58 results about "Multipath delay" patented technology

The invention discloses a communication transmission method and device based on multipath delay optimization and a storage medium, and relates to the technical field of communication, and the method comprises the steps: collecting link information in an SRv6 network through a routing protocol; calculating a plurality of preset paths through a maximum flow algorithm according to the link information; generating a segment routing table for each path in the plurality of preset paths; obtaining an SRv6 data packet to be forwarded; determining a target routing path from the segment routing table based on the to-be-forwarded SRv6 data packet; and performing data transmission on the to-be-forwarded SRv6 data packet according to the target routing path. The problems that a traditional end-to-end transmission protocol is poor in performance and high in packet loss rate in a long-distance network are solved, a network with committed quality is introduced again, the compatibility to an existing actual network is high, cross-platform extensibility is achieved, and the network transmission quality is improved.

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 GNSS (Global Navigation Satellite System) multi-path error correction method based on distance correlation modeling, which comprises the following steps of: resolving GNSS original data, and extracting to obtain a satellite position set and a residual error corresponding to the set; generating a uniformly distributed satellite position set on a unit hemispherical surface, calculating a variance-covariance matrix, and constructing a multi-path delay calculation model of the set; obtaining a currently observed to-be-calibrated satellite position set on a unit spherical surface, calculating a variance-covariance matrix, and constructing a multi-path delay calculation model of the set; the observation value of the set is corrected based on multi-path delay obtained through calculation of a multi-path delay calculation model of the set; the invention relates to an error correction method for modeling GNSS multi-path distance correlation characteristics by using least square configuration and a covariance function, which is suitable for multi-path suppression in high-precision GNSS positioning.

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 discloses a scene-adaptive multipath time delay alignment method and device for a wireless communication system, and the method comprises the steps: employing an SISO channel detection system to actually measure channel data, employing rectangular or RRC shaping filtering to generate a CAZAC oversampling sequence as a template function, calculating a cross-correlation matrix of an IQ signal and the template function, and enabling the CAZAC oversampling sequence to serve as the template function; a noise threshold is calculated based on the median power and the false alarm rate, dynamic threshold filtering is executed, a cross-correlation matrix after denoising is generated, and preliminary estimation of the time domain impulse response is completed; extracting multipath time delay and complex gain from the cross-correlation matrix by using an SAGE algorithm; drawing a power delay spectrum PDP for the channel impulse response; and performing alignment operation on the PDP in combination with the geographical location information of the transceiver during actual measurement. According to the method, the defect of traditional alignment in a severe scene is overcome, the statistical modeling accuracy is improved, the multipath time delay can be effectively aligned through experimental verification, and reliable support is provided for channel modeling.

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.

The invention relates to a self-adaptive adjustment method for underwater acoustic communication parameters, which comprises the following steps: estimating signal-to-noise ratio and channel maximum multipath time delay, at a receiving end, counting noise and signal energy to obtain received signal-to-noise ratio estimation, and carrying out matched filtering processing on a received synchronous signal to obtain channel maximum multipath time delay estimation; performing bit error rate statistics before error correction, sequentially performing de-interleaving, error correction decoding and CRC (Cyclic Redundancy Check) on a result output by signal demodulation, if the result is correct, performing error correction coding and interleaving processing on a decoding result again, and comparing a bit output after processing with a bit output by signal demodulation through bit judgment to finish bit error rate statistics before error correction. The adaptive capacity of underwater acoustic communication to channels can be effectively improved, the method is easy to implement, a transceiver does not need to shake hands for multiple times, and the method has good practical value.

Embodiments of the present application relate to the technical field of communications, and provide a symbol processing method and a communication apparatus. The method is applied to a communication apparatus, and comprises: generating a first time slot, which comprises a plurality of symbols, wherein the plurality of symbols comprise a first symbol and a second symbol which are adjacent in a time domain, the first symbol and the second symbol respectively comprise a first symbol component and a second symbol component, and the two symbol components are the same; and sending the first time slot. Specifically, a network device sends first indication information and second indication information, which are respectively an equivalent cyclic prefix of the first symbol and a correlation quantity of the first symbol component, a terminal device receives the first indication information and the second indication information, and the network device generates and sends a first time slot; or a network device sends first indication information and second indication information, and a terminal device receives the first indication information and the second indication information, and then generates and sends a first time slot. The length of the equivalent cyclic prefix of the first symbol is greater than or equal to the length of a maximum multipath delay, so that cyclic convolution recovery can be achieved, thereby avoiding inter-symbol interference.

Provided in the present application are a communication method and a related apparatus, which can be used in the technical field of communications. In the technical solution provided in the present application, a first network element can send first information and second information to a second network element, wherein the first information indicates a multipath angle of a first channel map and / or a multipath delay of the first channel map, and the second information is used for indicating a projection coefficient of a channel map basis of each channel sub-map in the first channel map; and correspondingly, after receiving the first information and the second information, the second network element can reconstruct the first channel map. The method facilitates the reduction of transmission overheads between a first network element and a second network element.

The present invention discloses a method for estimating the direction of arrival of a coherent signal, belonging to the field of ship radar and communication signal processing. The method comprises: a transmitting end sends a pilot signal of a target power to a receiving end, and the receiving end obtains the multipath delay structure of the channel based on the pilot signal; the transmitting end sends a normal pilot signal to the receiving end, and calculates the cross-correlation function between the received signal and the transmitted signal; the peak values ​​of the cross-correlation function are sorted in descending order to determine the candidate possibilities of the first delay, and the cross-correlation function after the composite path is calculated to determine the shortest delay; a cost function for the delay is constructed, and the cost function is differentiated with respect to two independent variables to obtain an estimated value of the arrival time difference; the direction of arrival is calculated from the estimated value of the arrival time difference, completing the one-dimensional direction of arrival estimation of the coherent signal applied to a uniform linear array. This method can improve the detection accuracy of passive radar and sonar equipment for targets and enhance the comprehensive detection capability of surface ships.

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.

The present application provides a method and system for three-dimensional coordinate positioning of drones based on distributed MIMO nodes. The present application first constructs a three-dimensional spatial layout covering the drone's activity area, then obtains a set of characteristic parameters, then compensates the transmitted signal based on the height difference relationship to generate a directional beam group, and then converts the multipath delay difference value and phase offset correlation value in the characteristic parameter set into a three-dimensional space vector component. Finally, through the spatial overlap relationship of the three-dimensional space vector components in the three-dimensional space layout, the real-time three-dimensional coordinate data of the drone in the target airspace is solved; the technical solution provided by the present application improves the positioning accuracy and anti-interference capability in a dynamic obstacle environment, realizes centimeter-level three-dimensional positioning in a GPS-free scenario, and reduces computational complexity and power consumption, achieving lightweight deployment and stable beam coverage in complex scenarios.

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 method for calculating the multipath delay of an evaporation waveguide and a scattering channel at different elevation angles, comprising: determining the propagation path length in the evaporation waveguide channel based on the radius of the earth and the central angle corresponding to the arc length of the propagation path in the evaporation waveguide channel; obtaining the propagation path length of the radio wave in the tropospheric scattering channel based on the angle between the line connecting the transmitting antenna and the scatterer and the center of the circle, the elevation angles of the transmitting and receiving antennas, and the angle between the line connecting the radio wave receiving antenna and the scatterer and the center of the circle, and the elevation angles of the transmitting and receiving antennas; then calculating the multipath delay of the hybrid channel; setting the symbol interval of the radio wave communication based on the multipath delay to adapt the radio wave communication to the switching of the communication mode. The calculation expression for the multipath delay of the hybrid channel obtained in the present application can quickly calculate the multipath delay of the evaporation waveguide and tropospheric scattering hybrid channel; setting the symbol interval of the radio wave communication based on the multipath delay to avoid inter-symbol interference and reduce the bit error rate.

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 an OTFS performance analysis method based on a 6G universal channel model, and relates to the technical field of wireless communication, and the method comprises the steps: building an overall framework of an OTFS system suitable for a high-mobility scene; setting a communication scene and channel environment parameters; based on a 6G universal channel model, multipath time delay, multipath power and Doppler frequency shift are calculated according to channel environment parameters; obtaining a channel impulse response of a time delay-Doppler domain required by the OTFS system; on the basis of the overall framework of the OTFS system, a random signal is input at the transmitting end of the OTFS system, a signal is finally output at the receiving end of the OTFS system according to the channel impulse response of the time delay-Doppler domain, and the signal is used for analyzing the error rate performance of the OTFS system under different channel parameters in a high mobility scene. According to the invention, a more accurate error rate analysis result is provided. According to the method, OTFS performance analysis under various typical high mobility scenes can be realized, and a more universal theoretical basis is provided for system optimization.

The invention relates to the field of wireless communication, and provides an environment reconstruction method and system based on multi-antenna broadband non-line-of-sight communication multipath components. The method comprises the steps that according to the number of the multiple paths, the time delay of each multiple path and environment perception arrival angle parameters, under the condition that single-hop reflection / scattering is considered, time delay constraint and angle constraint are combined to obtain the obstacle position corresponding to each multiple path, the time delay range of the multiple paths is calculated according to the system bandwidth, and the arrival angle range is calculated according to the number of antenna array elements. The obstacle position corresponding to each multipath is expanded into an area; constructing an occupation grid map, discretizing an obstacle position area corresponding to each multipath, converting the discretized areas into grid positions, counting occupation marks, and determining idle mark counts; and marking the grids higher than the occupancy threshold value as an occupancy state, and marking the grids lower than the idle threshold value as an idle state, so as to construct a grid map for sensing the surrounding environment.

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 present invention relates to the field of underwater acoustic positioning technology, and discloses an OFDM sound source distance and depth estimation method based on a single hydrophone, aiming to achieve parallel processing of communication and positioning tasks and efficient utilization of underwater time-frequency resources, and to promote the development of lightweight and low-power consumption devices suitable for underwater unmanned small platforms. The OFDM sound source distance and depth estimation method based on a single hydrophone proposed by the present invention combines the frequency-domain input-output relationship of a communication system under a multipath channel, uses comb-shaped pilots to construct an observation model for target positioning, constructs a multi-snapshot measurement matrix through spatial smoothing means, realizes multipath delay estimation based on the rotational invariance subspace algorithm, and then uses the channel delay feature matching method to achieve target positioning. The OFDM sound source distance and depth estimation method based on a single hydrophone provided by the present invention is applicable to the integrated information processing of a single hydrophone, has the advantages of miniaturization, lightweight, and portability, and is suitable for underwater unmanned small platforms.

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.

The embodiment of the invention provides a symbol processing method and a communication device, and relates to the technical field of communication. The method is applied to a communication device, and comprises the following steps: generating a first time slot comprising a plurality of symbols, the plurality of symbols comprising a first symbol and a second symbol which are adjacent in a time domain, the first symbol and the second symbol being respectively a first symbol component and a second symbol component, the two symbol components being the same; and sending the first time slot. Specifically, the network equipment sends first indication information and second indication information which are an equivalent cyclic prefix of a first symbol and a correlation quantity of a first symbol component respectively, the terminal equipment receives the first indication information and the second indication information, and the network equipment generates and sends a first time slot; or, the network equipment sends the first indication information and the second indication information, and the terminal equipment generates and sends the first time slot after receiving the first indication information and the second indication information. Wherein the length of the equivalent cyclic prefix of the first symbol is greater than or equal to the length of the maximum multipath time delay, so that cyclic convolution recovery can be realized, and inter-symbol interference is avoided.

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.