75 results about "Synchronization of chaos" patented technology

A method is provided for generating a coherent chaotic sequence spread spectrum communications system. The method includes phase modulating a carrier with information symbols. The method also includes generating a string of discrete time chaotic samples. The method further includes modulating the carrier in a chaotic manner using the string of discrete time chaotic samples. Each of the discrete time chaotic samples has a shorter sample time interval than the duration of the information symbols. The generating step includes selecting a plurality of polynomial equations. The generating step also includes using residue number system (RNS) arithmetic operations to respectively determine solutions for the polynomial equations. The solutions are iteratively computed and expressed as RNS residue values. The generating step further includes determining a series of digits in the weighted number system based on the RNS residue values. The method further includes synchronizing the chaos generated at the receiver with that generated at the transmitter without periodic transfer of state update information.

The invention discloses a method for generating a variable parameter chaotic signal, and a chaotic secure communication system. The method comprises the following steps: firstly, chaotic mapping is used to generate the chaotic signal; then a parameter set of the chaotic mapping is determined in advance, so as to process any pseudorandom signal, and enable the state of the pseudorandom signal and the elements of the parameter set to be in one-to-one correspondence; and a corresponding parameter is chosen to generate the variable parameter chaotic signal by chaotic mapping according to the state of the pseudorandom signal. The system comprises a chaotic signal generating module, an analog-to-digital conversion module, a parameter transformation module, a coding module, a multi-path choice switch, an encryption/decryption module, an encrypted message data cache, a plaintext data cache and a control module. The invention can increase the complexity of the output of the chaotic signal or a chaotic sequence, and effectively resist the analysis of the nonlinear prediction technology based on phase-space reconstruction. The output digital chaotic sequence can be taken as a pseudorandom number sequence or key stream to encrypt data; the output continuous chaotic signals can be used for designing a secret communication system based on chaos synchronization .

The invention belongs to the technical field of optical communication devices and relates to a passive mode-locking fiber laser delay feedback chaotization system based on graphene, comprising a pumping laser (1), a wavelength division multiplexing fiber coupler (2), a first fiber coupler (3), a mode-locking device (9), an erbium-doped fiber (7), a polarization controller (5), an isolator (6), a second fiber coupler (4), a photodetector (10), an A/D conversion circuit (11), a single chip microcomputer (15), an RS 232 interface (16) and an optical delay line (12), wherein the optical delay line (12) receives control signals and carries out delay feedback to enable the whole system to be in a chaotization state, and the mode-locking device (9) is a graphene mode-locking device. The invention can generate a femto-second order optical pulse without an external modulation source, has the advantages of easy synchronization, high output pulse peak power, easy installation and operation and simple structure, and the like and can realize all-fiber integration and create the foundation of realizing chaotization synchronization and secrete communication.

The invention discloses a chaos synchronization encrypting/decrypting method and device using data compression encoding. The device comprises a random number generator, a public key cryptography encipher, a public key cryptography decipher, a dynamical probability counter, an entropy encoder and an entropy decoder. The method comprises the steps of taking the entropy encoder and the dynamical probability counter used for the data compression as a chaotic dynamics system; enabling a compression coding process to form a chaotic cryptology encryption process; combining the public key cryptography encipher with the chaotic dynamics system, wherein after a randomly generated session key is encrypted in an asymmetrical encryption manner by a sender, the session key is sent to a receiver; initializing the respective chaotic dynamics system through the respective session key the sender and the receiver so that the system states of the sender and the receiver are synchronous; carrying out data compression encoding through the initialized system by the sender; and carrying out data uncompressing through a system with consistent state by the receiver. The method and the device provided by the invention support overlong session key and improve the encryption safety; and simultaneously, the encryption speed is not affected by the key length.

The invention provides a high-speed key distribution device based on semiconductor laser chaos synchronization. The high-speed key distribution device based on semiconductor laser chaos synchronization comprises a central control module and a user module; the central control module adjusts the feedback intensity and the polarization state of feedback light; chaotic signals can be output in two linear polarization modes of a driving laser; the user module respectively injects the chaotic signals generated by the driving laser into two response lasers; the two response lasers are each subjectedto polarization adjustable light feedback; the polarization state of the feedback light can be realized through an adjustable polarization controller controlled by two random bit sequences generated by a random bit generator; when the polarization states of the feedback light corresponding to the two response lasers are same, the two lasers can obtain the chaotic signals having better synchronization performance; and, after two chaotic signals output by the two response lasers are respectively sampled and filtered through two analog-digital converts (ADC) and two bit filters, a shared key canbe obtained.

The invention relates to a method for generating a digital chaos code in a chaotic secure communication system. The digital chaotic secure communication system comprises a channel for communication between an information sending terminal A and an information receiving terminal B and a digital chaotic network that is connected with the channel and is used for generating a chaotic digital numerical code; and a chaotic numerical code with a certain length is selected in numerical codes generated by the digital chaotic network and is converted into a chaotic code k1(t) by a code generation function g1 of chaotic coding, wherein the k1 (t) is expressed by the following formula: k1 (t)= g1 (X, p). The complex receiving and sending chaotic networks employ an identical method to carry out calculation so as to obtain a chaotic synchronous digital numerical code. A chaotic code is generated or decoded from the digital chaotic network based on chaotic code generation and a clear chaotic coding or decoding module by using the following method: a code k1 has the length of one bit or multiple bits, a certain amount P of digital construction codes are selected from chaotic numerical codes generated by the chaotic network according to a random or regular way and the k1 is expressed by the following formula: k1=g1 [X,p], wherein the p is less than or equal to the q; and a series of function bi operation is carried out on all original codes generated by the complex networks so as to generate a series of new digital functions.

A double-permanent magnet synchronous motor chaos synchronization control method based on an extended state observer comprises the steps of building a chaos model of a permanent magnet synchronous motor system, defining a synchronization error system, designing a nonlinear extended state observer, and designing an adaptive sliding mode controller. Through coordinate transformation, the chaos model of the permanent magnet synchronous motor system is built, and the synchronization error system is defined. The nonlinear extended state observer is designed to estimate and compensate uncertain items and external disturbance in the system. The adaptive sliding mode controller is designed to ensure that the state error between master and slave systems is stabilized quickly and converges to zero. Finally, synchronous control of the system is realized. The influence of chaos phenomenon and external disturbance in the system is compensated, the chattering problem of the traditional sliding mode control method is improved, the robustness of the system is enhanced, and chaos synchronization control of a double-permanent magnet synchronous motor system is realized.

The invention discloses a nonlinear term-free chaotic signal masking-based signal encryption transmission and restoration method. According to the method, driving chaotic system signals are generated through an improved nonlinear itemize-free chaotic system; the chaotic signals and information to be transmitted are superposed, so that the information can be masked; at a receiving end, the masked information and a key are adopted to construct a response chaotic system, and a kind of responsible variable-gain synchronization laws is constructed so as to realize the state synchronization of a driving system and a response system; and the information is restored from the encrypted information by means of the synchronized state, and therefore, the encryption and decryption restoration of the information can be realized. The information encryption and decryption method provided by the present invention has high security; the variable-gain synchronization method provided by the present invention makes chaotic synchronization have high precision, so that the recovered information has the advantage of small distortion, and therefore, the whole method of the invention has a high engineering application value.

The invention discloses an implementation method of multi-scroll chaotic attractors based on a piecewise function method. By introducing a piecewise function, the fractional-order chaotic system is subjected to translation transformation and parameters are set, and then 2(N+1)- and 2N+1- scroll attractors are generated. The fractional-order translation chaotic system perfects the field of fractional-order chaotic systems composed of three-dimensional one-time autonomous ordinary differentials. If the parameter settings of each subsystem are changed, and the subsystem can be equivalently transformed into other existing classical chaotic system. The system can be applied in the fields of chaotic synchronization, cryptography, circuit electronics, signal transmission, information processing,etc. Compared with the existing systems, the system is characterized in that the fractional order is more complex, so the fractional order has greater confidentiality and anti-interference ability when being used in the field of signal transmission and cryptography.

The invention proposes a method for detecting a weak signal frequency value in the background of strong noise by chaotic synchronization. The method comprises the steps of firstly, constructing a chaotic synchronization signal frequency detection system, and adjusting system relevant parameters and controller parameters to allow the chaotic system run in a chaotic state at both a drive end and a response end synchronously; then, introducing a signal to be measured into the drive end of the chaotic synchronization detection system, and obtaining synchronization errors at both ends; and finally, solving the power spectral density by Fourier transform of the synchronization error data, and determining the frequency value of a weak periodic signal to be measured. According to the invention, the noise immunity and the synchronization of the chaotic system are used to suppress the large amount of noise, and the weak periodic signal to be measured is amplified. The signal-to-noise ratio of the synchronization error data is greatly improved compared with the signal to be measured, and the detection capability of the weak periodic signal frequency value in the background of strong noise is effectively improved.

The invention provides a high-speed random number generating system based on a chaos network. The high-speed random number generating system comprises the digital chaos network, one or more random code registers connected with the digital chaos network, and one or more data interfaces connected with the random code registers. The parallel algorithm technology and the assembly line technology are adopted for the digital chaos network, random codes or pseudo-random codes generated among nodes of the digital chaos network are coupled, the frequency spectrum of the chaos network is broadened, and therefore the number of random codes of each digital variable of the digital chaos network is increased, and low-order random codes are obtained. The random codes of all the variables or a part of the variables of the digital chaos network are taken out and encoded according to a random arraying method to form high-speed random number sequence codes, and the high-speed random number sequence codes are outputted through the random code registers connected with the digital chaos network and through the data interfaces connected with the random code registers. By means of the random number generating system, random codes at the speed of more than Tbits/s can be generated, and the high-speed random number generating system can be used for encryption of high-speed information and used for decryption of information through chaotic synchronization.

A chaotic secret communication system based on a digital chaotic coding algorithm comprises (1) a channel used for enabling an information sending end A to be communicated with an information receiving end B and (2) digital chaotic networks connected with the channel and used for generating chaotic numerical codes. A function g1 is generated through codes of chaotic coding according to the selected chaotic numerical codes with certain lengths from the numerical codes generated in the digital chaotic networks and converted to a chaotic code k1(t), wherein an equation that k1(t)=g1(X, p) is satisfied. The digital chaotic networks are characterized in that (1) the digital chaotic networks are identical in topologic and dynamics structures, driven by common signals and in a chaotic synchronic state, the digital chaotic networks comprise a complex chaotic network which is of a random topologic structure, a regular network, a random network, a small-world network, a freedom scaling network and a module network; (2) the information sending end A is used for complex chaotic networks which generate the chaotic numerical codes and a kinetic equation is decrypted by a differential kinetic equation.

The invention discloses a Lorenz chaotic synchronization method based on intelligent gain feedback adjustment. By using the measurement information of a Lorenz driving chaotic system and a response system, an error system is formed, then a synchronization rule is formed by the intelligent gain feedback adjustment of an error, and finally the synchronization of an uncertain Lorenz driving chaotic system and a response chaotic system is realized. The method comprises the steps of (1) measuring the state information x1, y1 and z1 of the Lorenz driving chaotic system and constructing a driving chaotic system, (2) measuring the state information x2, y2 and z2 of a Lorenz response system and constructing the response chaotic system, (3) constructing a virtual error systems ex, ey and ez and calculating the states e1, e2 and e3 of the error system, and (4) constructing error feedback synchronization control rules u1, u2 and u3, and designing related coefficients. The invention provides the Lorenz chaotic synchronization method based on the intelligent gain feedback adjustment, and the scheme is simple to realize by only using the state error information of a driving response system.

The invention provides a secure communication system based on a silicon photon chaos source. The secure communication system comprises a chaos driving module, a response system, a signal input moduleand a signal receiving module; the chaos driving module generates one main chaos signal and injects into the response system; meanwhile, the response system generates a plurality of subordinated chaossignals by own, and injects different intensities of the main chaos signals into the response system till the plurality of subordinated chaos signals reach chaos synchronization; and the signal inputmodule and the signal receiving module are respectively and electrically connected with the response system. The secure communication system provided by the invention has the following beneficial effects: since the chaos source generated by a silicon photon in a photo crystal microcavity is adopted, the integration of a chaos generation device is implemented; the stability of the chaos source isgood, so the secure communication quality is improved, the miniaturization and the dexterity of the chaos source are implemented, the experimental cost is reduced and the production efficiency is improved; a reliable implementation solution is provided for a high-speed and quick secure communication generation device, and the requirement of modern secure communication is met.

The invention provides a distributed synchronous control method of a multi-motor network system, and belongs to the technical field of synchronous control of the multi-motor network system. Accordingto the invention, the appointed connecting edges are added or removed on the basis of the original connecting network, so that a plurality of appointed nodes have the same adjacent nodes, a symmetrical structure is presented in the whole network, and the nodes are regarded as a group of cluster network nodes, thereby researching the chaotic synchronization of the group of cluster network nodes. According to the method, local synchronization of a plurality of motor nodes in the multi-motor system can be realized, the method is correct and effective, and the coupling strength of the method is smaller than that of global synchronization.

The invention discloses a generalized synchronization method for a controlled Rucklidge system and a Genesio-Tesi system for encryption and decryption. The method comprises the following steps: 1), description of a generalized chaotic synchronization problem; 2), state transformation and feedback of a response system; 3), state transition of a drive system; 4), generalized synchronization. The invention provides the generalized chaotic synchronization method for the controlled Rucklidge system and the Genesio-Tesi system for encryption and decryption. The Genesio-Tesi chaotic system is used asthe drive system, and the single-input controlled Rucklidge system is used as the response system. A state space transition method is used for designing the chaotic synchronization method, thereby achieving generalized synchronization and high control quality.

The invention provides a method for synchronizing laser chaos pulses, which specifically comprises the steps of converting an optical chaos signal P1 and an optical chaos signal P2 generated by a transmitting terminal and a receiving terminal respectively into an electrical signal E1 and an electrical signal E2 and sampling the electrical signal E1 and the electrical signal E2; using a sampling value of the electrical signal E2 to decrease a sampling value of the electrical signal E1 and then multiply by coupling coefficient K to obtain a feedback signal of the transmitting terminal, and feeding the feedback signal back to the transmitting terminal to modulate the working current of a laser device of the transmitting terminal; and repeating the modulating steps till signals of the transmitting terminal and the receiving terminal are synchronized. The method for synchronizing the laser chaos pulses uses a pulse synchronization mode, the quantity of chaos signals transmitted in a channel is much less than the quantity of chaos signals transmitted by means of a common chaos synchronization method, and a chaos system is difficultly recovered through intercepted pulse signals if the signals are intercepted, thereby effectively improving safety of secret communication.

The invention discloses a Lorentz 10+4 chaotic secret communication circuit, comprising a transmitting system circuit and a receiving system circuit, wherein the transmitting system circuit is connected with the receiving system circuit via a channel, the transmitting system circuit comprises a first signal summing circuit A and a first three-order Lorentz 10+4 circuit B, and the receiving system circuit comprises a second signal summing circuit C and a second three-order Lorentz 10+4 circuit D; the first signal summing circuit A is connected with the first three-order Lorentz 10+4 circuit B, and the second signal summing circuit C is connected with the second three-order Lorentz 10+4 circuit D. The Lorentz 10+4 chaotic secret communication circuit and a jumper pin set constitute an experimental controllable Lorentz 10+4 chaotic secret communication circuit. The Lorentz 10+4 chaotic secret communication circuit is simple in structure, and can be used for all chaotic synchronous and asynchronous circuit experiments.

The invention discloses an audio frequency watermark algorithm based on a chaotic system, comprising steps of utilizing a related general chaos synchronization theorem to construct a new chaos synchronization system on the basis of an existing chaotic system, and applying a chaos series generated by the chaos synchronization system into a digital watermark after a series of processing. The audio frequency watermark algorithm disclosed by the invention can better prevent illegal manipulation and copy of the digital product. The algorithm appropriately applies the chaos sequence generated by the chaos synchronization system into the watermark embedding and detection. The audio frequency watermark algorithm not only improves the robustness of the audio frequency, but also accurately positions the embedding position of the watermark information, which improves the synchronization of the watermark information.

The present invention provides an image encryption method based on fractional order chaos synchronization. The method comprises the steps of reading a pixel matrix of digital images, obtaining a chaos sequence after the continuous iteration of a fractional order driving system, processing the chaos sequence to obtain an encrypted element set and further to obtain an encrypted image matrix. According to the present invention, the more complicated dynamics characteristics are obtained, the more parameter information is contained, the synchronization is realized more conveniently and rapidly, the confusion of the encrypted images is guaranteed, at the same time, the dimensionality of a secret key space can be increased, thereby improving the confidentiality resistance.

The invention provides a generalized synchronization method of a controlled Shimizu-Morioka system and a Chen system for secret communication. The method comprises the following steps: 1) generalizedchaotic synchronization problem description; 2) state transformation and feedback of a response system; 3) state conversion of a driving system; and 4) generalized synchronization. According to the generalized chaotic synchronization method of the controlled Shimizu-Morioka system and the Chen system for secret communication provided by the invention, the Chen system is used as the driving system,the single input controlled Shimizu-Morioka system is used as the response system, and a chaotic synchronization algorithm is designed by using the Li derivative method of a vector field in differential geometry to achieve generalized synchronization, and the control quality is relatively high.