8 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 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 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 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 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.