9 results about "Chaos communications" patented technology

The invention discloses a frequency modulation differential chaos phase shift keying communication method based on cyclic spectrum analysis and a related device. According to the invention, a block-level processing cyclic shift index and cosine frequency index dual modulation mechanism is introduced into a traditional DCSK framework, cyclic shift operation is carried out on a reference segment, cosine sequence multiplicative weighting is carried out on a frequency modulation emission sequence, and a detectable cyclostationary characteristic is introduced through a controllable cosine normalization frequency parameter, so that the accuracy of the frequency modulation transmission sequence is improved. Additional information bits are mapped to the shift index and the frequency index, so that the spectrum efficiency is remarkably improved; meanwhile, by using codebook coding of index bits, effective load bits are increased, the misjudgment probability is reduced, the communication reliability is effectively improved, and the technical problem that spectrum efficiency and general reliability are difficult to consider at the same time in an existing chaotic communication scheme is solved.

The invention discloses a terahertz secure communication and perception integrated system based on chaotic signals. The terahertz secure communication and perception integrated system comprises a multi-wavelength coherent light source module, a communication signal module, a chaotic perception signal module, a terahertz signal transmitting module, a communication signal receiving module and a perception signal receiving module. Based on a multi-wavelength coherent light source module, a communication signal module and a chaotic sensing signal module, a chaotic signal is generated by using a flexible optical architecture and is coupled with a plaintext optical signal to generate a chaotic communication sensing integrated signal, and chaotic encryption is realized at the same time; on the basis of a terahertz signal transmitting module, a flexible heterodyne beat frequency architecture is combined, so that generation of terahertz chaotic communication sensing integrated signals is realized, and the performance of the sensing integrated signals is effectively improved; the design complexity of the terahertz communication sensing integrated signal and the complexity of the transmitter are effectively reduced, and the safety of the terahertz communication sensing integrated system is effectively improved.

The present application relates to finite time reduced dimension observer design method and chaotic communication system, belong to information security and chaotic communication field. In view of the defects of traditional asymptotic observer slow, time is uncontrollable, sliding mode method exists chattering and message signal pollution output is difficult to construct observer, the present application establishes the chaotic drive system containing message signal embedding, constructs the equivalent system without unknown signal, designs finite time reduced dimension observer based on observer matching condition and strong observable condition. Compared with the traditional asymptotic convergence observer method, the present application can realize the complete synchronization of chaotic system within the user preset time, adopts continuous control law without chattering, and the message signal can be accurately recovered through algebraic formula. The synchronization time of the present application is controllable, the convergence speed is fast, the recovery precision is high, and the robustness is strong, which is suitable for various chaotic secure communication scenes, effectively improves the communication real-time, security and engineering practicability.

This invention provides an OFDM chaotic communication method, apparatus, device, and medium with reference signal multiplexing. The bit stream to be transmitted is divided into b... k Reference bit and b i Index bits, each reference bit triggers a generator group consisting of two heterogeneous chaotic mappings based on its 0 or 1 value, generating b. k A set of chaotic sequences of length β constitutes a reference sequence set R; b i The index bits are divided into G groups. Each group selects one chaotic sequence from R using an index selector as the data carrier sequence. The R and G data carrier sequences are then superimposed using OFDM modulation to form the transmitted signal. At the receiving end, the signal undergoes cyclic prefix removal, serial-to-parallel conversion, and FFT to separate the reference and index data portions. Finally, a deep neural network demodulation model recovers the data. k Reference bits and reconstruct R, then use the reconstructed R to perform cross-correlation detection on the index data to recover b. i Index bits. This allows the reference signal to synchronously complete reference transmission and user information transmission on the same time, frequency, and power resources, eliminating the pure overhead of the reference signal.

The application discloses a chaotic communication and sensing integrated signal processing method and device and a communication system. The scheme provided by the application divides an information bit sequence into a modulation bit sequence, an index bit sequence and a PPM bit sequence, processes an initial signal vector by combining a pulse position modulation technology, optimizes spectral utilization by double control of the modulation bit and the index bit, segments the initial modulation signal according to PPM orders and generates a signal vector, and offsets the signal vector in the time domain by combining a shift matrix. The scheme utilizes the good autocorrelation characteristics and the low cross-correlation characteristics of an LFM signal, and on the basis of the original DCSK-LFM modulation mode, combines pulse position modulation and index modulation, so that the same carrier can carry more information, thereby improving the transmission rate when applied to a JRC system and the overall performance of the communication system.

The application provides an OFDM chaotic communication method and device for reference signal multiplexing, equipment and medium. A to-be-transmitted bit stream is divided into b k reference bits and b i index bits, each reference bit is mapped according to a 0 or 1 value to trigger a generator group composed of two heterogeneous chaotic mappings, to generate b k chaotic sequences with a length of β to form a reference sequence set R; b i index bits are evenly divided into G groups, each group selects one chaotic sequence from R as a data-carrying sequence through an index selector; R and the G data-carrying sequences are superimposed through OFDM modulation to form a transmission signal. The receiving end separates the reference and index data parts through de-cyclic prefix, serial-parallel conversion and FFT, restores b k reference bits through a deep neural network demodulation model, and reconstructs R, and then performs cross-correlation detection on the index data with the reconstructed R to restore b i index bits. Thus, the reference signal synchronously completes reference transmission and user information transmission on the same time-frequency and power resources, and eliminates the pure overhead of the reference signal.

The application provides a kind of dynamic encryption security communication system device and method based on multi-longitudinal mode chaos synchronization, belongs to the technical field of chaos communication carrier and space division multiplexing technical field.The device includes chaos signal generation module, information encryption module, optical fiber transmission module, chaos signal synchronization module, information decryption module.In the chaos signal generation module, broadband noise drives Fabry-Perot laser to generate multiple longitudinal mode chaos signals, and the chaos signals of arbitrary longitudinal mode combination are used to encrypt the user information of different cores of seven-core optical fiber, thereby increasing the system key space.In the information encryption module, the confidential information of different users of seven-core optical fiber is first disturbed in intensity by a dispersion element, and then the chaos signals of different longitudinal mode combinations are used to phase-encrypt the confidential information, thereby realizing two-dimensional encryption of the confidential signal in intensity and phase.Meanwhile, the use of space division multiplexing technology effectively improves the communication capacity of the secure communication system.

The application provides a security-enhanced chaotic communication system and method based on external time-domain self-feedback encryption, and relates to the technical field of chaotic communication carrier. The application utilizes two dispersion components and a phase modulator in the middle of dispersion to form an encryption module, and under the joint action of the encryption module, the encrypted chaotic signal is processed in time domain and phase. At the receiving end, the encrypted information is recovered in time domain and phase by using a symmetric decryption structure. Since the encryption module suppresses the time delay characteristics embedded in the chaotic carrier and the time delay characteristics in the electro-optical self-feedback phase loop, the eavesdropper cannot crack the time delay information by calculating the autocorrelation and mutual information, so the key parameters of the system cannot be intercepted, and since the dispersion value and the phase modulation depth in the encryption module are controllable variables, the key space of the system is further increased, so the security of the system is ensured.

This invention discloses a chaotic communication system and signal detection method based on multi-domain orthogonal code indexing, belonging to the field of wireless communication and intelligent signal processing technology. The system includes a transmitter, a wireless channel, and a receiver. The transmitter first divides the input bitstream to obtain domain index information, code index information, and modulation information; then, it selects the corresponding orthogonal code domain based on the domain index information and the corresponding orthogonal codeword based on the code index information; it generates a chaotic sequence using Chebyshev mapping and constructs an orthogonal chaotic sequence pool using the Gram-Schmidt orthogonalization method; finally, it combines M-ary DCSK modulation and a multi-carrier, multi-slot transmission structure to form the transmitted signal. The receiver demodulates, filters, and samples the received signal, then inputs the time-domain features into a multi-task convolutional neural network for joint detection, realizing the recovery of the domain index, code index, and modulation information. This invention, by introducing a multi-domain orthogonal code indexing and deep learning joint detection mechanism, effectively improves the system's spectral efficiency, error rate performance, and physical layer security performance, making it suitable for wireless secure communication, IoT communication, and data transmission scenarios in complex wireless channel environments.