CN106291616B

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

Info

Publication number: CN106291616B
Application number: CN201610608250.2A
Authority: CN
Inventors: 何志彪; 肖模艳; 周扬眉
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2016-07-29
Filing date: 2016-07-29
Publication date: 2018-11-23
Anticipated expiration: 2036-07-29
Also published as: CN106291616A

Abstract

The invention discloses a kind of space-time chaos vector pseudo-noise code generator offset carrier modulator approach and systems, the present invention constructs vector pseudo-noise code generator, first, the current state value of component real and imaginary parts current location and deviation post to single plural vector is respectively adopted a variety of different nonlinear functions and acts on, respectively with diffusion coefficient, mutual coupling factor is that weight is added, subtract, multiply, or the hybrid operation removed, the plural pseudo-random number sequence being distributed at any time is generated by state iteration, secondly from state component real and imaginary parts correlated components tap extraction real number pseudo-random number sequence, again with after real number offset carrier modulation binaryzation and mould two and/or binaryzation with binaryzation real number offset carrier mould two and, it exports to obtain the ranging code of required frequency shift (FS) by bandpass filter at combination frequency.It the composite can be widely applied to satellite navigation system, it can also be used to various range-measurement systems, communication system, Broadcast and TV system, control system etc..

Description

Time-space 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 method and a system for modulating offset carrier waves of a space-time chaotic vector pseudo-random code generator.

Background

Currently, the four major Satellite Navigation systems in the world include a Global Positioning System (GPS) Satellite Navigation System in the united states, a Global Navigation Satellite Navigation System (GLONASS) Satellite Navigation System in russia, a Galileo Satellite Navigation System in the european union, and a BeiDou Satellite Navigation System in china. Except that GLONASS adopts a Frequency Division Multiple Access (FDMA) communication mode, other satellite navigation systems all adopt a Code Division Multiple Access (CDMA) communication mode. The distance measuring codes adopted by the satellite navigation system are classified into a civil coarse measuring code and a military precise code, the satellite navigation system using the coarse measuring code can perform coarse target positioning, and the satellite navigation system using the precise code can perform high-precision target positioning.

In order to utilize limited satellite navigation frequency point resources, the GPS, Galileo and BeiDou satellite navigation systems respectively adopt a Binary Offset Carrier (BOC) modulation technology in a square wave form and a development mode thereof, and can well solve the problems of mutual interference between signals, frequency spectrum aliasing and frequency band sharing.

The pseudo-random code generator for satellite navigation system to generate range finding code is divided into two kinds, one is binary pseudo-random code generator used in present satellite navigation system, the range finding code is generated by linear method, one or several certain series linear feedback shift registers are used to initialize registers by a section of short binary sequence, then the registers are shifted. In the aspect of Coarse measurement Code implementation, a C/A (Code Acquisition Code) Code of a GPS L1 signal is generated by two parallel 10-stage (20 stages in total) linear shift registers, and the Code length is 1023 bits; the rough measurement code of the Galileo E1 signal is realized by a truncated and combined M code generated by two parallel linear shift registers, and the code length is 4092 bits; the ranging code of GLONASS is generated by a linear shift register with a maximum length of 9 stages (M sequence), the code length being 511 bits; ranging code C at BeiDou B1I, B2I signal_B1ICode sum C_B2IThe code is generated by two parallel 11-stage (22 stages in total) linear shift registers, and the code length is 2046 bits. The precise cipher implementation aspect only provides an implementation method for GPS, namely two parallel linear shift register generation with 12 stages (24 stages in total) are respectively used. Because a pseudo-random code with a certain length needs a certain number of shift registers to be generated through shifting, the generated ranging code generally has the defects of low complexity, poor safety, fixed and short code length, limited code number and the like, and the shift register also needs to undertake linear feedback and satellite phase allocation work, so that the structure of the ranging code is complex.

The other is a real pseudo-random code generator discussed in the literature, which can provide a plurality of uncorrelated and random-like and determined reproducible signals by a nonlinear method by utilizing the sensitive dependence of a space-time chaotic system on an initial value, wherein the signals have the characteristics of pseudo-randomness, non-periodicity, long-term unpredictability and various histories, a space-time chaotic one-way coupling image lattice model is applied to a GPS system, and a 20-stage space-time chaotic real pseudo-random code generator is designed by a group of 20 space lattice points and replaces two parallel 10-stage linear shift registers of the GPS. Initializing a state value of a lattice point variable by using the same real number, generating a real number pseudo-random number distributed along with a time state under the action of a nonlinear mapping dynamic function (called a nonlinear function for short), acquiring a time state distribution value of the lattice point variable through a related lattice point variable tap, outputting a real number pseudo-random number sequence, and carrying out binarization and modulo two and obtaining a ranging code.

The non-linear function generally takes the form of a univariate polynomial f (x) — δ x²+1, i.e. the negative nonlinear strength multiplied by a low power variable plus an integer constant, δ being the nonlinear strength of the variable; the nonlinear function is composed of variable, variable parameter (including variable power, position number, nonlinear strength as variable weight) and integer constant term, the variable, variable parameter and constant term are called as nonlinear function parameter, and its diffusion coefficient (weight as nonlinear function value) is real number field [0,1]The sum of the diffusion coefficients of the non-linear function action values acting on different lattice point state variables is 1, and the different non-linear function action values can only be added mutually. The real pseudo-random code generator can overcome the defects of fixed and short code length and limited code number of the ranging code generated by the current binary pseudo-random code generator, but a nonlinear function is adopted and generally acts as a quadratic function, and the data precision is 10^-2The generated ranging code has low complexity and low safety, and uses too many space lattice points, and each lattice point state variable only generates one real pseudo-random number once.

In addition, when the BOC signal is demodulated, the BOC modulation destroys the pseudo-randomness of the spread spectrum signal of the navigation message of the navigation satellite, so that the demodulation signal has a fuzzy demodulation problem caused by multiple correlation peaks. The prior binary pseudorandom code generator can not restore the pseudorandom property thereof through parameter adjustment, and the main peak identification is mainly solved through subsequent processing of multi-correlation peaks at present. The main solutions to this problem at present include BPSK _ like method (BPSK), Autocorrelation Side Peak Cancellation method (aspact), and Offset quadrature Cross-Correlation method (OQCC), where the BPSK _ like method equates a BOC modulation signal to the sum of 2 BPSK modulation signals with different carrier frequencies, thereby eliminating ambiguity caused by subcarrier modulation, the aspact method improves the main-to-sub Peak ratio by reducing the sub-Peak of the Autocorrelation function, and reduces ambiguity, and the OQCC method eliminates the sub-Peak by improving the main-to-sub Peak separation degree.

Disclosure of Invention

Aiming at the technical problems, the invention provides a time-space chaos vector pseudo-random code generator offset carrier modulation method and system which can improve the performance of a ranging code, keep the pseudo-randomness of the ranging code and eliminate the problem of the current BOC modulation multi-correlation peak.

In order to solve the technical problems, the invention adopts the following technical scheme:

a time-space chaos vector pseudo-random code generator offset carrier modulation method is used for non-offset carrier modulation, and comprises 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 epsilon [ 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:

respectively recording nonlinear functions of current state values acting on the current position and the offset position of the real part of the effective complex state component as a nonlinear function of the current position of the real part and a nonlinear function of the offset position of the real part, and respectively recording nonlinear functions of current state values acting on the current position and the offset position of the imaginary part of the effective complex state component as a nonlinear function of the current position of the imaginary part and a nonlinear function of the offset position of the imaginary part; wherein:

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

nonlinear function of real part and current position is composed of LL₁₂Function with different parameter values of different powers and LL₁₃The variables with different parameter values of different powers; taking LL as the weight of the nonlinear strength of the negative of each function₁₁Weighted sum of functions to obtain the first function term of real part, and the (LL) of the remainder₁₂-LL₁₁) Weighting and summing the functions to obtain a second function term of a real part; weighted by the negative nonlinear strength of each variable, for LL₁₃Weighting and summing the variables to obtain a first variable term of a real part; multiplying the real part first variable term by the real part second function term, and adding the real part first function term and the first real constant term to obtain a polynomial, namely a real part current position nonlinear function;

the constructed nonlinear function of the current position of the real part is used for acting on the current state value of the current position of the real part of the effective complex state component;

the construction of the real part offset position nonlinear function specifically comprises the following steps:

the real offset nonlinear function consists of LL₂₁The variables with different parameter values of different powers; weighted by the negative nonlinear strength of each variable, for LL₂₁Weighting and summing the variables to obtain a real part second variable term, and adding the real part second variable term and the second real constant term to obtain a polynomial, namely a real part offset position nonlinear function;

the constructed real part offset position nonlinear function is used for acting on the current state value of the real part offset position of the effective complex state component;

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

the imaginary current position non-linear function is composed of LL₃₂Function with different parameter values of different powers and LL₃₃The variables with different parameter values of different powers; taking LL as the weight of the nonlinear strength of the negative of each function₃₁Weighted summation of individual functions to obtain imaginary first function term, for the remainder (LL)₃₂-LL₃₁) Weighting and summing the functions to obtain an imaginary part second function item; weighted by the negative nonlinear strength of each variable, for LL₃₃Weighting and summing the variables to obtain an imaginary part first variable term; dividing the imaginary part first variable term by the imaginary part second function term to obtain a division term, subtracting the division term from the imaginary part first function term, and adding a third real constant term to obtain a polynomial, namely an imaginary part current position nonlinear function;

the constructed non-linear function of the imaginary part current position is used for acting on the current state value of the effective complex state component imaginary part current position;

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

the imaginary offset position non-linear function is composed of LL₄₁The variables with different parameter values of different powers; weighted by the negative nonlinear strength of each variable, for LL₄₁Weighted summation of variables to obtain the second imaginary partA polynomial obtained by adding the second variable term of the imaginary part and the fourth real constant term, namely an imaginary part offset position nonlinear function;

the constructed imaginary part offset position nonlinear function is used for acting on the current state value of the effective complex state component imaginary part offset position;

the parameters of the function comprise working frequency, the power of the function, the amplitude value of the function, the phase position of the function, a position serial number, position offset and state translation amount; the position offset is the amount of increase or decrease of the position serial number, and the state translation amount is the amount of increase or decrease of the state value of the variable; the variable parameters comprise the power of the variable, a position serial number, a position offset and a state translation amount;

LL₁₂、LL₁₃、LL₂₁、LL₃₂、LL₃₃、LL₄₁the integers are all integers which are more than 0, and the values are set according to the needs; LL (LL)₁₁Is not greater than LL₁₂Positive integer of (LL), LL₃₁Is not greater than LL₃₂Positive integer of (LL), LL₁₁And LL₃₁The value is set according to the requirement;

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;

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

the method further comprises the following steps:

the real part state iteration is specifically as follows:

applying a plurality of groups of different real part current position nonlinear functions and imaginary part current position nonlinear functions to the current state values of the real part current position and the imaginary part current position of the effective complex state component respectively to obtain a plurality of groups of real part current position nonlinear function values and imaginary part current position nonlinear function values;

taking the diffusion coefficient as a weight, and carrying out weighted average on the nonlinear function value of the current position of the real part to obtain a first real part action value; carrying out arithmetic mean multiplication on the nonlinear function of the current position of the imaginary part by a mutual coupling coefficient to obtain a first imaginary part action value; adding, subtracting, multiplying or dividing the first real part action value and the first imaginary part action value to obtain a first mixed operation action value;

taking nonlinear function values of part of real parts at the current positions to calculate arithmetic mean to obtain a first mean value; multiplying the nonlinear function values of the current positions of the other real parts by corresponding diffusion coefficients respectively and then multiplying the multiplication result, dividing the multiplication result by the number of the nonlinear function values of the current positions of the other real parts to obtain a second average value, and subtracting the first average value from the second average value to obtain a second average value

Taking part of real part offset position nonlinear function values to calculate arithmetic mean to obtain a third mean value, multiplying the other real part offset position nonlinear function values with corresponding diffusion coefficients respectively and then multiplying the multiplication result, dividing the multiplication result by the number of the other real part offset position nonlinear function values to obtain a fourth mean value, and subtracting the third mean value and the fourth mean value to obtain a third mean valueDividing the first blending action value byObtaining the current position state value of the real part at the next moment;

the imaginary part state iteration specifically includes:

a plurality of groups of different virtual part current position nonlinear functions and real part current position nonlinear functions are adopted to respectively act on the current state values of the virtual part current position and the real part current position of the effective complex state component to obtain virtual part current position nonlinear function values and real part current position nonlinear function values;

taking the diffusion coefficient as a weight, and carrying out weighted average on the nonlinear function value of the current position of the imaginary part to obtain a second imaginary part action value; carrying out arithmetic mean multiplication on the nonlinear function of the current position of the real part by a mutual coupling coefficient to obtain a second real part action value; adding, subtracting, multiplying or dividing the second imaginary part action value and the second real part action value to obtain a second mixed operation action value;

taking part of the imaginary part current position nonlinear function values to calculate arithmetic mean to obtain a fifth average value, multiplying the other imaginary part current position nonlinear function values with the corresponding diffusion coefficients respectively and then multiplying the multiplication result, dividing the multiplication result by the number of the other imaginary part current position nonlinear function values to obtain a sixth average value, and adding the fifth average value and the sixth average value to obtain a sixth average value

Taking part of the imaginary part offset position nonlinear function values to calculate arithmetic mean to obtain a seventh mean value, multiplying all the imaginary part offset position nonlinear function values with corresponding diffusion coefficients respectively and then multiplying the multiplication result, dividing the multiplication result by the number of all the imaginary part offset position nonlinear function values to obtain an eighth mean value, and subtracting the seventh mean value and the eighth mean value to obtain a subtraction resultSecond blending operation function value divided byObtaining 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 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 mean value of adjacent values before and after the peak value of an absolute value larger than a 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;

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; if the pseudo-randomness of the ranging code without frequency offset is damaged, the diffusion coefficient and the mutual coupling coefficient of a nonlinear function, the nonlinear strength of a function and/or a variable, the working frequency and the phase of the function are finely adjusted, and a first reference value is finely adjusted to re-binarize a real part second pseudo-random number and an imaginary part second pseudo-random number;

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

The above tracking and capturing of the satellite navigation signal by using the frequency offset-free ranging code further comprises:

(1) acquiring and binarizing a satellite navigation message, and spreading the satellite navigation message by using a frequency offset-free ranging code to obtain a spread spectrum signal;

(2) modulating the spread spectrum signal by adopting a carrier signal with Doppler frequency offset, adding a Gaussian white noise signal, and outputting a baseband satellite navigation signal;

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

(4) generating a frequency offset-free ranging code and performing cyclic correlation processing based on FFT with the carrier wave removal signal, if a correlation peak exists, demodulating the satellite navigation message according to the position of the correlation peak, and ending; otherwise, repeating the steps S5-S10 to obtain the ranging code without frequency offset again, and then repeating the step.

In one specific embodiment, in the sub-step (2), the doppler frequency shift range of the carrier signal is [ -10kHz,10kHz ]; meanwhile, the signal-to-noise ratio of the added white Gaussian noise signal ranges from 0dB to-20 dB.

The time-space chaos vector pseudo-random code generator offset carrier modulation method is used for real offset carrier modulation and comprises the following steps:

S1-S7, similar to the steps S1-S7 of the first method;

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; here, the offset carrier, that is, the carrier having an operating frequency higher than the operating frequency of the real part first pseudo random number and the imaginary part first pseudo random number, shifts the real part first pseudo random number and the imaginary part first pseudo random number from the current operating frequency to the modulated combined frequency;

s9, replacing a peak value with an average 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 a 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; if the pseudo-randomness of the ranging code of the first frequency offset is damaged, the diffusion coefficient and the mutual coupling coefficient of a nonlinear function, the nonlinear strength of a function and/or a variable, or the working frequency and the phase of the function are finely adjusted, or the working frequency and the phase of a real offset carrier are finely adjusted, or a second reference value is finely adjusted to re-binarize a real fourth pseudo-random number and an imaginary fourth pseudo-random number;

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

The tracking and capturing of the satellite navigation signal by using the first frequency offset ranging code further includes:

(1) acquiring and binarizing a satellite navigation message, and spreading the satellite navigation message by adopting a first frequency offset ranging code to obtain a spread spectrum signal;

(4) generating a first frequency offset ranging code and performing cyclic correlation processing based on FFT with the carrier wave removal signal, if a correlation peak exists, demodulating a satellite navigation message according to the position of the correlation peak, and ending; otherwise, repeating steps S5-S12 to obtain the first frequency offset ranging code again, and then repeating the steps.

Thirdly, a space-time chaos vector pseudo-random code generator offset carrier modulation method is used for binary offset carrier modulation, and comprises the following steps:

S1-S10, similar to the steps S1-S10 of the first method;

s11 binarizes the third real offset carrier, specifically: taking the average value of the third real number offset carrier as a third reference value, wherein the real number offset carrier value larger than the third reference value in the third real number offset carrier takes a value of 1, and the real number 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; if the pseudo-randomness of the ranging code of the second frequency offset is damaged, the diffusion coefficient and the mutual coupling coefficient of the nonlinear function and the nonlinear strength of the function and/or the variable need to be adjusted, or the working frequency and the phase of the function are finely adjusted, or the working frequency and the phase of the third real number offset carrier wave are finely adjusted, or the first reference value is finely adjusted to re-binarize the real part second pseudo-random number and the imaginary part second pseudo-random number, or the third reference value is finely adjusted to re-binarize the third real number offset carrier wave;

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

The tracking and capturing of the satellite navigation signal by using the second frequency offset ranging code further includes:

(1) acquiring and binarizing a satellite navigation message, and spreading the satellite navigation message by adopting a second frequency offset ranging code to obtain a spread spectrum signal;

(4) generating a second frequency offset ranging code and performing cyclic correlation processing based on FFT with the carrier wave removal signal, if a correlation peak exists, demodulating the satellite navigation message according to the position of the correlation peak, and ending; otherwise, repeating steps S5-S13 to obtain the second frequency offset ranging code again, and then repeating the steps.

In step S2, the spread complex state components are used to assist the iteration of the state values of the complex state components of the position offsets in the vector pseudo-random code generator, and the number of the spread complex state components should be greater than or equal to the maximum value of the position offset of the complex state components.

In step S4 of the above three methods, a real number sequence composed of different real numbers initializes the effective complex state components in G and G₀And if the real number sequence cannot ensure the chaotic working state, the diffusion coefficient and the mutual coupling coefficient of the nonlinear function and the nonlinear strength of the function and/or the variable need to be adjusted.

In step S4 of the above three methods, a pseudo-random number sequence is used to initialize the effective 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 diffusion coefficient and the mutual coupling coefficient of the nonlinear function and the nonlinear strength of the function and/or the variable 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.

In step S9 of the first method, the first reference value is obtained by a sorting method, that is: the first reference values of the real part second pseudo random number and the imaginary part second pseudo random number are respectively intermediate values in which real pseudo random numbers are magnitude-ordered.

In step S10 of the second method, the second reference value is obtained by a sorting method, that is: the second reference values of the real part fourth pseudo random number and the imaginary part fourth pseudo random number are respectively intermediate values obtained by sorting the real pseudo random numbers in size.

In the invention, if the obtained frequency offset-free ranging code or the first or second frequency offset ranging code has poor pseudo-randomness, the non-linear strength of a function and/or a variable, the diffusion coefficient and the mutual coupling coefficient of the non-linear function need to be adjusted, or a first reference value is finely adjusted to re-binarize a second pseudo-random number of a real part and a second pseudo-random number of an imaginary part, or a second reference value is finely adjusted to re-binarize a fourth pseudo-random number of the real part and a fourth pseudo-random number of the imaginary part, or the working frequency and the phase of the function are finely adjusted, or the working frequency or the phase of a first real offset carrier and a second real offset carrier are finely adjusted, or a third reference value is finely adjusted, a third real offset carrier is re-binarized, the working frequency or the.

An offset carrier modulation system of a space-time chaos vector pseudo-random code generator is used for non-offset carrier modulation and comprises 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 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 their position serial numbersi∈[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 containing different parameter values with different powers, the negative nonlinear strength of the function is taken as a weight, one part of the functions are weighted and summed to obtain a first function item of the real part or the imaginary part, and the rest of the functions are weighted and summed to obtain a second function item of the real part or the imaginary part; taking the negative 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;

(5) the state iteration module is used for respectively acting the current state values of the real part and the offset position of the effective complex state component by using a plurality of groups of different nonlinear functions of the current position of the real part and nonlinear functions of the offset position of the real part to obtain real part action values; respectively acting the current position of the imaginary part of the effective complex state component and the current state value of the offset position by using a plurality of groups of different nonlinear functions of the current position of the imaginary part and the nonlinear function of the offset position of the imaginary part to obtain an acting value of the imaginary part; based on the diffusion coefficient and the mutual coupling coefficient, respectively performing addition, subtraction, multiplication and division on the real part action value and the imaginary part action value or mixed operation comprising at least two operations of addition, subtraction, multiplication and division, 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 an average 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.

Fifthly, the offset carrier modulation system of the space-time chaos vector pseudo-random code generator is used for real offset carrier modulation and comprises the following components:

(1) the vector pseudo-random code generator constructing module is the same as the vector pseudo-random code generator constructing module in the fourth system;

(2) the expansion module is the same as the expansion module in the system IV;

(3) the nonlinear function constructing module is the same as the nonlinear function constructing module in the system IV;

(4) the initialization module is the same as the initialization module in the system IV;

(5) the state iteration module is the same as the state iteration module in the system IV;

(6) the judging module is the same as the judging module in the system IV;

(7) a real pseudo-random number sequence extraction module which is the same as the real pseudo-random number sequence extraction module in the system IV;

(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; here, the offset carrier, that is, the carrier having an operating frequency higher than the operating frequency of the real part first pseudo random number and the imaginary part first pseudo random number, shifts the real part first pseudo random number and the imaginary part first pseudo random number from the current operating frequency to the modulated combined frequency;

(9) the peak removing signal module is used for replacing a peak value with an average 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.

Sixthly, a space-time chaos vector pseudo-random code generator offset carrier modulation system is used for binary offset carrier modulation, and comprises the following components:

(2) the expansion module is the same as the expansion module in the system IV;

(6) the judging module is the same as the judging module in the system IV;

(8) a peak signal removing module, which is the same as the peak signal removing module in the system IV;

(9) the first binarization module is the same as the fourth binarization module of the system;

(10) the first die two sum module is the same as the die two sum module in the system four;

(11) the second binarization module is used for binarizing a third real offset carrier, and specifically comprises: taking the average value of the third real number offset carrier as a third reference value, wherein the real number offset carrier value larger than the third reference value in the third real number offset carrier takes a value of 1, and the real number 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. .

The invention can overcome all technical defects of the ranging codes generated by the current binary pseudo-random code generator and the real pseudo-random code generator, greatly improves the performance of the ranging codes of the satellite navigation system, and simultaneously thoroughly solves the problem of multi-correlation peaks in the current binary offset carrier modulation technology.

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

(1) can obtain pseudo-random code with high complexity

The pseudo-random code is generated in an iterative mode through mutual coupling hybrid operation by using the combined action of a plurality of different nonlinear functions, and the complexity of the obtained pseudo-random code is high.

(2) Pseudo random code with strong safety can be obtained

Pseudo-random codes with high complexity can be generated, so that the high safety of the pseudo-random codes is fully ensured.

(3) Pseudo-random code length not limited by number of stages

The maximum code length of the generated random code distributed along with time is irrelevant to the use number of the pseudo-random code generator and can reach infinite length.

(4) Few number of stages

By means of complex number implementation, the pseudo random code generator number can be reduced to the maximum.

(5) Generating pseudo-random code pattern

The pseudo-random code type is determined by the parameter precision of the real number of the initialized complex state component state value, the parameters contained in the nonlinear function such as diffusion coefficient, nonlinear strength, mutual coupling coefficient and the like, and the parameter precision of the receiving end is at least 10^-5The pseudo-random code pattern that can be generated by the present invention is at least 10⁵And multiplied by L, wherein L is the code length.

(6) Can adjust the pseudo-random code characteristic at any time

When the pseudo-random code is damaged, the pseudo-random code can be recovered by adjusting the working frequency, the phase and the like of the nonlinear strength, the diffusion coefficient, the mutual coupling coefficient, the fine-tuning real number offset carrier or the binaryzation real number offset carrier.

(7) Generating ranging codes with offset carrier modulation

The ranging code and the offset carrier modulation signal are fused, the pseudo-randomness of the ranging code is kept, and the problem of multi-correlation peak caused by correlation demodulation is thoroughly solved.

Drawings

FIG. 1 is a schematic flow diagram of a process of the present invention;

FIG. 2 is a schematic flow chart of an implementation of tracking acquisition of a ranging code in an embodiment;

FIG. 3 shows example G₁2, pseudo-random number sequence obtained by mutual coupling hybrid operation is adopted for the state component;

FIG. 4 is a pseudo-random number sequence obtained after de-peaking the pseudo-random number sequence shown in FIG. 3;

FIG. 5 is a pseudo-random number sequence obtained after deglitching the pseudo-random number sequence of FIG. 3 using real offset carrier modulation;

FIG. 6 is a pseudo-random code obtained by applying a sorting process to the pseudo-random number sequence of FIG. 4;

FIG. 7 is a pseudo-random code obtained by applying a sorting process to the pseudo-random number sequence of FIG. 5;

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

fig. 9 is a real offset carrier modulated ranging code obtained in the embodiment;

FIG. 10 is a binarized real offset carrier modulated ranging code obtained in the example;

FIG. 11 is an autocorrelation function of the ranging code of FIG. 8;

FIG. 12 is an autocorrelation function of the ranging code of FIG. 9;

FIG. 13 is an autocorrelation function of the ranging code of FIG. 10;

FIG. 14 is a graph of the tracking acquisition characteristics of the ranging code of FIG. 8 at a signal-to-noise ratio of-10 dB, a code offset of 100 bytes, and a Doppler frequency offset of 20 Hz;

FIG. 15 is a graph of the tracking acquisition characteristics of the ranging code of FIG. 9 at a signal-to-noise ratio of-10 dB, a code offset of 100 bytes, and a Doppler frequency offset of 20 Hz;

FIG. 16 is a graph of the ranging code tracking acquisition characteristics of FIG. 10 at a signal-to-noise ratio of-10 dB, a code offset of 100 bytes, and a Doppler frequency offset of 20 Hz;

fig. 17 is a schematic diagram of the system of the present invention.

Detailed Description

The invention is described in further detail below in connection with an embodiment of forward spreading complex state components, the implementation steps according to fig. 1 being as follows:

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, and the value of N is taken as required; front I_MThe complex state component is marked as an extended complex state component, and the position sequence number I belongs to [1, I ]_M](ii) a The last 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]The effective complex state components { x (i) } and { y (i) } respectively constitute a pseudo-random code generator G₁、G₂。

S2 forward-spreading the complex state component to form G₀Expanding plural state divisionsThe number is greater than a preset maximum value of positional offset.

Get ratioLarge number I_MI.e. extending the number of complex state components, i.e. for ensuring subsequent computational efficiency_MThe value is not too large, and is generally not more than 10 positive integers.

S3: constructing nonlinear functions and state iterative formulas which act on the real part and the imaginary part of the effective complex state component;

(3-1) construction of a nonlinear function:

in formulae (1) to (2):

k represents a discrete time coordinate;

i denotes the position number of the effective complex state component, I ═ I_M+1,I_M+2,...I_M+N；

x_k(i)、y_k(i) Respectively representing the current position state values of the real part and the imaginary part of the effective complex state component with the position serial number i at the moment k; hereafter, the effective complex state component with the position serial number i is abbreviated as an effective complex state component i;

respectively representing non-linear functions acting on the real part current position, the real part offset position, the imaginary part current position, the imaginary part offset position of the effective complex state component i,respectively comprising a sin function and a cos function, the phases being phi_kAnd Φ'_k，The operating frequency of the respectively included function being m₁f₀，f₀At the fundamental operating frequency, m₁Is a positive integer of 2-10;

l₁、l₂、l₃、l₄respectively representing non-linear functionsThe serial number of (a), i.e.,indicating the current position of the real part acting on the effective complex state component i₁A non-linear function of the number of the first and second,indicating the location of the offset acting on the real part of the effective complex state component i₂A non-linear function of the number of the first and second,indicating the current position of the imaginary part acting on the effective complex state component i₃A non-linear function of the number of the first and second,indicating the location of imaginary offsets applied to the effective complex state component i₄A non-linear function;

ll₁₁、ll₁₂respectively representing non-linear functionsThe sequence numbers of the functions and variables contained therein; ll is₂Representing a non-linear functionThe number of the variable contained in (1); ll is₃₁、ll₃₂Respectively representing non-linear functionsThe sequence numbers of the functions and variables contained therein; ll is₄Representing a non-linear functionThe number of the variable contained in (1);

as a non-linear functionMiddle ll₁₁A function of power ofAs a non-linear functionMiddle ll₃₁A function of power of

LL₁₂、LL₁₃Respectively representing non-linear functionsMiddle functionAnd variable x_k(i) The number of (2); LL (LL)₂₁Representing a non-linear functionMiddle variable x_k(i) The number of (2); LL (LL)₃₂、LL₃₃Respectively representing non-linear functionsMiddle functionAnd variable y_k(i) The number of (2); LL (LL)₄₁Representing a non-linear functionMiddle variable y_k(i) The number of (2);

LL₁₂、LL₁₃、LL₂₁、LL₃₂、LL₃₃、LL₄₁the integers are all integers which are more than 0, and the values are set according to the needs; LL (LL)₁₁Is not greater than LL₁₂Positive integer of (LL), LL₃₁Is not greater than LL₃₂The value of the positive integer of (2) is set according to the requirement;

respectively representing non-linear functions at time kMiddle ll₁₁A functionAnd ll₁₂A variable quantityThe non-linear intensity of (d);

representing a non-linear function at time kMiddle ll₂A variable quantityThe non-linear intensity of (d);

respectively representing non-linear functions at time kMiddle ll₃₁A functionAnd ll₃₂A variable quantityThe non-linear intensity of (d);

as a non-linear function of time kMiddle ll₄A variable quantityThe non-linear intensity of (d);

as a non-linear functionMiddle ll₁₂A variable x_k(i) To the power of (a);as a non-linear functionMiddle ll₂A variable x_k(i) To the power of (a);as a non-linear functionMiddle ll₃₂A variable y_k(i) To the power of (a);as a non-linear functionMiddle ll₄A variable y_k(i) To the power of (a);

are respectively a non-linear functionThe value of the included real constant is set according to the requirement.

The nonlinear intensities are real numbers, the power numbers are positive integers larger than 1, and the values are set according to needs;

(3-2) iterative equation of State

The code length generated by a vector complex pseudo-random code generator G is set to be L, a plurality of groups of nonlinear functions containing different parameter values are used for acting on the current state values of the real part and the imaginary part of the effective complex state component and the current position of the offset position, and the complex state component generates a complex pseudo-random number distributed along with time by using a diffusion coefficient and a mutual coupling coefficient as weights through a mixed operation mode of at least one operation of addition, subtraction, multiplication and division.

Real part x of (k +1) time effective complex state component i obtained by means of hybrid operation_k+1(i) And imaginary part y_k+1(i) The state iteration formula of the state value of (1) is as follows:

wherein:

representing the real part of the complex state component i at time kA state value of each offset position;

representing the imaginary part of the complex state component i at time kA state value of each offset position;

L₁₂、L₂₂、L₃₂、L₄₂respectively representing non-linear functionsNumber of (2), L₁₂、L₂₂、L₃₂、L₄₂The integers are all integers which are more than 0, and the values are set according to the needs;

L₁₁、L₂₁、L₃₁、L₄₁are respectively not more than L₁₂、L₂₂、L₃₂、L₄₂The value of the positive integer of (2) is set according to the requirement;

andrespectively representing non-linear functions at time kAndthe included position offset amount;

respectively representing non-linear functionsAndthe amount of state translation involved;

are respectively a nonlinear function at the time of kAndthe amount of state translation involved;

respectively representing non-linear functions at time kThe action value of (c);

are respectively a non-linear functionThe diffusion coefficient at the time k is a real number;

γ_kand gamma'_kNon-linear functions applied to the current positions of the real and imaginary parts of the complex state component i at time k, respectivelyAndthe mutual coupling coefficient of the mean value of the action values is a real number.

S4: initializing the state values of the parameters and the complex state variables;

(4-1) parameter initialization

The parameters include the number of significant complex state components N (i.e., the number of stages), the code length L, the number of nonlinear functions, the nonlinear function parameters, the diffusion coefficient, and the mutual coupling coefficient. The nonlinear function is in a polynomial form containing functions and/or variables of different powers, the parameters further comprise functions and/or variables, and parameters of the functions and/or variables and real constant terms, wherein the parameters of the functions are working frequency, the powers of the functions, amplitude values of the functions, phases of the functions, position serial numbers, position offset and state translation quantity, and the parameters of the variables are the powers of the variables, the position serial numbers, the position offset and the state translation quantity.

In the invention, the function powers are all positive integers larger than 1, and the method has no upper limit requirement; the diffusion coefficients of each nonlinear function are real numbers. Non-linear functionRespectively comprising a sin function and a cos function, the phases being phi_kAnd Φ'_k，The operating frequency of the respectively included function being m₁f₀，f₀At the fundamental operating frequency, m₁Is a positive integer; non-linear functionRespectively contain a variable; non-linear functionNon-linear functions acting on the current position of the real and imaginary parts of the complex state component, respectivelyWhich are non-linear functions applied to the real and imaginary offset positions of the complex state components, respectively.

In this embodiment, the number of valid complex state components N is 3, the code length L is 511 bits, and the number of complex state components I is forward-extended_M5. Number L of non-linear functions acting on the current position of the real and imaginary parts of the effective complex state component, respectively₁₁＝1、L₁₂＝3、L₃₁＝1、L₃₂3; number L of non-linear functions acting on the real and imaginary forward offset positions of the effective complex state component, respectively₂₂＝L₄₂2. The highest powers of all nonlinear functions acting on the current position of the real part of the effective complex state component are respectively powers of 2, 4 and 6, and the highest powers of all nonlinear functions acting on the current position of the imaginary part of the effective complex state component are respectively powers of 3, 5 and 7; the highest powers of the nonlinear functions acting on the forward offset positions of the real parts of the effective complex state components are powers of 2 and 3 respectively, and the highest powers of the nonlinear functions acting on the forward offset positions of the imaginary parts of the effective complex state components are powers of 2 and 3 respectively.

The diffusion coefficients corresponding to the nonlinear functions applied to the real part and imaginary part current positions of the effective complex state component are respectively Wherein,respectively representing the 1 st, 2 nd and 3 rd nonlinear functions at the time 1The diffusion coefficient of (a) is,1 st, 2 nd and 3 rd nonlinear functions at the time 1The diffusion coefficient of (c).

The diffusion coefficients corresponding to the nonlinear functions applied to the forward offset positions of the real part and the imaginary part of the effective complex state component are respectivelyWherein,1 st and 2 nd nonlinear functions at time 1The diffusion coefficient of (a) is,1 st and 2 nd nonlinear functions at time 1The diffusion coefficient of (c).

Non-linear function acting on current position of real part of effective complex state componentHighest power function preceding LL respectively₁₁In each function, the corresponding nonlinear intensity isThe rest LL₁₁-1 function corresponds to a non-linear intensity of 0; LL (LL)₁₂-LL₁₁The nonlinear intensity corresponding to each function is set automatically; LL (LL)₁₃The nonlinear intensity corresponding to each variable is 0; the nonlinear strength corresponding to the highest power variable of the forward offset position is respectivelyThe rest LL₂₁-1 variable corresponds to a non-linear intensity of 0; non-linear function acting on current position of imaginary part of effective complex state componentHighest power function preceding LL respectively₃₁In each function, the corresponding nonlinear intensity isThe rest LL₃₁-1 function corresponds to a non-linear intensity of 0; LL (LL)₃₂-LL₃₁The nonlinear intensity corresponding to each function is set automatically; LL (LL)₃₃The nonlinear intensity corresponding to each variable is 0; the nonlinear strength corresponding to the highest power variable of the forward offset position is respectively The rest LL₄₁-1 variable corresponds to a non-linear intensity of 0; wherein,1 st, 2 nd and 3 rd nonlinear functions at the time 1Highest orderThe non-linear intensity corresponding to the square function,1 st and 2 nd nonlinear functions at time 1The non-linear intensity corresponding to the highest power variable, 1 st, 2 nd and 3 rd nonlinear functions at the time 1The non-linear intensity corresponding to the highest power function, 1 st and 2 nd nonlinear functions at time 1The highest power variable corresponds to the non-linear intensity.

The mutual coupling coefficients are respectively gamma₁＝8.80001、γ'₁8.60001, wherein γ₁、γ'₁And the mutual coupling coefficients are respectively the mean value of the 1 st, 2 nd and 3 th nonlinear function action values of the imaginary part of the complex state component at the current position and the mean value of the 1 st, 2 nd and 3 th nonlinear function action values of the real part at the current position at the moment of 1.

1 st, 2 nd and 3 rd nonlinear functions f of real part of effective complex state component at current position_l1Comprising real constants ofAndthe contained state translation amounts are 1.50005 respectively; 1 st, 2 nd and 3 rd nonlinear functions of the current position of the imaginary part of the effective complex state componentComprising real constants ofThe included state translation amounts are 2.50005; forward offset position 1 st and 2 nd nonlinear functions of real part of effective complex state componentComprising real constants ofAndthe contained state translation amounts are 1.50005 respectively; forward offset position 1,2 non-linear functions of imaginary part of effective complex state componentComprising real constants ofAndthe state translations are all 2.50005.

The forward position offsets are respectivelyRespectively representing the 1 st and 2 nd nonlinear functions at time 1The corresponding forward position offset is set to be,respectively representing the 1 st and 2 nd nonlinear functions at time 1A corresponding forward position offset; time 1 is the initial time.

f₀＝1.023Hz，m₁＝2，n_Φ16, single value interval is [0, pi/2]，f₀Providing a basic operating frequency, n, for the generated ranging code_ΦFor applying to non-linear functionsThe sin function and the cos function which are respectively contained carry out initial phase angle averaging in the phase of a single-value interval, and the amplitude values of all the functions are numerical values 1.

In the invention, the setting of the diffusion coefficient, the mutual coupling coefficient and the nonlinear strength of the function and/or the variable of each nonlinear function ensures that the system is in a chaotic working state, the series is set as the minimum series, and the nonlinear function corresponding to the current positionThe phase value of (a) is the product of the position number of the effective complex state component and the angle average of the single-valued interval, i.e. the interval in which the average and the function value are in one-to-one correspondence, and the total phase division number is n_Φ。

(4-2) initialization of Complex State component State values

The initialization can be performed by using a pseudo-random number sequence or a real number sequence composed of different real numbers, and the effective complex state component is ensured to work in a chaotic state. If the state values of the complex state components are initialized using pseudo-random number sequences, the pseudo-random number sequences can be obtained by using linear shift registers via correlation register taps.

A specific implementation of initializing the complex state components using a sequence of real numbers consisting of different real numbers will be provided below.

Multiplying the position serial number of the real part of the complex state component by 0.1, and then adding the product of the time and 0.00001 to form a real part value; the imaginary position index of the complex state component is multiplied by 0.2 and then added to the product of the time and 0.00001 to form the imaginary value. The real and imaginary values constitute the complex state component initialization values.

S5: respectively carrying out state iteration on each effective complex state component in the complex pseudo-random code generator G according to a formula (3) to generate a 530-bit complex pseudo-random number sequence distributed along with time;

the state iteration of the invention is realized based on the weight function of the nonlinear function, and the weight function of the nonlinear function is shown in a mutual coupling mixed operation mode shown in a formula (3).

S6: for G₀Multiplying the position serial number of each spreading complex state component by 0.001, and adding the multiplied position serial number and 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 spreading complex state component; multiplying the position sequence number by 0.003, and adding the imaginary part of the 530-bit complex pseudo-random number sequence obtained in S5 to obtain the imaginary part state value of the extended complex state component, thereby realizing G₀Modifying the state value of the middle-extension complex state component; then, the next valid complex state component in G is read, and step S5 is executed. When the state iteration is completed for all valid complex state components in G, step S7 is performed.

S7: delayed by 5 seconds to avoid the initial non-chaotic oscillating signal, from G₁The 2 nd and 3 rd state components extract the real first pseudo random number of a set of time state distributions of length 511 seconds, see FIG. 3, from G₂Extracting imaginary part first pseudo random numbers with 511 second time state distribution length for the 1 st and 3 rd state components, and if real offset carrier modulation is adopted, executing step S8; otherwise, step S9 is executed.

S8: respectively connecting the real part first pseudo random number and the imaginary part first pseudo random number with the frequencyIs m₂f₀Multiplying the first offset carrier wave of the sine function by the second offset carrier wave of the cosine function to perform offset carrier modulation, and obtaining a third pseudo-random number of a real part and a third pseudo-random number of an imaginary part; in this example, m₂＝5，m₂＞2m₁。

S9: and replacing a peak value of the absolute value of the real part first pseudo-random number and the imaginary part first pseudo-random number, which is larger than the absolute value of the first threshold value, with an average value of adjacent values before and after the peak value, so that a 'peak' signal in the modulation signal can be removed, and a real part second pseudo-random number and an imaginary part second pseudo-random number are obtained.

And replacing a peak value of the absolute value of the real part third pseudo-random number and the imaginary part third pseudo-random number, which is larger than the absolute value of the second threshold value, with the average value of adjacent values before and after the peak value, so that a 'peak' signal in the modulation signal can be removed, and a real part fourth pseudo-random number and an imaginary part fourth pseudo-random number can be obtained.

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

S10: comparing real random numbers in the real second or fourth pseudo random number and the imaginary second or fourth pseudo random number with a middle value obtained by a sorting method, namely a first or second reference value respectively according to a time sequence, and if the real random numbers are larger than the first or second reference value, taking a value of 1; otherwise, a value of 0 is taken, and a first pseudo random code, a second pseudo random code, a fourth pseudo random code or a fifth pseudo random code which are binarized can be obtained, as shown in fig. 6-7.

S11: the first and second or fourth and fifth pseudo-random codes are modulo-two summed to form a third (see fig. 8) or sixth pseudo-random code having a code length of 511 bits.

S12: if the binary real number offset carrier modulation is adopted, executing the step S13; otherwise, step S15 is executed.

S13: taking the average value of the offset carrier of the third real number as the thirdThe reference value pair has a frequency m formed by a group of odd cosine functions₂f₀And carrying out binarization on the third offset carrier wave, wherein a real offset carrier wave value larger than a third reference value is 1, and a real offset carrier wave value not larger than the third reference value is 0.

S14: and performing modulo two summation on the third pseudo random code and the binarized third offset carrier to obtain a seventh pseudo random code.

S15: the offset carrier modulated ranging code, i.e. the ranging code of the first or second frequency offset, is obtained from the sixth or seventh pseudo random code, see fig. 9-10.

The pseudo-randomness evaluation of the ranging codes is shown in tables 1-6 and FIGS. 11-13. The pseudo-randomness can be evaluated by using the balance, run length and autocorrelation. The balance is the percentage of the total number of values 0 and 1 in the ranging code, and ideally 0 and 1 account for 50% of the total number, respectively. The run length is the percentage of the runs of different lengths in the ranging code to the total run length, and ideally, the percentage of each length run length to the total run length isWhere a denotes a run length. The autocorrelation is the delta function characteristic of the ranging code autocorrelation function.

S16: and generating a binary satellite navigation message.

S17: spreading the satellite navigation message by a ranging code without frequency offset and the first or second frequency offset to obtain a spread spectrum signal;

s18: modulating a spread spectrum signal by a complex exponential carrier signal with the frequency of 60 multiplied by 1.023Hz and the Doppler frequency offset of 20 Hz;

s19: adding a-10 dB Gaussian white noise signal in the modulation signal;

s20: outputting a baseband satellite navigation signal;

s21: receiving a baseband satellite navigation signal, and intercepting a 511-bit long signal by a 100-byte code offset;

s22: generating a complex exponential local carrier signal having a frequency of 60 x 1.023 Hz;

s23: removing carriers of the intercepted signals by using a local carrier signal by using a matching method to obtain carrier-removed signals;

s24: generating a ranging code without a frequency offset and a first or second frequency offset for the navigation satellite according to the steps S5-S15;

s25: performing FFT-based cyclic correlation processing on the ranging code without the frequency offset and the first or second frequency offset and the de-carrier signal;

s26: if the correlation peak exists (see figures 14-16), demodulating the satellite navigation message from the received signal according to the position of the correlation peak, and ending; otherwise, the process returns to step S24.

TABLE 1 Balancing of ranging codes as shown in FIG. 8

Numerical value	Percentage of the total (%)
		0	53.03
1	46.97

Table 2 runlength of ranging code shown in fig. 8

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

Table 3 balance of ranging codes as shown in fig. 9

Numerical value	Percentage of the total (%)
		0	48.92
1	51.08

Table 4 runlength of ranging code shown in fig. 9

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

TABLE 5 Balancing of the ranging codes shown in FIG. 10

Numerical value	Percentage of the total (%)
		0	45.40
1	54.60

Table 6 fig. 10 shows the runlength of ranging codes

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

Claims

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；

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;

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;

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;

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:

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;

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;

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;

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;

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；

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;

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;

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;

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:

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;

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；

(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:

(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;

(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;

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；

(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;

(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;

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;

(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;

(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;

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