22 results about "Space modulation" patented technology

The invention discloses an unmanned aerial vehicle insulator zero-value acousto-optic detection method and an unmanned aerial vehicle insulator zero-value acousto-optic detection device, relates to the technical field of insulator detection, and solves the problems of poor detection safety, low efficiency and insufficient precision in the prior art. Establishing a coordinate system to generate flight control parameters to realize precise hovering; based on the distance vector, the rotatable multi-frequency coil group generates a spatial modulation electromagnetic field; the high-voltage testing device applies a cooperative modulation detection voltage according to electromagnetic field parameters to realize synchronous modulation of the two; the audio-video transmission device collects sound and light signals, and features are obtained through space-time fusion after distance attenuation compensation; constructing an evaluation model containing environment correction, and judging a zero value by taking 0.8 as a threshold value; according to the method, closed-loop detection is formed, the detection precision and efficiency are improved, and operation safety is guaranteed.

The application discloses a kind of based on space modulation and reverse scattering's synchronous sensing and reverse scattering communication method and device, it is related to communication technical field, including: through transmitting array to tag pilot signal and modulate the load impedance of tag again backscatter to receiving array;Using the receiving voltage generated by receiving array and original channel matrix determines clutter tag reflectivity and tag antenna reflectivity;Based on clutter tag reflectivity positioning and identification label;From original channel matrix, according to tag antenna reflectivity, extract and construct the target channel matrix of label;Information bits are spatially modulated by transmitting array, constellation symbol is generated and active label is determined;Using transmitting array, constellation symbol is backscattered to receiving array by active label, and combined with target channel matrix, demodulation and decoding output information bits.In the disorderly environment, reverse scattering label is accurately positioned and identified, and space modulation is integrated into reverse scattering communication, and the reliability of reverse scattering communication is improved.

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 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.

The application provides a delay-Doppler transmission method, device and equipment based on continuous domain mapping. Continuous amplitude modulation symbols generated by Shannon-Kotelnikov space filling mapping are sequentially filled into a delay-Doppler domain two-dimensional grid in a column priority rule, so that the geometric neighborhood relationship of continuous mapping is maintained in the delay-Doppler domain. The characteristics that each symbol in the domain experiences approximately uniform equivalent channel gain are utilized to avoid the destruction of the continuous mapping structure by double selected fading. Meanwhile, amplitude enhancement pilots are inserted in the grid and a guard band is set, and energy threshold adaptive adjustment based on a mapping scale parameter is combined to realize channel sparsity parameter estimation, so that the channel estimation and equalization process adapt to the continuous amplitude signal characteristics, thereby realizing the organic integration of analog joint source channel coding and orthogonal time-frequency-space modulation without relying on discrete constellation modulation.

The application discloses a two-stage modulation-based underwater polarization ghost imaging method and device, and relates to the fields of optical imaging and ocean detection. The method comprises the following steps: acquiring basic data of a target water area and constructing a backscattering point spread function; performing statistical decorrelation modulation on an original reference speckle sequence based on a first correlation coefficient, a second correlation coefficient and the backscattering point spread function, to obtain a primary modulation reference speckle distribution sequence; performing polarization space modulation on the primary modulation speckle sequence, to obtain a secondary modulation reference speckle distribution sequence; irradiating a target to be detected according to the secondary modulation reference speckle distribution sequence, acquiring a double-polarization bucket detection signal, and constructing a polarization difference signal sequence; and performing correlation reconstruction on the polarization difference signal sequence and the secondary modulation reference speckle distribution sequence, to obtain a reconstructed image. The application solves the problems of serious backscattering interference and insufficient imaging signal-to-noise ratio in a strong turbid underwater environment, and realizes high-quality underwater polarization ghost imaging.

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.

The invention discloses a downlink multiple access method for simultaneously serving high-speed and low-speed mobile users. Orthogonal time-frequency modulation is adopted for symbol modulation of the high-speed user, and the symbol modulation is only mapped to part of delay Doppler resources, then is periodically and repeatedly expanded to all delay Doppler resources, and only part of time-frequency resources are occupied after the symbol modulation is converted to a time-frequency domain. The time-frequency resource blocks which are not occupied by the high-speed users are used for transmitting symbols of the low-speed users, and the low-speed users occupy different time-frequency resources, so that orthogonal multiple access of the high-speed users and the low-speed users is realized. And the high-speed users and the low-speed users adopt a relatively complex equalization method to equalize the received signals. The invention also discloses a greedy algorithm for time-frequency resource allocation between low-speed users. Simulation results show that by the adoption of the multiple access and time-frequency resource allocation scheme, the system sum rate is only slightly lower than that of a high-low-speed user non-orthogonal multiple access scheme, but the user detection complexity is obviously lower.

The invention discloses a weld deformation tracking compensation method based on a convolutional neural network, and aims to solve the problem that continuous and stable tracking of a weld is difficult under complex working conditions such as arc light, smoke dust, splashing and welding gun shielding. Outputting a shielding probability graph by using the shielding sensing branch, and generating modulation parameters to perform channel and space modulation on the features; a weld joint probability graph is output through the weld joint position estimation branch, weld joint candidate points are determined, and meanwhile, a position variance graph is output through the uncertainty estimation branch to represent the positioning uncertainty of the candidate points; and determining a fitting weight by combining the shielding probability and the position variance, performing weighted geometric fitting on the candidate points to obtain a weld center line model, performing continuous gating on the compensation gain according to the fitting residual error and the tracking credibility, and smoothly outputting a compensation instruction in cooperation with amplitude limiting and time. Robust tracking and stable compensation control over the center line of the welding seam under shielding interference are achieved, and the tracking reliability and the welding track compensation stability are improved.

The invention belongs to the technical field of wireless communication, and particularly relates to an environment semantic perception assisted orthogonal time-frequency space channel estimation system and method. The method is executed by a communication access point, and specifically comprises the following steps: acquiring environment semantic information which comprises positions and movement characteristics of a transmitter, a receiver and a scatterer in a communication link; determining a time delay parameter and a Doppler frequency shift parameter of a channel based on the environmental semantic information, designing a low-overhead pilot frequency structure based on the time delay parameter and the Doppler frequency shift parameter, and setting a guard interval only at a time delay-Doppler grid point which is determined by the time delay parameter and the Doppler frequency shift parameter and possibly generates interference; and constructing a transmitting signal by using the low-overhead pilot frequency structure, and transmitting the transmitting signal after orthogonal time-frequency space modulation. According to the invention, the resource competition between sensing and a communication link is eliminated, the spectrum efficiency of the OTFS system is remarkably improved, and low-complexity fine-grained physical layer channel estimation is realized.

The application belongs to the technical field of OTFS modulation and demodulation, and discloses an interference suppression method suitable for orthogonal time frequency space modulation, which comprises the following steps: at the receiving end of the OTFS system, interference detection is performed on a time-frequency domain symbol matrix, and the detected interfered subcarriers are zeroed to obtain a time-frequency domain symbol matrix; after SFFT transformation to the DD domain, parallel-serial conversion, constellation demapping and channel decoding, a restored bit data sequence is obtained. The application utilizes the diffusion effect generated by SFFT transformation in the OTFS system, effectively compensates the information loss caused by zeroing of part of the time-frequency domain subcarriers, reduces the interference influence in the OTFS system, and successfully eliminates the error code platform caused by subcarrier zeroing under high signal-to-noise ratio by means of the method combining cascaded channel coding and inter-frame interleaving, and improves the error code performance, realizes wide-area interference suppression under the environment of large time delay and large Doppler frequency shift, and significantly improves the anti-interference ability of the system.

The invention discloses an aluminum alloy butt welding online quality monitoring method based on multi-sensor fusion, and relates to the technical field of aluminum alloy butt welding online quality monitoring. The invention provides a frequency domain dynamic convolution electric signal coding module, the electric signal coding module introduces multi-band modulation and global and local nuclear space modulation mechanisms based on a one-dimensional convolution signal coding structure of FDConv1d, and carries out time-frequency joint modeling on voltage and current time sequence signals under the constraints of fixed parameter quantity and calculation complexity, so that the time-frequency joint modeling is carried out on the voltage and current time sequence signals; components of different frequency bands are decomposed and weighted in a self-adaptive mode, and feature information related to welding states such as weld penetration change and arc instability is emphasized; a molten pool image feature extraction module based on lightweight DINOv2 and multi-order gating aggregation is provided, a DINOv2 small self-supervised visual Transform model is selected as a molten pool image coding backbone, and lightweight specialized design oriented to a welding scene is provided.

The application provides a sensing-assisted uplink channel estimation method and system based on orthogonal time-frequency-space modulation, comprising: generating pilot symbols in the time-delay Doppler domain, superimposing the pilot symbols with communication data symbols to form a transmission frame; converting the time-delay Doppler domain transmission frame into a time-domain uplink signal, and re-converting the time-domain uplink signal into a time-delay Doppler domain receiving signal at a receiving end base station; causing the base station to collect a sensing echo, and the backscattering signal formed by the most recently transmitted downlink signal being emitted or diffracted by a user and a potential target object; estimating the time-delay and Doppler parameters at the receiving end by using the uplink pilot and the sensing echo; and eliminating the interference of the communication data and the pilot symbols to each other at the receiving end by using the estimated time-delay and Doppler parameters, and simultaneously performing channel estimation and data detection. The method and system provided by the application have low complexity and are easy to implement; meanwhile, the channel estimation and data detection are more accurate, and the communication sensing capability of the orthogonal time-frequency-space waveform in a high-mobility scenario can be effectively utilized.

The application discloses a kind of multi-stage space-time modeling road target detection methods based on event data.The present application constructs a kind of target detection network of fusion spatial feature modeling, space modulation context broadcast (SM-CB) module, deep separable convolution gated unit (DSConvGRU) module, pulse timing memory (STM) module and feature fusion and detection module for the problems of strong event camera data sparsity, time sequence dependence is significant and the lack of space-time information modeling of existing method.The method is first time discretization and space accumulation to event stream data, generates structured event representation;Subsequently in multi-stage feature extraction process, realize spatial feature modeling by local and global self-attention mechanism;On this basis, introduce SM-CB module to aggregate and space modulation global semantic information, enhance feature expression ability;While combining DSConvGRU module and STM module, the dynamic change of event data is modeled;Finally, through multi-scale feature fusion and detection head, the detection and positioning of target are realized.The present application can effectively improve the precision and robustness of pedestrian and vehicle target detection in complex road scene.

The invention relates to a coherent signal source DOA estimation method, system and device and a storage medium, and belongs to the technical field of metasurface signal processing. The method comprises the following steps: establishing an orthogonal modulation metasurface array model in which metasurface units are uniformly arranged, and performing space-time modulation on an incident signal by using the model to form a single-channel receiving signal; sequentially performing de-spreading, down-conversion, integral zero clearing filtering and de-coherence processing based on a forward and backward spatial smoothing technology on the received signal to obtain an observation vector; and inputting the observation vector into the trained deep expansion ADMM network, sequentially executing sparse feature extraction, physical constraint projection and dual residual updating to obtain a sparse spatial spectrum vector, mapping the sparse spatial spectrum vector into a spatial power spectrum vector, and performing spectrum peak search on the spatial power spectrum vector to determine a DOA estimation value. By adopting the method, high-precision and high-efficiency DOA estimation can be realized under the condition of low signal-to-noise ratio, and the method has higher reliability.

The invention discloses a low earth orbit satellite orthogonal time-frequency spatial modulation system channel estimation method and device, and the method comprises the steps: receiving a time domain signal transmitted from a low earth orbit satellite, removing a cyclic prefix and windowing, then sequentially carrying out the Wiener transformation and the ShengFourier transformation, intercepting a preset part, and stacking the preset part into a vector, thereby obtaining a DD domain receiving signal; a DD domain receiving signal is utilized to carry out channel estimation based on a horseshoe-shaped prior variation sparse Bayesian learning channel estimation method, meanwhile, contraction of global variables is adjusted in combination with noise features so as to improve the precision of the channel estimation method, and finally a channel estimation value is obtained. The method is higher in precision.

The application relates to the field of image processing, and provides an image relighting method and system based on asymmetric frequency space modulation, which comprises the following steps: performing encoder decoupling to obtain spatial intrinsic features and global illumination embedding vectors; performing group normalization and convolution operation to obtain intermediate features, performing linear projection and spatial dimension broadcast to obtain spatial broadcast illumination features, and obtaining a spatial modulation map according to the spatial broadcast illumination features and the intermediate features; performing normalization and feature extraction activation on the intermediate features to obtain dynamic weights, so as to obtain low-frequency components and high-frequency components; obtaining modulated low-frequency components by using the spatial modulation map and the low-frequency components, performing high-frequency correction on the high-frequency components based on the spatial modulation map to obtain modulated high-frequency components, and using the modulated low-frequency components and the modulated high-frequency components to perform relighting on an original image to obtain an output image; and training model parameters and performing image output to obtain a target output image. The application is used for completing image relighting.

The application discloses a Doppler inter-cell interference suppression method based on a Gaussian learning factor particle swarm algorithm, and steps are as follows: pilot and data symbols are encoded to a resource grid in a two-dimensional time-delay Doppler domain through orthogonal time-frequency space modulation; at a transmitter, data on the time-delay Doppler domain grid is mapped to a time-frequency domain through inverse symplectic finite Fourier transform to obtain a time-frequency domain signal; a Heisenberg transform is performed on the time-frequency domain signal to obtain a time-domain sending signal; the time-domain sending signal is obtained after passing through a wireless channel to obtain a time-domain receiving signal; a Doppler compensation process is performed on the time-domain receiving signal by using a Doppler frequency shift to obtain a signal compensated by the Doppler; then the signal compensated by the Doppler is matched filtered with a receiving pulse, and sampling is performed to obtain a matched filter output signal; a symplectic Fourier transform is performed on the matched filter output signal to obtain a time-delay Doppler receiving signal, and the method can realize suppression of Doppler inter-cell interference to a certain extent.

This invention proposes a super-resolution time delay Doppler estimation method for vehicle-mounted radar based on orthogonal time-frequency conditioning. Compared with previous algorithms, this method has super-resolution characteristics and can effectively address the basis mismatch problem in the discrete domain that traditional estimation algorithms cannot handle, thus achieving higher accuracy in time delay and Doppler estimation. To address the off-grid problem in the discrete domain, this method uses a two-dimensional atomic norm to establish the estimation problem in the continuous domain. A positive semidefinite programming problem for solving continuous frequencies is established using the two-dimensional atomic norm and analyzed. Based on this, the alternating multiplier direction method is proposed, and an iterative approach is used to quickly solve the optimization problem.

The invention provides a joint semantic coding-transmission method for a high-mobility scene, and relates to the field of wireless communication. Comprising the steps that a sending end extracts original semantic features of original data to obtain an original data stream; the method comprises the following steps: mapping an original data stream to a time delay-Doppler domain resource grid through an orthogonal time-frequency space modulator, inserting a pilot frequency sequence to obtain an orthogonal time-frequency space frame, and modulating the orthogonal time-frequency space frame to obtain a time domain sending signal; the time domain sending signal reaches a receiving end through a channel of the high-mobility scene; a receiving end demodulates the time domain receiving signal through an orthogonal time-frequency space demodulator to obtain a time delay-Doppler domain receiving signal; receiving a signal by using the time delay-Doppler domain to obtain an estimated channel matrix; and receiving the signal by using the estimated channel matrix and the time delay-Doppler domain to obtain a reconstructed data stream, and obtaining reconstructed data by using the reconstructed data stream so as to improve the transmission performance of the semantic communication system in the high-mobility scene.