114 results about "Frequency space" patented technology

The invention provides a partial discharge mode recognition method based on multi-channel sound signal time-frequency space spectrogram fusion, and belongs to the technical field of partial discharge mode recognition. The problem that information redundancy and difference between existing multi-channel sound signals cannot be effectively fused and discriminant features cannot be extracted is solved. The method comprises the following steps: collecting and summarizing multichannel sound signal data corresponding to different partial discharge models as a data set; performing normalization processing on the original multichannel partial discharge sound signal, and mapping a time domain signal into time-frequency joint distribution to obtain a gray scale time-frequency spectrogram; performing multi-scale and multi-direction decomposition on the grayscale time-frequency spectrogram to obtain each channel sub-graph; different fusion strategies are used for fusing the channel sub-graphs obtained through decomposition; reconstructing a time-frequency space fusion spectrogram from the fused sub-graphs of each channel through inverse transformation; extracting features; identifying a partial discharge mode; the method is applied to partial discharge detection.

The invention discloses an I SAR fusion imaging method, system and device based on centralized multi-station networking, and relates to the technical field of radar imaging, and the method comprises the steps: obtaining I SAR frequency domain echo data of each subsystem; performing frequency domain space matching on the frequency domain echo data based on the observation angle difference of each radar; performing frequency domain alignment processing on the matched frequency domain data; and fusion and imaging are carried out. According to the I SAR fusion imaging method, system and device based on the centralized multi-station networking, the imaging resolution is remarkably improved, multi-station frequency domain data are mapped to a unified local frequency space through a coordinate transformation matrix, non-uniform data are subjected to uniform reconstruction in combination with a self-adaptive interpolation algorithm, and the imaging resolution is remarkably improved. The frequency domain integration interval is effectively expanded, compared with a single-station I SAR which only covers a local area of the total rotation angle of the target, the range resolution is further optimized through multi-station bandwidth synthesis in the range direction, and high-fidelity reconstruction of the target in the complex shape is achieved.

The application discloses a large-scale PDE neural operator pre-training method based on a high-frequency enhancement module, a partial differential equation (PDE) data set is composed into a mixed data set, a large-scale PDE neural operator is constructed, preprocessed PDE data is mapped to a latent representation space through a space-time encoder, a frequency decomposition module is used for frequency space mapping, the frequency decomposition module includes parallel high-frequency branches and low-frequency branches, and high-frequency features and low-frequency features are obtained respectively; a multi-frequency fusion module (GFM) adaptively fuses the high-frequency features and the low-frequency features through a gating mechanism; finally, a prediction head is used for processing the fused features, and final output features, i.e., predicted physical features of a next time step, are obtained. The application firstly introduces an explicit frequency division and a high-frequency enhancement mechanism, the input field is divided into low-frequency and high-frequency parts, the low-frequency branches / high-frequency branches are used for processing respectively, and thus the model can simultaneously consider global trend modeling and local gradient detail reconstruction.

The application provides a bridge damage assessment method and system caused by ship collision and a medium, and relates to the technical field of bridge health monitoring. The method comprises the following steps: collecting acceleration response signal arrays of different heights and positions of a bridge pier, and generating a time series matrix; drawing a time-frequency coherence spectrum under different base functions, and obtaining a coherence spectrum entropy; determining the optimal base function based on the information entropy principle; obtaining the local correlation coefficient of the time series matrix in the time-frequency space under the optimal base function, and drawing a time-frequency coherence spectrum; evaluating the correlation and dependence degree between time series according to the local correlation coefficient and the time-frequency coherence spectrum, and judging whether the ship-bridge collision damage occurs; if the collision damage occurs, calculating the time-frequency coherence damage factor of the time series matrix at different positions, and determining the collision position and the collision degree according to the maximum protruding value in the time-frequency coherence damage factor trajectory curve. The method can effectively separate the influence of environmental factors, and provides basic method support for establishing the ship-bridge collision damage assessment technology.

The present invention discloses a low-complex, reliable multidimensional orthogonal time-frequency space (ND-OTFS) modulation-based communication system for uplink and downlink wireless communication between resource-constrained Internet of Things (IoT) and machine-to-machine (M2M) devices comprising at least one transmitter configured to transmit bit stream involving N-Dimensional signal mapper and OTFS frame and at least one receiver configured to be integrated into said IoT or M2M devices, featuring a low-complexity detector for receiving the transmitted bit stream.

The invention discloses a vibration test and state monitoring method and system for an in-operation high-voltage circuit breaker, and the method comprises the steps: carrying out the energy propagation time sequence test of a multi-measurement-point vibration signal, constructing an energy flow direction topological graph, and precisely positioning a vibration source region through energy ratio analysis and path backtracking; acquiring a response time constant by adopting an impact response attenuation test, and converting a vibration source into a fault space positioning coordinate through space grid division and rate matching; a frequency-space mapping relation is established based on a fault position, and vibration characteristics are comprehensively described through peak frequency time sequence tracking and nonlinear component identification such as frequency multiplication, modulation and transient state; performing dispersion analysis on the continuous action impact peak value to form an action consistency deviation, and fusing a nonlinear feature set to quantitatively evaluate the mechanical degradation degree; the grading test density is generated according to the degradation state, the time period test unit is determined, the state grading test benchmark is established to realize mechanical state grade judgment, and the equipment operation reliability and the monitoring efficiency are improved.

The present disclosure proposes a precoding method, apparatus and device, and a storage medium, the method comprising: a sending device determining N layers of first signal streams needing to be sent in an orthogonal time-frequency-space OTFS system, N being a positive integer; converting the N layers of first signal streams from a time delay Doppler DD domain to a time frequency domain to obtain N layers of second signal streams; pre-coding the N layers of second signal streams to obtain M paths of third signal streams, wherein M is a positive integer; converting the M paths of third signal streams from a time-frequency domain to a time domain to obtain M paths of fourth signal streams; and sending the fourth signal stream to a receiving device. The embodiment of the invention provides a pre-coding method which can be applied to the OTFS system so as to successfully realize signal pre-coding in the OTFS system.

The application discloses a core RQD segmentation method based on frequency-space feature enhancement and long-distance dependence, comprising: spatial feature coding is performed on a core tank image to obtain output features, and a core feature map is determined; a morphological center axis of a core instance mask is extracted, and an accurate pixel length is calculated; a plurality of cores satisfying a core length threshold are screened, and a rock quality index in a region corresponding to the core tank is calculated. The application reduces technical bottlenecks such as loss of micro-fissure features, limited long-distance spatial dependence perception, discontinuous long-strip core segmentation and complex background interference in core segmentation; the average precision mean on the NEU-Rock dataset reaches 95.5%, which significantly reduces the parameter quantity and calculation amount compared with the prior art; and the core image can be converted into an accurate rock RQD index in real time and with high fidelity, thereby providing objective and robust digital support for mineral exploration and rock mass stability evaluation.

The application discloses a stratum absorption compensation method, system, device, storage medium and program product. The method comprises the following steps: converting an original seismic record into a frequency space domain seismic record; constructing a target function of a signal space prediction operator according to the frequency space domain seismic record and solving the target function to obtain a low-frequency signal space prediction operator; based on the frequency extendibility of the signal space prediction operator, a high-frequency signal space prediction operator is obtained by extrapolation of the low-frequency signal space prediction operator, and then a full-frequency signal space prediction operator is obtained; a full-frequency prediction error filter is obtained according to the full-frequency signal space prediction operator; and based on the full-frequency prediction error filter and the frequency space domain seismic record, a target function of stratum absorption compensation is constructed and solved to obtain an absorption-compensated seismic record. The application can inhibit the influence of noise interference on absorption compensation and improve the recovery precision of absorption compensation on seismic signals.

The application discloses a frequency-space domain alternating iteration seismic random noise suppression method and system, transforms a seismic signal from a time-space domain to a frequency-space domain, and obtains a frequency slice by taking data of a fixed frequency domain index; arranges the frequency slice into a Hankel matrix and performs singular value decomposition, selects singular values and corresponding singular vectors to perform rank reduction reconstruction on the Hankel matrix; obtains the reconstructed frequency slice, and takes the next frequency slice to complete spatial direction denoising; takes single seismic trace data of a fixed space domain index in the frequency-space domain data, arranges the single seismic trace data into a Hankel matrix and performs singular value decomposition, selects singular values and corresponding singular vectors to perform rank reduction reconstruction on the Hankel matrix; then, the reconstructed single seismic trace data is obtained through anti-diagonal average, the next seismic trace data is taken, the obtained frequency-space domain data after denoising is transformed back to the time-space domain, and a signal after noise suppression is obtained.

The invention discloses a large-scale PDE neural operator pre-training method based on a high-frequency enhancement module, and the method comprises the steps: forming a mixed data set through partial differential equation PDE data, constructing a large-scale PDE neural operator, mapping the preprocessed PDE data to a potential representation space through a space-time encoder, carrying out the frequency space mapping of the data through a frequency decomposition module, and carrying out the pre-training of the large-scale PDE neural operator. The frequency decomposition module comprises a high-frequency branch and a low-frequency branch which are parallel to obtain high-frequency features and low-frequency features respectively; the multi-frequency fusion module GFM adaptively fuses the high-frequency features and the low-frequency features through a gating mechanism; and finally, the fused features are processed through a prediction head, and final output features, namely predicted physical features of the next time step, are obtained. According to the method, an explicit frequency division and high-frequency enhancement mechanism is introduced for the first time, an input field is decomposed into a low-frequency part and a high-frequency part, and a low-frequency branch and a high-frequency branch are adopted for processing, so that the model can give consideration to global trend modeling and local gradient detail reconstruction at the same time.

The invention discloses a strain clamp X-ray image enhancement and defect identification method and system, and belongs to the technical field of image processing. The method comprises the following steps: acquiring an internal image of a wire clamp through X-rays, and performing feature reconstruction and defect modeling in a frequency space and a potential space; a multi-scale frequency encoder is adopted to extract detail features of a tension clamp image, a frequency domain structure selection module is combined to enhance defect edge response, and finally robust identification of an abnormal region is realized in a potential diffusion process. Therefore, good defect detection precision and boundary definition can be kept under the complex conditions of strong background noise interference, low image contrast and the like.

The invention belongs to the technical field of relay protection of a power distribution network of a power system, and provides a single-phase broken line grounding fault detection method for an ungrounded neutral system, which comprises the following steps of: 1, acquiring three-phase current signals of each feeder line; step 2, performing morphological filtering processing on the acquired negative sequence current signal; step 3, mapping the filtered negative sequence current signal to a time-frequency space with u as a variable; 4, searching an optimal twiddle factor according to the energy focusing characteristic of the time-frequency current signal; according to the method, the symmetric component method, the morphological filtering and the coordinate transformation technology are combined, so that the accuracy and the stability of single-phase broken line grounding fault feature extraction of the neutral ungrounded system are remarkably enhanced, and the precision and the reliability of fault detection are greatly improved; and meanwhile, the optimal twiddle factor is adaptively determined based on the feeder energy concentration ratio, so that the detection strategy can flexibly adapt to different fault conditions, and the fault detection efficiency and success rate under a complex power grid structure and variable operation conditions are effectively improved.

The invention discloses a distributed photovoltaic aggregation frequency modulation standby optimal configuration method considering node frequency security constraints under transmission and distribution cooperation. The method comprises the following steps: describing uncertainty of photovoltaic aggregation frequency modulation capability by using a Gaussian mixture model, and establishing a power transmission network node frequency response model containing frequency space distribution characteristics; taking minimization of system power generation and frequency modulation reserve cost as a target, and combining opportunity constraint planning to construct an optimal configuration model; a response model is reduced based on a frequency divider theory, a Bernstein polynomial approximates frequency dynamics, and a differential algebraic equation is converted into an algebraic equation; then, binary expansion and Gaussian mixture model linear invariance are utilized to convert the model into a mixed integer linear programming model, and Bernstein polynomial convex hull property tightening constraint is combined; and finally, solving the model to obtain the optimal photovoltaic aggregation frequency modulation reserve capacity and control parameters. The frequency space distribution is accurately described, the problem of insufficient frequency safety risk identification is solved, and the frequency safety level of a power system is improved.

The invention relates to the technical field of signal processing, in particular to a multi-dimensional signal simulation generation method based on user interface control, which comprises the following steps: S1, creating a three-dimensional visual coordinate system; s2, capturing a frame selection operation of a user in a three-dimensional coordinate system, and generating a dynamic coupling relation matrix; s3, cutting an original signal flow into N signal slice units according to the dynamic coupling relation matrix established in S2; s4, waveform recombination is carried out on the signal slice units generated in the S3, and recombination coupling signal flow is formed; and S5, decomposing the recombined coupling signal flow generated in the S4 into a time signal layer, a frequency signal layer and a space signal layer. According to the method, the dynamic coupling relation matrix is constructed, and the parameters of the frequency and the space slice are adjusted in real time, so that the precision and the flexibility of multi-dimensional signal simulation are effectively improved, and the consistency and the coordination of the signals in the time-frequency space are ensured.

The application relates to a kind of orthogonal time-frequency space (OTFS) signal detection methods based on message selective transmission, suitable for high-speed mobile communication scene.The application first adds the calculation of symbol log-likelihood ratio (LLR) on the basis of original MP detection algorithm, improves the accuracy of message transmission, and optimizes the factor graph structure by introducing edge grouping strategy to group edges with different channel coefficients, reduces the influence of loop effect on detection performance.Then, a damping factor is introduced in the iteration process to control the message oscillation amplitude in each iteration and accelerate the convergence speed of the algorithm.During the detection process, the D-MsP detector further improves the detection performance and convergence efficiency of the OTFS signal in the multipath channel by using the sparsity principle.The D-MsP detector achieves a good balance between performance and computational complexity, significantly reduces the computational overhead while ensuring high detection accuracy, and is particularly suitable for high-speed mobile communication scenarios.

A transmission station that performs wireless communication with a receiving station at a predetermined carrier frequency performs orthogonal frequency division multiplexing on a symbol sequence, performs orthogonal time frequency space multiplexing on a symbol sequence, performs switching between orthogonal frequency division multiplexing and orthogonal time frequency space multiplexing to input a symbol sequence obtained by mapping a bitstream to only one of them, obtains a relative velocity between the transmission station and a receiving station, controls the switching based on a velocity; and transmits a switching notification that is a control signal to the receiving station, when the switching is controlled.

A method and apparatus are disclosed to reduce MU-MIMO complexity in a receiver. In one embodiment, a method implemented in a network node includes determining a frequency dispersion of a channel for a wireless device (WD); and based at least in part on the determination of the frequency dispersion, determining at least one frequency spacing for at least one weight associated with the channel. In another embodiment, a method implemented in a WD includes transmitting a signal to the network node; and receiving an allocation of at least one time-frequency resource based at least in part on a determination of a frequency dispersion on the transmitted signal, the at least one time-frequency resource being shared between the WD and at least one other WD.

A communication frame for an Orthogonal Time-Frequency Space (OTFS) transmission system includes at least one first type block and at least one second type block. The first type block comprises data signals arranged in a two-dimensional pattern along the delay and Doppler domains, wherein at least one data signal has a superimposed pilot signal. The second type block comprises data signals arranged in a two-dimensional pattern along the delay and Doppler domains, which may or may not have a superimposed pilot signal. At least one second type block is surrounded by a first type block in the delay domain, and one or more first type blocks surrounding the second type block have at least one identical data symbol and an associated identical superimposed pilot symbol at the same position in the two-dimensional pattern. An OTFS transmitter generates and transmits the communication frame, and a receiver utilizes its characteristics for oscillator frequency offset compensation and channel estimation.

The present disclosure relates to a channel estimation method based on orthogonal time-frequency-space modulation technology. The method comprises establishing a model of orthogonal time-frequency-space channel estimation, which comprises a time-delay Doppler domain received signal, a sparsity adaptive matching pursuit algorithm and a denoising network; processing the time-delay Doppler domain received signal by using the sparsity adaptive matching pursuit algorithm to reconstruct a delay Doppler domain channel; and inputting the delay Doppler domain channel into the denoising network for denoising processing to obtain a denoised channel response. The method can reconstruct the delay Doppler domain channel without relying on prior information of the number of channel paths, and can eliminate the corresponding noise of the delay Doppler domain channel.

The invention relates to OTFS-based communications with improved resource allocation. An orthogonal time-frequency space (OTFS) communication method for communicating between a user equipment (UE) and a base station (BS) is provided. The OTFS communication method comprises the step of transmitting (103), in particular by the UE, a report comprising a delay and a Doppler shift to the BS.

The invention relates to the technical field of remote sensing image fusion, in particular to an image feature optimization fusion method, a panchromatic sharpening method and a product. According to the method, the low-frequency structural features of the PAN low-level features are enhanced through the FMB path in the HCB, the high-frequency detail features of the PAN low-level features are enhanced through the OLFAB path in the HCB, and the enhanced PAN features are generated from the enhanced low-frequency structural features and the enhanced high-frequency detail features at the tail end of the paths through addition. Similarly, the enhanced LRMS features are generated through the HCB. Through N times of HCB optimization, enhanced PAN features and LRMS features meeting preset requirements are obtained, high-frequency details are reconstructed and high-frequency response is enhanced while the continuity of a low-frequency space structure is kept, and spectrum fidelity and space detail recovery are considered; therefore, the technical problem that a traditional feature optimization fusion method is difficult to give consideration to spectrum fidelity and space detail recovery is solved.

The invention discloses a signal recovery method assisted by spatial modulation and space-time codes, which comprises the following steps of: 1, performing spatial modulation on information bit stream groups according to the number of time slots and the number of carriers to obtain spatial modulation symbols; 2, mapping the spatial modulation symbols into a space-time coding structure; 3, performing orthogonal time-frequency-space multi-carrier modulation on the spatial modulation symbols with the same transmission period, and transmitting the data symbols on a plurality of transmitting antennas respectively; and step 4, carrying out signal detection recovery on the transmission data symbols obtained in the step 3 based on the special sparsity of the signal structure. The method is used for recovering various source end signals which cannot be directly measured, high transmission rate and high diversity gain are realized, and the problems of poor signal detection performance and relatively high calculation complexity in the signal recovery process of a multi-antenna multi-carrier system are solved.

Methods and systems for orthogonal time frequency space (OTFS) communication using predefined basis signals are described. An example digital communication method includes receiving a signal over a communication channel, determining an estimate of the communication channel from one or more pilot symbols in the signal transmission. Herein the one or more pilot symbols are assigned along a delay-Doppler resource grid. The method further includes equalizing non-pilot symbols in the signal transmission by rotating the estimate of the communication channel according to grid locations of the one or more pilot symbols along the delay-Doppler resource grid at other grid locations, and recovering data bits from the equalized non-pilot symbols.

The application belongs to the technical field of seismic exploration signal processing, and discloses a method and system for suppressing Rayleigh surface waves based on adaptive frequency modulation characteristic mode decomposition, which comprises the following steps: converting a seismic signal to a frequency space domain by using Fourier transform, and extracting an intrinsic modal component by using an adaptive frequency modulation signal mode decomposition method; screening a modal component containing Rayleigh surface waves according to the characteristics of Rayleigh surface waves in the frequency space domain, and performing adaptive filtering to suppress Rayleigh surface waves in the intrinsic modal component; reconstructing signals of the intrinsic modal component after suppression and the remaining components after screening, and performing Fourier inverse transform, so that an effective signal is finally output, which is the result after Rayleigh surface wave suppression.

The invention relates to the technical field of power grids, and discloses a zero-flux-control iron core magnetic conductivity data analysis method and system, and the method comprises the following steps: obtaining iron core geometric parameters and harmonic signal data, and generating a frequency-space dynamic graph; inputting the frequency-space dynamic graph into a frequency perception graph neural network, and outputting a space-frequency mapping relation; calculating the dynamic magnetic conductivity of each position of the iron core by using a space-frequency mapping relation, and generating a magnetic conductivity distribution field; and calculating a compensation current based on the dynamic magnetic conductivity distribution, and outputting a final compensation current control instruction. According to the method, a unified modeling framework of frequency and space is established, and a complex frequency-space mapping relation is learned by using the graph neural network, so that accurate analysis and compensation on sub-harmonic space influence are realized, the technical problem of insufficient measurement accuracy of a new energy grid-connected point under a low-frequency oscillation condition is solved, and the measurement accuracy of the new energy grid-connected point is improved. And a reliable measurement basis is provided for stable operation of a new energy high-permeability power grid.

The invention discloses a signal detection method of an orthogonal time-frequency space modulation system, which is suitable for a high-speed mobile communication scene with a sparse multipath structure. According to the method, on the basis of a traditional message propagation algorithm, a layered message propagation mechanism is provided, observation nodes corresponding to received signals are divided into a plurality of layers, and message updating is executed layer by layer in each iteration: the observation nodes in each layer transmit interference term mean value and variance information to variable nodes; and the variable node immediately returns the updated symbol probability quality function. The transmission efficiency of the information in the factor graph is remarkably improved by allowing the updated information in the same round of iteration to participate in the next layer of calculation in advance. Compared with the original synchronous iteration mode, the method provided by the invention has the advantages that the convergence speed is accelerated and the overall calculation complexity is reduced while the similar bit error rate performance is maintained, and the method is suitable for a high-dynamic and low-delay wireless communication system.

This invention discloses a sound event detection method based on the fusion of multi-scale spatial features and coordinate attention, belonging to the field of sound event detection technology. It aims to address the problems in existing sound event detection methods, such as the limited receptive field of the network, which makes it difficult to capture multi-scale temporal span features, and the inability to accurately focus on target sounds and suppress noise in complex time-frequency spaces. This method innovatively introduces a multi-scale coordinate attention module into the sound event feature extraction network. This module first uses parallel dilated convolutions with an increasing time dilation rate to obtain multi-scale temporal features and performs fusion and dimensionality reduction. Then, it employs a dual-axis time-frequency decoupling mechanism, performing adaptive pooling aggregation along both the time and frequency dimensions to generate directional time attention weights and frequency attention weights. Finally, the dual-axis weights are used to recalibrate the multi-scale features. This method significantly improves the accuracy and robustness of sound event detection.

The application discloses a broadband high-frequency space power combiner, which comprises a partition plate and two bases, the partition plate is arranged between the two bases, the base and the partition plate form two waveguide cavities, a first PCB plate is arranged in each waveguide cavity, a radio frequency circuit is arranged on the first PCB plate, a second PCB plate is arranged on the two surfaces of the partition plate facing the first PCB plate, and an EBG structure is arranged on the second PCB plate. The EBG structure is arranged on the surface of the partition plate facing the PCB plate of the radio frequency circuit, so that the influence of resonance modes on the combiner can be effectively avoided; the EBG structure is arranged to inhibit resonance, so that the size of the waveguide cavity does not need to be reduced, and the EBG structure does not need to separate the waveguide cavities, and the circuit layout on the first PCB plate is not affected. The application can be widely applied in the field of power combiners.