14 results about "Chaos communications" patented technology

The invention discloses a chaos communication and perception integrated signal processing method and device and a communication system, and the method comprises the steps: segmenting an information bit sequence into a modulation bit sequence, an index bit sequence and a PPM bit sequence, and carrying out the processing of an initial signal vector through the combination of a pulse position modulation technology, according to the scheme, the frequency spectrum utilization rate is optimized through dual control of modulation bits and index bits, initial modulation signals are segmented according to PPM orders, signal vectors are generated, time domain offset is carried out on the signal vectors in combination with a shift matrix, the good self-correlation characteristic and the low cross-correlation characteristic of LFM signals are utilized, on the basis of an original DCSK-LFM modulation mode, the frequency spectrum utilization rate is improved, and the frequency spectrum utilization rate is improved. And in combination with pulse position modulation and index modulation, the same carrier can bear more information, so that the transmission rate when the method is applied to a JRC system and the overall performance of a communication system are improved.

The invention provides an enhanced OFDM-DCSK (Orthogonal Frequency Division Multiplexing-Chaos Shift Keying) chaotic communication method fused with deep reinforcement learning. The method comprises the following steps of: at a transmitting end, performing chaotic encryption on a chaotic sequence and user data to obtain a chaotic reference signal, and modulating the chaotic reference signal to an OFDM (Orthogonal Frequency Division Multiplexing) multi-subcarrier to be transmitted; at a receiving end, the chaos reference signal is demodulated by using the autocorrelation and incoherent demodulation principle of a chaos sequence, and time sequence data feature extraction is performed on the demodulated signal through a basic time sequence convolutional network TCN module; the objective of maximizing long-term rewards is to continuously explore and learn an optimal decision strategy through a DRQN reinforcement learning mechanism by using environment information based on time sequence data features. According to the method, the hierarchical feature extraction module is innovatively adopted to realize multi-scale time-frequency feature capture, the feature interaction capability is enhanced through an attention mechanism, and a deep reinforcement learning framework is utilized to realize model dynamic optimization, so that the system performance is remarkably improved.

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 present invention proposes a chaotic communication method and system based on initial value modulation, which relates to the technical field of signal transmission, including a chaotic transmission signal modulation process based on initial value modulation and a chaotic reception signal demodulation process based on initial value modulation; the chaotic transmission signal modulation process divides the initial information bits to be transmitted into modulation bits and sequence number bits, the modulation bits are carried by the polarity of the chaotic signal, and the sequence number bits are transmitted by using the initial value of the chaotic sequence; the chaotic reception signal demodulation process demodulates the modulation bits and the sequence number bits respectively, merges the estimated information bits obtained by demodulating the modulation bits and the sequence number bits, obtains the estimated information bits of all information bits, uses the initial state of the chaotic sequence to carry information, and can realize parallel transmission of multiple information bits without using multiple subcarriers, and improves the energy efficiency of the system by assisting with chaotic initial value modulation.

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.

This invention belongs to the field of chaotic communication technology, specifically relating to a broadband chaotic entropy source based on mutual injection of modulated semiconductor lasers. It includes a first multimode chaotic laser module, an injection module, a second multimode chaotic laser module, and a photodetector. Its key feature is that: firstly, the chaotic semiconductor laser is directly modulated by optical feedback perturbation, causing the semiconductor laser to output a raw multimode chaotic laser signal. Then, using mutual injection perturbation, each longitudinal mode of the two raw multimode chaotic laser modules with different modulation frequencies undergoes beat frequency interaction. Furthermore, the detuning of the longitudinal mode undergoing beat frequency interaction gradually increases as it moves away from the center wavelength. Under the beat frequency interaction of multiple different detuning spectral modes, the output spectrum generated after photoelectric conversion is sequentially spliced ​​together, thereby achieving a significant increase in the bandwidth of the chaotic entropy source signal spectrum, theoretically reaching hundreds of GHz.

The present invention discloses a non-coherent chaotic communication method and device based on deep learning, which relates to the field of data processing, including: obtaining a chaotic receiving signal to be demodulated and performing power spectrum density estimation, obtaining a PSD sequence and inputting it into a trained chaotic receiving signal demodulation model, receiving the PSD sequence through an input layer, the PSD sequence passes through a first BiLSTM layer, extracting a first time domain feature of the PSD sequence, and then passing through a self-attention layer to obtain a first intermediate feature, the first intermediate feature passes through a first Dropout layer to obtain a second intermediate feature, the second intermediate feature passes through a second BiLSTM layer, extracting a second time domain feature of the PSD sequence, and then passing through a second Dropout layer to obtain a third intermediate feature; the third intermediate feature is input into a fully connected layer and a Softmax layer for feature integration to obtain a probability distribution vector, the probability distribution vector is subjected to maximum likelihood judgment through a classification layer, and estimated binary information bits are obtained. The present invention solves the problem of low spectrum efficiency of existing chaotic communication systems.

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.