudo-random sequence rz to carry out XOR and obtain rx:

$rx=rz\⊕y;$

(2) rx [1:5000] is carried out 5 times of compressions, every 5 code words one group, 11111 boil down to 1,00000 boil down tos 0, obtain sequence Row rx [1:1000], the authentic and valid information i.e. receiving.

9. one kind comprises the anti-of as described in the claim 1-8 any one pattern modulation frequency hopping Anti TBIgG method based on Constructing Chaotic Code Intercept and capture and strengthen model.