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1956 results about "Center frequency" patented technology

In electrical engineering and telecommunications, the center frequency of a filter or channel is a measure of a central frequency between the upper and lower cutoff frequencies. It is usually defined as either the arithmetic mean or the geometric mean of the lower cutoff frequency and the upper cutoff frequency of a band-pass system or a band-stop system.

Satellite-borne multi-band synthetic aperture radar signal processing optimization method and system

The invention provides a satellite-borne multi-band synthetic aperture radar signal processing optimization method and system, and relates to the technical field of signal processing, and the method comprises the steps: obtaining original echo data of a satellite-borne multi-band synthetic aperture radar, carrying out Doppler center frequency estimation, carrying out two-dimensional matrix product operation, and obtaining compensation echo data; distance direction position information and scattering intensity information are obtained based on a distance direction matching filtering algorithm of sub-band decomposition; determining spatial distribution density, performing adaptive block processing, and performing phase error modeling in each block to generate a continuous phase correction function; performing wavelet domain convolution operation to obtain corrected echo data, obtaining a multi-band two-dimensional image, extracting a multi-dimensional feature vector through a deep neural network, performing weight learning, performing nonlinear weighted fusion, and performing adaptive histogram equalization enhancement to determine a synthetic aperture radar imaging result.
Owner:CHANGDE YUNCHUANG TECHNOLOGY DEVELOPMENT CO LTD

Panoramic intelligent sensing method for state of power distribution network

The invention discloses a power distribution network state panoramic intelligent sensing method, relates to the technical field of power distribution network monitoring management, and is used for solving the problem of poor power distribution network abnormity monitoring. According to the method, multi-scale decomposition and baseline construction of the signals are realized through accurate acquisition and preprocessing of the node signals of the power distribution network, steady-state and abnormal dynamic characteristics of the power distribution network are effectively extracted, a variational mode decomposition technology is used, and a low-frequency mode is screened through a center frequency to construct a baseline, so that the reliability of the power distribution network is improved. Constructing a robust residual error and an abnormal energy index by combining the difference between a baseline and an original signal, accurately determining an abnormal event, switching a power distribution network node to an ultrahigh frequency sampling mode after abnormal triggering, extracting a local disturbance characteristic by using time domain difference, and adaptively adjusting a filtering parameter according to a local edge ratio through robust filtering noise reduction, so as to achieve the purpose of reducing noise. Therefore, the abnormal edge information is fully reserved, the real-time and high-precision perception of the abnormal state of the power distribution network is realized, and the response speed and accuracy of the panoramic perception of the power distribution network are improved.
Owner:SHENZHEN TOPCHANCE WECAN TECH DEV

Adaptive test method and system for dynamic range of multi-band radio frequency power amplifier

The invention provides a multi-band radio frequency power amplifier dynamic range adaptive test method and a system thereof. The method comprises the following steps: acquiring an output signal frequency spectrum of a tested radio frequency power amplifier, extracting characteristic frequency points including a center frequency and a bandwidth, matching the characteristic frequency points with a preset frequency band database, and automatically loading a test scheme of a corresponding frequency band. According to the method, the frequency bands are automatically matched through spectrum sensing, the test scheme is loaded, the multi-frequency-band characteristics can be rapidly adapted without manual parameter configuration, index missing test is avoided, and the switching efficiency is improved; dynamically optimizing test parameters by using a genetic algorithm, and accurately capturing a nonlinear distortion critical point while balancing coverage and efficiency; by combining multi-dimensional signal analysis and a deep learning model, the problem of missing detection of traditional single-domain analysis is solved, and the abnormal signal recognition capability is remarkably enhanced; through linear model correction, impedance dynamic matching and index threshold iteration, full automation and high precision of the test are realized, the environmental interference influence is effectively reduced, and a self-adaptive test system is constructed.
Owner:SHENZHEN HAIYI TECHNOLOGY ELECTRONICS CO LTD

Time series data prediction method based on deep ensemble learning model and high and low frequency separation

The invention belongs to the technical field of time series prediction, and more specifically relates to a time series data prediction method based on a deep integrated learning model and high and low frequency separation. The method comprises the following steps: collecting time sequence data in a system, and preprocessing the obtained data; vMD variational mode decomposition is carried out on original time sequence data, and a time sequence is decomposed into K mode components with limited bandwidth; combining a maximum information coefficient method and a reconstruction error analysis method to determine an optimal decomposition mode number K; dividing high and low frequency components for all decomposed modes by using a zero-crossing rate and a center frequency; appropriate prediction models are established for the high-frequency component and the low-frequency component respectively; and superposing all modal prediction results to obtain a final time sequence prediction result. According to the method, multiple deep learning models are combined, so that the prediction method has higher flexibility and adaptability, and proper models can be selected for components with different characteristics for prediction, thereby improving the overall performance.
Owner:QILU UNIVERSITY OF TECHNOLOGY (SHANDONG ACADEMY OF SCIENCES) +2

Direct current power source power allocation method and system for generator status monitoring apparatus

The present invention relates to the technical field of power source power allocation. Disclosed are a direct current power source power allocation method and system for a generator status monitoring apparatus. The method comprises the following steps: by means of system data, constructing a variational problem model; solving the constructed variational problem model, and using a particle swarm optimization algorithm to optimize computing parameters of the variational problem model; and, on the basis of a computing result of the variational problem model, allocating the total output power of a hybrid energy storage system to an energy-type storage device and a power-type storage device according to a ratio. By means of using the convergence-guaranteed particle swarm optimization algorithm, the present invention not only excels in the solving speed but also shows significant advantages in computational accuracy; furthermore, by means of solving the variational problem model, more accurate allocation ratios are obtained; variational mode decomposition can achieve adaptive matching of the optimal center frequency and bandwidth for each mode, thus effectively separating intrinsic mode components and achieving frequency domain partitioning of signals.
Owner:HUANENG YAKESHI POWER GENERATION CO LTD

Management and control method of electric power material digital intelligence professional warehouse

The invention relates to the field of electric power material warehouse management and control, in particular to an electric power material digital intelligent professional warehouse management and control method, which comprises the following steps: acquiring electromagnetic spectrum data, identifying a central frequency point energy distribution diagram and an electromagnetic interference intensity level, constructing a three-dimensional electromagnetic field intensity distribution model of a professional warehouse, and dynamically adjusting the working mode of an RFID reader-writer; the method comprises the following steps: deploying a multi-modal check node in a storage area of a professional warehouse, and generating a composite check result through an infrared contour matching method and a UWB coordinate verification method when the confidence coefficient of electric power material data read by an RFID reader-writer is lower than a preset confidence coefficient threshold value; updating an electric power material inventory database according to a composite verification result, and performing electric power material inventory state analysis in real time through an edge computing node; the problems that inventory data distortion and material positioning deviation are caused by reduction of the accuracy rate of RFID in a strong electromagnetic environment, and inventory accuracy management of an electric power material warehouse is seriously restricted are solved.
Owner:STATE GRID FUJIAN ELECTRIC POWER CO LTD

Marine mixture target identification method and system based on modal decomposition and reconstruction

The invention belongs to the technical field of radar signal processing and target identification, and particularly relates to a maritime hybrid target identification method and system based on modal decomposition and reconstruction, and the method comprises the steps: carrying out the variational modal decomposition of a radar echo signal of a maritime hybrid target, and decomposing an original signal into a plurality of intrinsic modal signals; estimating a background noise energy reference and removing noise modals based on the decomposed modal signals, clustering the remaining modals according to the center frequency, and combining the modals with the frequency within the center frequency range into an independent single-target signal which is of the same target and is reconstructed into an independent single-target signal; respectively carrying out time-frequency analysis on each reconstructed single target signal to obtain a corresponding time-frequency diagram, and extracting time-frequency domain features from the time-frequency diagram; and inputting the extracted features into a trained support vector machine classifier to realize automatic identification of the ship target and the floating target. A ship target and a floating target can be distinguished more accurately in a mixture scene, and the stability of tracking identification is improved.
Owner:NAVAL AVIATION UNIV

Neural Network Accelerated Simulation Method for Wideband Target Group Radar Scattering Field

The present invention discloses a neural network accelerated simulation method for the radar scattering field of a wide-band target group, belonging to the technical field of electromagnetic simulation. The method of the present invention constructs a KAN neural network model at the central frequency of the wide band, and constructs KAN neural network models at other target frequencies through transfer learning or direct training; uses the trained KAN neural network model to generate a multi-frequency point numerical Green's function data set, and then constructs a wide-band training sample to train the multi-task learning model to realize the global prediction of the numerical Green's function of the entire target wide band; uses the numerical Green's function output by the multi-task learning model to realize the fast simulation of the scattering field of the wide-band target group. The method of the present invention can realize the fast and accurate simulation of the radar scattering field of the wide-band target group.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Nonlinear ultrasonic guided wave phased array imaging method based on mixed array elements and time reversal

The invention relates to a nonlinear ultrasonic guided wave phased array imaging method based on mixed array elements and time reversal. The method comprises the following steps: exciting a fundamental wave and receiving a second harmonic wave at piezoelectric array elements of the fundamental wave and the second harmonic wave of an ultrasonic guided wave by using a center frequency respectively; full-matrix data of ultrasonic guided wave signals in the detected workpiece are obtained in a one-transmitting and one-receiving mode; a fundamental wave signal is suppressed and a second harmonic signal is enhanced by adopting a pulse inversion mode; for the full-matrix data after pulse inversion, utilizing continuous wavelet transform filtering to extract a second harmonic signal; respectively calculating the distance from the discretized imaging area to the excitation array element and the distance from the discretized imaging area to the receiving array element; and for each discrete pixel point, according to an excitation signal of a distance forward propagation fundamental wave and a received second harmonic signal back propagation, a pixel value is calculated by using a time domain topology energy equation, and local acoustic nonlinear imaging of the plate-shaped structure is realized.
Owner:EAST CHINA UNIV OF SCI & TECH

Optical cable icing galloping online monitoring system based on BOTDR (Brillouin Optical Time Domain Reflectometer)

The invention discloses an optical cable icing galloping online monitoring system based on a BOTDR, and belongs to the technical field of distributed optical fiber sensing. The system comprises an optical module, a signal processing module and a data processing module, the optical module is used for generating a detection light signal and interacting with a sensing optical fiber to obtain a Brillouin scattering signal, and then the Brillouin scattering signal is converted into an electric signal; the signal processing module is used for performing frequency down-conversion, signal filtering and digital acquisition on the electric signal to obtain multiple groups of Brillouin scattering signal data; the data processing module is used for processing the multiple groups of Brillouin scattering signal data and extracting a Brillouin frequency shift center frequency; temperature and strain distribution along the optical cable is obtained according to the frequency shift, and temperature and strain states are transmitted to a QT upper computer through PCIE for real-time display. According to the invention, high-precision and long-distance optical cable icing galloping monitoring can be realized, reliable early warning and safety guarantee are provided, and technical support is provided for maintenance and management of an electric power system.
Owner:YANGZHOU POWER SUPPLY BRANCH OF STATE GRID JIANGSU ELECTRIC POWER CO LTD

Bridge dynamic displacement measurement method based on unmanned aerial vehicle

The invention provides a bridge dynamic displacement measurement method based on an unmanned aerial vehicle, and relates to the field of bridge health monitoring, and the method comprises the steps: obtaining a bridge image sequence through the unmanned aerial vehicle; obtaining transformation matrixes according to the relation between the other frames of images and the fixed measurement points of the reference frame, correcting the coordinates of the motion measurement points of the corresponding frames of images according to the transformation matrixes, obtaining a corrected bridge image sequence, and further obtaining an initial displacement signal; variational mode decomposition is carried out on the initial displacement signal, a constraint variational optimization problem is constructed, the optimization problem is solved through iteration to obtain each mode component of variational mode decomposition and a corresponding center frequency, and a low-frequency mode component is removed to obtain a displacement signal after secondary correction of the influence of the unmanned aerial vehicle; and obtaining the real displacement according to the scale factor between the image obtained by the unmanned aerial vehicle and the real world. The influence caused by the movement of the unmanned aerial vehicle is corrected, and the accuracy, reliability and stability of a measurement result are effectively improved.
Owner:XIAMEN UNIV

Method and system for detecting high-resistance grounding fault of power distribution network

The invention discloses a power distribution network high-resistance grounding fault detection method and system, and relates to the technical field of power distribution network fault detection. A power distribution network high-resistance grounding fault detection method comprises the following steps: S1, collecting a transient zero-sequence voltage signal of a target feeder line as a to-be-decomposed electric quantity signal; s2, variational mode decomposition is carried out on the to-be-decomposed electric quantity signals, mode functions obtained by decomposing the single to-be-decomposed electric quantity signals are arranged according to the center frequency from low to high, and one-dimensional feature vectors of the to-be-decomposed electric quantity signals are obtained; and S3, inputting the one-dimensional feature vector of the electric quantity signal to be decomposed into a pre-constructed Transform model to obtain a detection result. According to the method, the high-resistance grounding fault and the disturbance condition can be accurately identified, the fault identification accuracy is very high, and the power distribution network fault detection efficiency is improved.
Owner:STATE GRID SICHUAN ELECTRIC POWER CORP ELECTRIC POWER RES INST

Time-varying channel transmittance estimation method and device based on frequency division multiplexing pilot frequency

The invention discloses a method for estimating the transmittance of a time-varying channel based on a frequency division multiplexing pilot frequency, and aims to solve the problem that the existing method for estimating the transmittance by adopting average transmittance does not have the capabilities of timely feedback and dynamic adjustment. The method comprises the following steps of: measuring a regular position component and a regular momentum component of a received signal by receiving a quantum signal and a pilot signal of frequency division multiplexing in a local local oscillator continuous variable quantum key distribution system generated by a transmitting end in real time; compensating phase noise caused by frequency offset and channel jitter due to different center frequencies of two independent lasers at a receiving end and a transmitting end by using a frequency offset compensation and phase recovery algorithm, and performing band-pass filtering to obtain a recovered pilot signal; and calculating the power ratio of the obtained pilot signal to the pre-calibrated pilot signal at each moment to obtain the time-varying free space transmittance. The performance change of the system in different time periods can be accurately reflected, the communication performance of the CVQKD system can be optimized, the success rate of key transmission can be improved, and the adaptability and robustness of the system can be improved.
Owner:SHANGHAI QUANTUM SCI RES CENT +2

Signaling for center frequency ambiguity for carrier phase measurements

Disclosed are techniques for wireless communication. In an aspect, a network node receives, from a network entity, a configuration for reporting carrier phase measurements of one or more reference signal resources spanning a plurality of subcarriers, wherein the configuration indicates one or more center frequencies to use for reporting the carrier phase measurements, obtains one or more carrier phase measurements of the one or more reference signal resources based on the one or more center frequencies, and reports, to the network entity, the one or more carrier phase measurements.
Owner:QUALCOMM INC

Integrated Lithium Niobate Photonic Millimeter-Wave Radar

A centimeter-resolution integrated photonic millimeter-wave (mmWave) radar chip operating in the mmWave V band based on a 4-inch wafer-scale thin-film lithium niobate (TFLN) technology is provided. The fabricated TFLN photonic mmWave integrated circuit has a first electro-optic modulator (EOM) capable of generating a broadband linear frequency modulated mmWave radar waveform through optical frequency multiplication of a low-frequency input signal, and a second EOM for frequency de-chirp of the reflected echo wave, thereby greatly relieving bandwidth requirements for the digital-to-analog converter in the transmitter and analog-to-digital converter in the receiver. In the absence of optical and electrical filters, the radar chip features continuous on-demand tunability of the center frequency and bandwidth, currently only limited by the bandwidths of electrical amplifiers. The radar chip provides a promising way to achieve high resolution sensing and detection for vehicle radar, airborne radar, and smart home in the 6G era.
Owner:CITY UNIVERSITY OF HONG KONG

Rolling bearing fault diagnosis method based on envelope spectrum knowledge distillation

The invention requests to protect a rolling bearing fault diagnosis method based on envelope spectrum knowledge distillation. The method comprises the following steps: obtaining a rolling bearing vibration signal, and carrying out sample division and normalization processing; the spectral kurtosis of the source working condition sample is calculated, the center frequency and bandwidth of envelope demodulation are determined according to the spectral kurtosis, envelope demodulation is carried out, and the demodulation sample is sent to a teacher network phi for pre-training; respectively inputting an original vibration sample and an envelope spectrum sample under a source working condition into a student network psi and a pre-trained teacher network phi, and extracting bearing health state representations learned by the two networks to establish envelope spectrum knowledge distillation loss; calculating the prediction loss of the student network, the cross-working-condition sample probability distribution alignment loss and the diversity loss represented by the health state; carrying out multi-loss back propagation, and optimizing the weight and bias of the fault diagnosis network by adopting an Adam optimizer; and finally, inputting the target working condition sample into the trained fault diagnosis model for performance testing.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Multi-path interference suppression method and device based on improved VMD-SVD collaborative noise reduction and storage medium

The invention discloses a multipath interference suppression method and device during in-pipe detection and a storage medium, and belongs to the technical field of radar signal processing. According to the method, a CFAR detection and clustering algorithm combined method is adopted, and the target number and the center frequency are automatically extracted from a radar amplitude-frequency signal; an original noisy signal is decomposed into a target number of modal components by using an improved variational modal model, and an improved power reference analysis method is proposed to divide the modal components into effective modals and ineffective modals; sVD noise reduction is carried out on the effective mode; and performing signal reconstruction on the plurality of modal components after SVD noise reduction to obtain a signal after multipath interference suppression. According to the method, the problem that the decomposition number and the center frequency of the variational mode decomposition algorithm are difficult to determine is effectively solved, the influence of inaccurate parameters is reduced, multipath interference suppression during complex environment detection is facilitated, and the effectiveness of the algorithm is verified through actual measurement.
Owner:HARBIN ENG UNIV

Method for jointly detecting corrosion defect of pressure pipeline by utilizing multiple guided wave modes

The invention discloses a method for jointly detecting corrosion defects of a pressure pipeline by utilizing multiple guided wave modes, relates to an ultrasonic non-destructive testing technology, and is used for solving the problem that the accuracy is relatively low when a single guided wave mode is used for detecting. The method for detecting the corrosion defect of the pressure pipeline comprises the following steps: calculating ultrasonic guided wave dispersion data of the pressure pipeline, and determining the center frequency of a transducer according to the dispersion data; the method comprises the following steps: arranging ultrasonic transducer annular arrays on two sides of a to-be-detected pressure pipeline, and acquiring ultrasonic guided wave data detected by the pressure pipeline in an L (0, 1) mode and a T (0, 2) mode; preprocessing the array waveform data to obtain detection data which can be used for guided wave imaging; according to the L (0, 1) mode guided wave data, a full waveform inversion method is adopted to invert the wall thickness of the pipeline corrosion defect; judging whether the pipeline defect exceeds the detection depth range of the T (0, 2) mode, and if the pipeline defect exceeds the detection depth range, ending; and if not, inverting the wall thickness of the pipeline corrosion defect by adopting a full-waveform inversion method according to the T (0, 2) mode guided wave data.
Owner:GUANGDONG INSPECTION & RES INST OF SPECIAL EQUIP ZHUHAI INSPECTION INST +1

Parallel backscatter communication method and system based on LoRa

The invention discloses a LoRa-based parallel backscatter communication method and system. The method comprises the following steps: transmitting a single-tone radio frequency source signal as a signal excitation source; designing a backscattering label, and performing backscattering modulation processing on the environmental perception data in combination with the signal excitation source to obtain a modulated standard LoRa data packet; and the receiver presets the center frequency of a communication link, and performs frequency band distinguishing and demodulation processing on the modulated standard LoRa data packet to complete parallel backscatter communication of the LoRa data. According to the invention, while a parallel backscattering LoRa communication system compatible with commercial LoRa equipment is realized, the throughput of the system is improved, and frequency division multiple access parallel transmission is realized. The LoRa-based parallel backscatter communication method and system can be widely applied to the technical field of parallel backscatter communication.
Owner:SUN YAT SEN UNIV

Signal acquisition and processing method and system based on multifunctional radar

The invention discloses a signal acquisition and processing method and system based on a multifunctional radar, and relates to the technical field of signal acquisition and processing, and the method comprises the steps: employing a quantum genetic algorithm to optimize radar transmission waveform parameters, including center frequency, bandwidth and frequency modulation slope, and generating a nonlinear frequency modulation waveform through FPGA hardware; a non-uniform sparse array is adopted to receive a target echo signal, time domain random interval sampling and frequency domain pseudo-random frequency point selection are synchronously implemented, and time-space-frequency three-dimensional compressed sensing observation data are formed; performing trilinear tensor joint sparse reconstruction on time-space-frequency three-dimensional compressed sensing observation data, decomposing a polarization scattering matrix eigenvalue from a reconstructed signal, and calculating a coupling characteristic quantity of eigenvalue entropy and micro-Doppler frequency; inputting the coupling characteristic quantity into a deep reinforcement learning model, and dynamically outputting a constant false alarm detection threshold, a moving target display filter order and a resource allocation weight; and detecting a threshold based on a constant false alarm rate.
Owner:XIAN XINCHEN ELECTRONIC TECH CO LTD

Systems and methods for radio-frequency adversarial deep-learning inference for automated network coverage estimation

Example systems and methods for radio-frequency adversarial deep-learning inference for automated network coverage estimation include a generative adversarial network (GAN) based approach for synthesizing RF maps in indoor scenarios. In some examples, a semantic map is utilized—a high-level representation of the indoor environment to encode spatial relationships and attributes of objects within the environment and guide the radio frequency (RF) map generation process. A new gradient-based loss function is introduced that computes the magnitude and direction of change in RSS values from a point within the environment. Some examples incorporate this loss function along with the antenna pattern to capture signal propagation within a given indoor configuration and generate new patterns under new configuration, antenna (beam) pattern, and center frequency.
Owner:THE ARIZONA BOARD OF REGENTS ON BEHALF OF THE UNIV OF ARIZONA

Composite fault signal separation method based on adaptive spectral kurtosis deconvolution

The invention discloses a composite fault signal separation method based on adaptive spectral kurtosis deconvolution. The method comprises the following steps: S1, carrying out noise reduction processing on an original composite fault signal; s2, separating the composite fault signal after noise reduction through Hilbert envelope demodulation; s3, optimizing a low-pass filter and a high-pass filter through a Bayesian objective function, and constructing a band-pass filter and a band elimination filter; and S4, carrying out iterative filtering on the composite fault signal after noise reduction through a band-pass filter and a band elimination filter, constructing a frequency-bandwidth fast spectral kurtosis graph according to a fast spectral kurtosis deconvolution method, obtaining a center frequency and bandwidth range corresponding to the maximum spectral kurtosis, and separating out the weak fault signal in the step S2. According to the method, a spectral kurtosis graph is constructed by combining a low-pass filter and a high-pass filter through a fast spectral kurtosis deconvolution method to determine the center frequency and the bandwidth range, targeted separation is carried out on composite fault signals, an initial filtering parameter range is provided for Bayesian optimization, and the fault separation efficiency and accuracy are improved.
Owner:NANCHANG INST OF TECH

Hydroelectric generating set state online monitoring system and method based on data analysis

The invention discloses a hydroelectric generating set state online monitoring system and method based on data analysis, and relates to the technical field of data analysis. The method comprises the following steps: setting a training period, extracting a time domain feature vector and a frequency domain feature vector of each data packet, and training to generate a gated attention mechanism model; training and generating a mixed density network model according to the data packet containing the fault state label; according to the real-time fault risk probability, the latent variable representation vector and the real-time center frequency, whether abnormal features are analyzed or not is judged, if the abnormal features are analyzed, the contribution degree of each input feature to the real-time fault risk probability is calculated through a gradient approximation method, and an influence degree score is calculated; and taking the corresponding input features exceeding the influence degree score threshold as abnormal features, and outputting prompt information for operation and maintenance personnel to check, thereby improving dynamic environment response, identification precision degree and reliability of a monitoring system.
Owner:HUNAN WULING POWER TECH CO LTD

Metal microcrack ultrasonic detection method

The invention belongs to the technical field of metal crack detection, and discloses a metal microcrack ultrasonic detection method, which comprises the following modules: an ultrahigh frequency composite array probe with a center frequency dynamic adjustable range of 5-50 MHz; the dual-mode excitation and receiving module is used for independently generating a pulse reflection mode excitation signal and a diffraction mode chirp frequency modulation signal; the phase-controlled synthetic aperture dynamic focusing module is used for realizing + / -60-degree deflection and sub-wavelength level focusing of acoustic beams; the nonlinear harmonic enhancement module is used for exciting a crack nonlinear effect by superposing 1-2MHz fundamental waves; and a time-space-frequency three-domain data fusion module. According to the method, signal-to-noise ratio collapse caused by the diffraction effect in a traditional method is overcome, more importantly, the system has low-frequency penetrability and high-frequency resolution at the same time due to 80%-120% of broadband coverage of chirp frequency modulation signals, the diffraction signal gain is increased by 20 dB or above, a near-surface blind area is compressed to be within 0.2 mm, and the system can be applied to the field of radar imaging. And the core pain point of missing detection of the near-surface microcracks of the thin-wall component is solved.
Owner:ANHUA PRECISION TECH (SUZHOU) CO LTD

Interference filtering system for monitoring partial discharge signal of power equipment

The invention discloses an interference filtering system for power equipment partial discharge signal monitoring, relates to the technical field of power equipment partial discharge monitoring, and effectively inhibits interference of interference signals on partial discharge signal detection. According to the method, the partial discharge signal of the power equipment is collected, Fourier transform is performed on the partial discharge signal to generate the corresponding partial discharge spectrum signal, the center frequency of the interference signal is extracted from the partial discharge spectrum data, and the suppression frequency point is established according to the center frequency of the interference signal. The method comprises the following steps of: generating real-time partial discharge spectrum data, extracting spectrum data of an interference signal from the real-time partial discharge spectrum data according to a suppression frequency point, further obtaining pure spectrum data, generating a partial discharge time domain signal according to the pure spectrum data, and further performing peak searching processing on the partial discharge time domain signal to obtain PRPS characteristic spectrogram data.
Owner:HUAYUAN CABLE (TIANJIN) CO LTD

High-precision spectral interference signal demodulation method for micro distance measurement

The invention discloses a high-precision spectral interference signal demodulation method for micro distance measurement. The method comprises the steps of S1, interference spectrum shaping; measuring an interference spectrum and a reference spectrum; selecting a six-item combined cosine window as a primary function of an interference signal to obtain a shaped interference spectrum; s2, performing non-uniform Fourier transform to obtain a frequency spectrum of the target signal; s3, on the basis of a multi-spectral-line interpolation algorithm, interpolation is carried out on the window function to solve a fitting function, and a center frequency k is obtained; and S4, outputting a result. And solving and outputting an optical path difference d. According to the method, a six-item cosine combination window is selected as a primary function of an interference signal, and the problem that the accuracy of signal extraction is influenced by mutual superposition of side lobes and even main lobes of a direct current item and a solved frequency item is solved; an interference spectrum is processed by using a fast non-uniform Fourier transform algorithm, accuracy can still be kept under the conditions that the distance to be measured is increased and sampling is gradually sparse, and the problem of resampling deviation caused by a traditional interpolation method can be solved.
Owner:HEFEI UNIV OF TECH

Effective signal filtering and noise reduction method and system for tunnel water and mud inrush disaster micro-seismic event

The invention provides an effective signal filtering and noise reduction method and system for a micro-seismic event of a tunnel water and mud inrush disaster, and relates to the technical field of signal processing. Comprising the following steps: acquiring original signals of water-inrush and mud-inrush micro-seismic events; performing modal decomposition on the original signal by using a variational modal decomposition method to obtain a plurality of modal components; calculating a cross correlation coefficient between the original signal and each modal component; based on the center frequency of each modal component and in combination with the cross correlation coefficient, performing primary noise reduction on the plurality of modal components; performing de-trend fluctuation analysis on the modal components after the primary noise reduction screening to obtain scale indexes of the modal components after the primary noise reduction screening, and performing secondary noise reduction based on the scale indexes; and reconstructing the modal component after the secondary noise reduction screening to obtain a micro-seismic signal after noise reduction filtering. According to the method, the problem that noise and effective signals in part of modal components are mixed is solved, and the weak signal extraction capacity is improved.
Owner:SHANDONG UNIV +2

Puncturing-based 240 MHz transmission

In a wireless local area network (WLAN) system, a transmission STA can transmit a PPDU via a 320 MHz channel, and a Medium Access Control (MAC) signal may be generated for the PPDU. The MAC signal may include puncturing pattern information and channel center frequency segment (CCFS) information for a 320 MHz band. The CCFS information may include a first CCFS field related to channel center frequency (CCF) information of a primary 160 MHz channel, and a second CCFS field related to CCF information of a 320 MHz channel.
Owner:LG ELECTRONICS INC

Multi-mode communication and perception channel twin AI data set generation method

The invention discloses a multi-mode communication and perception channel twinborn AI data set generation method. The method comprises the following steps: establishing a high-precision three-dimensional indoor scene model and an outdoor scene model; configuring parameters of a signal receiving and transmitting end and the RIS, determining dielectric constants and magnetic conductivities of different object surfaces in a scene according to a signal center frequency, and determining reflection, refraction, scattering and diffraction effects of electromagnetic waves in different media based on a geometric optical theory and a geometric diffraction theory; calculating channel parameters of each ray, generating a channel matrix and a channel intensity thermodynamic diagram based on the channel parameters, and generating a complete data set in combination with scene information; and aligning the coordinates of the scene and the ray, loading and rendering ray data and a channel intensity thermodynamic diagram based on a moving path selected by a user, and obtaining a visual file of the multi-modal channel twin AI data set. According to the invention, refined materials and electromagnetic properties are given to objects in a scene, and efficient simulation and second speed visualization of electromagnetic wave propagation are realized.
Owner:ZHEJIANG UNIV

Parameter optimization method for W-band coupling multi-band filter

The invention discloses a W-band coupling multi-band filter parameter optimization method, which is characterized in that each step from the determination of an ideal characteristic function to the adjustment of a final performance index has a clear guidance and optimization target through a systematic design process, so that the design efficiency is improved, and the design cost is reduced. And the frequency response characteristic of the filter can accurately meet the expectation. The design indexes of the filter, such as center frequency and bandwidth, are determined, so that the design process is more accurate, and the filter can meet the requirements of a specific communication system. And the accurate coupling matrix is automatically generated by utilizing the coupling matrix comprehensive software, so that the design efficiency and accuracy are improved. By converting the coupling matrix into specific physical design parameters, detailed guidance is provided for actual manufacturing of the filter, and seamless joint from design to manufacturing is ensured. The resonant frequency of the resonant cavity is calculated to ensure that the filter works at the predetermined frequency, and the selectivity and insertion loss performance of the filter are improved.
Owner:AEROSPACE SCI & IND ACAD OF COMM TECH