35 results about "Multipath delay" patented technology

The invention provides a synchronization adjustment method and system, computer equipment and a storage medium, and relates to the technical field of communication, and the method comprises the steps: obtaining synchronization information and an air interface signal of a current cell where a terminal is located; generating a first time domain signal based on the synchronization information; performing down-sampling processing on the air interface signal to obtain a second time domain signal; performing correlation calculation on the first time domain signal and the second time domain signal to obtain a correlation value sequence; and carrying out weight gravity center estimation on a peak value in the correlation value sequence, determining a timing offset, and adjusting a windowing position according to the timing offset to complete synchronous adjustment. According to the synchronization information disclosed by the invention, the accurate timing position is obtained by carrying out weight-based correlation calculation on the synchronization information and the air interface signal, so that the time drift error of the terminal in the signal receiving process is counteracted. The method is especially suitable for scenes with wide coverage and multipath delay exceeding the cyclic prefix length, can significantly reduce inter-symbol interference, and improves the synchronization precision and overall demodulation performance of a terminal receiver.

The invention relates to a waveguide and scattering mixed channel multipath time delay calculation method in different waveguide environments, which comprises the following steps of: determining the propagation path length of electric waves in an evaporation waveguide channel according to the height of an evaporation waveguide and the heights of transmitting and receiving antennas of a maritime beyond visual range communication system by utilizing a ray tracing model; calculating the propagation path length of the electric wave in the troposphere scattering channel; the multi-path time delay of the evaporation waveguide and troposphere scattering mixed channel under different elevation angles of the transmitting and receiving antennas is obtained by utilizing the height of the evaporation waveguide, the heights of the transmitting and receiving antennas of the maritime beyond-the-horizon communication system, the propagation path length of electric waves in the evaporation waveguide and troposphere scattering channel and the propagation speed of the electric waves. According to the method, the evaporation waveguide height, the transmitting antenna height and the communication distance are substituted into the ray tracing model, the multipath time delay of the evaporation waveguide and the troposphere scattering mixed channel is calculated, and the multipath time delay of the evaporation waveguide and the troposphere scattering mixed channel under the offshore beyond-visual-range condition can be rapidly calculated.

The invention relates to a precision improvement method for data completion of an intelligent electric meter. The method comprises the following steps: sampling a plurality of first electric meter data sequences to generate an electric meter sequence matrix and a mask matrix; performing multi-path delay embedding transformation on the electric meter sequence matrix and the mask matrix, dividing an obtained first tensor and a mask tensor into first sub-tensors and mask sub-tensors of a plurality of time blocks, and decomposing each first sub-tensor into a first core sub-tensor and a factor matrix based on the mask sub-tensors; inputting a first target sequence generated based on the plurality of first core sub-tensors and a corresponding position coding result into a Transform model to obtain a plurality of second core sub-tensors; and inverse tensor decomposition is carried out according to the plurality of second core sub-tensors and the factor matrix, inverse multipath delay embedding transformation is carried out on the obtained second tensor, parameter adjustment is carried out according to the numerical difference of the second ammeter data sequence after inverse transformation and the first ammeter data sequence at the same missing position, and a completion model is trained iteratively. The method can improve the accuracy of data completion.

The present invention discloses a two-stage target positioning method under a long L-shaped building layout, which is applied to the field of target positioning technology in complex urban environments. In order to solve the problem that the existing technology can only effectively detect targets in the first-order reflection area, the present invention first divides the long L-shaped scene into multiple reflection areas according to the ray tracing model, and analyzes the electromagnetic propagation model therein respectively; then, based on the fact that diffraction paths exist in all non-line-of-sight areas, the area where the target may exist is delineated using the time delay corresponding to the diffraction path; secondly, the area is divided into different grids according to the radar range resolution, and the corresponding theoretical time delay is calculated according to the established multipath model; finally, the accurate target position is obtained by matching the grid theoretical multipath delay with the received echo multipath delay. The method of the present invention can realize non-line-of-sight target positioning in a large depth scene, and reduces the complexity of the calculation while ensuring the positioning accuracy.

A channel feedback method, apparatus and system. The method comprises: acquiring multipath component information of a communication channel between a first device and a second device; on the basis of a self-supervised neural network, performing processing on the multipath component information and second channel information, so as to obtain intermediate information; and sending the intermediate information, wherein the second channel information is determined on the basis of first channel information and multipath delay information, the second channel information comprises a variable channel impulse response (CIR), the first channel information comprises a channel frequency response (CFR), which is obtained by means of a measurement, and the intermediate information and the multipath component information are used for determining a reconstructed CIR. By means of the solution, channel feedback is performed in combination with multipath component information and a self-supervised neural network, thereby reducing measurement overheads and feedback overheads.

This disclosure provides a method for estimating target depth and velocity based on multipath delay calculation. The method includes: estimating multipath delay values ​​using cepstral analysis based on acoustic signals received by a hydrophone; calculating target depth and velocity using three consecutive multipath delay measurements based on the relationship between multipath delay values ​​and target depth and velocity under different reflection conditions, obtaining the target depth and velocity range under different reflection conditions through point-by-point calculation; and removing unreasonable data based on a reasonable range of parameters determined by actual environmental information, selecting the final target depth and velocity range as the estimation result. This invention avoids the difficulty of traditional methods that simultaneously utilize both surface and seabed multipath delays or combine surface / seabed multipath delays with pitch angles for target depth and velocity estimation; it can also achieve depth and velocity measurement of targets by underwater unmanned platforms even with weak target signals.

This invention discloses a deep learning-based NLOS recognition method applicable to complex environments in multiple scenarios. First, the collected UWB channel impulse response data from multiple scenarios is transformed to obtain discrete multipath impulse response data. Multipath delay power data and multipath similarity data are then calculated to construct a new sample dataset, followed by data preprocessing. Next, a dual-input feature fusion deep learning NLOS recognition model based on multipath information is constructed to complete NLOS classification in UWB positioning systems. This deep learning-based NLOS recognition method, applicable to complex environments in multiple scenarios, can solve the problems of low recognition capability, poor generalization accuracy, and poor recognition effect in complex scenarios with limited data, thereby achieving high NLOS recognition accuracy and effectively improving UWB positioning accuracy in complex environments.

The present invention discloses a FPGA-based real-time radio frequency environment calculation device. Based on the calculation device, the present invention also discloses an FPGA-based real-time radio frequency environment calculation method, comprising: obtaining a channel characteristic information set and a signal sampling time value; the channel characteristic information set includes a channel multipath information set; the channel multipath information set includes each multipath channel path length and a corresponding channel response sequence; performing time delay calculation processing on the channel characteristic information set and the signal sampling time value to obtain a multipath delay value set; and performing calculation processing on the collected original signal based on the multipath delay value set and the channel characteristic information set to obtain a radio frequency environment signal.

The invention discloses a communication method and device. The method comprises the following steps: a sending end determines the length of a guard interval sequence according to a first parameter; the first parameter comprises at least one of the following items: the number of effective subcarriers of the scheduling bandwidth, an inverse fast Fourier transform (IFFT) length, a modulation and coding strategy (MCS), and a ratio of the number of occupied subcarriers to the number of effective subcarriers; a first symbol sequence is generated, the first symbol sequence comprises a guard interval sequence, and the first symbol sequence is a symbol sequence before precoding conversion; and outputting the first symbol sequence. Thus, when the sending end determines the length of the guard interval sequence, parameters of different dimensions such as the number of effective subcarriers, the IFFT length, the MCS, the ratio of the number of occupied subcarriers to the number of effective subcarriers and the like are considered, so that multipath delay interference of a single-carrier system is reduced conveniently through the guard interval sequence, and the transmission performance of the single-carrier system is improved.

The application discloses a power line channel estimation method, device and medium, and the method comprises the following steps: S1, a Vandermonde structure manifold matrix containing multipath delay information is constructed; S2, based on the Vandermonde structure manifold matrix, a super-complete manifold matrix containing all potential delay point positions is constructed, and a channel estimation problem is converted into a sparse representation problem; S3, an unconstrained optimization objective function is constructed; S4, singular value decomposition is performed on received OFDM pilot signal data of multiple time periods, a signal subspace is extracted, and compression and noise suppression of sampling data are realized; S5, the data compressed through step S4 is substituted into the optimization objective function constructed in step S3 to obtain high-precision multipath delay estimation; and S6, based on the multipath delay estimation, a complete power line channel response is reconstructed, and high-resolution and high-robustness channel estimation results are obtained in a power line channel environment with high noise and strong multipath interference at a relatively low calculation complexity.

The present invention discloses a method for calculating the maximum multipath delay based on the propagation path length within the line-of-sight range at sea. The method comprises the following steps: when the radio waves for communication between a first ship and a second ship are propagated via a direct path, the direct path length of the radio waves propagating within the line-of-sight range at sea is obtained based on the height of the transmitting antenna, the height of the receiving antenna, and the distance between the first ship and the second ship. The present invention solves the technical problem in existing line-of-sight communication scenarios at sea, in which the signal from the transmitting end reaches the receiving end via a direct path and multiple reflection paths, and the length of each path is different, resulting in different arrival times of the signal at the receiving end, thereby generating multipath delay. Larger multipath delays will cause inter-symbol interference, resulting in a decrease in the signal quality at the receiving end, an increase in the bit error rate, and further degradation of system performance.

The application is suitable for the technical field of filter data optimization, and provides a filter performance automatic evaluation method and system.The method comprises the following steps: generating a time delay shaping strategy according to the deviation direction and deviation amount between the current equivalent multipath delay spread parameter and the historical optimal interval; and performing time delay shaping processing on the echo signal of an input target filter based on the time delay shaping strategy, so that the equivalent multipath delay spread of the shaped echo signal falls into the historical optimal interval when entering the target filter, so that the echo peak value resolution is in an optimal state.The application does not depend on changing the structure of the filter itself, but realizes performance optimization by regulating the input signal characteristics, can further tap the processing potential of the existing filter, and improves the stability of the filtering effect and the accuracy of subsequent target identification.

The application discloses a signal processing method of power carrier communication based on OFDM modulation, relates to the technical field of power carrier communication, and comprises the following steps: S1, cyclic prefix and guard interval design and insertion; S2, improved synchronization algorithm for frequency offset processing; S3, noise suppression optimization of a front-end signal processing module; S4, parallel processing architecture design and task allocation; S5, channel estimation at a receiving end; S6, frequency domain equalization processing; S7, OFDM demodulation processing; and S8, symbol synchronization and data recovery. Through the steps S1 and S2, the effects of effectively resisting power line channel multipath delay, reducing inter-symbol interference and inter-carrier interference are achieved. Through the steps S3, S5 and S6, the effects of accurately identifying power line impulse noise and Gaussian noise characteristics and dynamically suppressing noise are achieved. Through the steps S4 and S8, the effects of improving signal processing efficiency by using a parallel processing architecture and avoiding processor overload are achieved, and meanwhile, the data error correction capability is enhanced by convolution coding or Turbo coding, so that the real-time performance and reliability of high-speed data transmission are ensured.

The invention relates to the technical field of underwater acoustic signal processing, in particular to a deep sea target sound source positioning system and method, and aims at solving the problem that a traditional DOA estimation positioning method has large errors. The invention provides a deep-sea target sound source positioning system and method. The method comprises the following steps: S1, performing two-dimensional plane conventional beam forming processing on a received deep-sea target signal to obtain a receiving arrival angle of the deep-sea target signal; s2, receiving arrival angle information according to the receiving arrival angle of the deep sea target, and reversely constructing a target position fuzzy surface in combination with an acoustic propagation model; s3, constructing a multi-path delay inequality fuzzy surface based on the propagation delay inequality of the receiving angle of arrival of the deep sea target among the multi-path paths; and S4, performing joint matching on the target position fuzzy surface in the S2 and the multi-path delay inequality fuzzy surface in the S3, and determining the accurate position of the target through a fuzzy function intersection point. According to the positioning system and method for the deep sea target sound source, the positioning precision is improved, and the error influence is reduced.

The invention discloses an ad hoc network duplex voice long-distance transmission method based on OFDM (Orthogonal Frequency Division Multiplexing), relates to the technical field of wireless communication, and effectively solves the contradiction of low spectrum efficiency and insufficient anti-interference capability of a traditional OFDM system in low-rate voice transmission through an adaptive subcarrier allocation and parameter optimization mechanism. The total bandwidth is dynamically divided into a voice dedicated subcarrier group and a data service subcarrier group, and a narrower subcarrier interval is adopted for a voice service to accurately match the bandwidth requirement of the voice service, so that the spectrum utilization rate is greatly improved on the premise of ensuring the voice quality, and the bandwidth of the voice service is greatly improved in the face of complex and changeable multipath interference in a riding environment. The cyclic prefix length is dynamically adjusted according to the channel maximum multipath delay estimated in real time, it is ensured that inter-symbol interference caused by multipath can be completely eliminated, frequency spectrum resource waste caused by a fixed long cyclic prefix is avoided, and intelligent linkage of the volume and the riding state is achieved.

This application provides a method and apparatus for determining a subarray of XL-MIMO line-of-sight. The method for determining a subarray of XL-MIMO line-of-sight includes: acquiring the channel impulse response of multiple antenna elements in a MIMO array; for each antenna element, calculating a first metric and a second metric based on the channel impulse response of the antenna element; the first metric characterizing the received energy level, and the second metric characterizing the degree of multipath delay dispersion; establishing a negative correlation coupling model between the first metric and the second metric based on a sample set composed of the first metric and the second metric of the multiple antenna elements; and determining a target antenna subarray from the MIMO array according to the negative correlation coupling model; wherein the multipath delay dispersion of the target antenna subarray is suppressed under the condition of satisfying the received energy requirements.

This application relates to a multi-source sensor fusion localization method and system for partial discharge in primary equipment of a substation. The method includes: constructing a digital twin model based on the equipment's three-dimensional geometric parameters, electromagnetic properties of the internal medium, and acoustic properties; acquiring ultra-high frequency electromagnetic wave signals and acoustic emission signals and performing multipath decomposition to obtain electromagnetic wave multipath delay cluster feature vectors and acoustic wave multipath delay cluster feature vectors; calculating path mismatch degrees for all hypothetical source point locations based on the feature vectors to obtain a path dependency matrix; calculating a wave velocity collaborative correction factor for each hypothetical source point location based on this matrix, and performing joint likelihood estimation by combining electromagnetic wave and acoustic wave path mismatch degrees to obtain a preliminary spatial likelihood distribution; and performing variational Bayesian inference on this distribution to obtain the localization result and confidence interval evaluation index. This method can effectively eliminate false localization points and significantly improve the accuracy and reliability of partial discharge localization in complex structural equipment.

This invention relates to the field of wireless communication transmission technology and discloses a data transmission method for weak network environments. The method includes: acquiring the channel impulse response of the first and second symbol periods of a wireless channel; extracting multipath delay parameters, signal amplitude parameters, and discrete time axis coordinates; mapping the parameters to a spatiotemporal parametric coordinate system; generating first and second channel feature surfaces; calculating the curvature variance of the first channel feature surface; when the curvature variance is lower than a preset correlation distortion threshold; extending the second channel feature surface along the evolution gradient trend to generate a predicted channel feature surface; thereby determining the equalizer tap coefficients and compensating for data symbol distortion. This invention enhances transmission reliability in highly dynamic weak network environments by locking the gradient divergence path generated by the linear algorithm in a Doppler shift environment through geometric surface physical continuity constraints.

The application discloses a long-distance duplex voice transmission method based on OFDM in an ad hoc network, and relates to the technical field of wireless communication.The application effectively solves the contradiction between low spectral efficiency and insufficient anti-interference capability of a traditional OFDM system in low-rate voice transmission through an adaptive subcarrier allocation and parameter optimization mechanism, dynamically divides the total bandwidth into a voice-dedicated subcarrier group and a data service subcarrier group, adopts a narrower subcarrier interval for voice service to accurately match the bandwidth requirement, thereby greatly improving spectral utilization rate under the premise of ensuring voice quality, and dynamically adjusts the cyclic prefix length according to the real-time estimated maximum multipath delay of a channel to ensure that the inter-symbol interference caused by multipath can be completely eliminated, and the spectral resource waste caused by a fixed-length cyclic prefix is avoided, and the intelligent linkage of volume and riding state is realized.

DMRS transmission methods and apparatuses, a device, and a storage medium, which relate to the technical field of communications. A method is executed by a terminal device. The method comprises: using K physical resource blocks (PRBs) as a unit to send or receive a DMRS of a data channel on at least one DMRS port, wherein the K PRBs include a plurality of DMRS ports, DMRS ports included in different PRBs are not completely the same, the at least one DMRS port is indicated by a network device from among the plurality of DMRS ports, and K is an integer greater than 1 (310). In the method, a large number of DMRS ports are distributed to a plurality of PRBs, thereby reducing DMRS resource overheads on each PRB; thus, the multiplexing of a large number of DMRS ports is supported by means of relatively low resource overheads in a low multipath delay scenario, thereby improving the spectral efficiency of data transmission.

The invention relates to the technical field of signal analysis, and discloses a navigation antenna signal identification system, which comprises an intermediate frequency signal identification module, a signal characteristic analysis module, a multipath effect analysis module and a signal analysis module, the intermediate frequency signal identification module is used for extracting a digital intermediate frequency signal of the original navigation signal; the signal characteristic analysis module is used for identifying the time-frequency characteristic and the array response characteristic of the digital intermediate frequency signal so as to identify the interference power spectrum density and the interference incoming wave direction of the signal and further determine the interference intensity and the interference type; the multipath effect analysis module is used for analyzing the multipath time delay distribution state and the multipath signal attenuation coefficient of the signal so as to evaluate the multipath effect severity of the signal; and the signal analysis module is used for adjusting analysis parameters of the signal based on the interference intensity, the interference type and the multipath effect severity so as to analyze the signal. According to the invention, the identification accuracy of the spaceflight line signal can be improved.

The invention discloses a signal processing method for power line carrier communication based on OFDM (Orthogonal Frequency Division Multiplexing) modulation, which relates to the technical field of power line carrier communication, and comprises the steps of S1, designing and inserting a cyclic prefix and a guard interval, S2, improving a synchronization algorithm to realize frequency offset processing, S3, performing noise suppression optimization on a front-end signal processing module, and S4, designing a parallel processing architecture and allocating tasks. S5, receiving end channel estimation, S6, frequency domain equalization processing, S7, OFDM demodulation processing, and S8, symbol synchronization and data recovery. According to the invention, through the steps S1 and S2, multipath time delay of a power line channel is effectively resisted, and inter-symbol interference and inter-carrier interference are reduced; through the steps S3, S5 and S6, the effects of accurately identifying the pulse noise and Gaussian noise characteristics of the power line and dynamically suppressing the noise are achieved; through the steps S4 and S8, the parallel processing architecture is utilized to improve the signal processing efficiency and avoid the overload effect of the processor, and meanwhile, the data error correction capability is enhanced through convolutional coding or Turbo coding, so that the real-time performance and reliability of high-speed data transmission are ensured.

The invention discloses a distributed moving target passive positioning method and system based on deep sea multipath time delay combination, and belongs to the technical field of deep sea target detection and positioning. In order to solve the problems that Doppler compensation and multipath time delay combined processing cannot be considered at the same time and a special positioning scheme for a moving target is lacked in the prior art, two hydrophone nodes horizontally arranged near the seabed are utilized; relative Doppler and multipath delay inequality information of radiation signals of a moving target reaching two hydrophone nodes through different propagation paths are combined, a multipath propagation geometrical relationship positioning model of the moving target is constructed by combining a spatial position relationship between the moving target and the hydrophone nodes, and the model is optimized and solved, so that the positioning precision of the moving target is improved. And continuous high-precision positioning of a moving target track is realized. According to the method, the huge calculated amount of matching field processing is avoided, the positioning precision is high, simple, efficient and robust positioning is realized, and the engineering applicability is remarkably improved.

The invention provides an inland river scene wireless channel lightweight modeling method based on a multipath energy ratio, and the method comprises the following steps: S1, constructing a 1: 1 three-dimensional model of an inland river scene through fusing a satellite map and a design drawing, and endowing ground features with corresponding electromagnetic parameters; s2, a dynamic convergence threshold value and an energy contribution threshold value are adopted to quantify multipath energy proportions of various ground features, and key ground features are screened; s3, dynamically adjusting the modeling range and the scene complexity based on the energy ratio; s4, counting the multi-path number proportion and energy distribution of each type of ground features, calculating single multi-path receiving power and total energy contribution, and providing data support for channel modeling; and S5, configuring simulation parameters, performing ray tracing simulation, optimizing a noise threshold value, and verifying the accuracy of multipath time delay and energy distribution through actually measured data. Through the method, classification statistics is effectively carried out on various ground feature types, so that scene settlement acceleration simulation is simplified, and the accuracy of scene modeling simulation is improved.

The invention discloses a device and a method for calibrating multipath delay parameters of a channel simulator, and relates to the technical field of wireless communication. Comprising an arbitrary waveform generator, an up-converter, a power divider, a channel simulator, a digital oscilloscope, a reference clock, a computer and a calibration reference plane. The method can avoid or improve the defects of the time domain pulse technology for calibrating the multipath delay parameter of the channel simulator, and provides a channel simulator multipath delay parameter calibration result with higher precision and larger bandwidth for the fields of broadband digital communication, 5G / 6G communication, radar signal processing, Internet of Things and the like.

The present invention provides a vehicle channel modeling method based on a geometric model and related equipment. The method includes constructing a broadband GBSM based on a dual-ring model, four quarter-cylinder models, and multiple confocal semi-ellipsoid models; determining the position information of a target scatterer in the broadband GBSM; calculating the CIR from a first vehicle array to a second vehicle array based on the broadband GBSM; and calculating channel characteristics based on the CIR. The present invention provides a broadband GBSM constructed based on the dual-ring model, four quarter-cylinder models, and multiple confocal semi-ellipsoid models, which can flexibly and efficiently simulate the distribution positions of scatterers in a city; and sets a multipath delay partitioning scheme based on different propagation delay differences and time-varying Doppler frequency shifts, and uses time-varying Doppler frequency shifts in channel characteristic calculations in the channel model, thereby more accurately characterizing the wireless propagation environment of urban V2V communication and thereby better describing the characteristics of urban vehicle flow density.

An information transmission method and apparatus are disclosed, to reduce the waste of transmission resources and improve the communication performance of a non-terrestrial network. A first communication apparatus receives configuration information regarding a first time unit, and performs information transmission on a non-terrestrial network channel based on the configuration information regarding the first time unit. The configuration information indicates a quantity (N) of symbols in the first time unit and a cyclic prefix (CP) corresponding to each symbol in the first time unit. A value of N and a value of the CP correspond to a multipath delay spread of the NTN channel, and N is a positive integer.

This invention relates to the field of digital information transmission technology, specifically to a bandwidth-adaptive dynamic rate-limited data distribution system. The system includes a physical layer state acquisition front-end, a signal-to-noise ratio (SNR) trend prediction front-end, a cross-layer rate-limiting decision front-end, and a distribution execution front-end. The physical layer state acquisition front-end acquires the SNR sequence of the target distribution link; the SNR trend prediction front-end inputs the SNR sequence into a Kalman filter model and outputs a predicted value of the available bandwidth of the link, the state transition matrix parameters of which are dynamically determined by the multipath delay spread value of the current link; the cross-layer rate-limiting decision front-end compares the predicted value of the available bandwidth of the link with the current sliding window congestion window value of the transport layer and takes the smaller value as the dynamic rate-limiting threshold; the distribution execution front-end adjusts the data packet transmission interval of the transmission queue according to the dynamic rate-limiting threshold. This scheme reduces the transmission rate in advance based on the bandwidth prediction results before physical layer channel fading causes packet loss at the transport layer.

This application relates to a method for improving the accuracy of smart meter data completion, comprising: sampling multiple first meter data sequences to generate a meter sequence matrix and a mask matrix; performing a multipath delay embedding transformation on the meter sequence matrix and the mask matrix, dividing the obtained first tensor and mask tensor into multiple time-block first sub-tensors and mask sub-tensors, and decomposing each first sub-tensor into a first core sub-tensor and a factor matrix based on the mask sub-tensors; inputting the first target sequence generated based on the multiple first core sub-tensors and the corresponding position encoding results into a Transformer model to obtain multiple second core sub-tensors; performing inverse tensor decomposition based on the multiple second core sub-tensors and the factor matrix, performing an inverse multipath delay embedding transformation on the obtained second tensors, and adjusting parameters based on the numerical differences between the inversely transformed second meter data sequences and the first meter data sequences at the same missing position, thereby iteratively training the completion model. This method can improve the accuracy of data completion.