CN106291616B - Space-time chaos vector pseudo-noise code generator offset carrier modulator approach and system - Google Patents

Abstract

The invention discloses a space-time chaos vector pseudo-random code generator offset carrier modulation method and system. The invention constructs a vector pseudo-random code generator. First, the current position and the imaginary part of the real and imaginary components of a single complex state vector The current state value of the offset position is acted on by a variety of different nonlinear functions, and the mixed operation of addition, subtraction, multiplication, or division is performed with the diffusion coefficient and mutual coupling coefficient as the weight, and the time-distributed value is generated through state iteration. Complex pseudo-random number sequence, and then extract the real pseudo-random number sequence from the real part and imaginary part of the relevant component taps of the state component, and then use the real number offset carrier modulation to binarize and modulo two sum or binarize with the binarized real number partial The second sum of the carrier modes is shifted, and the ranging code of the required frequency offset is obtained through a band-pass filter output at the combined frequency. The invention can be widely used in satellite navigation systems, and can also be used in various ranging systems, communication systems, radio and television systems, control systems and the like.

Description

Space-time chaos vector pseudo-random code generator offset carrier modulation method and system

technical field

The invention relates to the technical field of satellite navigation, in particular to a space-time chaos vector pseudo-random code generator offset carrier modulation method and system.

Background technique

At present, the four major satellite navigation systems in the world are the GPS (Global Positioning System) satellite navigation system of the United States, the GLONASS (Global Navigation Satellite System) satellite navigation system of Russia, the Galileo satellite navigation system of the European Union and the BeiDou satellite navigation system of China . Except for GLONASS which adopts frequency division multiple access (FDMA, Frequency Division Multiple Access) communication mode, other satellite navigation systems adopt code division multiple access (CDMA, Code Division Multiple Access) communication mode. The ranging codes used by them are divided into two categories: civilian coarse codes and military fine codes. Satellite navigation systems using coarse codes can perform rough positioning of targets, while satellite navigation systems using fine codes can perform high-precision positioning of targets.

In order to utilize the limited satellite navigation frequency point resources, GPS, Galileo and BeiDou satellite navigation systems respectively adopt binary offset carrier (BOC, Binary offset Carrier) modulation technology and its development method in the form of square wave, which can well solve the signal Interfering with each other, spectral aliasing and sharing frequency bands.

There are two types of pseudo-random code generators used by satellite navigation systems to generate ranging codes. One is the binary pseudo-random code generator currently used by satellite navigation systems. The digital linear feedback shift register first initializes the register through a short binary sequence, and then generates it by shifting the register. The C/A (Coarse Acquisition Code) code of the GPS L1 signal is generated by two parallel 10-stage (total 20) linear shift registers in terms of the realization of the coarse code, and the code length is 1023 bits; the coarse code of the Galileo E1 signal is generated by two Two parallel linear shift registers generate truncated and combined M codes, with a code length of 4092 bits; GLONASS ranging codes are generated by a linear shift register with a maximum length of 9 levels (M sequence), and the code length is 511 bits ; The ranging codes C _B1I and C _B2I at BeiDou B1I and B2I signals are generated by two parallel 11-stage (total 22) linear shift registers, and the code length is 2046 bits. Only GPS provides a realization method in terms of fine code implementation, that is, two parallel 12-stage (total 24-stage) linear shift registers are used to generate. Since a pseudo-random code of a certain length needs a certain number of shift registers to be generated by shifting, the generated ranging codes generally have disadvantages such as low complexity, poor security, fixed and short code length, and limited number of codes. The bit register also needs to undertake the work of linear feedback and satellite phase distribution, which makes the structure complicated.

The other is the real pseudo-random code generator discussed in the literature, which uses the sensitive dependence of the space-time chaotic system on the initial value through a nonlinear method, and can provide a large number of non-correlated, quasi-random and deterministically reproducible code generators. These signals have the characteristics of pseudo-randomness, aperiodicity, long-term unpredictability, and ergodicity. The space-time chaotic one-way coupled mapping lattice model is applied to the GPS system, and a set of 20 spatial grid points is used to design 20 levels The space-time chaotic real number pseudo-random code generator is used to replace two parallel 10-level linear shift registers of GPS. Firstly, the same real number is used to initialize the state value of the grid variable, and then under the action of the nonlinear mapping dynamic function (referred to as "non-linear function"), a real pseudo-random number distributed with the time state is generated, and then the relevant grid variable tap is used to obtain the The time state distribution value of the lattice variable, and output the real number pseudo-random number sequence, binarize and modulo two sum to be the ranging code.

The nonlinear function generally adopts the polynomial form of univariate f(x)=-δx ² +1, that is, a low-order variable multiplied by the negative nonlinear strength plus an integer constant, and δ is the nonlinear strength of the variable; the nonlinear function It is composed of variables, parameters of variables (including the power of variables, position number, nonlinear strength as variable weight) and integer constant items. Variables, parameters of variables and constant items are called parameters of nonlinear functions, and its diffusion The coefficient (weight as the value of the nonlinear function) is a real number in the real number field [0,1], the sum of the diffusion coefficients of the nonlinear function value acting on the state variables of different grid points is 1, and different nonlinear functions Action values can only be added to each other. The real pseudo-random code generator can overcome the disadvantages of the current binary pseudo-random code generator that the ranging code length is fixed and short and the number of codes is limited. However, due to the use of a nonlinear function and generally a quadratic function , and the data accuracy is 10 ^-2 , so that the generated ranging code has low complexity and low security, and there are too many space grid points, and each grid point state variable only generates a real pseudo-random number at a time.

In addition, when demodulating the BOC signal, because the BOC modulation destroys the pseudo-randomness of the spread-spectrum signal of the navigation message of the navigation satellite, the demodulated signal has a fuzzy demodulation problem caused by multiple correlation peaks. However, the current binary pseudo-random code generator cannot restore pseudo-randomness through parameter adjustment. At present, the identification of the main peak is mainly solved by subsequent processing of multiple correlation peaks. At present, the main solutions are BPSK_like method (BPSK, Binary Phase Shift Key), autocorrelation side peak elimination method (ASPeCT, Autocorrelation Side-Peak Cancellation Technique), offset positive cross correlation method (OQCC, Offset Quadratic Cross Correlation), Among them, in the BPSK_like method, the BOC modulation signal is equivalent to the sum of two BPSK modulation signals with different carrier frequencies, thereby eliminating the ambiguity caused by subcarrier modulation. Reduce ambiguity, and the OQCC method eliminates the secondary peaks by improving the separation of the main and secondary peaks.

Contents of the invention

In view of the above technical problems, the present invention provides a space-time chaos vector pseudo-random code generator offset carrier modulation method and system that can improve the performance of the ranging code and maintain the pseudo-randomness of the ranging code and eliminate the problem of multiple correlation peaks in the current BOC modulation .

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

One, a space-time chaotic vector pseudo-random code generator offset carrier modulation method, used for no offset carrier modulation, comprising:

S1 constructs a vector pseudo-random code generator G, G is composed of a single complex state vector X+Yj, and its component is {x(i)+y(i)j} in the I _M +N dimensional linear space, which is called a complex state component , {x(i)} and {y(i)} are a series of sequentially arranged and coupled state components; i represents the position number of the complex state component, i=1,2,...I _M +N, Both I _M and N are positive integers, and the first or last I _M complex state components are recorded as extended complex state components, and their position numbers i∈[1,I _M ] or i∈[N+1,N+I _M ]; The last or first N complex state components are recorded as effective complex state components, and their position numbers i∈[I _M +1,I _M +N] or i∈[1,N], effective complex state components {x(i)} and {y(i)} constitute pseudo-random code generators G ₁ and G ₂ respectively;

S2 Extended complex state components constitute G ₀ , and the number of extended complex state components is greater than or equal to the preset maximum value of position offset;

S3 constructs nonlinear functions that act on the current position of the real and imaginary parts of the effective complex state component and the current state value of the offset position, specifically:

The nonlinear functions acting on the current position of the real part of the effective complex state component and the current state value of the offset position are respectively recorded as the nonlinear function of the current position of the real part and the nonlinear function of the offset position of the real part, and will act on the effective complex state component The nonlinear functions of the current position of the imaginary part and the current state value of the offset position are respectively denoted as the nonlinear function of the current position of the imaginary part and the nonlinear function of the offset position of the imaginary part; where:

The construction of the nonlinear function of the current position of the real part is as follows:

The real part of the nonlinear function of the current position is composed of ₁₂ different powers of LL functions with different parameter values and LL ₁₃ different powers of variables with different parameter values; taking the negative nonlinear strength of each function as the weight, take LL The first function item of the real part is obtained by the weighted summation of ₁₁ functions, and the second function item of the real part is obtained by the weighted summation of the remaining (LL ₁₂ -LL ₁₁ ) functions; The weighted sum of ₁₃ variables obtains the first variable item of the real part; the first variable item of the real part is multiplied by the second function item of the real part, and the first function item and the first real constant item of the real part are added, and the obtained polynomial is the current part of the real part position nonlinear function;

The constructed real part current position nonlinear function is used to act on the current state value of the real part current position of the effective complex state component;

The construction of the real part offset position nonlinear function is as follows:

The real part offset position nonlinear function is composed of LL ₂₁ variables with different powers and different parameter values; with the negative nonlinear strength of each variable as the weight, the ₂₁ variables of LL are weighted and summed to obtain the second variable item of the real part , the polynomial obtained by adding the second variable item of the real part and the second real constant item is the nonlinear function of the offset position of the real part;

The constructed real part offset position nonlinear function is used to act on the current state value of the real part offset position of the effective complex state component;

The construction of the nonlinear function of the current position of the imaginary part is as follows:

The imaginary part of the current position nonlinear function is composed of ₃₂ different powers of LL functions with different parameter values and LL ₃₃ different powers of variables with different parameter values; taking the negative nonlinear strength of each function as the weight, take LL The first function item of the imaginary part is obtained by the weighted sum of ₃₁ functions, and the second function item of the imaginary part is obtained by the weighted sum of the remaining (LL ₃₂ -LL ₃₁ ) functions; the negative nonlinear strength of each variable is used as the weight, and the LL ₃₃ variables are weighted and summed to get the first variable item of the imaginary part; the first variable item of the imaginary part is divided by the second function item of the imaginary part to get the division item, the first function item of the imaginary part is subtracted from the division item, and the third The real constant term, the obtained polynomial is the nonlinear function of the current position of the imaginary part;

The constructed nonlinear function of the current position of the imaginary part is used to act on the current state value of the current position of the imaginary part of the effective complex state component;

The construction of the nonlinear function of the imaginary part offset position is as follows:

The imaginary part offset position nonlinear function is composed of LL ₄₁ variables with different powers and different parameter values; with the negative nonlinear strength of each variable as the weight, the ₄₁ variables of LL are weighted and summed to obtain the second variable item of the imaginary part , the polynomial obtained by adding the second variable item of the imaginary part and the fourth real constant item is the nonlinear function of the imaginary part offset position;

The constructed imaginary part offset position nonlinear function is used to act on the current state value of the effective complex state component imaginary part offset position;

Among them, the parameters of the function include the working frequency, the power of the function, the amplitude value of the function, the phase of the function, the position number, the position offset and the state translation; the position offset is the amount by which the position number increases or decreases, and the state translation The amount is the amount of increase or decrease of the variable state value; the parameters of the variable include the power of the variable, the position number, the position offset and the state translation amount;

LL ₁₂ , LL ₁₃ , LL ₂₁ , LL ₃₂ , LL ₃₃ , and LL ₄₁ are all integers greater than 0, and their values can be set as required; LL ₁₁ is a positive integer not greater than LL ₁₂ , and LL ₃₁ is not greater than LL ₃₂ The positive integers of LL ₁₁ and LL ₃₁ are set according to the needs;

S4 parameter initialization and the use of pseudo-random number sequences or real number sequences composed of different real numbers to initialize the effective complex state components in G and the state values of the extended complex state components in G0 _;

S5 uses multiple groups of different real part current position nonlinear functions and real part offset position nonlinear functions to respectively act on the current state values of the real part current position and the offset position of the effective complex state component to obtain the real part action value; Use multiple sets of different imaginary part current position nonlinear functions and imaginary part offset position nonlinear functions to act on the current state value of the effective complex state component imaginary part current position and offset position respectively, and obtain the imaginary part action value; based on Diffusion coefficient, mutual coupling coefficient, adding, subtracting, multiplying, and dividing the real part action value and the imaginary part action value respectively or a mixed operation including at least two operations in addition, subtraction, multiplication, and division, and generating A distributed sequence of complex pseudorandom numbers;

This step further includes:

Real part state iteration, specifically:

Using multiple sets of different real part current position nonlinear functions and imaginary part current position nonlinear functions to act on the current state value of the real part current position and imaginary part current position of the effective complex state component respectively, multiple sets of real part current position nonlinearity Function value and imaginary part current position nonlinear function value;

Taking the diffusion coefficient as the weight, the real part is weighted and averaged at the current position of the nonlinear function to obtain the first real part action value; the imaginary part is arithmetically averaged at the current position of the nonlinear function and multiplied by the mutual coupling coefficient to obtain the first imaginary part Action value; add, subtract, multiply or divide the first real part action value and the first imaginary part action value to obtain the first mixed operation action value;

Take part of the real part of the current position nonlinear function value and calculate the arithmetic average to get the first average value; the other real part current position nonlinear function values are multiplied by the corresponding diffusion coefficient and then multiplied, and the multiplied value is divided by the rest of the real part current The number of position nonlinear function values is the second average value, and the first average value and the second average value are subtracted to obtain

Take part of the real part offset position nonlinear function value and calculate the arithmetic mean to get the third average value, and the other real part offset position nonlinear function values are multiplied by the corresponding diffusion coefficient and then multiplied, and the multiplied value is divided by the remaining real The fourth average value is obtained by subtracting the third average value and the fourth average value The value of the first mixed operation divided by Get the current position state value of the real part at the next moment;

The imaginary part state iteration, specifically:

Using multiple sets of different imaginary part current position nonlinear functions and real part current position nonlinear functions to act on the current state values of the effective complex state component imaginary part current position and real part current position respectively, to obtain the imaginary part current position nonlinear function value and the real part of the current position nonlinear function value;

Taking the diffusion coefficient as the weight, the weighted average of the nonlinear function value of the current position of the imaginary part is carried out to obtain the second imaginary part action value; the arithmetic mean of the nonlinear function of the current position of the real part is multiplied by the mutual coupling coefficient to obtain the second real part Action value; add, subtract, multiply or divide the second imaginary part action value and the second real part action value to obtain the second mixed operation action value;

Take part of the current position nonlinear function value of the imaginary part and calculate the arithmetic average to get the fifth average value. The remaining imaginary part current position nonlinear function value is multiplied by the corresponding diffusion coefficient and then multiplied. The multiplied value is divided by the remaining imaginary part current value. The number of position nonlinear function values is the sixth average value, and the fifth average value and the sixth average value are added together to obtain

Take part of the imaginary part offset position nonlinear function value and calculate the arithmetic average to get the seventh average value, all the imaginary part offset position nonlinear function values are multiplied by the corresponding diffusion coefficient and then multiplied, and the multiplied value is divided by all imaginary The eighth average value is obtained by subtracting the seventh average value and the eighth average value The value of the second blending action is divided by Get the current position state value of the imaginary part at the next moment;

S6 uses the complex pseudo-random number sequence or real _number sequence obtained by the current effective complex state component to modify the state value of the extended complex state component in G0, or use these modified state values to recombine and arrange each other; then, read G For the next effective complex state component, execute step S5 for the next effective complex state component; when all effective complex state components in G have completed state iteration, execute step S7;

S7 extracts the time-distributed real number pseudo-random number sequence from relevant component taps in G ₁ and G ₂ respectively, which are respectively recorded as the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part;

S8 For the spike value whose absolute value is greater than the absolute value of the first threshold in the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part, replace the peak value with the mean value of the adjacent values before and after the peak value, and obtain the second pseudo-random value of the real part The random number and the imaginary part of the second pseudo-random number; the peak removal is used to adjust the state value of the pseudo-random number and change the pattern of the subsequent ranging code; the first threshold is set to one time the absolute value of the adjacent value before or after the peak value value;

S9 compares each real random number in the second pseudo-random number of the real part and the second pseudo-random number of the imaginary part with the first reference value in chronological order, and if it is greater than the first reference value, the real random number takes a value of 1; otherwise If the value is 0, the binarized first pseudo-random code and the second pseudo-random code can be obtained; the first reference value is the real pseudo-random number describing the second pseudo-random number of the real part and the second pseudo-random number of the imaginary part respectively Statistics of median size;

S10 performs the modulo two sum of the first pseudo-random code and the second pseudo-random code to obtain a third pseudo-random code with good pseudo-randomness, that is, a ranging code without frequency offset; if the pseudo-random code of the ranging code without frequency offset If the randomness is destroyed, then it is necessary to adjust the diffusion coefficient and mutual coupling coefficient of the nonlinear function, the nonlinear strength of the function and/or variable, fine-tune the operating frequency and phase of the function, fine-tune the first reference value and re-binarize the real part of the second Pseudo-random number and imaginary part second pseudo-random number;

S11 uses the frequency-offset-free ranging code to track and capture satellite navigation signals.

The above-mentioned tracking and capturing of satellite navigation signals by using the frequency-offset ranging code further includes:

(1) Obtain and binarize the satellite navigation message, and use the frequency-free ranging code to spread the satellite navigation message to obtain a spread spectrum signal;

(2) The spread spectrum signal is modulated by a carrier signal with a Doppler frequency offset, and a Gaussian white noise signal is added to output a baseband satellite navigation signal;

(3) receiving and intercepting a section of baseband satellite navigation signal to generate a local carrier signal, and adopting a matching method to remove the carrier of the intercepted satellite navigation signal to obtain the carrier removal signal;

(4) Generate the ranging code without frequency offset and perform FFT-based cyclic correlation processing with the decarrier signal. If there is a correlation peak, demodulate the satellite navigation message according to the correlation peak position, and end; otherwise, repeat steps S5 to S10 to obtain again No frequency offset ranging code, and then repeat this step.

As a specific implementation, in substep (2), the Doppler frequency offset range of the carrier signal is [-10kHz, 10kHz]; meanwhile, the signal-to-noise ratio range of the Gaussian white noise signal added is [0dB, -20dB].

Two, a space-time chaotic vector pseudo-random code generator offset carrier modulation method, used for real number offset carrier modulation, comprising:

S1～S7, same as steps S1～S7 in the first method;

S8 multiplies the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part by the phase-orthogonal first real number offset carrier and the second real number offset carrier respectively to obtain the third pseudo-random number and the imaginary part of the real part The third pseudo-random number; here, the offset carrier is the carrier whose operating frequency is higher than the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part. The pseudo-random number is moved from the current working frequency to the modulated combined frequency;

S9 For the spike value whose absolute value is greater than the absolute value of the second threshold in the third pseudo-random number of the real part and the third pseudo-random number of the imaginary part, replace the peak value with the mean value of the adjacent values before and after the peak value to obtain the fourth pseudo-random value of the real part The random number and the fourth pseudo-random number of the imaginary part; the peak removal is used to adjust the state value of the pseudo-random number and change the code pattern of the subsequent ranging code; the second threshold is set to double the absolute value of the adjacent value before or after the peak value value;

S10 compares each real random number in the fourth pseudo-random number of the real part and the fourth pseudo-random number of the imaginary part with the second reference value in chronological order, and if it is greater than the second reference value, the real random number takes a value of 1; otherwise If the value is 0, the binarized fourth pseudo-random code and fifth pseudo-random code can be obtained; the second reference value is the real number pseudo-random number describing the fourth pseudo-random number of the real part and the fourth pseudo-random number of the imaginary part respectively Statistics of median size;

S11 performs a modular sum of the fourth pseudo-random code and the fifth pseudo-random code to obtain a sixth pseudo-random code;

S12 Obtain a ranging code modulated by an offset carrier with good pseudo-randomness from the sixth pseudo-random code, that is, the first frequency offset ranging code; if the pseudo-randomness of the ranging code with the first frequency offset is destroyed, Then it is necessary to adjust the diffusion coefficient and mutual coupling coefficient of the nonlinear function, the nonlinear strength of the function and/or variable, or fine-tune the operating frequency and phase of the function, or fine-tune the operating frequency and phase of the real number offset carrier, or fine-tune the second reference The value re-binarizes the fourth pseudo-random number of the real part and the fourth pseudo-random number of the imaginary part;

S13 Use the first frequency offset ranging code to track and capture the satellite navigation signal.

The above-mentioned adopting the first frequency offset ranging code to track and capture the satellite navigation signal further includes:

(1) Obtain and binarize the satellite navigation message, and use the first frequency offset ranging code to spread the satellite navigation message to obtain a spread spectrum signal;

(2) The spread spectrum signal is modulated by a carrier signal with a Doppler frequency offset, and a Gaussian white noise signal is added to output a baseband satellite navigation signal;

(3) receiving and intercepting a section of baseband satellite navigation signal to generate a local carrier signal, and adopting a matching method to remove the carrier of the intercepted satellite navigation signal to obtain the carrier removal signal;

(4) Generate the first frequency offset ranging code and perform FFT-based cyclic correlation processing with the decarrier signal. If there is a correlation peak, demodulate the satellite navigation message according to the correlation peak position, and end; otherwise, repeat steps S5 to S12 again Obtain the first frequency offset ranging code, and then repeat this step.

As a specific implementation, in substep (2), the Doppler frequency offset range of the carrier signal is [-10kHz, 10kHz]; meanwhile, the signal-to-noise ratio range of the Gaussian white noise signal added is [0dB, -20dB].

Three, a space-time chaotic vector pseudo-random code generator offset carrier modulation method, used for binarization offset carrier modulation, comprising:

S1～S10, same as steps S1～S10 in the first method;

S11 Binarize the third real number offset carrier, specifically: take the average value of the third real number offset carrier as the third reference value, and take the value of the real number offset carrier greater than the third reference value in the third real number offset carrier 1. The real number offset carrier value not greater than the third reference value is 0;

S12 performs a modulo two sum of the third pseudo-random code and the binarized third real-number offset carrier to obtain a seventh pseudo-random code;

S13 Obtain a ranging code modulated by an offset carrier with good pseudo-randomness from the seventh pseudo-random code, that is, the second frequency offset ranging code; if the pseudo-randomness of the ranging code with the second frequency offset is destroyed, Then it is necessary to adjust the diffusion coefficient and mutual coupling coefficient of the nonlinear function, the nonlinear strength of the function and/or variable, or fine-tune the operating frequency and phase of the function, or fine-tune the operating frequency and phase of the third real number offset carrier, or fine-tune the first A reference value re-binarizes the real part of the second pseudo-random number and the imaginary part of the second pseudo-random number, or fine-tunes the third reference value and re-binarizes the third real number offset carrier;

S14 Use the second frequency offset ranging code to track and capture the satellite navigation signal.

The above-mentioned adopting the second frequency offset ranging code to track and capture the satellite navigation signal further includes:

(1) Obtain and binarize the satellite navigation message, and use the second frequency offset ranging code to spread the satellite navigation message to obtain a spread spectrum signal;

(2) The spread spectrum signal is modulated by a carrier signal with a Doppler frequency offset, and a Gaussian white noise signal is added to output a baseband satellite navigation signal;

(3) receiving and intercepting a section of baseband satellite navigation signal to generate a local carrier signal, and adopting a matching method to remove the carrier of the intercepted satellite navigation signal to obtain the carrier removal signal;

(4) Generate the second frequency offset ranging code and perform FFT-based cyclic correlation processing with the decarrier signal. If there is a correlation peak, demodulate the satellite navigation message according to the correlation peak position, and end; otherwise, repeat steps S5 to S13 again Obtain the second frequency offset ranging code, and then repeat this step.

As a specific implementation, in substep (2), the Doppler frequency offset range of the carrier signal is [-10kHz, 10kHz]; meanwhile, the signal-to-noise ratio range of the Gaussian white noise signal added is [0dB, -20dB].

In step S2 of the above three methods, the extended complex state component is used to iterate the state value of the complex state component of the position offset in the auxiliary vector pseudo-random code generator, and its number should be greater than or equal to the preset position offset of the complex state component amount maximum.

In the step S4 of above-mentioned three kinds of methods, the real number sequence that is formed by different real numbers initializes the effective complex number state component in G and the state value of the extended complex _number state component in G0, and described real number sequence will ensure that the effective complex number state component in G is in chaos In the working state, if the real number sequence cannot guarantee the chaotic working state, it is necessary to adjust the diffusion coefficient and mutual coupling coefficient of the nonlinear function, and the nonlinear strength of the function and/or variable.

In the step S4 of above-mentioned three kinds of methods, adopt pseudo-random number sequence to initialize the effective complex number state component in G and the state value of extended complex _number state component in G0, specifically:

Construct two linear pseudo-random code generators respectively, denoted as the first linear pseudo-random code generator and the second linear pseudo-random code generator;

Drive the first linear pseudo-random code generator and the second linear pseudo-random code generator respectively and output the eighth pseudo-random code and the ninth pseudo-random code from relevant register taps;

Set 0 and 1 in the eighth pseudo-random code and the ninth pseudo-random code to different decimals respectively, and convert them into the fifth pseudo-random number and the sixth pseudo-random number; if the obtained pseudo-random number cannot ensure that the effective complex state component is in chaotic operation state, the diffusion coefficient and mutual coupling coefficient of the nonlinear function need to be adjusted, and the nonlinear strength of the function and/or variable;

The fifth pseudo-random number and the sixth pseudo-random number are the initial values of the real part and the imaginary part of the complex state component respectively.

In the step S9 of the above-mentioned method 1, the first reference value is obtained by sorting method, that is, the first reference value of the second pseudo-random number of the real part and the second pseudo-random number of the imaginary part are obtained by sorting the real number pseudo-random number by size Median.

In the step S10 of the above-mentioned method 2, the second reference value is obtained by sorting method, that is, the second reference value of the fourth pseudo-random number of the real part and the fourth pseudo-random number of the imaginary part are respectively obtained by sorting the pseudo-random numbers of the real number by size Median.

In the present invention, if the obtained no frequency offset, the first or second frequency offset ranging code has poor pseudo-randomness, it is necessary to adjust the nonlinear strength of the function and/or variable, the diffusion coefficient of the nonlinear function, and the mutual coupling Coefficient, or fine-tune the first reference value, re-binarize the second pseudo-random number of the real part and the second pseudo-random number of the imaginary part, or fine-tune the second reference value, re-binarize the fourth pseudo-random number of the real part and the fourth pseudo-random number of the imaginary part Pseudo-random numbers, or fine-tune the operating frequency and phase of the function, or fine-tune the operating frequency or phase of the first and second real-number offset carriers, or fine-tune the third reference value, re-binarize the third real-number offset carrier, and fine-tune the first Three real numbers offset the working frequency or phase of the carrier, and fine-tune the working frequency or phase of the seventh pseudo-random code.

Four, a space-time chaotic vector pseudo-random code generator offset carrier modulation system, used for no offset carrier modulation, including:

(1) The vector pseudo-random code generator building block is used to construct the vector pseudo-random code generator G, G is made of a single complex state vector X+Yj, and its component is {x(i) in I _M +N dimensional linear space +y(i)j}, called the complex state component, {x(i)} and {y(i)} are a series of sequentially arranged and coupled state components; i represents the position number of the complex state component, i =1,2,...I _M +N, I _M and N are both positive integers, the first or last I _M complex state components are recorded as extended complex state components, and their position numbers i∈[1,I _M ] or i∈[N+1,N+I _M ]; the next or first N complex state components are recorded as effective complex state components, and their position numbers i∈[I _M +1,I _M +N] or i∈[1, N], the effective complex state components {x(i)} and {y(i)} constitute pseudo-random code generators G ₁ , G ₂ respectively;

(2) An expansion module, which is used to expand the complex state components to form G ₀ , and the number of expanded complex state components is greater than or equal to the preset maximum value of position offset;

(3) The nonlinear function building block is used to construct nonlinear functions that act on the current position of the real part and the imaginary part of the effective complex state component and the current state value of the offset position, specifically: act on the current position of the real part or the imaginary part The nonlinear function of the offset position and the current state value is a set of functions and/or variables with different powers and different parameter values. The negative nonlinear strength of the function is used as the weight, and the real part or For the first function item of the imaginary part, weighted and summed the remaining functions to obtain the second function item of the real or imaginary part; with the negative nonlinear strength of the variable as the weight, weighted and summed some variables to obtain the real or imaginary part The first variable item, the second variable item of the real part or the imaginary part is obtained by weighting and summing the remaining variables; the first function item, the second function item, the first variable item and the second variable item are included and added according to the preset method A mixed operation of at least two operations in, subtraction, multiplication, and division, plus the corresponding real constant term, the resulting polynomial is a nonlinear function that acts on the current position of the real or imaginary part and the current state value of the offset position;

(4) initialization module, used for parameter initialization and adopting pseudo-random number sequence or the real number sequence initialization G that is made of different real numbers effective complex state component and the state value of extended complex state component in G ₀ ;

(5) The state iteration module is used to use multiple groups of different real part current position nonlinear functions and real part offset position nonlinear functions to respectively carry out the current state values of the real part current position and offset position of the effective complex state component Action, get the action value of the real part; use multiple sets of different imaginary part current position nonlinear functions and imaginary part offset position nonlinear functions to respectively act on the current state value of the effective complex state component imaginary part current position and offset position , to get the value of the imaginary part; based on the diffusion coefficient and the mutual coupling coefficient, add, subtract, multiply, and divide the value of the real part and the value of the imaginary part respectively, or a mixture of at least two operations including addition, subtraction, multiplication, and division Operation, through state iteration to generate complex pseudo-random number sequences distributed over time;

(6) Judgment module, used to modify the state value of the extended complex state component in G0 by using the complex pseudo-random number sequence or real _number sequence obtained by the current effective complex state component, or use these modified state values to recombine and arrange each other ; Then, read the next effective complex state component in G, and forward to the state iteration module for the next effective complex state component; when all the effective complex state components in G have completed the state iteration, proceed to the real pseudorandom number sequence extraction module;

(7) Real number pseudo-random number sequence extraction module, used to extract the real number pseudo-random number sequence distributed _over time from relevant component taps in _G1 and G2 respectively, which are respectively recorded as the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part pseudorandom number;

(8) The spike signal module is used to replace the peak value of the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part with an absolute value greater than the absolute value of the first threshold with the mean value of the adjacent values before and after the peak value Spike value to obtain the second pseudo-random number of the real part and the second pseudo-random number of the imaginary part; de-peak is used to adjust the state value of the pseudo-random number and change the code pattern of the subsequent ranging code; the first threshold is set before the peak value or double the absolute value of the next adjacent value;

(9) binarization module, for comparing each real number random number in the second pseudo-random number of the real part and the second pseudo-random number of the imaginary part with the first reference value in time order, if greater than the first reference value, then The real random number takes a value of 1; otherwise, it takes a value of 0 to obtain a binarized first pseudo-random code and a second pseudo-random code; The statistic of the median size of the real pseudo-random number in the two pseudo-random numbers;

(10) modulus two and module, for carrying out modulo two and the first pseudo-random code and the second pseudo-random code, obtain the third pseudo-random code with good pseudo-randomness, i.e. no frequency offset ranging code;

(11) A tracking and capturing module, used for tracking and capturing satellite navigation signals by using a frequency-offset-free ranging code.

Five, a space-time chaotic vector pseudo-random code generator offset carrier modulation system, used for real number offset carrier modulation, comprising:

(1) The vector pseudo-random code generator building block is the same as the vector pseudo-random code generator building block in the above-mentioned system four;

(2) expansion module, the same as the expansion module in the above-mentioned system four;

(3) Non-linear function building block, the same as the non-linear function building block in the above-mentioned system four;

(4) initialization module, same as the initialization module in the above-mentioned system four;

(5) The state iteration module is the same as the state iteration module in the above-mentioned system four;

(6) judging module, same as the judging module in the above-mentioned system four;

(7) Real number pseudo-random number sequence extraction module is the same as the real number pseudo-random number sequence extraction module in the above-mentioned system four;

(8) Offset carrier modulation module, for multiplying the first real number offset carrier and the second real number offset carrier by the first real number offset carrier and the second real number offset carrier respectively with the first real number offset carrier and the imaginary first pseudo random number of the real part, to obtain The third pseudo-random number of the real part and the third pseudo-random number of the imaginary part; here, the offset carrier is the carrier whose operating frequency is higher than the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part. The first pseudo-random number and the imaginary part of the first pseudo-random number are moved from the current operating frequency to the modulated combined frequency;

(9) spike signal module, for the peak value of the absolute value greater than the absolute value of the second threshold in the third pseudo-random number of the real part and the third pseudo-random number of the imaginary part, replace with the mean value of the adjacent values before and after the peak value Spike value to obtain the fourth pseudo-random number of the real part and the fourth pseudo-random number of the imaginary part; de-peak is used to adjust the state value of the pseudo-random number and change the code pattern of the subsequent ranging code; the second threshold is set before the peak value or double the absolute value of the next adjacent value;

(10) Binarization module, for comparing each real number random number in the fourth pseudo-random number of the real part and the fourth pseudo-random number of the imaginary part with the second reference value in time order, if greater than the second reference value, then The value of the real random number is 1; otherwise, the value is 0, and the binarized fourth pseudo-random code and the fifth pseudo-random code can be obtained; the second reference value is the fourth pseudo-random number describing the real part and the first The statistic of the median size of the real pseudo-random number in the four pseudo-random numbers;

(11) modulus two and module, for carrying out modulo two and the 4th pseudo-random code and the 5th pseudo-random code, obtain the 6th pseudo-random code;

(12) A frequency offset ranging code acquisition module, used to obtain a ranging code modulated by an offset carrier with good pseudo-randomness from the sixth pseudo-random code, that is, the first frequency offset ranging code;

(13) A tracking and capturing module, configured to track and capture satellite navigation signals by using the first frequency offset ranging code.

Six, a space-time chaotic vector pseudo-random code generator offset carrier modulation system, used for binarization offset carrier modulation, including:

(1) The vector pseudo-random code generator building block is the same as the vector pseudo-random code generator building block in the above-mentioned system four;

(2) expansion module, the same as the expansion module in the above-mentioned system four;

(3) Non-linear function building block, the same as the non-linear function building block in the above-mentioned system four;

(4) initialization module, same as the initialization module in the above-mentioned system four;

(5) The state iteration module is the same as the state iteration module in the above-mentioned system four;

(6) judging module, same as the judging module in the above-mentioned system four;

(7) Real number pseudo-random number sequence extraction module is the same as the real number pseudo-random number sequence extraction module in the above-mentioned system four;

(8) The peak signal removal module is the same as the peak signal removal module in the above-mentioned system four;

(9) The first binarization module is the same as the binarization module in the above-mentioned system four;

(10) the first model two and the module, the same as the above-mentioned system four middle model two and the module;

(11) The second binarization module is used to binarize the third real number offset carrier, specifically: the average value of the third real number offset carrier is the third reference value, and the third real number offset carrier is greater than the first The real number offset carrier value of the three reference values takes the value 1, and the real number offset carrier value not greater than the third reference value takes the value 0;

(12) The second modulo two and module, for carrying out modulo two and the third pseudo-random code and the binarized third real number offset carrier to obtain the seventh pseudo-random code;

(13) A frequency offset ranging code acquisition module, used to obtain a ranging code modulated by an offset carrier with good pseudo-randomness from the seventh pseudo-random code, that is, a second frequency offset ranging code;

(14) A tracking and capturing module, configured to track and capture satellite navigation signals by using the second frequency offset ranging code. .

The present invention can overcome all the technical defects in the ranging codes produced by current binary pseudo-random code generators and real pseudo-random code generators, greatly improve the performance of ranging codes in satellite navigation systems, and also completely solve the problem of current binary offset carrier waves. The problem of multiple correlation peaks in the modulation technique.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) Pseudo-random codes with high complexity can be obtained

A variety of different nonlinear functions are used together to generate pseudo-random codes in an iterative manner through mutual coupling and mixed operations, and the obtained pseudo-random codes have high complexity.

(2) Pseudo-random codes with strong security can be obtained

A pseudo-random code with high complexity can be generated, thereby fully ensuring the high security of the pseudo-random code.

(3) The code length of the pseudo-random code is not limited by the number of series

The maximum code length of the generated random code distributed over time has nothing to do with the number of stages used by the pseudo-random code generator, and can be infinitely long.

(4) Very few series

With complex number implementation, the number of pseudo-random code generator stages can be minimized.

(5) There are many pseudo-random code patterns generated

The pseudo-random code pattern of the present invention is determined by the real number of the initial state value of the complex state component, and the parameter accuracy of the parameters included in the nonlinear function, such as the diffusion coefficient, nonlinear strength, and mutual coupling coefficient. The accuracy of these parameters at the receiving end is at least 10 ^-5 , The number of pseudo-random code patterns that can be generated by the present invention is at least 10 ⁵ ×L, where L is the code length.

(6) Pseudo-random code characteristics can be adjusted at any time

When the pseudo-randomness of the pseudo-random code is destroyed, it can be restored by adjusting the nonlinear strength, diffusion coefficient, mutual coupling coefficient, fine-tuning the operating frequency and phase of the real-number offset carrier or the binarized real-number offset carrier.

(7) Generate ranging code with offset carrier modulation

The ranging code is fused with the offset carrier modulation signal, the pseudo-randomness of the ranging code is maintained, and the problem of multiple correlation peaks caused by correlation demodulation is completely solved.

Description of drawings

Fig. 1 is the concrete flow chart diagram of the inventive method;

Fig. 2 is a schematic diagram of the implementation process of ranging code tracking and capture in the embodiment;

Fig. 3 is the pseudo-random number sequence that the second state component of _G1 adopts mutual coupling mixed operation to obtain in the embodiment;

Fig. 4 is the pseudo-random number sequence obtained after removing the peak of the pseudo-random number sequence shown in Fig. 3;

Fig. 5 is the pseudo-random number sequence obtained after using the real number offset carrier modulation to remove the peak to the pseudo-random number sequence shown in Fig. 3;

Fig. 6 is the pseudo-random code obtained after the pseudo-random number sequence shown in Fig. 4 is processed by sorting method;

Fig. 7 is the pseudo-random code obtained after adopting sorting method to the pseudo-random number sequence shown in Fig. 5;

Fig. 8 is the ranging code obtained in the embodiment without offset carrier modulation;

Fig. 9 is the ranging code of real number offset carrier modulation obtained in the embodiment;

Fig. 10 is the ranging code of the binarized real offset carrier modulation obtained in the embodiment;

Fig. 11 is the autocorrelation function of the ranging code shown in Fig. 8;

Fig. 12 is the autocorrelation function of the ranging code shown in Fig. 9;

Fig. 13 is the autocorrelation function of ranging code shown in Fig. 10;

Figure 14 shows the tracking and acquisition characteristics of the ranging code shown in Figure 8 under the condition that the signal-to-noise ratio is -10dB, the code offset is 100 bytes, and the Doppler frequency offset is 20Hz;

Fig. 15 shows the tracking and acquisition characteristics of the ranging code shown in Fig. 9 under the condition that the signal-to-noise ratio is -10dB, the code offset is 100 bytes, and the Doppler frequency offset is 20Hz;

Figure 16 shows the tracking and acquisition characteristics of the ranging code shown in Figure 10 under the condition that the signal-to-noise ratio is -10dB, the code offset is 100 bytes, and the Doppler frequency offset is 20Hz;

Fig. 17 is a schematic diagram of the system structure of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the embodiment of forward-extending complex state components, and the implementation steps according to Fig. 1 are as follows:

S1 constructs a vector pseudo-random code generator G, G is composed of a single complex state vector X+Yj, and its component is {x(i)+y(i)j} in the I _M +N dimensional linear space, which is called a complex state component , {x(i)} and {y(i)} are a series of sequentially arranged and coupled state components; i represents the position number of the complex state component, i=1,2,...I _M +N, Both I _M and N are positive integers, and N takes a value as required; the first I _M complex state components are recorded as extended complex state components, and their position numbers i∈[1,I _M ]; the last N complex state components are recorded as valid The complex state components, whose position number i∈[I _M +1, I _M +N], the effective complex state components {x(i)} and {y(i)} constitute the pseudo-random code generators G ₁ and G ₂ respectively .

S2 forwardly expands the complex state components to form G ₀ , and the number of expanded complex state components is greater than the preset maximum value of the position offset.

take ratio A large value I _M refers to the number of extended complex state components. In order to ensure the efficiency of subsequent calculations, the value of I _M should not be too large, generally a positive integer not greater than 10.

S3: Construction of nonlinear functions and state iteration formulas acting on real and imaginary parts of effective complex state components;

(3-1) Construction of nonlinear function:

In formula (1)～(2):

k represents a discrete time coordinate;

i represents the position number of the effective complex state component, i=I _M +1,I _M +2,...I _M +N;

x _k (i) and y _k (i) represent the current position state values of the real and imaginary parts of the effective complex state component with the position number i at time k respectively; the effective complex state component with the position number i is abbreviated as effective complex state component i;

respectively represent the nonlinear functions acting on the current position of the real part, the offset position of the real part, the current position of the imaginary part and the offset position of the imaginary part of the effective complex state component i, contain the sin function and the cos function respectively, and the phases are Φ _k and Φ' _k , The operating frequency of the functions included respectively is m ₁ f ₀ , f ₀ is the basic operating frequency, and m ₁ is a positive integer ranging from 2 to 10;

l ₁ , l ₂ , l ₃ , l ₄ represent nonlinear functions respectively serial number, that is, represents the _l1th nonlinear function acting on the current position of the real part of the effective complex state component i, represents the l2th nonlinear function acting _on the offset position of the real part of the effective complex state component i, represents the l _3rd nonlinear function acting on the current position of the imaginary part of effective complex state component i, Indicates the l _4th nonlinear function acting on the offset position of the imaginary part of the effective complex state component i;

ll ₁₁ and ll ₁₂ represent nonlinear functions respectively The sequence numbers of the functions and variables contained in ; ll ₂ represents a nonlinear function The serial number of the variable contained in ; ll ₃₁ , ll ₃₂ represent the nonlinear function respectively The serial number of the function and variable contained in ; ll ₄ represents a nonlinear function The serial number of the variable contained in ;

is a nonlinear function In the ll _11th function, the next power is is a nonlinear function In the ll _31st function, the next power is

LL ₁₂ and LL ₁₃ represent nonlinear functions respectively middle function and the number of variables x _k (i); LL ₂₁ represents the nonlinear function The number of variables x _k (i) in the middle; LL ₃₂ , LL ₃₃ respectively represent the nonlinear function middle function and the number of variables y _k (i); LL ₄₁ represents the non-linear function The number of variables y _k (i) in ;

LL ₁₂ , LL ₁₃ , LL ₂₁ , LL ₃₂ , LL ₃₃ , and LL ₄₁ are all integers greater than 0, and their values can be set as required; LL ₁₁ is a positive integer not greater than LL ₁₂ , and LL ₃₁ is not greater than LL ₃₂ is a positive integer, and its value can be set according to the needs;

Respectively represent the k-time nonlinear function The ll _11th function in and the ll _12th variable The nonlinear strength of;

Represents the k-time nonlinear function The ll _2nd variable in The nonlinear strength of;

Respectively represent the k-time nonlinear function The ll _31st function in and the ll _32nd variable The nonlinear strength of;

is a nonlinear function at time k The ll _4th variable in The nonlinear strength of;

is a nonlinear function The power of the _12th variable x _k (i) in the ll; is a nonlinear function In the power of the ll ₂ variable x _k (i); is a nonlinear function In the power of the ll _32nd variable y _k (i); is a nonlinear function The power of the ll _4th variable y _k (i) in ;

are non-linear functions Included real constants, whose values can be set as needed.

The above-mentioned nonlinear strengths are all real numbers, and the above-mentioned powers are positive integers greater than 1, and their values are set according to the needs;

(3-2) State iteration formula

Let the code length generated by the vector complex pseudo-random code generator G be L, and use multiple sets of nonlinear functions containing different parameter values to act on the current state value of the real part and imaginary part of the effective complex state component and the current position of the offset position, so as to Diffusion coefficients and mutual coupling coefficients are weights, and the complex state components generate complex pseudo-random numbers distributed over time through a mixed operation method including at least one operation of addition, subtraction, multiplication, and division.

The state iteration formula of the state value of the real part x _k+1 (i) and the imaginary part y _k+1 (i) of the effective complex state component i at (k+1) obtained by the mixed operation method is as follows:

in:

Represents the real part of the complex state component i at time k The state value of offset position;

Indicates the imaginary part of the complex state component i at time k The state value of offset position;

L ₁₂ , L ₂₂ , L ₃₂ , and L ₄₂ respectively represent nonlinear functions The number of L ₁₂ , L ₂₂ , L ₃₂ , and L ₄₂ are all integers greater than 0, and their values are set according to the needs;

L ₁₁ , L ₂₁ , L ₃₁ , and L ₄₁ are positive integers not greater than L ₁₂ , L ₂₂ , L ₃₂ , and L ₄₂ respectively, and their values are set according to the needs;

and Respectively represent the k-time nonlinear function and Included position offset;

Represents the non-linear function and Included state translation amount;

are nonlinear functions at time k and Included state translation amount;

Respectively represent the k-time nonlinear function the effect value;

are non-linear functions Diffusion coefficient at time k, a real number;

γ _k and γ' _k are the nonlinear functions acting on the current position of the real part and imaginary part of the complex state component i at time k respectively and Mutual coupling coefficient for the mean of the action values, as a real number.

S4: initialization of parameters and state values of complex state variables;

(4-1) Parameter initialization

The parameters include the number N of effective complex state components (that is, the number of series), the code length L, the number of nonlinear functions, parameters of nonlinear functions, diffusion coefficients, and mutual coupling coefficients. The nonlinear function is a polynomial form containing different power functions and/or variables, and the parameters further include functions and/or variables, parameters and real constants of the functions and/or variables, wherein the parameters of the function are the operating frequency, the degree of the function Square, function amplitude value, function phase, position number, position offset, state translation, variable parameters are variable power, position number, position offset, state translation.

In the present invention, the function powers are all positive integers greater than 1, and there is no upper limit requirement; the diffusion coefficients of each nonlinear function are all real numbers. nonlinear function contain the sin function and the cos function respectively, and the phases are Φ _k and Φ' _k , The operating frequency of the functions contained respectively is m ₁ f ₀ , f ₀ is the basic operating frequency, m ₁ is a positive integer; the nonlinear function Include variables separately; non-linear functions are the nonlinear functions acting on the current positions of the real and imaginary parts of the complex state components respectively, and the nonlinear functions are nonlinear functions acting on the offset positions of the real and imaginary components of the complex state, respectively.

In this embodiment, the number of effective complex state components is N=3, the code length L=511 bits, and the number of forward-extended complex state components I _M =5. The number of nonlinear functions L ₁₁ =1, L ₁₂ =3, L ₃₁ =1, L ₃₂ =3 acting on the current position of the real part and the imaginary part of the effective complex state component respectively; The number of non-linear functions L ₂₂ =L ₄₂ =2 for the imaginary part forward offset position. The highest powers of each nonlinear function acting on the current position of the real part of the effective complex state component are 2, 4, and 6 respectively, and the highest powers of each nonlinear function acting on the current position of the imaginary part of the effective complex state component are respectively 3, 5, 7 powers; the highest powers of each nonlinear function acting on the forward offset position of the real part of the effective complex state component are 2 and 3 powers respectively, and acting on the forward offset of the imaginary part of the effective complex state component The highest powers of each nonlinear function of position are 2 and 3 powers respectively.

The diffusion coefficients corresponding to the nonlinear functions acting on the current positions of the real and imaginary parts of the effective complex state components are respectively in, represent the first, second, and third nonlinear functions at time 1, respectively The diffusion coefficient, They are the 1st, 2nd, and 3rd nonlinear functions at time 1 respectively The diffusion coefficient.

The diffusion coefficients corresponding to the nonlinear functions acting on the real and imaginary parts of the effective complex state component to the forward offset position are respectively in, Respectively, the first and second nonlinear functions at time 1 The diffusion coefficient, Respectively, the first and second nonlinear functions at time 1 The diffusion coefficient.

nonlinear function acting on the current position of the real part of the effective complex state component The highest power functions are in the first ₁₁ functions of LL, and the corresponding nonlinear strengths are The nonlinear strength corresponding to the remaining LL ₁₁ -1 functions is 0; the nonlinear strength corresponding to the LL ₁₂ -LL ₁₁ functions is set by yourself; the nonlinear strength corresponding to the LL ₁₃ variables is 0; its forward offset position is the highest The nonlinear strength corresponding to the power variable is The nonlinear strength corresponding to the remaining LL ₂₁ -1 variables is 0; the nonlinear function acting on the current position of the imaginary part of the effective complex state component The highest power functions are in the first ₃₁ functions of LL, and the corresponding nonlinear strengths are The nonlinear strength corresponding to the remaining LL ₃₁ -1 functions is 0; the nonlinear strength corresponding to the LL ₃₂ -LL ₃₁ functions is set by itself; the nonlinear strength corresponding to the LL ₃₃ variables is 0; its forward offset position is the highest The nonlinear strength corresponding to the power variable is The remaining LL ₄₁ -1 variables correspond to a non-linear strength of 0; among them, They are the 1st, 2nd, and 3rd nonlinear functions at time 1 respectively The nonlinear strength corresponding to the highest power function, Respectively, the first and second nonlinear functions at time 1 The nonlinear strength corresponding to the highest power variable, They are the 1st, 2nd, and 3rd nonlinear functions at time 1 respectively The nonlinear strength corresponding to the highest power function, Respectively, the first and second nonlinear functions at time 1 The nonlinear strength corresponding to the highest power variable.

Mutual coupling coefficients are γ ₁ =8.80001, γ' ₁ =8.60001 respectively, where γ ₁ and γ' ₁ are respectively the action values of the first, second and third nonlinear functions at the current position of the imaginary part of the complex state component at time 1 Mutual coupling coefficient of the mean value and the mean value of the 1st, 2nd, and 3rd nonlinear function action values at the current position of the real part.

The real constants contained in the first, second, and third nonlinear functions f _l1 of the current position of the real part of the effective complex state component are respectively and The included state translation amounts are 1.50005 respectively; the current position of the imaginary part of the effective complex state component is the 1st, 2nd, and 3rd nonlinear functions The real constants involved are The included state translation amount is 2.50005; the real part of the effective complex state component is shifted forward. The first and second nonlinear functions The real constants involved are and The included state translation amounts are all 1.50005; the imaginary part of the effective complex state component is forward-shifted by the first and second nonlinear functions The real constants involved are and The included state translations are all 2.50005.

The forward position offsets are respectively represent the first and second nonlinear functions at time 1 The corresponding forward position offset, respectively represent the first and second nonlinear functions at time 1 The corresponding forward position offset; time 1 is the initial time.

f ₀ =1.023Hz, m ₁ =2, n _Φ =16, the single-value range is [0,π/2], f ₀ provides the basic operating frequency for the generated ranging code, n _Φ is used for nonlinear function The phases of the sin function and cos function included in the single-valued interval are equally divided by the initial phase angle, and the amplitude values of all functions are the value 1.

In the present invention, the setting of the diffusion coefficient of each nonlinear function, the mutual coupling coefficient and the nonlinear strength of the function and/or variable should ensure that the system is in a chaotic working state, and the series is set to the minimum series, corresponding to the nonlinear function of the current position The phase value of is the product of the position number of the effective complex state component and the angle mean division of the single-valued interval. The single-valued interval is the interval corresponding to the mean component and its function value one-to-one. The total division number of the phase is n _Φ .

(4-2) Initialization of complex state component state values

It can be initialized with a pseudo-random number sequence or a real number sequence composed of different real numbers, and it is necessary to ensure that the effective complex state components work in a chaotic state. If a pseudo-random number sequence is used to initialize the state value of the complex state component, the pseudo-random number sequence can be obtained by using a linear shift register through a tap of a relevant register.

The following will provide a specific implementation process of initializing the complex state component by using a real number sequence composed of different real numbers.

Multiply the position number of the real part of the complex state component by 0.1, and then add the product of time and 0.00001 to form the real part value; then multiply the position number of the imaginary part of the complex state component by 0.2, and then add the product of time and 0.00001, Form the imaginary part value. The real part value and the imaginary part value constitute the initialization value of the complex state component.

S5: Perform state iteration on each effective complex state component in the complex pseudo-random code generator G according to formula (3), and generate a 530-bit complex pseudo-random number sequence distributed over time;

The state iteration of the present invention is realized based on the non-linear function weight function, and the non-linear function weight value function is shown in the mutual coupling hybrid operation mode shown in the formula (3).

S6 _: For each extended complex state component in G0, multiply its position number by 0.001 and add the real part value of the 530-bit complex pseudo-random number sequence obtained in S5 to obtain the real part state value of the extended complex state component; Then multiply the imaginary part value of the 530-bit complex pseudo-random number sequence obtained by S5 with its position sequence number multiplied by 0.003 to get the imaginary part state value of the extended complex state component, and realize the expansion of the complex state component state value in G ₀ Modify; then read the next effective complex state component in G, and execute step S5. When the state iteration is completed for all effective complex state components in G, step S7 is executed.

S7: Delay for 5 seconds, to avoid the initial non-chaotic oscillation signal, extract the first pseudo-random number of the real part of the time state distribution with a length of 511 seconds from the second and third state components of _G1 , see Figure 3, from G ₂ The first and third state components extract the first pseudo-random number of the imaginary part of the time state distribution with a length of 511 seconds. If real number offset carrier modulation is used, go to step S8; otherwise, go to step S9.

S8: Multiply the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part by the first offset carrier of the sine function and the second offset carrier of the cosine function with a frequency of m ₂ f ₀ to offset the carrier modulation to obtain the third pseudo-random number of the real part and the third pseudo-random number of the imaginary part; in this embodiment, m ₂ =5, m ₂ >2m ₁ .

S9: For the peak value whose absolute value is greater than the absolute value of the first threshold in the first pseudo-random number of the real part and the first pseudo-random number of the imaginary part, the peak value is replaced by the mean value of the adjacent values before and after the peak value, so that the modulation can be removed The "spike" signal in the signal is used to obtain the second pseudo-random number of the real part and the second pseudo-random number of the imaginary part.

For the peak value whose absolute value is greater than the absolute value of the second threshold in the third pseudo-random number of the real part and the third pseudo-random number of the imaginary part, the peak value is replaced by the mean value of the adjacent values before and after the peak value, so that the modulation signal can be removed "Spike" signal, get the fourth pseudo-random number of the real part and the fourth pseudo-random number of the imaginary part.

The results of this step are shown in FIGS. 4-5 ; in this embodiment, the absolute values of the first threshold and the second threshold are both set to 2.

S10: Comparing each real random number in the second or fourth pseudo-random number of the real part and the second or fourth pseudo-random number of the imaginary part with the intermediate value obtained by the sorting method, that is, the first or second reference value, respectively in time order , if it is greater than the first or second reference value, the real random number takes a value of 1; otherwise, it takes a value of 0 to obtain a binarized first pseudo-random code, second pseudo-random code or fourth pseudo-random code, The fifth pseudo-random code, see Figures 6-7.

S11: Carry out modulo two summing of the first pseudo-random code and the second pseudo-random code, or the fourth pseudo-random code and the fifth pseudo-random code, to form a code length of 511-bit third pseudo-random code (see Figure 8) or The sixth pseudo-random code.

S12: If the binary real offset carrier modulation is adopted, go to step S13; otherwise, go to step S15.

S13: Use the average value of the third real number offset carrier as the third reference value to binarize the third offset carrier with the frequency m ₂ f ₀ formed by a group of odd cosine functions, and the real number offset greater than the third reference value The shifted carrier value takes a value of 1, and the real offset carrier value not greater than the third reference value takes a value of 0.

S14: Perform a modulo two sum of the third pseudo-random code and the binarized third offset carrier to obtain a seventh pseudo-random code.

S15: Obtain a ranging code modulated by an offset carrier from the sixth pseudo-random code or the seventh pseudo-random code, that is, the ranging code with the first or second frequency offset, see FIGS. 9-10 .

See Tables 1-6 and Figures 11-13 for the pseudo-randomness evaluation of ranging codes. Pseudo-randomness can be evaluated by balance, run length and autocorrelation. The balance is the percentage of the values 0 and 1 in the ranging code to the total number, ideally 0 and 1 account for 50% of the total number respectively. The run-length property is the percentage of runs of different lengths in the ranging code to the total number of runs. Ideally, the percentage of runs of each length to the total number of runs is Among them, a represents the run length. The autocorrelation is the delta function characteristic of the autocorrelation function of the ranging code.

S16: Generate a binarized satellite navigation message.

S17: Spread the satellite navigation message with the ranging code without frequency offset, first or second frequency offset to obtain a spread spectrum signal;

S18: Modulate the spread spectrum signal with a complex exponential carrier signal with a frequency of 60×1.023 Hz and a Doppler frequency offset of 20 Hz;

S19: adding -10dB Gaussian white noise signal to the modulated signal;

S20: Output baseband satellite navigation signals;

S21: receiving the baseband satellite navigation signal, and intercepting a 511-bit long signal with a code offset of 100 bytes;

S22: generating a complex exponential local carrier signal with a frequency of 60×1.023Hz;

S23: Use the local carrier signal to remove the carrier by matching method to the intercepted signal to obtain the carrier-removed signal;

S24: Generate the ranging code of the navigation satellite without frequency offset, first or second frequency offset according to steps S5-S15;

S25: Perform FFT-based cyclic correlation processing on the ranging code without frequency offset, first or second frequency offset, and the decarrier signal;

S26: If there is a correlation peak (see Figures 14-16), demodulate the satellite navigation message from the received signal according to the position of the correlation peak, and end; otherwise, return to step S24.

The balance of the ranging code shown in Table 1 and Figure 8

value Percentage of total (%) 0 53.03 1 46.97

Table 2 The run length of the ranging code shown in Figure 8

run length Percentage of total runs (%) 1 49.80 2 27.89 3 8.76 4 4.78 5 1.99 6 0.80

The balance of the ranging code shown in Table 3 and Figure 9

value Percentage of total (%) 0 48.92 1 51.08

The run length of the ranging code shown in Table 4 and Figure 9

run length Percentage of total runs (%) 1 50.20 2 26.72 3 9.31 4 4.05 5 2.02 6 0.81

The balance of the ranging code shown in Table 5 and Figure 10

value Percentage of total (%) 0 45.40 1 54.60

Table 6 and Figure 10 show the run length of the ranging code

run length Percentage of total runs (%) 1 46.72 2 24.45 3 13.54 4 6.55 5 1.31 6 0.00

Claims (9)

1. A time-space chaos vector pseudo-random code generator offset carrier modulation method is used for non-offset carrier modulation, and is characterized by comprising the following steps:

S1A vector pseudo-random code generator G is constructed, G consisting of a single complex state vector X + Yj, at I_MA + N-dimensional linear space whose components are { x (i) + y (i) j }, called complex state components, { x (i) } and { y (i) } are a series of sequentially arranged state components respectively coupled to each other; i denotes the position number of the complex state component, I1, 2_M+N，I_MN is a positive integer, before or after_MThe complex state component is marked as an extended complex state component, and the position sequence number I belongs to [1, I ]_M]Or I is as [ N +1, N + I ]_M](ii) a The last or first N complex state components are marked as effective complex state components, and the position sequence number I belongs to [ I ∈ ]_M+1,I_M+N]Or i is e [1, N ∈]The effective complex state components { x (i) } and { y (i) } respectively constitute a pseudo-random code generator G₁、G₂；

S2 expanding complex state components to form G₀The number of the extended complex state components is greater than or equal to a preset maximum value of the position offset;

s3, constructing nonlinear functions respectively applied to the real and imaginary current positions of the effective complex state component and the current state value of the offset position, specifically:

the nonlinear function acting on the current state values of the real part or the imaginary part and the offset position is a group of functions and/or variables with the same power or different powers and containing different parameter values, the nonlinear strength of the functions is taken as a weight, a part of functions are weighted and summed to obtain a first function item of the real part or the imaginary part, and the rest functions are weighted and summed to obtain a second function item of the real part or the imaginary part; taking the nonlinear strength of the variables as a weight, weighting and summing a part of the variables to obtain a first variable term of a real part or an imaginary part, and weighting and summing the rest of the variables to obtain a second variable term of the real part or the imaginary part; performing mixed operation including at least two operations of addition, subtraction, multiplication and division on the first function item, the second function item, the first variable item and the second variable item according to a preset mode, and adding a corresponding real constant item to obtain a polynomial, namely a nonlinear function acting on a real part or imaginary part current position and an offset position current state value;

s4 parameter initialization and initialization of effective complex state components in G and G using pseudo-random number sequence or real number sequence composed of different real numbers₀State values of the medium-spread complex state components; the pseudo random number sequence and the real number sequence need to ensure that the effective complex state component in the G is in a chaotic working state, and if the real number sequence cannot ensure the chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted; if the pseudo-random number does not guarantee that the valid complex state components are in a mixtureIn a chaos working state, the non-linear intensity of a function and/or a variable, the diffusion coefficient and the mutual coupling coefficient of the non-linear function need to be adjusted;

s5, using the multiple groups of nonlinear functions to act on the real part and the imaginary part of the effective complex state component and the current state value of the offset position respectively to obtain a real part action value and an imaginary part action value; respectively performing addition, subtraction, multiplication and division or mixed operation comprising at least two operations of addition, subtraction, multiplication and division on the real part action value and the imaginary part action value by using different diffusion coefficients and mutual coupling coefficients as weighting coefficients of the real part action value and the imaginary part action value, and generating a complex pseudo-random number sequence distributed along with time through state iteration;

s6 uses the complex pseudo-random number sequence or real number sequence obtained by current effective complex state component to modify G₀Expanding the state values of the complex state components or utilizing the modified state values to carry out recombination arrangement among the state values; then, the next valid complex state component in G is read, and step S5 is performed on the next valid complex state component; when all the valid complex state components in G complete state iteration, step S7 is executed;

s7 from G respectively₁And G₂Extracting a real pseudo-random number sequence distributed along with time by the related component tap, and respectively recording the real pseudo-random number sequence as a real first pseudo-random number and an imaginary first pseudo-random number sequence;

s8, replacing a peak value with a statistical analysis value of adjacent values before and after the peak value for the peak value of the absolute value of the real part first pseudo-random number and the imaginary part first pseudo-random number larger than the first threshold value to obtain a real part second pseudo-random number and an imaginary part second pseudo-random number; the peak removal is used for adjusting the state value of the pseudo random number and changing the code pattern of the subsequent generated ranging code; the first threshold value is set to a value twice the absolute value of the vicinity value before or after the peaked value;

s9, real random numbers in the real second pseudo random number and the imaginary second pseudo random number are respectively compared with a first reference value in time sequence, and if the real random numbers are larger than the first reference value, the real random numbers take a value of 1; otherwise, taking a value of 0 to obtain a first binary pseudo-random code and a second binary pseudo-random code; the first reference value is respectively a statistic for describing the magnitude of the median value of real pseudo random numbers in the real second pseudo random number and the imaginary second pseudo random number;

s10, modulo-two summation is carried out on the first pseudo random code and the second pseudo random code to obtain a third pseudo random code with good pseudo random property, namely a frequency offset-free ranging code;

s11 tracking and acquiring the satellite navigation signals by using the frequency offset-free ranging codes.

2. A time-space chaos vector pseudo-random code generator offset carrier modulation method is used for real offset carrier modulation, and is characterized by comprising the following steps:

S1A vector pseudo-random code generator G is constructed, G consisting of a single complex state vector X + Yj, at I_MA + N-dimensional linear space whose components are { x (i) + y (i) j }, called complex state components, { x (i) } and { y (i) } are a series of sequentially arranged state components respectively coupled to each other; i denotes the position number of the complex state component, I1, 2_M+N，I_MN is a positive integer, before or after_MThe complex state component is marked as an extended complex state component, and the position sequence number I belongs to [1, I ]_M]Or I is as [ N +1, N + I ]_M](ii) a The last or first N complex state components are marked as effective complex state components, and the position sequence number I belongs to [ I ∈ ]_M+1,I_M+N]Or i is e [1, N ∈]The effective complex state components { x (i) } and { y (i) } respectively constitute a pseudo-random code generator G₁、G₂；

S2 expanding complex state components to form G₀The number of the extended complex state components is greater than or equal to a preset maximum value of the position offset;

s3, constructing nonlinear functions respectively applied to the real and imaginary current positions of the effective complex state component and the current state value of the offset position, specifically:

the nonlinear function acting on the current state values of the real part or the imaginary part and the offset position is a group of functions and/or variables with the same power or different powers and containing different parameter values, the nonlinear strength of the functions is taken as a weight, a part of functions are weighted and summed to obtain a first function item of the real part or the imaginary part, and the rest functions are weighted and summed to obtain a second function item of the real part or the imaginary part; taking the nonlinear strength of the variables as a weight, weighting and summing a part of the variables to obtain a first variable term of a real part or an imaginary part, and weighting and summing the rest of the variables to obtain a second variable term of the real part or the imaginary part; performing mixed operation including at least two operations of addition, subtraction, multiplication and division on the first function item, the second function item, the first variable item and the second variable item according to a preset mode, and adding a corresponding real constant item to obtain a polynomial, namely a nonlinear function acting on a real part or imaginary part current position and an offset position current state value;

s4 parameter initialization and initialization of effective complex state components in G and G using pseudo-random number sequence or real number sequence composed of different real numbers₀State values of the medium-spread complex state components; the pseudo random number sequence and the real number sequence need to ensure that the effective complex state component in the G is in a chaotic working state, and if the real number sequence cannot ensure the chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted; if the pseudo random number can not ensure that the effective complex state component is in a chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted;

s5, using the multiple groups of nonlinear functions to act on the real part and the imaginary part of the effective complex state component and the current state value of the offset position respectively to obtain a real part action value and an imaginary part action value; respectively performing addition, subtraction, multiplication and division or mixed operation comprising at least two operations of addition, subtraction, multiplication and division on the real part action value and the imaginary part action value by using different diffusion coefficients and mutual coupling coefficients as weighting coefficients of the real part action value and the imaginary part action value, and generating a complex pseudo-random number sequence distributed along with time through state iteration;

s6 uses the complex pseudo-random number sequence or real number sequence obtained by current effective complex state component to modify G₀Expanding the state values of the complex state components or utilizing the modified state values to carry out recombination arrangement among the state values; then, the next valid complex state component in G is read, and step S5 is performed on the next valid complex state component; when all the effective complex state components in G complete state iterationStep S7 is executed;

s7 from G respectively₁And G₂Extracting a real pseudo-random number sequence distributed along with time by the related component tap, and respectively recording the real pseudo-random number sequence as a real first pseudo-random number and an imaginary first pseudo-random number sequence;

s8, multiplying the real part first pseudo-random number and the imaginary part first pseudo-random number respectively with a first real number offset carrier and a second real number offset carrier which are orthogonal in phase to obtain a real part third pseudo-random number and an imaginary part third pseudo-random number;

s9, replacing a peak value with a statistical analysis value of adjacent values before and after the peak value for the peak value of the absolute value of the real part third pseudo-random number and the imaginary part third pseudo-random number larger than the second threshold value to obtain a real part fourth pseudo-random number and an imaginary part fourth pseudo-random number; the peak removal is used for adjusting the state value of the pseudo random number and changing the code pattern of the subsequent generated ranging code; the second threshold value is set to a value twice the absolute value of the vicinity value before or after the peaked value;

s10, real random numbers in the real fourth pseudo random number and the imaginary fourth pseudo random number are respectively compared with a second reference value in time sequence, and if the real random numbers are larger than the second reference value, the real random numbers take a value of 1; otherwise, the value is 0, and the fourth pseudo random code and the fifth pseudo random code which are binarized can be obtained; the second reference value is respectively a statistic for describing the magnitude of the median value of real pseudo random numbers in the real fourth pseudo random number and the imaginary fourth pseudo random number;

s11, modulo two and the fourth pseudo random code and the fifth pseudo random code to get the sixth pseudo random code;

s12 obtaining a shifted carrier modulated ranging code with good pseudo-randomness, i.e., a first frequency shifted ranging code, from the sixth pseudo-random code;

s13 tracking and acquiring the satellite navigation signal by using the first frequency offset ranging code.

3. A time-space chaos vector pseudo-random code generator offset carrier modulation method is used for binary offset carrier modulation, and is characterized by comprising the following steps:

S1A vector pseudo-random code generator G is constructed, G consisting of a single complex state vector X + Yj, at I_M+ N dimensionLinear space whose components are { x (i) + y (i) j }, called complex state components, { x (i) } and { y (i) } are a series of sequentially arranged state components respectively coupled to each other; i denotes the position number of the complex state component, I1, 2_M+N，I_MN is a positive integer, before or after_MThe complex state component is marked as an extended complex state component, and the position sequence number I belongs to [1, I ]_M]Or I is as [ N +1, N + I ]_M](ii) a The last or first N complex state components are marked as effective complex state components, and the position sequence number I belongs to [ I ∈ ]_M+1,I_M+N]Or i is e [1, N ∈]The effective complex state components { x (i) } and { y (i) } respectively constitute a pseudo-random code generator G₁、G₂；

S2 expanding complex state components to form G₀The number of the extended complex state components is greater than or equal to a preset maximum value of the position offset;

s3, constructing nonlinear functions respectively applied to the real and imaginary current positions of the effective complex state component and the current state value of the offset position, specifically:

the nonlinear function acting on the current state values of the real part or the imaginary part and the offset position is a group of functions and/or variables with the same power or different powers and containing different parameters, the nonlinear strength of the functions is taken as a weight, a part of functions are weighted and summed to obtain a first function item of the real part or the imaginary part, and the rest functions are weighted and summed to obtain a second function item of the real part or the imaginary part; taking the nonlinear strength of the variables as a weight, weighting and summing a part of the variables to obtain a first variable term of a real part or an imaginary part, and weighting and summing the rest of the variables to obtain a second variable term of the real part or the imaginary part; performing mixed operation including at least two operations of addition, subtraction, multiplication and division on the first function item, the second function item, the first variable item and the second variable item according to a preset mode, and adding a corresponding real constant item to obtain a polynomial, namely a nonlinear function acting on a real part or imaginary part current position and an offset position current state value;

s4 parameter initialization and initialization of effective complex state components in G and G using pseudo-random number sequence or real number sequence composed of different real numbers₀State values of the medium-spread complex state components; the pseudo-random number sequence and the real number sequence are ensuredG, effective complex state components are in a chaotic working state, and if a real number sequence cannot guarantee the chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted; if the pseudo random number can not ensure that the effective complex state component is in a chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted;

s5, using the multiple groups of nonlinear functions to act on the real part and the imaginary part of the effective complex state component and the current state value of the offset position respectively to obtain a real part action value and an imaginary part action value; respectively performing addition, subtraction, multiplication and division or mixed operation comprising at least two operations of addition, subtraction, multiplication and division on the real part action value and the imaginary part action value by using different diffusion coefficients and mutual coupling coefficients as weighting coefficients of the real part action value and the imaginary part action value, and generating a complex pseudo-random number sequence distributed along with time through state iteration;

s6 uses the complex pseudo-random number sequence or real number sequence obtained by current effective complex state component to modify G₀Expanding the state values of the complex state components or utilizing the modified state values to carry out recombination arrangement among the state values; then, the next valid complex state component in G is read, and step S5 is performed on the next valid complex state component; when all the valid complex state components in G complete state iteration, step S7 is executed;

s7 from G respectively₁And G₂Extracting a real pseudo-random number sequence distributed along with time by the related component tap, and respectively recording the real pseudo-random number sequence as a real first pseudo-random number and an imaginary first pseudo-random number sequence;

s8, replacing a peak value with a statistical analysis value of adjacent values before and after the peak value for the peak value of the absolute value of the real part first pseudo-random number and the imaginary part first pseudo-random number larger than the first threshold value to obtain a real part second pseudo-random number and an imaginary part second pseudo-random number; the peak removal is used for adjusting the state value of the pseudo random number and changing the code pattern of the subsequent generated ranging code; the first threshold value is set to a value twice the absolute value of the vicinity value before or after the peaked value;

s9, real random numbers in the real second pseudo random number and the imaginary second pseudo random number are respectively compared with a first reference value in time sequence, and if the real random numbers are larger than the first reference value, the real random numbers take a value of 1; otherwise, taking a value of 0 to obtain a first binary pseudo-random code and a second binary pseudo-random code; the first reference value is respectively a statistic for describing the magnitude of the median value of real pseudo random numbers in the real second pseudo random number and the imaginary second pseudo random number;

s10, modulo-two summation is carried out on the first pseudo random code and the second pseudo random code to obtain a third pseudo random code with good pseudo random property;

s11 binarizes the third real offset carrier, specifically: taking the statistical analysis value of the third real offset carrier as a third reference value, wherein the real offset carrier value larger than the third reference value in the third real offset carrier takes a value of 1, and the real offset carrier value not larger than the third reference value takes a value of 0;

s12, modulo-two summation is carried out on the third pseudo random code and the binarized third real number offset carrier to obtain a seventh pseudo random code;

s13 obtaining a shifted carrier modulated ranging code with good pseudo-randomness, i.e., a second frequency shifted ranging code, from the seventh pseudo-random code;

and S14, tracking and acquiring the satellite navigation signal by using the second frequency offset ranging code.

4. The spatiotemporal chaos vector pseudorandom code generator offset carrier modulation method according to any one of claims 1 to 3, characterized by:

in step S3, the nonlinear function is a polynomial composed of a set of functions and/or variables of the same power or different powers and containing different parameter values, and nonlinear strength and real constant as weight of each function and/or variable, where the parameters contained in the function are operating frequency, power of the function, amplitude value of the function, phase value of the function, position number, position offset, and state translation, the parameters contained in the variable are power of the variable, position number, position offset, and state translation, and real number precision in the parameter is 10^-5And the phases of the functions contained in the real and imaginary nonlinear functions of the effective complex state components are respectively orthogonalin the nonlinear function, the functions and/or variables with nonlinear intensity as weight are/is added, subtracted, multiplied or divided, and the preset mixed operation is performed.

5. The spatiotemporal chaos vector pseudorandom code generator offset carrier modulation method according to any one of claims 1 to 3, characterized by:

in step S4, a pseudo-random number sequence is used to initialize the significant complex state component in G and G₀The state value of the middle-extended complex state component specifically includes:

respectively constructing two linear pseudorandom code generators, and recording the two linear pseudorandom code generators as a first linear pseudorandom code generator and a second linear pseudorandom code generator;

driving a first linear pseudo-random code generator and a second linear pseudo-random code generator, respectively, and outputting an eighth pseudo-random code and a ninth pseudo-random code from a correlation register tap;

setting 0 and 1 in the eighth pseudo random code and the ninth pseudo random code as different decimal numbers respectively, and converting the decimal numbers into a fifth pseudo random number and a sixth pseudo random number; if the obtained pseudo random number can not ensure that the effective complex state component is in a chaotic working state, the nonlinear strength of a function and/or a composite function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of the nonlinear function need to be adjusted;

the fifth and sixth pseudo random numbers are the initial values of the real and imaginary parts of the complex state component, respectively.

6. The spatiotemporal chaos vector pseudorandom code generator offset carrier modulation method according to any one of claims 1 to 3, characterized by:

in step S5, the action value of the nonlinear function acting on the real part and the imaginary part of the effective complex state component is subjected to (③) an addition, subtraction, multiplication, or division operation, (④) a preset blending operation, (iii) an addition, subtraction, multiplication, or division operation using the diffusion coefficient or the mutual coupling coefficient as a weight, or (iv) a preset blending operation using the diffusion coefficient or the mutual coupling coefficient as a weight.

7. A time-space chaos vector pseudo-random code generator offset carrier modulation system is used for non-offset carrier modulation, and is characterized by comprising the following components:

(1) a vector pseudo-random code generator construction module for constructing a vector pseudo-random code generator G, G consisting of a single complex state vector X + Yj, in I_MA + N-dimensional linear space whose components are { x (i) + y (i) j }, called complex state components, { x (i) } and { y (i) } are a series of sequentially arranged state components respectively coupled to each other; i denotes the position number of the complex state component,

i＝1,2,...I_M+N，I_Mn is a positive integer, before or after_MThe complex state component is marked as an extended complex state component, and the position sequence number I belongs to [1, I ]_M]Or I is as [ N +1, N + I ]_M](ii) a The last or first N complex state components are marked as effective complex state components, and the position sequence number I belongs to [ I ∈ ]_M+1,I_M+N]Or i is e [1, N ∈]The effective complex state components { x (i) } and { y (i) } respectively constitute a pseudo-random code generator G₁、G₂；

(2) An expansion module for expanding the complex state components to form G₀The number of the extended complex state components is greater than or equal to a preset maximum value of the position offset;

(3) a nonlinear function constructing module, configured to construct a nonlinear function that acts on the real part and the imaginary part of the effective complex state component, respectively, and the current state value of the offset position, specifically:

the nonlinear function acting on the current state values of the real part or the imaginary part and the offset position is a group of functions and/or variables with the same power or different powers and containing different parameter values, the nonlinear strength of the functions is taken as a weight, a part of functions are weighted and summed to obtain a first function item of the real part or the imaginary part, and the rest functions are weighted and summed to obtain a second function item of the real part or the imaginary part; taking the nonlinear strength of the variables as a weight, weighting and summing a part of the variables to obtain a first variable term of a real part or an imaginary part, and weighting and summing the rest of the variables to obtain a second variable term of the real part or the imaginary part; performing mixed operation including at least two operations of addition, subtraction, multiplication and division on the first function item, the second function item, the first variable item and the second variable item according to a preset mode, and adding a corresponding real constant item to obtain a polynomial, namely a nonlinear function acting on a real part or imaginary part current position and an offset position current state value;

(4) an initialization module for parameter initialization and initialization of the effective complex state components G and G in G using pseudo-random number sequences or real number sequences consisting of different real numbers₀State values of the medium-spread complex state components; the pseudo random number sequence and the real number sequence need to ensure that the effective complex state component in the G is in a chaotic working state, and if the real number sequence cannot ensure the chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted; if the pseudo random number can not ensure that the effective complex state component is in a chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted; (5) the state iteration module is used for respectively acting on the current state values of the real part and the imaginary part of the effective complex state component and the current state value of the offset position by using the constructed multiple groups of nonlinear functions to obtain a real part action value and an imaginary part action value; respectively performing addition, subtraction, multiplication and division or mixed operation comprising at least two operations of addition, subtraction, multiplication and division on the real part action value and the imaginary part action value by using different diffusion coefficients and mutual coupling coefficients as weighting coefficients of the real part action value and the imaginary part action value, and generating a complex pseudo-random number sequence distributed along with time through state iteration;

(6) a judging module for modifying G by using complex pseudo random number sequence or real number sequence obtained by current effective complex state component₀Expanding the state values of the complex state components or utilizing the modified state values to carry out recombination arrangement among the state values; then, reading the next effective complex state component in G, and transferring the next effective complex state component to a state iteration module; when all the effective complex state components in the G complete state iteration, switching to a real pseudo-random number sequence extraction module;

(7) a real pseudo-random number sequence extraction module for respectively extracting from G₁And G₂Extracting real pseudo-random number sequences distributed over time from the related component tapsA first pseudo random number marked as a real part and a first pseudo random number marked as an imaginary part;

(8) the peak removing signal module is used for replacing a peak value with a statistical analysis value of adjacent values before and after the peak value for the peak value of which the absolute value is larger than the first threshold value in the real part first pseudo-random number and the imaginary part first pseudo-random number to obtain a real part second pseudo-random number and an imaginary part second pseudo-random number; the peak removal is used for adjusting the state value of the pseudo random number and changing the code pattern of the subsequent generated ranging code; the first threshold value is set to a value twice the absolute value of the vicinity value before or after the peaked value;

(9) the binarization module is used for comparing real random numbers in the real second pseudo random number and the imaginary second pseudo random number with a first reference value in a time sequence, and if the real random numbers are larger than the first reference value, the real random numbers take a value of 1; otherwise, taking a value of 0 to obtain a first binary pseudo-random code and a second binary pseudo-random code; the first reference value is respectively a statistic for describing the magnitude of the median value of real pseudo random numbers in the real second pseudo random number and the imaginary second pseudo random number;

(10) the modulo two sum module is used for performing modulo two sum on the first pseudo random code and the second pseudo random code to obtain a third pseudo random code with good pseudo random property, namely a frequency offset-free ranging code;

(11) and the tracking acquisition module is used for tracking and acquiring the satellite navigation signal by adopting the frequency offset-free ranging code.

8. A time-space chaos vector pseudo-random code generator offset carrier modulation system is used for real offset carrier modulation, and is characterized by comprising the following components:

(1) a vector pseudo-random code generator construction module for constructing a vector pseudo-random code generator G, G consisting of a single complex state vector X + Yj, in I_MA + N-dimensional linear space whose components are { x (i) + y (i) j }, called complex state components, { x (i) } and { y (i) } are a series of sequentially arranged state components respectively coupled to each other; i denotes the position number of the complex state component, I1, 2_M+N，I_MN is a positive integer, before or after_MThe complex state components are marked as extended complex state components, with the position index i ∈ [1,I_M]or I is as [ N +1, N + I ]_M](ii) a The last or first N complex state components are marked as effective complex state components, and the position sequence number I belongs to [ I ∈ ]_M+1,I_M+N]Or i is e [1, N ∈]The effective complex state components { x (i) } and { y (i) } respectively constitute a pseudo-random code generator G₁、G₂；

(2) An expansion module for expanding the complex state components to form G₀The number of the extended complex state components is greater than or equal to a preset maximum value of the position offset;

(3) a nonlinear function constructing module, configured to construct a nonlinear function that acts on the real part and the imaginary part of the effective complex state component, respectively, and the current state value of the offset position, specifically:

the nonlinear function acting on the current state values of the real part or the imaginary part and the offset position is a group of functions and/or variables with the same power or different powers and containing different parameter values, the nonlinear strength of the functions is taken as a weight, a part of functions are weighted and summed to obtain a first function item of the real part or the imaginary part, and the rest functions are weighted and summed to obtain a second function item of the real part or the imaginary part; taking the nonlinear strength of the variables as a weight, weighting and summing a part of the variables to obtain a first variable term of a real part or an imaginary part, and weighting and summing the rest of the variables to obtain a second variable term of the real part or the imaginary part; performing mixed operation including at least two operations of addition, subtraction, multiplication and division on the first function item, the second function item, the first variable item and the second variable item according to a preset mode, and adding a corresponding real constant item to obtain a polynomial, namely a nonlinear function acting on a real part or imaginary part current position and an offset position current state value;

(4) an initialization module for parameter initialization and initialization of the effective complex state components G and G in G using pseudo-random number sequences or real number sequences consisting of different real numbers₀State values of the medium-spread complex state components; the pseudo random number sequence and the real number sequence need to ensure that the effective complex state component in the G is in a chaotic working state, and if the real number sequence cannot ensure the chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted; if the pseudo-random number does not guarantee that the valid complex state component is inThe chaotic working state needs to adjust the nonlinear strength of functions and/or variables, and the diffusion coefficient and mutual coupling coefficient of nonlinear functions;

(5) the state iteration module is used for respectively acting on the current state values of the real part and the imaginary part of the effective complex state component and the current state value of the offset position by using the constructed multiple groups of nonlinear functions to obtain a real part action value and an imaginary part action value; respectively performing addition, subtraction, multiplication and division or mixed operation comprising at least two operations of addition, subtraction, multiplication and division on the real part action value and the imaginary part action value by using different diffusion coefficients and mutual coupling coefficients as weighting coefficients of the real part action value and the imaginary part action value, and generating a complex pseudo-random number sequence distributed along with time through state iteration;

(6) a judging module for modifying G by using complex pseudo random number sequence or real number sequence obtained by current effective complex state component₀Expanding the state values of the complex state components or utilizing the modified state values to carry out recombination arrangement among the state values; then, reading the next effective complex state component in G, and transferring the next effective complex state component to a state iteration module; when all the effective complex state components in the G complete state iteration, switching to a real pseudo-random number sequence extraction module;

(7) a real pseudo-random number sequence extraction module for respectively extracting from G₁And G₂Extracting a real pseudo-random number sequence distributed along with time by the related component tap, and respectively recording the real pseudo-random number sequence as a real first pseudo-random number and an imaginary first pseudo-random number sequence;

(8) the offset carrier modulation module is used for multiplying the first pseudo random number of the real part and the first pseudo random number of the imaginary part with a first real offset carrier and a second real offset carrier which are orthogonal in phase respectively to obtain a third pseudo random number of the real part and a third pseudo random number of the imaginary part;

(9) the peak removing signal module is used for replacing a peak value with a statistical analysis value of adjacent values before and after the peak value for the peak value of which the absolute value is larger than a second threshold value in the real part third pseudo random number and the imaginary part third pseudo random number to obtain a real part fourth pseudo random number and an imaginary part fourth pseudo random number; the peak removal is used for adjusting the state value of the pseudo random number and changing the code pattern of the subsequent generated ranging code; the second threshold value is set to a value twice the absolute value of the vicinity value before or after the peaked value;

(10) the binarization module is used for comparing real random numbers in the real part fourth pseudo random number and the imaginary part fourth pseudo random number with a second reference value respectively according to a time sequence, and if the real random numbers are larger than the second reference value, the real random numbers take a value of 1; otherwise, the value is 0, and the fourth pseudo random code and the fifth pseudo random code which are binarized can be obtained; the second reference value is respectively a statistic for describing the magnitude of the median value of real pseudo random numbers in the real fourth pseudo random number and the imaginary fourth pseudo random number;

(11) the modulo two sum module is used for performing modulo two sum on the fourth pseudo random code and the fifth pseudo random code to obtain a sixth pseudo random code;

(12) a frequency offset ranging code acquisition module, configured to acquire a ranging code modulated by an offset carrier with good pseudo-randomness, i.e., a first frequency offset ranging code, from the sixth pseudo-random code;

(13) and the tracking acquisition module is used for tracking and acquiring the satellite navigation signal by adopting the first frequency offset ranging code.

9. A time-space chaos vector pseudo-random code generator offset carrier modulation system is used for binary offset carrier modulation, and is characterized by comprising the following components:

(1) construction of vector pseudo-random code generators G, G consisting of a single complex state vector X + Yj, at I_MA + N-dimensional linear space whose components are { x (i) + y (i) j }, called complex state components, { x (i) } and { y (i) } are a series of sequentially arranged state components respectively coupled to each other; i denotes the position number of the complex state component, I1, 2_M+N，I_MN is a positive integer, before or after_MThe complex state component is marked as an extended complex state component, and the position sequence number I belongs to [1, I ]_M]Or I is as [ N +1, N + I ]_M](ii) a The last or first N complex state components are marked as effective complex state components, and the position sequence number I belongs to [ I ∈ ]_M+1,I_M+N]Or i is e [1, N ∈]The effective complex state components { x (i) } and { y (i) } respectively constitute a pseudo-random code generator G₁、G₂；

(2) Expanding deviceA spreading module for spreading the complex state components to form G₀The number of the extended complex state components is greater than or equal to a preset maximum value of the position offset;

(3) a nonlinear function constructing module, configured to construct a nonlinear function that acts on the real part and the imaginary part of the effective complex state component, respectively, and the current state value of the offset position, specifically:

the nonlinear function acting on the current state values of the real part or the imaginary part and the offset position is a group of functions and/or variables with the same power or different powers and containing different parameter values, the nonlinear strength of the functions is taken as a weight, a part of functions are weighted and summed to obtain a first function item of the real part or the imaginary part, and the rest functions are weighted and summed to obtain a second function item of the real part or the imaginary part; taking the nonlinear strength of the variables as a weight, weighting and summing a part of the variables to obtain a first variable term of a real part or an imaginary part, and weighting and summing the rest of the variables to obtain a second variable term of the real part or the imaginary part; performing mixed operation including at least two operations of addition, subtraction, multiplication and division on the first function item, the second function item, the first variable item and the second variable item according to a preset mode, and adding a corresponding real constant item to obtain a polynomial, namely a nonlinear function acting on a real part or imaginary part current position and an offset position current state value;

(4) an initialization module for parameter initialization and initialization of the effective complex state components G and G in G using pseudo-random number sequences or real number sequences consisting of different real numbers₀State values of the medium-spread complex state components; the pseudo random number sequence and the real number sequence need to ensure that the effective complex state component in the G is in a chaotic working state, and if the real number sequence cannot ensure the chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted; if the pseudo random number can not ensure that the effective complex state component is in a chaotic working state, the nonlinear strength of a function and/or a variable, and the diffusion coefficient and the mutual coupling coefficient of a nonlinear function need to be adjusted;

(5) the state iteration module is used for respectively acting on the current state values of the real part and the imaginary part of the effective complex state component and the current state value of the offset position by using the constructed multiple groups of nonlinear functions to obtain a real part action value and an imaginary part action value; respectively performing addition, subtraction, multiplication and division or mixed operation comprising at least two operations of addition, subtraction, multiplication and division on the real part action value and the imaginary part action value by using different diffusion coefficients and mutual coupling coefficients as weighting coefficients of the real part action value and the imaginary part action value, and generating a complex pseudo-random number sequence distributed along with time through state iteration;

(6) a judging module for modifying G by using complex pseudo random number sequence or real number sequence obtained by current effective complex state component₀Expanding the state values of the complex state components or utilizing the modified state values to carry out recombination arrangement among the state values; then, reading the next effective complex state component in G, and transferring the next effective complex state component to a state iteration module; when all the effective complex state components in the G complete state iteration, switching to a real pseudo-random number sequence extraction module;

(7) a real pseudo-random number sequence extraction module for respectively extracting from G₁And G₂Extracting a real pseudo-random number sequence distributed along with time by the related component tap, and respectively recording the real pseudo-random number sequence as a real first pseudo-random number and an imaginary first pseudo-random number sequence;

(8) the peak removing signal module is used for replacing a peak value with a statistical analysis value of adjacent values before and after the peak value for the peak value of which the absolute value is larger than the first threshold value in the real part first pseudo-random number and the imaginary part first pseudo-random number to obtain a real part second pseudo-random number and an imaginary part second pseudo-random number; the peak removal is used for adjusting the state value of the pseudo random number and changing the code pattern of the subsequent generated ranging code; the first threshold value is set to a value twice the absolute value of the vicinity value before or after the peaked value;

(9) the first binarization module is used for comparing real random numbers in the real part second pseudo random number and the imaginary part second pseudo random number with a first reference value respectively according to a time sequence, and if the real random numbers are larger than the first reference value, the real random numbers take a value of 1; otherwise, taking a value of 0 to obtain a first binary pseudo-random code and a second binary pseudo-random code; the first reference value is respectively a statistic for describing the magnitude of the median value of real pseudo random numbers in the real second pseudo random number and the imaginary second pseudo random number;

(10) the first modulo two sum module is used for modulo two sum of the first pseudo random code and the second pseudo random code to obtain a third pseudo random code;

(11) the second binarization module is used for binarizing a third real offset carrier, and specifically comprises: taking the statistical analysis value of the third real offset carrier as a third reference value, wherein the real offset carrier value larger than the third reference value in the third real offset carrier takes a value of 1, and the real offset carrier value not larger than the third reference value takes a value of 0;

(12) the second modulo-two sum module is used for performing modulo-two sum on the third pseudo random code and the binarized third real number offset carrier to obtain a seventh pseudo random code;

(13) a frequency offset ranging code acquisition module for acquiring a ranging code modulated by an offset carrier with good pseudo-random property, namely a second frequency offset ranging code, from the seventh pseudo-random code;

(14) and the tracking acquisition module is used for tracking and acquiring the satellite navigation signal by adopting the second frequency offset ranging code.