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1802 results about "Frequency offset" patented technology

In radio engineering, a frequency offset is an intentional slight shift of broadcast radio frequency (RF), to reduce interference with other transmitters.

Equipment supervision data real-time analysis method and system

The invention provides an equipment supervision data real-time analysis method and system, and the method comprises the steps: calculating an energy value of a frequency band corresponding to a sub-band signal, determining the energy characteristics of the surface roughness and dust deposition distribution uniformity of a blade in each sub-band in a square sum form, and generating energy distribution vectors which are arranged according to a frequency band sequence; performing time-frequency analysis on the vibration signal by using the acquired real-time rotating speed information of the gas turbine, identifying a frequency component corresponding to the eccentric distance value of the rotor and the vibration frequency offset, and determining the amplitude of the frequency component; according to the classification result and the real-time rotating speed information, the comprehensive influence index of the material density change rate and the ash deposition layer thickness difference is calculated, the fault early warning level is determined through a weighted average method, and an early warning signal is generated; and according to the change trend of the early warning signal and the blade edge wear degree, a random forest algorithm is adopted to predict a development curve of the vibration frequency offset in the future target time, and real-time equipment supervision analysis data are obtained.
Owner:ZHONG KE SHU DONG GONG CHENG ZI XUN (GUANG ZHOU) YOU XIAN GONG SI

Intelligent sensing array early warning system for full-life damage of mixed tower structure

The invention discloses a mixed tower structure full-life damage intelligent sensing array early warning system, which relates to the field of mixed tower structure detection and comprises a multi-modal data collection module, an array topology optimization module, a self-adaptive signal processing module, a digital twin life prediction module, a grading early warning module and a visualization system. The multi-modal data collection module comprises a multi-modal sensor array, a self-powered module and a wireless transmission module. According to the invention, a full-scale sensing network is constructed, full-dimension damage perception from distributed monitoring to sudden damage capture and structural modal analysis is realized, wavelet transform and blind source separation are combined to eliminate environmental noise interference, a damage characteristic ultrasonic attenuation coefficient, an acoustic emission energy spectrum peak value, optical fiber strain gradient anomaly and vibration modal frequency deviation are extracted, and the detection accuracy is improved. And classification and positioning of damage types and intelligent diagnosis of severity levels are realized through a convolutional neural network and long and short memory neural network hybrid model, and a closed-loop processing flow from data acquisition to feature analysis is formed.
Owner:HENAN CHENGJIAN INSPECTION & TESTING TECH CO LTD

Electromechanical equipment noise reduction method based on machine learning

The invention discloses an electromechanical equipment noise reduction method based on machine learning, and relates to the field of electromechanical equipment noise reduction, and the method comprises the steps: collecting sound pressure and vibration signals during the operation of electromechanical equipment, and collecting the operation state data of the electromechanical equipment; sparse reconstruction is carried out on the noise features; carrying out sound source localization on the reconstructed noise features by using a beam forming algorithm to obtain a noise distribution diagram; constructing a noise reduction model based on deep learning to obtain noise signals after noise reduction; extracting the frequency of the noise signal in a preset frequency range through a peak search algorithm; analyzing the acquired running state data by using a time-varying linear predictive coding algorithm TVLPC to obtain a noise frequency offset caused by the abnormal running state of the electromechanical equipment; generating an optimal solution by using a particle swarm algorithm; and according to the optimal solution of noise control, noise dominant frequency components are extracted for separation, and a plurality of phase-reversal noise reduction control signals are obtained. Aiming at low noise reduction precision of electromechanical equipment in the prior art, the noise reduction control precision is improved.
Owner:CHINA CONSTR EIGHT ENG DIV CORP LTD

Machine tool dynamic characteristic sensing and intelligent processing control method and system based on knowledge graph and large model

The invention relates to the technical field of intelligent manufacturing and numerical control machining control, and discloses a machine tool dynamic characteristic sensing and intelligent machining control method and system based on a knowledge graph and a large model, and the method comprises the following steps: extracting frequency domain parameters through a vibration sensor, obtaining vibration displacement in combination with laser displacement, and comparing the vibration displacement with modal data to construct a graph; processing parameters and displacement are synchronously sampled, time sequence characteristics are extracted to generate tensors, dynamic characteristics are predicted and corrected, and frequency response adjustment rotating speed is matched to generate optimized track control parameters which are converted into G code instructions. According to the method, a dynamic characteristic map is constructed by fusing vibration signals and displacement, a sliding window synchronizes processing parameters and vibration data, LSTM extracts joint characteristics, GRU predicts rigidity and damping ratio, an attention mechanism dynamically corrects weight, characteristic coupling analysis and prediction precision is improved, nonlinear modeling captures dominant frequency offset and harmonic distribution, response speed is enhanced, and the method has the advantages of being high in precision and high in precision. Cutting vibration is inhibited, and the process stability is guaranteed.
Owner:INST OF ENGINEERING THERMOPHYSICS - CHINESE ACAD OF SCI

Doppler and pseudo-range fusion positioning method and system for low-orbit satellite conduction signals

The invention discloses a Doppler and pseudo-range fusion positioning method and system for low-orbit satellite conduction signals, and relates to satellite positioning. The method comprises the steps that a Doppler and pseudo-range observation equation is established; performing least square residual calculation on the calculated Doppler and pseudo-range theoretical values and the observed Doppler and pseudo-range measured values, and taking a grid center point coordinate corresponding to a two-norm minimum value as a receiver position initial value; performing Taylor series expansion on the Doppler and pseudo-range observation equation, and representing a state updating matrix by using the established state transition matrix and receiver position, clock error and frequency offset correction; the inverse matrix of the observation noise covariance is used as a weight matrix to be distributed to the state transition matrix; and iterating the initial position value of the receiver, updating the state updating matrix, and stopping iteration until the two-norm of the residual solution is smaller than a set threshold value, so as to obtain the position, clock error and frequency offset results of the receiver. According to the method, the low-orbit satellite positioning algorithm model can be optimized, the convergence time is shortened, and the positioning precision is improved.
Owner:THE 20TH RESEARCH INSTITUTE OF CHINA ELECTRONICS TECHNOLOGY GROUP CORP

Porcelain insulator pulse excitation detection method based on multi-mode coupling analysis

The invention provides a porcelain insulator pulse excitation detection method based on multi-mode coupling analysis, and belongs to the technical field of intelligent detection of power equipment, and the method comprises the following steps: applying a mechanical pulse excitation signal with an adjustable amplitude; collecting a vibration response signal and constructing a temperature-frequency compensation model; separating the vibration mode of each section: constructing an equivalent mass-rigidity-damping model of a plurality of sections of insulators; extracting instantaneous frequency from the separated multi-mode signal, capturing the non-stationary characteristic of the vibration signal, and capturing the local rigidity change; and calculating a crack quantitative index and outputting a diagnosis result, including establishing a crack depth-frequency offset mapping database, and acquiring an actual bending form of the vibration mode by identifying the position of the crack. The method has the advantages that the three-dimensional characteristic spectrum of the crack is constructed through joint analysis of multi-dimensional data such as the vibration mode, the instantaneous frequency and the curvature distribution, the limitation of traditional single parameter detection is broken through, and refined distinguishing of defect property cracks, aging and the like is achieved.
Owner:NANYANG POWER SUPPLY COMPANY OF STATE GRID HENAN ELECTRIC POWER

Multi-band processing system for electronic communication

ActiveCN119945467ALine balance variation compensationTransmitter/receiver shaping networksBandpass filteringMulti band
The invention relates to the technical field of information transmission, in particular to a multi-band processing system for electronic communication, which comprises a signal separation module, a frequency deviation compensation module, an amplitude correction module, a phase correction module and a dynamic feedback adjustment module. According to the invention, a plurality of frequency bands are extracted to execute band-pass filtering to separate signal components, short-time power spectral density is calculated to describe energy distribution, normalization coefficient operation is carried out to enhance frequency domain balance, high-energy component screening is carried out to reduce noise interference, signal effectiveness is improved, and frequency offset compensation calculates a change rate based on adjacent phase data and eliminates abnormal fluctuation. A time domain coefficient is adjusted to correct a frequency offset error, amplitude correction depends on short-time Fourier transform to screen the maximum amplitude to optimize signal consistency, phase adjustment fits a group delay error curve to optimize compensation parameters, dynamic feedback optimizes a strategy according to a signal-to-noise ratio to enhance compensation precision, and signal transmission quality and stability are improved.
Owner:ZHEJIANG ELECTROMECHANICAL VOCATIONAL & TECH COLLEGE

Latency and coverage enhancement for subband non-overlapping full duplex

A wireless transmit / receive unit (WTRU) may receive subband non-overlapping full duplex (SBFD) configuration information. The SBFD configuration information may be associated with subbands for uplink transmission and subbands for downlink reception. The WTRU may receive scheduling information associated with physical uplink shared channel (PUSCH) transmissions. The scheduling information may comprise a first frequency domain resource allocation (FDRA). The WTRU may transmit a first PUSCH transmission using a first frequency resource. The WTRU may determine that at least a second PUSCH transmission is to be sent using at least one OFDM symbol. The WTRU may determine that the first frequency resource overlaps. The WTRU may receive one or more of a second FDRA or a frequency offset for the second PUSCH transmission. The WTRU may determine a second frequency resource for transmitting the second PUSCH transmission. The WTRU may transmit the second PUSCH transmission using the second frequency resource.
Owner:INTERDIGITAL PATENT HOLDINGS INC

GFSK-based time-frequency synchronization tracking and judging method

The invention discloses a time-frequency synchronization tracking and judging method based on GFSK (Gaussian Frequency Shift Keying). The method comprises the following steps: S1, positioning the initial position of a synchronization word by detecting a lead code; s2, extracting a fixed synchronization word, completing frame synchronization based on correlation matching, and positioning a starting point of an effective data segment; s3, a range cycle counter collects a central sampling point and two adjacent sampling points to form a candidate sampling point sequence; s4, dynamically and finely adjusting the range cycle counter to form a time sequence calibration sampling point sequence; s5, performing phase difference calculation on the time sequence calibration sampling point sequence, estimating continuous frequency offset and generating a compensation value; s6, applying the compensation value to construct a decision feedback equalizer with delay front and back terms; s7, performing interference suppression on the compensation sampling point sequence by using a decision feedback equalizer with delay front and back items, and outputting a soft decision value; and S8, executing three times of judgment, constructing a sliding reference sequence, and outputting a final bit judgment result. According to the method, the problem of poor GFSK demodulation robustness under Doppler disturbance is solved.
Owner:BEIJING LANLING XINGTONG TECH CO LTD

Fault identification method and system for buried optical fiber

ActiveCN120090700AElectromagnetic transmissionEngineeringPolarization mode dispersion
The invention provides a fault identification method and system for a buried optical fiber, and relates to the technical field of computers, the polarization mode dispersion change rate and the time-frequency double-domain disturbance coefficient of an optical signal of a to-be-detected buried optical fiber can be obtained, and the time-frequency double-domain disturbance coefficient is determined according to the amplitude fluctuation coefficient and the frequency offset of the optical signal; under the condition that the polarization mode dispersion change rate is greater than a preset first threshold value and the time-frequency double-domain disturbance coefficient is greater than a preset second threshold value, acquiring environment state information and physical excitation parameters of the buried optical fiber; inputting the environment state information, the polarization mode dispersion change rate, the physical excitation parameter and the amplitude fluctuation coefficient into a pre-trained micro-bending strain identification model to obtain a micro-bending strain state index of the buried optical fiber; and inputting the micro-bending strain state index, the environment state information and the time-frequency double-domain disturbance coefficient into a preset optical fiber fault classification model to obtain a fault identification result of the buried optical fiber. And fault identification can be carried out on the buried optical fiber comprehensively and accurately.
Owner:QINGDAO HUIAN VALLEY TECH DEV CO LTD

OTFS radar communication integrated signal processing method and system based on time-frequency-space domain joint optimization

The invention provides an OTFS radar communication integrated signal processing method and system based on time-frequency-space domain joint optimization. According to the method, pilot symbol positions and densities are configured in an OTFS time-frequency grid according to channel time-varying characteristics and bandwidths, and a Doppler index range is set to optimize channel information acquisition; deploying a controllable reflecting surface, constructing a phase modulation matrix based on a target position and communication channel parameters, dynamically adjusting a phase gradient direction, and separating energy of a target echo and a communication signal; within a set Doppler index range, calculating frequency offset estimation, correcting a time domain sampling point of a received signal, and generating a phase correction vector; and positioning a spatial aliasing main interference area, and inhibiting symbol interference and spatial aliasing caused by a high-speed target through frequency domain beam forming weighting and phase rotation compensation in combination with a phase correction vector and a sub-Doppler parameter in the area. According to the invention, time-frequency-space domain cooperative efficient processing of OTFS radar communication integrated signals is realized.
Owner:BEIJING INST OF REMOTE SENSING EQUIP

Foreign matter detection method and system for wireless charging system and storage medium

The invention relates to the technical field of wireless charging, and provides a foreign matter detection method and system for a wireless charging system and a storage medium. The method comprises the following steps: firstly, calibrating at multiple temperature points and establishing a temperature-parameter comparison table under the condition of no foreign matters; in a no-load standby state, the inversion module sends out detection drive and collects voltage, current and temperature; calculating a real-time quality factor and resonant frequency according to sampling, obtaining a compensation reference according to a temperature look-up table, and solving the variation of the quality factor and the resonant frequency; and performing fusion judgment by adopting dual-condition locking or weighted scoring, and triggering fault protection when a foreign matter is confirmed. Due to the fact that equivalent inductance and resistance changes are caused by metal foreign matters, quality factors are remarkably reduced along with resonant frequency deviation, temperature excursion and foreign matter effects are distinguished through temperature compensation, and dual-condition locking or weighted scoring fusion judgment is combined, the interference immunity and accuracy of detection are improved, false alarms and missing alarms are remarkably reduced, and the detection accuracy is improved. The method is suitable for high-power wireless charging scenes.
Owner:DONGGUAN SIYOTO ELECTRONICS CO LTD

Channel estimation method based on frequency domain deviation compensation and dynamic DCT denoising

The invention relates to a channel estimation method based on frequency domain deviation compensation and dynamic DCT denoising, and belongs to the technical field of wireless communication. The method comprises the following steps: establishing a wireless channel model and an OFDM system model; estimating the frequency offset in the received signal by using the phase rotation characteristic of the pilot signal; calculating a preliminary channel frequency domain response # imgabs2 # at a pilot frequency position through a least square criterion based on the compensation signal # imgabs1 #; obtaining a receiving pilot frequency signal # imgabs4 # according to the sending pilot frequency Xp and the roughly estimated channel frequency response # imgabs3 #; estimating a current signal-to-noise ratio SNRest based on the pilot frequency signal # imgabs5 # and a noise power ratio; and establishing an adaptive DCT denoising strategy based on a signal-to-noise ratio threshold, and selecting different denoising strategies according to different signal-to-noise ratios to perform denoising processing on # imgabs6 # to obtain final channel estimation # imgabs7 #. The adaptive denoising strategy design of the invention effectively balances the relationship between noise suppression and channel structure fidelity, and improves the precision and stability of overall channel estimation.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

High-sensitivity metal micro-strain sensor label and detection method thereof

The invention discloses a high-sensitivity metal micro-strain sensor label and a detection method thereof, which are applied to the field of nondestructive testing and the field of structural health monitoring. The problems that an existing tag antenna is low in strain detection sensitivity and difficult in micro-strain detection are solved. The high-sensitivity metal micro-strain RFID sensing tag is attached to the surface of a component, when the tag deforms, the impedance change of the tag is Zsened, and the radar cross section changes accordingly; the reader can remotely monitor antenna parameters according to the change of the RCS0, the RCS1 and the intensity while communicating with the tag, so that the change of the intensity RSSI of an echo signal is deduced, and the deformation of the tag is indirectly known; when the impedance of the tag antenna changes, the resonant frequency of the tag changes accordingly, and the deformation information of the tag can be indirectly obtained by analyzing the deviation of the resonant frequency.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Frequency offset correction algorithm in HPLC + HRF dual-mode communication

The invention relates to the technical field of ecological system service function evaluation. The invention relates to a frequency offset correction algorithm in HPLC (High Performance Liquid Chromatography) + HRF (High Radio Frequency) dual-mode communication. The method comprises the following steps: S1, collecting phase sequence data from an HPLC communication link, collecting frequency offset estimation data and corresponding confidence data from an HRF communication link, and adaptively adjusting a preset detection threshold value of the phase sequence data according to the confidence data; s2, performing pulse abnormal sample point detection and elimination on the phase sequence data according to the adjusted preset detection threshold value; according to the method, the detection threshold is dynamically adjusted through the confidence data, so that the anomaly detection process can be matched with the current interference environment in real time, the integrity of the phase sequence data is maintained, and the problem of insufficient adaptability of a fixed detection threshold in an electromagnetic interference dynamic change scene is solved; and a more reliable phase data basis is provided for subsequent interpolation compensation and frequency offset estimation, so that the frequency offset correction precision of the dual-mode communication system is improved.
Owner:ZHONGKE GUOYUAN (LIAONING) ELECTRONIC TECH CO LTD

Anorectal surgery postoperative care rehabilitation evaluation method and system

The invention provides an anorectal surgery postoperative care rehabilitation evaluation method and system. Wherein a vibration sensor is constructed through a machine tool machining vibration monitoring technology, vibration frequency offset of the dressing after absorbing wound seepage is detected in real time, and the vibration frequency offset is associated with dressing weight variation; meanwhile, an optical scattering measurement technology is adopted for carrying out scattering spectrum analysis on wound exudate, and the protein concentration index is analyzed. And carrying out time sequence correlation on the weight change data corresponding to the vibration frequency offset and the protein concentration index to generate a seepage component dynamic change curve. And through a wireless transmission unit in the remote measurement system, performing remote synchronous comparison on the dynamic change curve and a preset healing stage reference curve, and when the vibration frequency offset exceeding the standard seepage amount continuously appears in the curve and the protein concentration index breaks through the threshold range, triggering a remote early warning signal of wound healing abnormity. According to the technical scheme provided by the invention, the nursing rehabilitation efficiency and precision are improved.
Owner:SHAANXI NUCLEAR IND 215 HOSPITAL

Space-time synchronization method and device, electronic equipment and medium

The embodiment of the invention provides a time-space synchronization method and device, electronic equipment and a medium, which are used for solving the problem of inaccuracy of a local clock in related technologies. In the embodiment of the invention, the electronic equipment combines the average deviation pseudo-range, the RTT jitter and the target frequency offset into the multi-dimensional observation vector, so that the error source of clock synchronization is fully covered. The time deviation and the frequency deviation of the clock are accurately and effectively determined through a Kalman filtering algorithm, recursive processing of observation vectors and dynamic estimation of the time deviation and the frequency deviation of the clock, and high-precision synchronization of the local clock in a complex environment is achieved in combination with the optimization capability of the Kalman filtering algorithm. And the time of the local clock is the time determined according to the time of the multiple clocks, so that the clocks are more accurate.
Owner:CHINA TELECOM CORP LTD TECHNOLOGY INNOVATION CENTER +1

Self-adaptive synchronization method and system for multi-protocol signal transmission

The invention discloses a self-adaptive synchronization method and system for multi-protocol signal transmission, and relates to the technical field of signal processing, and the method comprises the steps: receiving and preprocessing a multi-protocol signal, building a state space model based on the preprocessed signal, and carrying out the multi-step prediction of a clock state; future frequency deviation and delay compensation of the signals are calculated based on prediction results, the results are integrated into a calibration parameter set, rolling optimization control is carried out based on the calibration parameter set, and frequency and phase calibration is completed; and outputting the calibrated synchronizing signal and storing the calibrated synchronizing signal in a database. According to the method, the precision and adaptability of signal synchronization are remarkably improved, the frequency deviation and dynamic delay characteristics of the signals can be effectively extracted and utilized, high-precision synchronization of different protocol signals is achieved by combining modal decomposition and correlation weight calculation, the frequency and phase calibration parameters can be adjusted in real time through the self-adaptive rolling optimization control method, and high-precision synchronization of the signals is achieved. And the time reference consistency of the signals is ensured.
Owner:中央广播电视总台

Active island detection method and system based on harmonic impedance characteristic identification

The invention discloses an active island detection method and system based on harmonic impedance characteristic identification, and the method comprises the steps: analyzing the harmonic impedance difference of grid-connected points in a grid-connected state and an island state, and building a state criterion based on resonant frequency deviation and impedance amplitude through the comparison of the frequency response characteristics of island impedance and grid-connected impedance; fitting the grid impedance into an RLC parallel model in a selected frequency band, and mapping the topological difference of the power grid into a parameter difference; embedding a low-voltage ride-through strategy in the control of the voltage source converter, and adjusting reactive current in a grading manner according to the voltage drop degree of a grid-connected point; fundamental waves and harmonic waves are separated through a cascade notch filter, two synchronous harmonic waves are injected into the system through constant current control, and it is ensured that injection signals of a multi-voltage source converter are in the same phase in a phase locking link; and solving an overdetermined equation set based on the double-frequency response data to identify RLC parameters, setting an island criterion, and synchronously completing island judgment in a low-voltage ride-through time window. Detection precision is improved, dynamic response is optimized, and power generation efficiency is improved.
Owner:TONGCHUAN POWER SUPPLY CO OF STATE GRID SHAANXI ELECTRIC POWER CO LTD

Wind turbine generator blade damage judgment method and detection system based on voiceprint detection

The invention discloses a wind turbine generator blade damage judgment method and detection system based on voiceprint detection, and belongs to the technical field of wind turbine generator blade detection. The damage judgment method comprises the following steps: acquiring environmental parameters of a wind power plant, and establishing a sound velocity correction model based on the environmental parameters; acquiring a blade resonance sound signal, and correcting the blade resonance sound signal based on the sound velocity correction model to obtain a blade resonance sound signal with a high signal-to-noise ratio; performing FFT spectrum analysis on the blade resonance sound signal with the high signal-to-noise ratio, identifying the peak position of the first three-order natural resonance frequency of the blade, and performing analysis to obtain the current modal frequency, damping ratio and sub-band energy distribution entropy value of the blade; historical baselines of the modal frequency, the damping ratio and the sub-band energy distribution entropy of the blade in the healthy state are obtained, and the modal frequency offset, the damping ratio change rate and the acoustic impedance spectrum entropy of the blade are obtained; and wind turbine generator blade damage determination is carried out by using a high-precision time difference detection technology.
Owner:HUANENG CHONGQING FENGJIE WIND POWER CO LTD +1

Compressor lubricating oil online monitoring vibration diagnosis method and system

The invention relates to the technical field of lubricating oil monitoring, in particular to a compressor lubricating oil online monitoring vibration diagnosis method and system, and the method comprises the steps: obtaining vibration signal data of a compressor bearing, a connecting rod mechanism and a piston assembly and lubricating oil medium parameters, arranging the data according to a time sequence, and generating a lubrication working condition time sequence signal data set; according to the method, through time sequence matching of vibration signal data and lubricating oil state parameters, a lubricating working condition time sequence signal data set is established, and in combination with time window division, the bearing vibration frequency offset, the piston transverse impact amplitude and the connecting rod torsional vibration change rate are extracted; and calculating the viscosity drop rate, the temperature change range and the pollutant particle growth rate of the lubricating oil, screening the correlation trend of the bearing vibration frequency offset before and after the change of the lubricating state, and enhancing the lubricating state recognition capability.
Owner:HUANENG DONGGUAN GAS TURBINE THERMAL POWER CO LTD +1

Clock and data recovery circuit without reference clock, use method and integrated circuit

The invention discloses a reference-clock-free clock and data recovery circuit, a use method and an integrated circuit. The circuit comprises a first circuit and a second circuit, the first circuit comprises a voltage-controlled oscillator, the second circuit comprises a comparison module and a frequency capture module, and the comparison module is used for comparing a first clock signal with a high-speed serial data signal, generating a first signal and outputting the first signal to the frequency capture module. The frequency capture module outputs a first control signal, the first control signal is used for adjusting the first oscillation frequency so as to enable the frequency deviation between the first oscillation frequency and the second oscillation frequency to be smaller than a first deviation threshold value, and the second circuit generates a second clock signal and outputs the second clock signal to the first circuit; the first circuit adjusts the voltage-controlled oscillator using a second clock signal such that the frequency offset is less than a second offset threshold. According to the invention, the CDR and PLL functions are fused and an external reference clock is replaced by the CDR recovery clock, so that a clock and data recovery system without an external clock is realized.
Owner:TORUN SEMICONDUCTOR (BEIJING) CO LTD

Construction method and modulation method of three-port multi-frequency MMC topology based on bridge arm multiplexing

The invention discloses a construction method and a modulation method of a three-port multi-frequency MMC topology based on bridge arm multiplexing, and relates to the technical field of power electronics. The construction method comprises the steps that sub-modules of a traditional double-bridge-arm MMC are integrated and optimized into a three-bridge-arm structure through a current conversion branch, independent energy interaction of three ports is achieved through an auxiliary bridge arm, multi-frequency operation modes of power frequency, frequency division, direct current and the like are supported at the same time, and therefore the utilization rate of the bridge arm sub-modules is increased, and the energy utilization rate of the MMC is increased. And the overall size and the manufacturing cost of the converter are reduced. Based on three-port multi-frequency coordination control and power balance requirements, a modulation method of the topological structure is provided, a multi-frequency coordination modulation strategy is adopted, frequency offset is performed through an auxiliary bridge arm to reduce cross interference of port frequency, and output waveform quality is improved through multi-objective optimized capacitor voltage balance control. And meanwhile, direct-current side faults are effectively eliminated by means of the auxiliary bridge arm.
Owner:ZHENGZHOU UNIV

Multi-channel cooperative communication method

The invention discloses a multi-path cooperative communication method, belongs to the technical field of wireless communication, and is used for solving the problems of inaccurate path selection, unreasonable power distribution and inaccurate signal combination caused by dynamic change of a channel state in multi-path communication. The method comprises the following steps: acquiring channel state information of at least three communication paths in real time through a transmitting end, wherein the channel state information comprises signal strength, frequency offset and noise power spectral density; dynamically dividing and distributing the data stream to each path based on the path quality factor, and adjusting the transmitting power by combining the signal strength and the noise difference value; a receiving end carries out time domain alignment by adopting a sliding window cross-correlation algorithm, and carries out phase compensation based on a minimum mean square error criterion; path reallocation is triggered when the continuous bit error rate exceeds a threshold. According to the method, the multi-path resource utilization rate can be optimized, and the communication stability and the data transmission efficiency are improved.
Owner:BEIJING XINXUN COMM ELECTRONICS TECH

Millimeter wave backscatter communication positioning and identification system for multiple tags

The invention relates to the technical field of wireless communication, and discloses a millimeter wave backscatter communication positioning and identification system for multiple tags, which comprises a Chirp signal sending module used for generating and transmitting continuous Chirp signals and receiving signals reflected by customized backscatter tags; and the received signal processing module is used for carrying out demodulation and frequency analysis on the received radar echo signal, determining the distance of the target backscattering tag by measuring the frequency offset of the intermediate frequency signal, and determining the azimuth of the tag through the antenna array of the receiving module. The identity label of the backscattering label is extracted by analyzing the signal intensity; the customized backscattering label is used for adjusting the intensity of the signal reflected back to the radar by changing the reflection state of the backscattering label so as to transmit the identity label of the backscattering label; and the DSSS coding module is used for coding the identity label of the backscattering label so as to increase the signal bandwidth and reduce the signal interference between the labels. According to the method, the customized backscattering tag is matched with the FMCW radar, so that positioning and identification of multiple tags are realized, and the method has a wide application prospect.
Owner:UNIV OF SCI & TECH OF CHINA

Frequency difference of arrival-based positioning

Disclosed are techniques for wireless positioning. In an aspect, a user equipment (UE) receives, from a location server, assistance data for a positioning procedure, obtains a frequency offset measurement of one or more positioning reference signal (PRS) resources transmitted by at least one transmission-reception point (TRP) based on the assistance data, and enables a location of the UE to be determined based, at least in part, on the frequency offset measurement.
Owner:QUALCOMM INC

Average consistency time synchronization method based on multi-hop virtual link and event triggering

The present invention relates to the technical field of wireless sensor networks, and to an average consistency time synchronization method based on a multi-hop virtual link and event triggering. According to the method, in the case that a communication delay is present in a wireless network, a least squares estimator is used to restrain the effect of the delay in the relative frequency offset estimation process; clock information of nodes is fully called by means of the multi-hop virtual link for update, thereby effectively increasing the clock synchronization speed; an event triggering policy is used to reduce a transmission frequency between the nodes, thereby effectively reducing communication overhead; and a consistency algorithm is used to update logic clock parameters of the nodes, thereby realizing global consistency of clocks of the nodes in a wireless sensor network. According to the present invention, the effect of the communication delay in the wireless sensor network is taken into consideration, an iterative least squares estimator is used to obtain a high-precision relative frequency offset value to improve the synchronization precision, and by using an interaction mechanism of the multi-hop virtual link and event triggering, the communication overhead is effectively reduced while increasing the convergence speed of a clock synchronization error.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Unmanned aerial vehicle individual countering method and system based on radio frequency identification and dynamic interference

The invention discloses an unmanned aerial vehicle individual countering method and system based on radio frequency identification and dynamic interference, and belongs to the technical field of unmanned aerial vehicles, and the method comprises the steps: collecting wide-band IQ data, extracting hidden features such as instantaneous frequency offset fluctuation and envelope entropy abnormity, and achieving high-dimensional embedded expression through a variational auto-encoder. Structured recognition is carried out on signals in combination with a graph neural network, the discrimination capability of frequency hopping, spread spectrum or Wi-Fi / LTE simulation signals is remarkably improved, a dynamic interference strategy is finally generated according to a recognition result, accurate recognition and intelligent suppression of illegal unmanned aerial vehicle communication are achieved, and the method is suitable for popularization and application. The technical defect that an existing system is insufficient in recognition robustness and countering effectiveness in a complex environment is effectively overcome.
Owner:TIESHI (HANGZHOU) EMERGENCY SAFETY TECHNOLOGY CO LTD

Intelligent peak regulation method with optimized combination of energy storage and conventional peak regulation means

The invention discloses an intelligent peak regulation method with optimized combination of energy storage and conventional peak regulation means, and the method comprises the following steps: building a holographic situation awareness layer: capturing the voltage, current phase angle and frequency deviation of a power grid, and monitoring the pressure fluctuation in a diesel engine cylinder; data transmission and preprocessing: encrypting data of the miniature phasor measurement unit and the quantum sensor by using a quantum key distribution technology; the self-adaptive decision engine is used for performing Nash equilibrium calculation by utilizing a federal reinforcement learning architecture, through a local Agent based on a power generation / energy storage unit state autonomous optimization control strategy and in combination with a digital twin platform, solving multi-target conflicts of economy, reliability and carbon emission, and generating a global optimal scheduling instruction; the execution control layer is used for tracking resonance points and dispersing harmonic energy spectrums; dynamic topology reconstruction: a harmonic source is positioned by using a digital twin platform, and the topology of the energy storage system is automatically switched according to the harmonic frequency and position; continuously optimizing the digital twin platform; and full-process closed-loop feedback and self-learning are carried out.
Owner:STATE GRID GANSU ELECTRIC POWER CORP +1

Calculation method and system for multi-point detection of gas nonmetal pipeline based on active sound source

The invention discloses a calculation method and system for multi-point detection of a gas nonmetal pipeline based on an active sound source, and relates to the technical field of pipeline monitoring and management, and the method comprises the following steps: 1, monitoring the change of a sound signal in the gas nonmetal pipeline according to the change of a transmitted laser signal through an optical fiber of a distributed acoustic assembly as a sensing medium, according to the invention, the optical fiber of the distributed acoustic assembly is used for monitoring the change of the acoustic signal in the gas non-metal pipeline, the frequency offset, intensity and delay change of the laser signal are converted into the frequency, amplitude intensity and sound wave source of the acoustic signal in a correlation manner, and the adaptive filter is used for dynamically updating the filter coefficient. A window function is adopted to carry out framing processing on sound signals, short-time Fourier transform is applied, real classification labels are distributed to the sound signals through a random forest algorithm, a triangulation positioning method is applied to determine space coordinates of the sound signals, and accurate monitoring and classification of the pipeline state are achieved.
Owner:XIAN GUANCHANG ENVIRONMENTAL PROTECTION TECH CO LTD