20 results about "Shift matrix" patented technology

A communication method and a communication apparatus in which a device may perform encoding or decoding based on an LDPC matrix, the LDPC matrix being determined based on an LDPC basis matrix, Zc, a, and b, a first region of the basis matrix including L types of elements, 2 < = L < = 2a * b, a and b not being 1 at the same time, Zc, a, and b being used to lift the elements in the first region to a (a * Zc) * (b * Zc) matrix, the matrix including (a * b) (Zc * Zc) matrices, each Zc * Zc matrix is an all-zero matrix or a cyclic shift matrix, the first sub-matrixes of the L elements are different, and the first sub-matrixes are matrixes formed by replacing the cyclic shift matrixes in (a * b) (Zc * Zc) matrixes of the matrix with the lifted corresponding elements with Zc * Zc unit matrixes. According to the method, the decoding performance of the LDPC code can be improved.

The application discloses a wireless covert detection method and system based on intelligent reflecting surface assistance. The method is as follows: a system model is established, and detection error probabilities of a legal receiver and an illegal detector are derived; an optimal detection threshold is obtained by analyzing an expression of the detection error probability, and the detection error probability is determined; a joint optimization problem of an intelligent reflecting surface phase shift matrix and a transmission power is established; a lower bound of the optimization problem is selected to simplify the optimization problem, and a simplified optimization problem is obtained; the simplified optimization problem is solved, and an optimal intelligent reflecting surface phase shift matrix is determined, and a feasible transmission power is selected to meet a covert constraint requirement. The system comprises a model establishment module, a detection error probability determination module, a joint optimization problem construction module, an optimization problem simplification module and an optimal intelligent reflecting surface phase shift matrix determination module. The application improves the detection performance of the legal receiver, and reduces the detection performance of the illegal detector, so that the requirement of the covert constraint is met.

The application discloses a quasi-cyclic low-density parity-check code decoding method, system, device and medium, acquires a predetermined parity-check matrix; adjusts the parity-check matrix into a target operation matrix composed of a unit matrix and a displacement matrix, the dimensions of the unit matrix and the displacement matrix are both p x p; acquires a target codeword to be decoded corresponding to a current decoding recursion number; splits the target codeword into target sub-codewords with a length of p; in the target operation matrix, determines a target operation sub-matrix corresponding to each target sub-codeword; performs parallel operation on the target sub-codewords and the target operation sub-matrix to obtain a syndrome value of the target codeword; determines a current decoding result of the current decoding recursion number based on the syndrome value, and determines a target decoding result based on the current decoding result. In the application, parallel operation is performed on the corresponding target operation sub-matrix and the target sub-codeword, the operation efficiency of the syndrome value can be improved, and the operation efficiency of the entire decoding method is further improved.

The application discloses a data encryption method, and belongs to the technical field of text encryption. First, the text data is converted into binary code and split into odd and even bit sequences, and corresponding matrices are constructed respectively; the odd and even shift matrices are obtained by generating matrix row / column state bits, calculating shift amount and performing cyclic shift; then the rows and columns of the shift matrix are converted into decimal numerical vectors, combined with fractal offset key vectors for encryption, and four types of encryption matrices of odd row, odd column, even row and even column are generated; the same type of matrices are subjected to XOR processing, and the confusion value is generated based on the odd part and the even part related value, so that the mixed enhanced encryption matrix is obtained; finally, the two types of enhanced matrices are restored into sequences and reorganized according to the odd and even bits, and the ciphertext is output. Through the multilevel processing of bit splitting, matrix shifting, fractal key encryption and XOR confusion, the complexity and anti-cracking ability of data encryption are significantly improved, and the safety of data transmission and storage is ensured.

This invention discloses a lithography simulation method and system based on circular sampling function decomposition and superimposed pupil shift matrix. The method includes: sampling the shape function and pupil function of the extended light source to obtain the corresponding superimposed pupil shift matrix; processing the superimposed pupil shift matrix, the frequency domain circular sampling function matrix of the extended light source and the pupil plane to obtain the frequency domain cross-transmission coefficient matrix and the projection matrix; performing singular value decomposition on the projection matrix to obtain the singular value decomposition result; processing the spatial domain circular sampling function matrix based on the singular vectors to obtain the convolution kernel matrix; constructing a spatial domain image simulation model based on the singular value decomposition result, the convolution kernel matrix and the initial Hopkins model; and obtaining the spatial domain image simulation result based on the spatial domain image simulation model. This invention utilizes the superimposed pupil shift matrix method and analytical circular sampling function decomposition, which can reduce the direct calculation and storage of the TCC matrix and significantly reduce the computational cost required to obtain the kernel.

The present invention discloses a wireless communication optimization method and system based on a reconfigurable intelligent surface, which relates to the technical field of wireless communication. The method includes collecting environmental data and network load data, performing a product operation by combining the user density and the network load index to calculate the resource demand index, comparing the resource demand index with a classification threshold range, selecting a BD-RIS architecture, using the Rician fading formula to calculate the corrected channel parameters, and generating a channel matrix; constructing an initial phase shift matrix according to the BD-RIS architecture type, and constructing an objective function based on the initial phase shift matrix; by comprehensively analyzing the network load data and the user density, dynamically setting the RIS architecture to enhance the accurate evaluation and flexible adaptation of the network state, calculating the channel gain benchmark through the Euclidean distance formula and the path loss formula, and optimizing the channel parameters in combination with the phase analysis in the channel state information and the Rician fading formula to reduce signal attenuation and interference, and improve the main channel gain and spectral efficiency.

The application discloses an intelligent experiment table multi-sensing data distributed storage method based on edge calculation and relates to the technical field of edge calculation, which comprises the following steps: generating a double-layer segment matrix based on continuous sampling data of an intelligent experiment table; obtaining a tail trace residual matrix based on the double-layer segment matrix; constructing a shift matrix based on the tail trace residual matrix and generating a tail trace adhesion-propagation matrix based on the shift matrix; calculating a tail trace cutting cost based on the tail trace adhesion-propagation matrix; calculating the fitness of each particle in a particle swarm based on the tail trace cutting cost; iteratively updating the speed and position of each particle in the particle swarm based on the fitness to determine an optimal distributed write matrix; and obtaining a distributed storage result based on the optimal distributed write matrix; and the application improves the experiment data recovery efficiency in a distributed storage environment.

The present disclosure provides a transfer treatment bed positioning calibration method. The transfer treatment bed positioning calibration method comprises: statistically distributing pose error of a transfer treatment bed in a motion process based on historical motion data; constructing a transition probability function and an observation probability function based on the pose error distribution; constructing a state transition matrix and an observation probability matrix based on the transition probability function and the observation probability function, and constructing a hidden Markov model; solving the hidden Markov model to obtain a best candidate error of the transfer treatment bed in a current motion process, and further obtaining an optimal candidate pose; calculating a shift matrix between a simulated image of the optimal candidate pose of the transfer treatment bed and an actual image to correct the optimal candidate pose and obtain a target pose; generating a motion trajectory based on a quintic polynomial trajectory planning algorithm to adjust the transfer treatment bed to the target pose. The present disclosure also provides a transfer treatment bed positioning calibration device, equipment, storage medium and program product.

The application belongs to the technical field of numerical simulation, and provides a crack calculation method and system based on parallel calculation and matrix near-field dynamics. The application firstly constructs a neighborhood matrix, a coordinate matrix, a displacement matrix, a load density matrix and a marking matrix; then, the force of a material point at each time step is calculated in combination with the coordinate matrix and the marking matrix; the marking matrix is used to filter the calculation result of the load density matrix, the resultant force of each material point is determined by summing each row of the load density matrix, and the deformation and displacement of the material point are solved by the resultant force of the material point; by converting all variables used in the near-field dynamics calculation process into a matrix format, based on the basic control equation of near-field dynamics, the CPU / GPU parallel matrix operation is used to realize efficient solution of near-field dynamics, and the problem of high time cost in the iterative calculation process by using the traditional method of successive search is avoided.

The application discloses a chaotic communication and sensing integrated signal processing method and device and a communication system. The scheme provided by the application divides an information bit sequence into a modulation bit sequence, an index bit sequence and a PPM bit sequence, processes an initial signal vector by combining a pulse position modulation technology, optimizes spectral utilization by double control of the modulation bit and the index bit, segments the initial modulation signal according to PPM orders and generates a signal vector, and offsets the signal vector in the time domain by combining a shift matrix. The scheme utilizes the good autocorrelation characteristics and the low cross-correlation characteristics of an LFM signal, and on the basis of the original DCSK-LFM modulation mode, combines pulse position modulation and index modulation, so that the same carrier can carry more information, thereby improving the transmission rate when applied to a JRC system and the overall performance of the communication system.

The invention belongs to the technical field of position estimation in the aviation field, and discloses a relative position estimation method and system in the approaching or landing process of an aircraft, and the method comprises the steps: determining the displacement and attitude of the current aircraft relative to a reference position and a reference attitude according to the current attitude and position of the aircraft; then, constructing a virtual runway image by utilizing the airport landscapes three-dimensional database, constructing a displacement matrix space and a rotation matrix space at the same time, and searching an optimal displacement matrix and an optimal rotation matrix in the matrix space by using an iteration method; the matrix can minimize an error between a virtual runway image feature and a runway feature on an image obtained by a real EVS, so that the displacement of an aircraft relative to a runway is accurately estimated by using an optimal displacement matrix. According to the invention, the problem of inaccurate relative position estimation in the approaching or landing process of the existing aircraft is solved.

The method aims at solving the problems of beam pointing deviation and beam misalignment caused by high-speed movement of an unmanned aerial vehicle and sharp change of a channel state. The invention provides a novel intelligent reflector-assisted opportunistic cognitive unmanned aerial vehicle network beam tracking method. The method comprises the following steps: firstly, predicting space angle information of a potential moving area of an unmanned aerial vehicle by adopting a long-short-term memory model based on an attention mechanism, and designing a self-adaptive dual-beam coverage range and a dual-beam alignment center according to a prediction result; and secondly, constructing an optimization problem in which spectrum sensing duration, an intelligent reflector shift matrix of two stages and secondary base station beamforming are jointly designed by taking maximization of the unmanned aerial vehicle sum rate as a target. As optimization variables have high coupling, the complex non-convex optimization problem is decoupled into four sub-problems, a binary search method, a Lagrange multiplier method and a continuous convex approximation method are used to solve the four sub-problems, and finally, an alternating iteration algorithm is used to carry out alternating iteration to obtain a high-quality suboptimal solution. And finally, performing linear weighting on the optimal secondary base station beam forming vector and the intelligent reflecting surface shift matrix in the data transmission stage to realize dual-beam alignment from the secondary base station and the intelligent reflecting surface to the unmanned aerial vehicle. A simulation result shows that compared with a traditional beam alignment scheme, the scheme provided by the invention not only relieves the problem of insufficient spectrum authorization, but also has more stable communication performance.

This invention discloses an active RIS-ISAC system beamforming method for preventing eavesdropping and interference. It establishes a system model including a dual-function radar-communication base station, an active RIS, legitimate users, illegal eavesdroppers, and jammers, and sets communication, sensing, and power consumption performance indicators. Then, it constructs an optimization problem that aims to minimize the total system power consumption while satisfying communication and sensing constraints, jointly optimizing the base station's transmit beamforming vector and the active RIS's phase shift matrix. The non-convex optimization problem is further decomposed into two sub-problems, and the optimal configurations of the base station and RIS are solved separately. Finally, an alternating optimization algorithm is used to obtain the optimal solution. The advantage is that, even in the presence of both illegal eavesdroppers and malicious adversaries, it achieves improved communication performance, suppression of eavesdropping and interference, and a reduction in total system power consumption by jointly designing the base station's transmit beamforming vector and the active RIS's phase shift matrix.

The embodiment of the invention provides a coding method of an IRA-LDPC code for a DVB-S2 / S2X protocol, and the method comprises the steps: carrying out the preprocessing of each code rate check matrix under the DVB-S2 / S2X protocol, and generating a basic shift matrix of a system part and an index of the basic shift matrix; segmenting the check bit twice, and generating and storing a lookup table by taking the length of the check bit segmented twice as table lookup parallelism; determining a table lookup index value according to the basic shift matrix of the system part and the index of the basic shift matrix, and performing value lookup on the lookup table according to the table lookup index value; determining a target check bit according to the searched check bit value, extracting the target check bit at an interval preset length and interleaving and rearranging to obtain a check sequence, outputting the check sequence to the tail of a system bit as a coding result, and compressing a check matrix through a basic shift matrix and a lookup table to obtain a coding result. And in the encoding process, vector multiplication and addition are replaced by a table look-up method and a cyclic shift method, so that the encoding complexity is low and the encoding efficiency is high.

This invention discloses a bidirectional asymptotic isogeometric topology optimization method based on volume subdivision. The method first initializes the density of all hexahedral elements in the input hexahedral mesh solid model M, and then subdivides M by k1 times to obtain the optimized model M1. Next, a three-variable Bézier spline is constructed, and external loads on M are applied to their corresponding splines. The displacement matrix U is solved using isogeometric analysis. The initial stiffness matrix of the Bézier spline corresponding to each subdivided element in M1 is then constructed. Finally, a judgment is made based on the target volume fraction and the convergence formula. If the target volume fraction and the convergence formula are satisfied, the iteration ends, and the topology optimization model is obtained; otherwise, the volume fraction for the next iteration is updated, the element sensitivity of optimized M1 is calculated, and the density of each element in M1 is updated, and the iteration is repeated. This invention efficiently performs isogeometric topology optimization and obtains topology optimization results with clearly defined spline representations.

The application relates to a digital password encryption and decryption method of an intelligent door lock. The encryption method comprises the following steps: S1, constructing a substitution matrix and a shift matrix: constructing an M*M substitution matrix and an N*N shift matrix, wherein M is the bit number of the digital keyboard of the intelligent door lock, the substitution matrix is generated by random numbers, and each horizontal data and each vertical data is not repeated, N is the data bit number participating in operation, the shift matrix is generated by random numbers, and each horizontal data and each vertical data is not repeated, and M is greater than N; S2, shifting; S3, substituting; the decryption method comprises the following steps: S1, reverse substitution; S2, reverse shifting. The application provides a digital password encryption and decryption method of an intelligent door lock. Compared with the existing digital password encryption and decryption method, the method in the application is suitable for the form of digital keyboard input of the intelligent door lock, and the encryption and decryption data length meets the use requirement of the intelligent door lock industry.

Disclosed is an optimization method for resource allocation in a perception-enhanced cognitive radio network based on an IRS (intelligent reflecting surface). The method includes: acquiring BS (base station)-to-IRS and IRS-to-user channel state information; defining diagonal phase-shift matrices of the IRS in perception stage and transmission stage, and establishing an optimization model according to the channel state information; using the optimization model to optimize that the diagonal phase-shift matrix of the IRS in the perception stage assists the secondary base station (SBS) in perceiving a spectrum occupancy of a primary network; entering the transmission stage, and using the optimization model to optimize beamforming vectors of the SBS and the diagonal phase-shift matrices of the IRS in the transmission stage in the case of different perception results; transmitting transmission information according to optimization results to achieve an improvement in a spectrum efficiency of a system when constraints interfere with primary users.

The invention discloses a data encryption method, and belongs to the technical field of text encryption. The method comprises the following steps: firstly, converting text data into binary codes, splitting the binary codes into odd bit sequences and even bit sequences, and respectively constructing corresponding matrixes; the method comprises the following steps: generating a matrix row / column status bit, calculating a shift amount and executing cyclic shift to obtain an odd shift matrix and an even shift matrix; converting rows / columns of the shift matrix into decimal numeric vectors, and performing encryption in combination with fractal offset key vectors to generate four types of encryption matrixes of odd rows, odd columns, even rows and even columns; xOR processing is performed on the same type of matrixes, and a confusion value is generated based on correlation values of odd parts and even parts, so that a hybrid enhanced encryption matrix is obtained; and finally, restoring the two types of enhanced matrixes into a sequence, recombining according to odd and even bits, and outputting a ciphertext. According to the method, through multi-level processing of bit splitting, matrix shifting, fractal key encryption and XOR confusion, the complexity and cracking resistance of data encryption are remarkably improved, and the security of data transmission and storage is guaranteed.

Various aspects of the present disclosure generally relate to wireless communication. Various aspects relate generally to determining information metrics associated with an eigenvalue decomposition (EVD) operation associated with a four by four Hermitian matrix. Some aspects more specifically relate to determining a scalar (e.g., an eigenvalue or an approximation of an eigenvalue) of the four by four Hermitian matrix and determining a shifted matrix by subtracting a product of the scalar and an identity matrix from the four by four Hermitian matrix. A QR decomposition may be performed on the shifted matrix to determine first derived information, representable by a three by three Hermitian matrix. An eigenvalue decomposition operation may be performed on the three by three Hermitian matrix to determine the eigenvalues and eigenvectors of the four by four Hermitian matrix.

This application belongs to the field of structural finite element analysis, and particularly relates to a parallel supernode sparse triangular solution method for structural finite element stiffness equations. The method includes: performing finite element division on an aircraft structure to obtain the stiffness matrix and load matrix of the finite element model of the aircraft structure, and constructing the structural finite element stiffness equation Ax = B ; performing a first-row permutation operation on the load matrix B ; performing forward substitution based on the supernode data structure; performing backward substitution based on the supernode data structure; performing a second-row permutation operation on the load matrix B that is opposite to the first-row permutation operation to obtain the displacement matrix x ; performing finite element analysis of the aircraft structure according to the displacement matrix x . This application adopts triangular matrix solution and matrix multiply-add operations for a new parallel sparse triangular solution. Taking supernodes as units, forward substitution and backward substitution are performed for each supernode, greatly improving the efficiency of forward substitution and backward substitution.