16 results about "Frequency-hopping spread spectrum" patented technology

The invention relates to the technical field of communication, in particular to a satellite communication anti-interference transmission method based on a frequency hopping and spread spectrum fusion algorithm. According to the method, interference power is collected at multiple nodes, multiple sub-carrier frequencies and multiple moments to construct an interference observation tensor, interference features are extracted through low-rank tensor decomposition, and interference of each sub-carrier frequency in a future frequency hopping time slot is predicted; calculating a signal to interference plus noise ratio and capacity according to predicted interference in combination with transmitting power and noise, constructing a utility function containing a service weight and a balance coefficient, and distributing working sub-carrier frequency to each satellite communication node under concurrency constraint to generate a frequency hopping sequence; a transmitting end performs channel coding, modulation and spectrum spreading on service data and transmits the service data according to a frequency hopping sequence, and a receiving end completes synchronization, de-spreading and decoding and performs weighting processing by utilizing predicted interference. The method improves the spectrum utilization rate and the interference suppression capability, and enhances the satellite communication reliability.

The invention discloses an anti-electromagnetic interference type unmanned aerial vehicle defense matrix, which relates to the field of electromagnetism, and comprises a multi-node defense unit array which is distributed to form a three-dimensional defense network; each node defense unit is coated with the electromagnetic shielding layer, and the electromagnetic shielding layer is made of a conductive composite material; the anti-interference communication module adopts a frequency hopping spread spectrum technology and an encrypted channel; the main control system is used for dynamically distributing defense resources and monitoring electromagnetic interference intensity in real time; and the energy module provides redundant power supply for each unit. Multilayer electromagnetic shielding effectiveness is achieved, the full-band electromagnetic shielding effectiveness is larger than or equal to 50 dB through the composite structure of the metal nanofiber layer and the ferrite wave-absorbing material, the protection capacity is improved by 150% compared with that of a traditional aluminum alloy shell, and it is ensured that the system stably operates in the strong electromagnetic interference environment.

The application relates to the technical field of intercom communication, and discloses a multi-scene adaptive intercom communication method and system based on a radio Mesh, wherein the method comprises the following steps: identifying the scene type code of a current intercom node, and broadcasting a node discovery frame to surrounding intercom nodes; calculating the comprehensive score of a neighbor link quality according to the node discovery frame, and determining a link mode flag word together with the reference signal receiving power detected by a cellular network module; carrying out noise reduction on a first voice signal collected by a microphone according to the scene type code, obtaining a second voice signal, carrying out encryption, generating an encrypted audio frame, and transmitting the encrypted audio frame through a radio Mesh frequency hopping spread spectrum channel or a cellular network channel pointed by the link mode flag word; and the application solves the problem that the existing Bluetooth chain topology single node disconnection leads to full link fracture, and realizes adaptive call quality guarantee in multiple types of differentiated noise scenes such as motorcycle riding, extremely cold skiing, surfing and referee law enforcement.

The application discloses a LoRa device identification system and method based on clock fingerprint characteristics, and belongs to the technical field of device identification. A time synchronization module utilizes frequency hopping spread spectrum in the LoRa device to change the time stamp when the channel interruption record sends the preamble and header of a data packet, writes the time stamp into a radio frequency FIFO to be sent together with the message, and records the time stamp when the receiving party receives the completed message, calculates the compensation time through the transmission parameters and the data packet size, and obtains a time stamp pair reflecting the clock crystal relationship of the device; a feature extraction module fits the clock relationship between the devices through the least square method, obtains the clock offset reflecting the clock crystal characteristics of the device as the device fingerprint; a fingerprint identification module maintains a fingerprint library of the legal devices, performs fingerprint matching of the devices through the nearest neighbor algorithm and a set threshold, and realizes identification of the devices. The application has the advantages of being not easy to be attacked, high safety, and low cost.

The invention discloses a converter station GIS indoor unmanned aerial vehicle inspection system and a working method thereof. The system is composed of an unmanned aerial vehicle body subsystem, a positioning navigation subsystem, a multi-dimensional detection subsystem, an anti-interference communication subsystem, a ground control subsystem and an energy management subsystem, aiming at the characteristics that a GIS indoor space is closed, equipment is dense and an electromagnetic environment is complex, the system adopts a multi-source fusion positioning technology to ensure accurate navigation, and a special detection module is integrated to realize infrared temperature measurement and visual identification, so that the system is high in reliability. Reliable communication is guaranteed through frequency hopping and spread spectrum and a relay network, full-automatic inspection and charging capacity is achieved, and the working method comprises the whole process of environment modeling, autonomous flight, cooperative detection, exception handling and data summarization. According to the method, the defects of manual and existing automatic inspection modes are overcome, efficient, safe, comprehensive and accurate nondestructive inspection of the GIS equipment of the converter station is realized, and the intelligent level of operation and maintenance of a power system is remarkably improved.

The application provides a Doppler positioning method based on frequency hopping spread spectrum, and belongs to the technical field of radio positioning, to solve the problem that the fixed carrier frequency mode adopted by the traditional Doppler positioning technology makes the signal extremely easy to be intercepted, oriented and interfered. The method comprises the following steps: step 1: describing an application scenario; step 2: in the application scenario, a frequency hopping measurement signal is sent by a transmitting end; step 3: in the application scenario, a receiving end performs frequency hopping synchronization and measures a Doppler shift; step 4: a Doppler shift is preprocessed; and step 5: the preprocessed Doppler shift is used to calculate the position of a terminal to be positioned in combination with the relative motion of the transmitting end and the receiving end. The method can obtain the low interception rate and anti-interference ability given by the rapid change of the carrier frequency, and can also use the frequency diversity characteristics of frequency hopping to reduce the positioning performance deterioration caused by the multipath effect, and is suitable for application scenarios with high requirements for robustness, positioning accuracy and other performances.

The invention relates to the technical field of communication, and discloses a monitoring signal wireless transmission method and system for safety belt online monitoring. The method comprises the following steps: integrating a near-field magnetic induction transceiver unit in a safety belt lock catch, and arranging distributed relay nodes supporting near-field magnetic induction and frequency hopping spread spectrum radio frequency dual-mode communication along a braid; adaptively switching communication modes based on channel quality, and dynamically selecting an optimal frequency hopping point in combination with an environmental electromagnetic characteristic database; original signals of a sensor are locally compressed and coded and then transmitted to a regional convergence gateway hop by hop, and the gateway completes timestamp calibration, integrity verification and redundancy elimination and finally uploads the signals to a central monitoring platform. The system comprises a safety belt body, a miniature near-field magnetic induction unit, a distributed relay node, a regional convergence gateway and a central monitoring platform. According to the technical scheme, high-reliability, low-time-delay and low-cost wireless return of safety belt monitoring signals in the extreme shielding environment is achieved.

The invention relates to an energy management system based on multi-network fusion and a control method thereof, and relates to the technical field of energy management, and the control method comprises the steps: obtaining and processing original operation parameters of all energy equipment, and obtaining standard time sequence parameters of a power grid end, an energy storage end and a load end; generating a plurality of data transmission channels according to the type of the energy equipment, and transmitting a standard time sequence parameter in combination with a preset frequency hopping spread spectrum mechanism; according to the historical operation parameters, abnormity identification is carried out on the standard time sequence parameters of the energy equipment, abnormal operation parameters are obtained, and corresponding abnormity correction instructions and alarm information are generated; correcting and controlling the abnormal operation states of all the energy equipment according to the abnormal correction instruction, and pushing alarm information to the user side; an energy management strategy is configured or selected, and the working operation states of all energy equipment are regulated and displayed; the reliability of data transmission is improved through a multi-protocol communication scheduling algorithm, and quick response and accurate management are realized by combining real-time monitoring and an intelligent analysis algorithm.

The application belongs to the technical field of channel coding and decoding of communication systems, and particularly relates to a channel coding method of a micro-frequency hopping multiple access communication system, which comprises frame header coding and payload coding; the frame header coding adopts a polar code, and the payload coding adopts an RS code; the polar code coding is based on channel confidence to select information bits and frozen bits; the payload coding uses the RS code to enhance error correction capability; micro-frequency hopping symbol mapping adjusts the number of bits borne by each symbol according to a spreading factor SF; and gray code conversion ensures the robustness of data transmission; and the application further improves the sensitivity and anti-interference capability of the micro-frequency hopping spread spectrum multiple access communication system on the basis of the original advantages of the micro-frequency hopping multiple access communication system through coding and decoding technology.

The invention discloses a low-frequency time code system and method based on a two-dimensional composite chaotic sequence, and relates to the technical field of wireless communication, and the low-frequency time code system based on the two-dimensional composite chaotic sequence mainly comprises a transmitting end and a receiving end. The transmitting end comprises a time coding module, a direct sequence spread spectrum module, an amplitude shift keying modulation module and a frequency hopping spread spectrum module; and the receiving end comprises a de-hopping module, an amplitude shift keying module, a de-spreading module, a filtering module, a judgment module and a decoding module. According to the low-frequency time code system and method based on the two-dimensional composite chaos sequence, the complexity, randomness and statistical property of the chaos spread spectrum sequence can be improved, and the anti-jamming capability, safety and environmental adaptability of the low-frequency time code system are improved.

The invention discloses a communication and data transmission method and system suitable for a high electromagnetic environment, and the communication method comprises the following steps: obtaining a space coordinate of a degraded insulator through a wireless carrier communication module of a terminal on a tower; controlling a laser beam deflection angle of the long-distance non-electromagnetic transmission module based on the coordinates; establishing an optical communication link with a ground receiving terminal to form an electromagnetic immune backbone network; and when the backbone network is abnormal or reaches a frequency hopping spread spectrum starting condition, starting a frequency hopping spread spectrum backup communication link. The method can be suitable for a strong electromagnetic environment of a 500kV and above high-voltage transmission line, reliable communication and data transmission can be maintained when the communication distance between the tower and the ground exceeds 100m, and the detection requirement of the extra-high voltage degraded insulator is met.

The invention provides a QRNG-based high-security frequency hopping spread spectrum communication method and device, and the method comprises the steps: a QRNG module generates a quantum random number sequence, packages the quantum random number sequence into a secret key, and distributes the secret key to a transmitting end and a receiving end; the transmitting end stores the secret key copy, obtains a quantum random number sequence based on the secret key copy, generates a frequency hopping sequence by using the quantum random number sequence, adjusts the frequency of the original signal by using the generated frequency hopping sequence, and sends the modulation signal to the receiving end; and the receiving end stores the key copy, obtains the quantum random number sequence based on the key copy, receives the synchronization parameter of the frequency hopping sequence generated by the transmitting end, restores the frequency hopping sequence based on the synchronization parameter and the quantum random number sequence, and demodulates the modulation signal by using the restored frequency hopping sequence to obtain the information needing to be transmitted. According to the invention, the quantum random number generator is introduced, so that the concealment and the anti-interference capability of the signal can be effectively enhanced, and the communication security is improved through the unpredictability of quantum randomness.

The invention discloses a method for monitoring finger activity of an anesthetized patient and transmitting a signal to a central monitoring system based on inertial measurement, relates to the field of patient anesthesia monitoring, and is based on a monitoring system which comprises an inertial measurement unit, a signal processing module, a wireless transmission module and the central monitoring system. According to the anesthetic patient finger activity monitoring system based on inertia measurement, precise anesthesia management is achieved through multi-technology fusion. The system integrates a high-sensitivity inertial measurement unit, a multi-dimensional signal processing algorithm, a low-power-consumption wireless transmission protocol and an intelligent central monitoring system to form a full-closed-loop process from data acquisition to anesthesia scheme adjustment. The sensor can capture fine movement of the finger, and the data reliability is improved by combining Kalman filtering and a machine learning algorithm; a frequency hopping and spread spectrum technology is matched to guarantee real-time and stable transmission of data; the central monitoring system is integrated with a hospital information system to realize anesthesia depth dynamic evaluation and complication early warning. And the operation safety is improved.

The invention relates to the technical field of talkback communication, and discloses a multi-scene adaptive talkback communication method and system based on radio Mesh, and the method comprises the steps: recognizing a scene type code of a current talkback node, and broadcasting a node discovery frame to peripheral talkback nodes; calculating a neighbor link quality comprehensive score according to the node discovery frame, and determining a link mode flag word with reference signal receiving power detected by the cellular network module; noise reduction is carried out on a first voice signal collected by a microphone according to the scene type code to obtain a second voice signal, encryption is carried out to generate an encrypted audio frame, and the encrypted audio frame is transmitted according to a radio Mesh frequency hopping spread spectrum channel or a cellular network channel pointed by the link mode flag word to obtain a second voice signal; according to the invention, the problem of full-link breakage caused by single-node chain separation of the existing Bluetooth chain type topology is solved, and adaptive call quality guarantee under various differential noise scenes such as motorcycle riding, extremely cold skiing, surfing and judge law enforcement is realized.

The present application relates to the technical field of communication, disclose a monitoring signal wireless transmission method and system for seat belt online monitoring, the method comprises: integrating near field magnetic induction transceiver unit in the seat belt lock catch, along the tape cloth support near field magnetic induction and frequency hopping spread spectrum radio frequency dual mode communication distributed relay node;Based on channel quality adaptive switching communication mode, and dynamic selection of optimal frequency hopping frequency point is combined with environmental electromagnetic characteristic database;Local compression encoding is carried out to sensor original signal, and hop by hop transmission to regional convergence gateway, and time stamp calibration, integrity check and redundancy elimination are completed by the gateway, finally uploaded to the central monitoring platform.The system includes seat belt body, miniature near field magnetic induction unit, distributed relay node, regional convergence gateway and central monitoring platform.The system realizes high reliability, low delay, low cost wireless backhaul of seat belt monitoring signal in extreme shielding environment through the above technical scheme.

A kind of detection interference cooperative control method for spread spectrum, frequency hopping unmanned aerial vehicle, including real-time acquisition of the detection data of radar, form first identification information;Real-time acquisition of the detection data of photoelectric equipment, form second identification information;Real-time acquisition of the detection data of radio reconnaissance equipment deployed in multiple positions, obtain third classification identification result;The first identification information, second identification information and third classification identification result are input into data fusion system in real time, and dynamic comprehensive processing is carried out, obtains final identification information and generates interference radiation power regulation parameter, and dynamic generation control instruction is transmitted to interference equipment;Interference equipment releases interference information to target unmanned aerial vehicle, until realizing complete countermeasure to target unmanned aerial vehicle;The present application solves the defects of traditional means in timeliness, accuracy, systematization through the closed-loop architecture of "intelligent perception-collaborative decision-making-accurate execution", realizes the effective interference to frequency hopping, spread spectrum unmanned aerial vehicle, reduces collateral damage.