71 results about "Multipath propagation" patented technology

The invention relates to an ultrasonic phased array full-focusing imaging method for acoustic wave multi-path propagation compensation of a layered composite material, which is characterized by comprising the following steps of: arranging an ultrasonic phased array probe with N array elements on a composite material piece to be detected, obtaining complete echo data by taking each array element as a transmitting array element and taking all array elements as receiving array elements in sequence in a full-matrix acquisition mode; a two-dimensional pixel grid is established in an imaging area, a Monte-Carlo perturbation mechanism used for representing the acoustic wave propagation uncertainty in the layered composite material is introduced into a propagation model for each emission array element-receiving array element-pixel point combination, and the acoustic beam emission direction, the propagation path and the equivalent acoustic velocity are subjected to random perturbation, so that the acoustic wave propagation uncertainty in the layered composite material can be represented. Generating a plurality of equivalent sound wave propagation paths, calculating two-way propagation time of each path, and performing weighted statistics on energy contributions of different paths according to array element sound beam directivity to obtain equivalent propagation time delays of pixel points; and performing delay correction on a full-matrix echo signal by using the equivalent propagation time delay, and performing coherent superposition on signals of all transmitting-receiving array element combinations to realize dynamic focusing of a full-pixel grid, and finally reconstructing an ultrasonic full-focusing imaging image with high resolution and high signal-to-noise ratio. The time delay error caused by propagation path deviation and sound velocity non-uniformity in the layered composite material can be effectively compensated, the focusing precision and spatial resolution of full-focusing imaging are improved, meanwhile, an existing TFM imaging frame does not need to be changed, and the method has good engineering implementability and popularization and application value.

The invention discloses a bionic joint humanoid robot navigation positioning method, device and equipment, and the method comprises the steps: monitoring a landing shock wave signal and reflection echo data of a robot, carrying out the time domain expansion of the shock wave signal to form a pulse characteristic spectrum, extracting multipath propagation components, and carrying out the time difference correlation to generate an environment response value. Screening a direct wave component by using an environmental response value, positioning a sound wave propagation trajectory, and detecting impedance mutation to construct an acoustic matrix. A strong reflection zone is identified through node analysis, a sound pressure gradient field is extracted to determine an obstacle boundary, and a landmark feature bit is determined in combination with an environmental response value. And adjusting a dynamic stride frequency interval based on a landmark feature bit, forming an adaptive detection sequence, and performing sparse processing to construct path configuration. The mechanical vibration component of the shock wave signal is used for piezoelectric conversion to generate recycled electric quantity, the recycled electric quantity is matched with path configuration power to determine a sensing period, intermittent sensing is executed to obtain detection data to construct a detection convergence field, and finally an accurate positioning window is determined and converted into position coordinates.

The invention discloses a non-line-of-sight moving target three-dimensional reconstruction method based on an MIMO millimeter wave radar, and is applied to the technical field of radar target detection in a complex urban environment. Aiming at the problem of difficulty in realizing three-dimensional reconstruction of a non-line-of-sight moving target in the existing radar target detection technology, the method comprises the following steps: firstly, establishing a non-line-of-sight multipath propagation model, and exporting a multipath signal model of an MIMO millimeter wave radar; the invention further provides a multipath signal departure angle (DoD) / arrival angle (DoA) unambiguous estimation algorithm, and solves the problem that a main lobe and a grating lobe are difficult to distinguish in the DoD / DoA estimation process of an existing commercial MIMO radar. And finally, proposing a path-oriented non-line-of-sight target three-dimensional positioning algorithm, respectively positioning the non-line-of-sight target by using different paths, and fusing different path positioning results to form a three-dimensional point cloud. According to the method, three-dimensional reconstruction of a plurality of non-line-of-sight moving targets can be realized, and the correlation problem between paths does not need to be considered.

The invention relates to the field of mine wireless communication security, and discloses a wireless instruction encryption method and system for mining intrinsic safety type equipment. The method comprises the following steps: collecting historical mine environment data and extracting features to obtain characterization environment description; constructing a nonlinear mapping function of the multipath propagation characteristic and the interference degree of the signal; collecting current environment data to calibrate the nonlinear mapping function to obtain a calibrated model; obtaining an encryption strength prediction value based on the current environment data in combination with the calibrated model; if the predicted value is lower than the encryption strength threshold value, key parameters are adjusted to generate optimized encryption configuration; based on the configuration, a support vector machine is adopted to classify the dynamic environment data, an interference area is divided, and an adjustment coefficient of the interference area is determined; and adjusting the encryption parameter in real time according to the coefficient to obtain an encryption strength adjustment scheme matched with the actual demand. According to the method, the problem that the wireless instruction encryption strength is not matched in a complex mine environment is solved, and the wireless instruction transmission safety and adaptability are improved.

The invention discloses a low-orbit satellite Doppler frequency offset pre-compensation dynamic optimization algorithm, which comprises the steps of multipath signal separation and path identification: identifying a line-of-sight path and at least one non-line-of-sight reflection path through power delay spectrum analysis of satellite receiving signals, wherein the signal power of the non-line-of-sight reflection path is not lower than-10dB of the line-of-sight path power; and reflection path geometric parameter extraction: based on time delay information of each path in the power time delay spectrum, reversely deducing propagation distances corresponding to a line-of-sight path and a non-line-of-sight reflection path, calculating a direct distance between the satellite and the terminal and a total distance of a reflection path from the satellite to a reflection point and then to the terminal by combining satellite orbit parameters and real-time position information of the terminal, and calculating geometric parameters of the reflection path. According to the method, the multi-path scene compensation precision is improved, the limitation that only the sight distance path is compensated traditionally is broken through by independently identifying the non-sight distance reflection path and establishing the exclusive frequency offset model, the frequency offset superposition error caused by multi-path propagation is solved, and the demodulation error rate in a complex environment is remarkably reduced.

The invention discloses a UWB single base station-based positioning method, system and device, a medium and a product, and relates to the technical field of positioning, and the method comprises the steps: comparing the position deviation of UWB initial positioning data and IMU positioning data with a set threshold value, and judging whether the UWB initial positioning data is abnormal or not; when the data is abnormal, performing strong compensation on the UWB initial positioning data by using IMU positioning data based on a Kalman filtering method; when the data is normal, performing weak compensation or non-compensation on the UWB initial positioning data by using IMU positioning data by adopting a weighted average method; when the UWB signal of the positioning tag is lost by the UWB single base station, the IMU positioning data is used as a positioning result, the UWB initial positioning data is corrected by using the IMU positioning data, the UWB single base station positioning data drift caused by factors such as multipath propagation and non-line-of-sight propagation can be effectively inhibited, and the positioning accuracy is improved.

The invention discloses a cloud computing analysis method based on a time mark pulse sequence, and belongs to the technical field of signal processing. The method is used for solving the technical problems that in an existing scheme, delay nonlinearity caused by multipath propagation is not considered, and effective decoupling cannot be achieved due to a coupling effect existing in atomic clock error estimation and system deviation. A direct component and a scattering component can be distinguished through time scale layered mapping, and the amplitude-phase-frequency coupling effect of multi-path propagation is covered by fusing the three-dimensional characteristics of delay inequality, amplitude attenuation and frequency drift; the nonlinear mapping capability of the hyperbolic tangent kernel function is superior to that of a linear model, and the hyperbolic tangent kernel function can adapt to time delay nonlinear change in a complex electromagnetic environment; clock error, time delay parameters and system deviation are modeled in a unified mode, error accumulation caused by traditional separation estimation is avoided, variable dependency is quantized through an information theory tool, mutual information decoupling is achieved, robustness is enhanced, and a decoupling result directly corresponds to an atomic clock core index and system interference.

The invention provides a system for adjusting ship data transmission in real time according to a ship navigation state, and relates to the technical field of ship data transmission. The system comprises a ship data acquisition module, a signal processing module, a data transmission adjustment module, a multi-node data transmission module, a feedback control module and a shore end receiving module. According to the invention, the signal processing module fuses sensor signals through a self-adaptive weighting algorithm and performs noise reduction through Kalman filtering, so that the data accuracy and the system robustness are improved; the multi-node data transmission module is used for avoiding single-point faults, improving transmission reliability and fault tolerance, realizing higher throughput, enhancing anti-interference capability and flexibility and reducing navigation risks by constructing a plurality of parallel transmission paths; the multi-path propagation increases signal receiving energy, improves signal strength and quality, provides signal redundancy, dynamically adjusts a transmission path to avoid network congestion and transmission delay, and can improve real-time performance and reduce ship operation cost.

The invention discloses a wireless communication spectrum space digital twinning method, which comprises the following steps of: generating basic static channel characteristics under a given environment model and a base station deployment condition; wherein the static channel characteristics comprise a path loss distribution characteristic, a shadow fading characteristic and a multipath propagation characteristic; associating the static channel feature with target vehicle information, and generating a single-frame channel feature when a vehicle exists; and capturing dynamic evolution information of channel characteristics in a vehicle movement process, and expanding the single-frame channel characteristics into sequential dynamic channel characteristics to obtain a digital twinborn model of a dynamic scene spectrum space. According to the method, the influence of a dynamic blocking body can be further considered on the basis of static channel generation, channel feature generation in a dynamic environment is realized, and the reality sense and application applicability of digital twinning are remarkably improved.

The utility model provides an OTA test darkroom integrated with an environment simulation function, which comprises a darkroom body, a test mechanism for placing an object to be tested is arranged in the middle of the inner side of the darkroom body, an adjusting mechanism is arranged on the inner side of the darkroom body, the adjusting mechanism is distributed in the darkroom body in a mirror image manner, and an antenna mechanism for testing the object to be tested is arranged in the middle of the adjusting mechanism; the adjusting mechanism comprises electric guide rails, adjusting plates and mounting arc-shaped plates, the electric guide rails are arranged at the top and the bottom of the inner side of the darkroom body in a mirroring mode, the adjusting plates are arranged on the sides, away from the darkroom body, of the adjusting plates, and the adjusting plates and the electric guide rails are clamped and slide. According to the utility model, the adjusting mechanism controls the antenna mechanism to move horizontally, and cooperates with the antenna main body in the antenna mechanism to lift and rotate above the mounting arc-shaped plate, so that the antenna main body can be adjusted and tested in multiple directions when testing an object to be tested, the multipath test of the antenna main body is facilitated, and the test efficiency is improved. And complex multipath propagation simulation is realized.

An information display device is a device worn on a user's head. Here, the information display device includes a processor and an antenna capable of receiving multipath propagating radio waves. The processor analyzes the multipath propagation information of the radio waves received by the antenna. If the processor detects the presence of a moving object based on the analysis results, it alerts the user.

The application is suitable for the field of wireless communication technology, and provides a kind of air-ground channel dynamic modeling method and system for high maneuverable unmanned aerial vehicle, the method includes the following steps: constructing unmanned aerial vehicle dynamics model, and quantifying the antenna position offset caused by unmanned aerial vehicle attitude change;Based on terrain data and obstacle data, a three-dimensional digital scene model that restores the real scene is constructed, ray tracing method is used to simulate multipath propagation, and channel statistical characteristic parameters are extracted;A statistical model of unmanned aerial vehicle jitter characteristics is constructed, and the position offset of unmanned aerial vehicle under the action of jitter is quantified;According to unmanned aerial vehicle dynamics model, channel statistical characteristic parameters and the statistical model of unmanned aerial vehicle jitter characteristics, the channel model that fuses attitude dynamics and jitter effect is constructed by using analytical method.The method solves the problem of how to fully consider attitude dynamics and jitter effect to accurately model channel characteristics and quantify key parameters in unmanned aerial vehicle communication, and has high applicability to complex and variable unmanned aerial vehicle communication scenarios.

The application provides a kind of slope three-dimensional deformation non-contact measurement method and system based on navigation reflection signal, belong to remote sensing technical field, including: constructing slope signal reflection model;Collect direct signal and multiple reflection signals, carry out multi-channel file reading and separation to direct signal and reflection signal, calculate the carrier phase difference of direct signal and reflection signal, carry out inversion to multiple carrier phase differences between adjacent transmission periods, obtain reflection signal multipath propagation distance variation;Reflection signal multipath propagation distance variation is substituted into slope signal reflection model to obtain reflection surface deformation variable-reflection signal propagation distance variation equation, and the reflection surface deformation variable-reflection signal propagation distance variation equation is inverted to obtain the inversion result of slope three-dimensional deformation variable.The application uses satellite navigation signal and multiple reflection antennas to calculate slope deformation variable, realizes low-cost, non-contact and high-accuracy slope three-dimensional deformation inversion process.

Method for determining the antenna gain of an antenna (21) to be tested in free space, wherein the method comprises the following steps: Acquisition of measurement results of a transmitted power of a measurement signal (24a, 24b) transmitted between a reference antenna (22) and an antenna to be tested (21); Determining an input reflection factor ( P e _ TP e _ R ) | P g _ R = 0 the antenna (21) to be tested and an input reflection factor ( P g _ TP g _ R ) | P e _ R = 0 the reference antenna (22); Detecting polarization losses based on an angle between the unit vector of the electric field vector (p̂) T ) the antenna (21) to be tested and the electric field vector (p̂ R ) the reference antenna (22); where the detection takes place in the frequency domain; Converting the recorded measurement results into the time domain; Applying a time domain filter (26) to the measurement results converted into the time domain, wherein a filter width of the time domain filter (26) is determined as a function of a spatial distance (r) between the reference antenna (22) and the antenna (21) to be tested, so that measurement result components (24b) resulting from multipath propagation of the measurement signal (24a, 24b) between the reference antenna (22) and the antenna (21) to be tested are reduced or removed; Converting the filtered measurement results into the frequency domain; and Determining the antenna gain G T (ϑ, φ) of the antenna (21) to be tested, taking into account the recorded input reflection factors and polarization losses, based on the filtered measurement results available in the frequency domain using the following equation: GT ( ϑ , ϕ ) = 10 log 10 ( P _ TP g _ R ) − 20 log 10 ( λ 4 π r ) − GREF ( ϑ , φ ) − ( 10 log ( 1 − ( P _ TP g _ R ) | P g _ R = 0 ) + 10 log ( 1 − ( P g _ TP g _ R ) |. P _ R = 0 ) + 20 log |

The invention discloses an offshore microwave signal time-frequency joint equalization method, system and device based on a Transform model and a medium, and belongs to the technical field of deep learning models and signal processing, and the method comprises the steps: collecting and preprocessing offshore microwave radio frequency signal data, and obtaining a complex baseband signal sequence; generating a time-frequency spectrum matrix; constructing an auxiliary feature vector sequence; dividing the auxiliary feature vector sequence into time frequency units to form a token sequence; the token sequence is input into an improved Linformer-Transformer model, and a hidden representation sequence is obtained; outputting a combined equalization coefficient vector; carrying out amplitude-phase correction to obtain a balanced complex baseband signal sequence; and obtaining an equalized time-frequency spectrum matrix and a reconstructed complex baseband signal sequence. According to the invention, time-frequency joint equalization of signals is realized, the transmission reliability and signal quality of offshore microwave communication are improved, and the problems of amplitude distortion and phase distortion caused by multipath propagation, frequency selective fading and phase random drift in an offshore microwave channel are effectively solved.

The invention discloses a super-resolution combined time delay-Doppler estimation method for a double-station cooperative sensing system, which comprises the following steps of: 1, modeling for a double-station cooperative sensing channel, and establishing a double-station sensing channel model containing multipath propagation, time delay and Doppler parameters; 2, carrying out 2D-FFT (fast Fourier transform) preprocessing to quickly obtain a coarse-grained time delay estimation value, a Doppler estimation value and a rough parameter range, and providing an initial estimation reference for a refined grid and SBL estimation; step 3, on the basis of the rough estimation range obtained in the step 2, refining grid sampling positions on a time delay domain and a Doppler domain, and constructing a dictionary matrix and a sparse modeling framework required by sparse estimation; 4, introducing a Root-SBL algorithm, and carrying out the super-resolution estimation of the time delay through a frequency domain signal structure; step 5, introducing a Root-SBL algorithm, and performing super-resolution estimation on Doppler by using a time domain signal structure; and step 6, in combination with an initial parameter matching result obtained by 2D-FFT, matching a multi-target high-precision time delay-Doppler estimation result, and ensuring multi-target matching correctness and parameter estimation consistency and physical interpretability. According to the invention, the stability and robustness of the sensing system in a low signal-to-noise ratio and multi-path complex environment can be improved.

The invention relates to the technical field of wireless communication, in particular to an intelligent base station antenna system, which comprises a multi-source sensing fusion step: acquiring base station work parameters and a terminal measurement report in real time, analyzing and extracting signal features and performing time sequence alignment, and generating a multi-dimensional sensing data set; a space-time topology reconstruction step: performing multipath propagation environment inversion based on the data set, and constructing a three-dimensional telephone traffic thermodynamic diagram reflecting the user density in a three-dimensional space; interference potential energy analysis: simulating beam overflow based on the thermodynamic diagram, calculating overlapping coverage and generating an interference potential energy evaluation result; an intelligent decision optimization step: constructing a multi-objective optimization function, and carrying out global search to solve optimal antenna weight configuration containing amplitude and phase weight; a self-adaptive reconstruction execution step: converting the weight into a beam forming instruction, driving an antenna to adjust a radiation pattern and monitoring performance in real time; according to the invention, a traditional rigid mode is broken, automatic adjustment of the coverage envelope along with traffic flow is realized, and the overall capacity of the network is improved.

Embodiments of the disclosure describe a method for dynamically configured beam forming that mitigates remote interference experienced by a second base station (200) while scheduling at least one of uplink and downlink transmission for a plurality of UEs (201) associated with the second base station (200). The method includes receiving a plurality of Radio Frequency (RF) signals from a first base station (100). The plurality of RF signals is traversed through a multipath propagation channel and has been interfered by the atmospheric ducting propagation. The method includes determining a multipath channel impulse response (Hij) corresponding to each path and scatterer associated with the plurality of received RF signals. The method includes dynamically configuring beam forming for the plurality of UEs (201) associated with the second base station (200). The beamforming is dynamically configured based on the multipath channel impulse response (Hij).

The invention discloses an electromagnetic propagation response prediction method and device of a target object. The specific technical scheme comprises the steps of obtaining geometric structure information, sending equipment position information and receiving equipment position information of the target object and multipath propagation parameters corresponding to the target object; determining structure nodes and structure edges according to key position point information in the geometric structure information and connection relation information among the key position point information; according to the position information of the sending equipment, the position information of the receiving equipment and response information of the structure nodes to the electromagnetic signals, constructing propagation nodes and propagation edges to obtain multipath propagation graph structure data; performing graph convolution processing on the multipath propagation graph structure data to obtain multipath propagation graph geometric features; and performing mapping operation on the geometrical characteristics of the multipath propagation graph to obtain a predicted electromagnetic propagation response corresponding to the target object. Thus, electromagnetic propagation response prediction is performed by using the structural features and the reflection features of the target object, and the accuracy of the prediction result is improved.

The invention discloses a reinforcement learning-based low-altitude unmanned aerial vehicle radar anti-interference method, and aims to solve the problems of training window pollution, covariance estimation mismatch and high false alarm rate caused by low-altitude multipath and ground object strong clutter superposition interference. According to the method, disturbance superposition is carried out on training echoes by constructing a disturbance parameter set of multipath propagation disturbance, ground clutter disturbance and interference disturbance to generate adversarial echo data, and a reinforcement learning decision module and a deep expanded robust space-time suppression network are jointly trained according to the adversarial echo data; during online operation, a distance Doppler map is generated for a current echo, state features such as clutter intensity, spectrum broadening, multipath degree and interference degree are extracted, a reinforcement learning decision module outputs a training sample mask and a space-time suppression parameter, short-time and long-time covariance is calculated based on mask weighting and fused by a gating coefficient, and a target object is obtained. And inputting the depth expansion network to obtain a space-time filtering weight, completing space-time suppression and performing target detection, thereby realizing the technical effects of improving the covariance estimation stability, reducing the false alarm rate and enhancing the anti-interference robustness in a non-stationary clutter and multipath scene.

The embodiment of the invention relates to a positioning method and device and a medium, and the method comprises the steps: obtaining target multipath propagation component (MPC) data obtained through the measurement of a target signal by a transmitting / receiving node (TRP) after the TRP receives the target signal transmitted by to-be-positioned target user equipment; obtaining a predetermined virtual anchor point VA coordinate set corresponding to the TRP; according to the target MPC data and the VA coordinate set, screening out a target matching relationship between the target MPC data and the target VA coordinate according to a direct path propagation mode of the target MPC data; and determining the position of the target user equipment according to the target matching relationship. In the technical scheme, on the basis of reducing the positioning cost, the positioning of the user equipment in the multipath propagation environment is realized.

The application discloses a kind of Buddha jumps over the wall flow circulation traceability system, specifically relates to supply chain management technical field;It is by obtaining the radio frequency identification tag data and corresponding cold-chain storage metal shelf space coordinate data set on Buddha jumps over the wall package, the main path signal feature sequence and reflection path signal feature sequence are formed to radio frequency identification tag read-write signal is carried out multipath propagation decomposition;The main path signal feature sequence and reflection path signal feature sequence are carried out time delay difference value matching, obtain the radio frequency identification tag effective identification sequence that satisfies preset time delay stability condition;Based on radio frequency identification tag effective identification sequence, Buddha jumps over the wall freeze-drying processing batch data and cold-chain storage batch data are carried out batch mapping verification, and flow batch association data is generated;Flow batch association data is carried out continuous time window consistency verification, and forms cold-chain flow effective traceability data;According to cold-chain flow effective traceability data, update Buddha jumps over the wall flow circulation traceability database and output real-time traceability record.

The invention provides a communication and sensing integrated sensing burst set design and signal parameter estimation method and device, and relates to the technical field of wireless communication. The method comprises the following steps: designing a general-inductance integrated sensing signal SSB burst set; describing transmission and receiving processes of sensing signals of the MISO system modulated by the OFDM in the dynamic multipath environment; the method comprises the following steps: initializing carrier frequency offset, channel frequency response and Doppler frequency shift estimation according to a digital baseband signal in a mobile mode of a receiver, constructing a mathematical expression for receiving a sensing signal in a stable state, and estimating a multipath number according to an MDL criterion; and designing a signal parameter estimation architecture of the receiver in a tracking state. The signal structure designed by the invention is compatible with the existing system, the coverage range of the sensing signal is improved, the provided signal parameter estimation architecture can effectively estimate the multipath propagation, AoD and ToA of the signal in a complex environment, and the method is suitable for accurate environment sensing and positioning in large-range mobile scenes such as intelligent traffic and the Internet of Vehicles.

Apparatus and methods for apparatus positioning are provided. Solution includes receiving (300) by an apparatus from a network element a signal having multipath propagated signal components and obtaining time domain samples of the multipath propagated signal components, mapping (302) the time domain samples to one or more frequency offset-delay pairs to obtain frequency offsets and delays of the received multipath propagated signal components, calculating (304) angle of arrival of one or more multipath propagated signal components, determining (306) the multipath propagated signal component corresponding to the direct propagation path between the apparatus and the network element, and controlling (308) the utilisation of the angle of arrival and delay of the multipath propagated signal component corresponding to the direct propagation path in the determination of the location of the apparatus.

The invention is suitable for the technical field of wireless communication, and provides an air-ground channel dynamic modeling method and system for a high-mobility unmanned aerial vehicle, and the method comprises the following steps: constructing an unmanned aerial vehicle dynamic model, and quantifying the antenna position offset caused by the attitude change of the unmanned aerial vehicle; based on topographic data and obstacle data, constructing a three-dimensional digital scene model for restoring a real scene, simulating multipath propagation by adopting a ray tracing method, and extracting channel statistical characteristic parameters; constructing a statistical model of the jitter characteristics of the unmanned aerial vehicle, and quantifying the position offset of the unmanned aerial vehicle under the jitter effect; and according to the unmanned aerial vehicle kinetic model, the channel statistical characteristic parameters and the statistical model of the unmanned aerial vehicle jitter characteristics, constructing a channel model fusing the attitude dynamics and the jitter effect by using an analytical method. The method solves the problem of how to fully consider attitude dynamics and jitter effects in unmanned aerial vehicle communication to accurately model channel characteristics and quantify key parameters, and has high applicability to complex and changeable unmanned aerial vehicle communication scenes.

The invention discloses a geometric random underwater acoustic channel modeling method considering non-equal sound velocity. The method comprises the following steps: 1) constructing a shallow sea layered sound velocity profile; 2) multi-path propagation including a direct path, a sea surface reflection path and a seabed reflection path is considered; 3) calculating a propagation angle, a Doppler frequency shift, a propagation distance and a time delay parameter of a path between the receiving end and the transmitting end based on the layered sound velocity profile in combination with a geometric acoustic principle and a Snell law; and 4) establishing a channel impulse response and transmission function, calculating a time self-correlation function and a frequency correlation function at the same time, and performing analysis. According to the method, the non-equal sound velocity profile is introduced into the geometric random underwater acoustic channel model for the first time, the time-frequency fading characteristics of the channel under the equal sound velocity condition and the non-equal sound velocity condition are compared and analyzed, the physical authenticity and calculation precision of the model are improved, and reliable technical support is provided for design and performance evaluation of an underwater communication system.

A method is provided for generating a corrected channel impulse response (CIR) estimate by a receiver of a ultra-wideband (UWB) device. The method includes, computing a correction matrix based on a sequence of chips, a number of the chips being N; receiving a pulse signal corresponding to the sequence of chips, the pulse signal being a multi-path propagated signal corresponding to a non-zero chip in the sequence of chips; determining a CIR estimate for the pulse signal; and computing the corrected CIR estimate for the pulse signal based on the correction matrix and the CIR estimate.

The invention discloses a model training and positioning method. The model training method comprises the following steps: acquiring signal strength indexes and position information of a plurality of distributed base stations; the distributed base stations are mapped into nodes in the graph structure, and signal strength indexes and position information are constructed to serve as feature representation of the nodes; fusing the features of the nodes in different modes to obtain fused feature representation of the nodes; aggregating the fused feature representation of the node and the fused feature representation of the neighbor node of the node to update the feature representation of the node; determining predicted position information of terminal equipment in the target cell according to the updated node features; and training the graph neural network model, and obtaining a trained graph neural network model under the condition that a preset stop condition is met. According to the method and the device, the technical problem that the position of the terminal equipment is difficult to accurately determine under a non-line-of-sight condition and a multipath propagation environment due to limited positioning precision and insufficient robustness of a related positioning technology under a complex environment is solved.

The application relates to a smart metering communication channel modeling method for a basement environment, which comprises the following steps: obtaining smart metering communication system channel information through a joint ray tracing method and a channel measurement method; obtaining channel parameters of multipath propagation based on channel data, and establishing a corresponding wireless channel model; obtaining typical channel characteristics of the smart metering communication system based on the established wireless channel model; and realizing system optimization and network deployment in the smart metering system transmission by analyzing the typical channel characteristics. The application provides a reference for the deployment and optimization of the receiving and sending ends in the smart metering communication by analyzing the channel propagation characteristics and adjusting the sending end position to optimize signal transmission.

The invention belongs to the technical field of radar signal processing and target identification, and particularly discloses a millimeter wave radar multipath calculation method based on a radio wave propagation geometric model, and the method comprises the following steps: obtaining the position information of a millimeter wave radar, the position information of a real target, and a normal vector of a reflection surface; the normal vector of the reflecting surface is adaptively generated through a curvature sensitive sampling algorithm; according to the position information of the real target and the normal vector of the reflecting surface, calculating the position of a reflecting point by adopting a vector symmetric projection algorithm; and according to the position of the millimeter wave radar, the position of the real target and the position of the reflection point, calculating the coordinate of a false target point generated due to the multipath propagation effect, namely, the position of a multipath point. According to the invention, the accuracy and efficiency of radar multi-path point calculation can be effectively improved.