36 results about "DFT matrix" patented technology

The invention provides an information processing method and device, and the method comprises the steps: an access network device can carry out the line-column transformation of a matrix formed by a current orthogonal coverage code, and obtains a first matrix; the access network device can also send indication information of an orthogonal cover code to the terminal, wherein the orthogonal cover code is obtained according to one row of the first matrix. Analysis is carried out on the first matrix, and it can be known that if Doppler frequency shift exists, the frequency offset resistance of the first matrix is superior to that of a current matrix (such as a Walsh matrix and / or a DFT matrix) formed by orthogonal cover codes. Therefore, the new orthogonal cover code obtained based on the first matrix has high anti-frequency offset capability.

The present invention discloses a single-cell massive MIMO beam-complemented channel estimation method, comprising the following steps: (1) a base station establishes a space-frequency domain received signal model for an angle-delay domain channel based on a received pilot signal and a beam-based channel characterization model; (2) each oversampled DFT matrix constituting a sensing matrix in the receiving model is completed into a DFT matrix, and received signal and noise completion are performed simultaneously to obtain a completed received signal model; (3) the completed signal and angle-delay domain channel are iteratively solved using an EM algorithm until convergence or a fixed number of iterations are reached, at which point the channel obtained is the estimated value of the angle-delay domain channel. The present invention can significantly resolve the complex matrix inversion problem in MMSE estimation, thereby reducing time complexity and space complexity, and can quickly converge to a better estimated value given a small number of iterations.

The present application provides an information processing method and apparatus. The method comprises: an access network device performs row and column transformation on a matrix formed by a current orthogonal cover code, so as to obtain a first matrix; and the access network device further sends indication information of the orthogonal cover code to a terminal, the orthogonal cover code being obtained on the basis of one row of the first matrix. It can be learned from the analysis on the first matrix that if a Doppler frequency shift occurs, the anti-frequency shift performance of the first matrix is better than that of a matrix (e.g., a Walsh matrix and / or a DFT matrix) formed by the current orthogonal cover code. Therefore, a new orthogonal cover code obtained on the basis of the first matrix has a higher anti-frequency shift capability.

Provided is a discrete Fourier transform (DFT)-spread orthogonal frequency division multiplexing (OFDM) transmission method and transmitter including a phase shifter configured to generate a pi / 2-binary phase shift keying (BPSK) symbol vector by phase-shifting a vector including M BPSK symbols, a DFT spreader configured to generate a DFT-spread pi / 2-BPSK symbol vector by spreading the pi / 2-BPSK symbol vector using an M-point DFT matrix, a circular extender configured to generate a circularly extended pi / 2-BPSK symbol vector by periodically extending the DFT-spread pi / 2-BPSK symbol vector, a frequency domain spectrum shaper configured to generate a frequency domain spectrum shaped pi / 2-BPSK symbol vector by multiplying each element of the circularly extended pi / 2-BPSK symbol vector by each element of a first shaping vector, and a subcarrier allocator configured to allocate the frequency domain spectrum shaped pi / 2-BPSK symbol vector to subcarriers in an allocated frequency range.

The present disclosure relates to methods and devices (including apparatuses, such as UEs and / or base stations) for wireless communication. The apparatus can select one or more rows or one or more columns of a DFT matrix, the one or more rows being even rows in the DFT matrix and the one or more columns being even columns in the DFT matrix. The apparatus can also determine an orthogonal matrix based on the one or more rows or the one or more columns of the DFT matrix, the orthogonal matrix having a size of (MxN)x(MxN) with MxN rows and MxN columns. Additionally, the apparatus can determine a codebook based on the orthogonal matrix, the codebook including a plurality of codepoints. The apparatus can also transmit at least one signal including a first codepoint of the plurality of codepoints in the codebook in an uplink resource.

The invention provides a power distribution transmission method and device under an OCDM frequency selection channel, and the method comprises the steps: converting a time domain signal into a frequency domain through a discrete Fourier transform matrix at a transmitting end, generating a power distribution matrix through combining channel state information and adopting a water injection algorithm, and carrying out the dynamic power precoding of a frequency domain subcarrier; generating a time domain OCDM signal through an inverse discrete Fourier transform matrix and an inverse discrete Fresnel transform matrix, adding a cyclic prefix, and transmitting the time domain OCDM signal; after a receiving end is subjected to prefix removal, a discrete Fourier transform matrix is converted into a frequency domain, a frequency domain equalizer is designed on the basis of a minimum mean square error criterion by utilizing channel diagonalization characteristics, signals are equalized in combination with transmitting power information, and finally time domain information is recovered through an inverse discrete Fourier transform matrix; therefore, the problem of traditional power distribution failure caused by OCDM channel energy dispersion is solved, and through receiving and transmitting joint optimization, diversity gain is fully mined, frequency selective channel fading is adaptively matched, the anti-interference and anti-multipath capabilities of the system are improved, and the spectrum efficiency and the transmission performance are maximized.

The invention provides an all-optical fast Fourier transform calculation implementation method and a photonic device. The method comprises the following steps: demultiplexing a time sampling vector based on a first array waveguide grating to obtain a parallel multi-wavelength signal; carrying out column-by-column phase modulation on the parallel multi-wavelength signals according to a discrete Fourier transform matrix based on a phase shift waveguide array to obtain weighted signals; and combining the weighted signals based on the second array waveguide grating to obtain an output optical signal. According to the method provided by the invention, a parallel multi-wavelength signal is obtained by demultiplexing a time sampling vector based on a first array waveguide grating; carrying out column-by-column phase modulation on the parallel multi-wavelength signals according to a discrete Fourier transform matrix based on a phase shift waveguide array to obtain weighted signals; and on the basis of the second array waveguide grating, weighted signals are combined to obtain output optical signals, the physical characteristics of high selectivity and low loss of an integrated photonic device are fully utilized, and efficient and high-fidelity Fourier transform calculation is realized in an integrated form with low structural complexity.

The embodiments of the present application relate to the field of communications. Provided are a communication method and apparatus, which can meet precoding requirements in a complex communication scenario. The method comprises: acquiring a first precoding matrix, and sending first information, wherein the first information is precoded by the first precoding matrix, the first precoding matrix is a precoding matrix in a precoding matrix set, the precoding matrix set is associated with the number of antenna ports of a terminal device and the number of transmission layers of the terminal device, the precoding matrix set comprises N precoding matrices, and any non-zero element in any precoding matrix among the N precoding matrices meets wi, a substrate w being determined by means of a discrete Fourier transform (DFT) matrix with a length of X, the value of X being associated with the number of antenna ports, and the number of antenna ports being an integer multiple of 3, where i=0, 1, 2,..., X-1, and N is a positive integer.

This invention discloses a V-OFDM secure transmission method, system, device, and medium based on a dynamic feedback chaotic system. The method constructs a three-dimensional Lorenz chaotic mapping model based on dynamic feedback factors, controls the row and column transformations of the orthogonal DFT matrix, and independently encrypts each vector block. The system, device, and medium are used to implement this method. The method fully utilizes the vector block characteristics of V-OFDM, introducing dynamic row and column permutations of the DFT matrix, resulting in a spherical chaotic state in the encrypted constellation diagram, making it difficult for eavesdroppers to crack. This greatly enhances the system's resistance to signal interception, effectively strengthens the security of the physical layer, and reduces the system's peak-to-average power ratio (PAPR).

A communication device providing CSI feedback in a wireless communication system includes a transceiver to receive downlink reference signals and downlink signals including a reference signal configuration. A processor estimates an explicit CSI in the frequency domain. The processor selects a Doppler-delay-beam precoder matrix for a composite Doppler-delay-beam three-stage precoder, which is based on one or more codebooks includingone or more transmit-side spatial beam components,one or more delay components, andone or more Doppler-frequency components,The processor calculates a CQI and / or a PMI and / or a rank indicator, RI, using the explicit CSI and the composite Doppler-delay-beam three-stage precoder, and reports the CSI feedback including the CQI, and / or the PMI and / or the RI. The one or more delay and / or Doppler-frequency components are defined by one or more sub-matrices of a DFT matrix or an oversampled DFT matrix.

The present disclosure relates to machine vision systems and methods for performing optical flow calculations. Machine vision systems in accordance with many embodiments of the invention use GPU tensor processing cores to perform one-dimensional Discrete Fourier Transform (DFT) calculations using real DFT matrices, enabling efficient separable window correlation for optical flow. In one embodiment, the machine vision system includes: a camera; a processor; a processor comprising tensor processing cores; and a memory containing instructions. Executing the instructions using the processors causes the machine vision system to: obtain a pair of sequential images from the camera; identify windows in the images; perform optical flow calculations using separable window correlation, wherein the separable window correlation calculations comprise performing one-dimensional discrete Fourier transform (DFT) calculations using the tensor processing cores, and wherein the one-dimensional DFT calculations are performed on the tensor processing cores using real DFT matrices; and output optical flow information.

A pilot design method, a channel estimation method and a device for an OCDM communication system belong to the field of communication technologies, and solve the problem of unstable frequency-domain channel estimation caused by improper pilot design in the existing OCDM communication system. The pilot design method of the present invention includes: selecting a block pilot structure in the modulation domain and pre-designing a pilot sequence for the current transmitted data block; obtaining a vector Γ after the pilot sequence is transformed into the frequency domain H Fx p , where Γ is a diagonal matrix composed of Zadoff-Chu root sequences, and F is a discrete Fourier transform matrix; checking whether the pilot sequence x p satisfies the constraint condition: there are no elements with a value of 0 in the vector Γ H Fx p ; if the constraint condition is not satisfied, the pilot sequence x p is reconstructed until the constraint condition is satisfied; if the constraint condition is satisfied, the pilot sequence is selected as the pilot sequence for the current transmitted data block. The present invention also realizes channel estimation based on the pilot design method. The present invention is applicable to OCDM communication systems.

The present application belongs to the technical field of calibration of phased array radar, and relates to a two-stage grouping asynchronous rotating electric vector radar array antenna calibration method, and the specific process is as follows: an attenuator and a phase shifter are configured to each element channel of the array antenna to be measured, and signals received by all channels are synthesized through a power divider; the phased array radar to be measured is equally grouped by channel number in a first stage; a grouping matrix is constructed based on a Hadamard matrix, and the channels grouped in the first stage are divided into rotating groups and fixed groups according to elements in the grouping matrix; a phase shift matrix for phase shift measurement of each row in different grouping matrices is constructed based on a discrete Fourier transform matrix with an order of N, and phase shift is performed; linear equations are constructed according to measurement results and solved, and the ambiguity coefficient, the amplitude of each channel and the phase difference between each channel are obtained, and each field normalization amplitude and phase is solved; amplitude and phase compensation of the channels is completed based on each field normalization amplitude and phase, and finally the amplitude and phase of all channels are consistent.

A receiver processes a radio signal received via a radio channel from a transmitter employing a plurality of antenna ports, determines complex precoder coefficients and delays of one or more space-delay precoders for one or more transmission layers and antenna ports at the transmitter so as to achieve a predefined property for a communication over the radio channel, and feeds back, explicitly or implicitly, delays and the complex precoder. The space-delay precoder has a dual-stage structure having a spatial codebook matrix including spatial beamforming vectors, a frequency-domain codebook matrix, and a combining element per layer for complex scaling or combining one or more of the vectors selected from the spatial and / or frequency-domain codebook matrices. The frequency-domain codebook matrix is defined by a sub-matrix of a DFT matrix, which the sub-matrix of the DFT matrix is associated with a range of delay values.

The embodiments of the present application relate to the field of communications. Provided are a communication method and apparatus, which can meet precoding requirements in a complex communication scenario. The method comprises: acquiring a first precoding matrix, and sending first information, wherein the first information is precoded by the first precoding matrix, the first precoding matrix is a precoding matrix in a precoding matrix set, the precoding matrix set is associated with the number of antenna ports of a terminal device and the number of transmission layers of the terminal device, the precoding matrix set comprises N precoding matrices, and any non-zero element in any precoding matrix among the N precoding matrices meets wi, a substrate w being determined by means of a discrete Fourier transform (DFT) matrix with a length of X, the value of X being associated with the number of antenna ports, and the number of antenna ports being an integer multiple of 3, where i=0, 1, 2,..., X-1, and N is a positive integer.

The invention discloses a three-dimensional fingerprint positioning algorithm based on phase optimization and a lightweight deep neural network under the assistance of an intelligent reflecting surface. According to the method, the Cramer-Rao lower bound based on the channel state information fingerprint positioning error is minimized, and the phase configuration of the intelligent reflecting surface is optimized. And then, processing the optimized channel state information fingerprint by using a phase shift discrete Fourier transform matrix to realize decoupling of vertical angle information and horizontal angle information. The optimized fingerprints provide feature representation with higher discriminability, and decoupling of rich angle information further improves the positioning performance. Then, a lightweight neural network architecture for positioning is provided, and the architecture greatly reduces the parameter quantity of a deep network by integrating an Inception structure in GoogLeNet and packet convolution in ResNeXt. In addition, a self-attention residual learning mechanism is introduced to enhance the ability to extract deep features.

The present invention relates to a harmonic wavelet inverse synthetic aperture radar imaging method and device based on ADMM. The method comprises: acquiring range unit signals, constructing a discrete Fourier transform matrix based on the range unit signals; determining a window function, processing each time point of the range unit signals according to a sliding window, and determining the signal within the local time window; constructing a local harmonic wavelet basis matrix based on the discrete Fourier transform matrix and the window function; then constructing an optimization model based on the local harmonic wavelet basis matrix and the signal within the local time window; introducing auxiliary variables and dual variables to iteratively update the optimization model to obtain final harmonic wavelet coefficients; calculating local energy distribution based on the harmonic wavelet coefficients, constructing a time-frequency matrix based on the local energy distribution, and reconstructing the target image based on the time-frequency matrix to obtain the final ISAR image. The present invention can improve resolution, reduce cross-term interference, and achieve high imaging accuracy.

The invention relates to a harmonic wavelet inverse synthetic aperture radar imaging method and device based on ADMM. The method comprises the following steps: acquiring a distance unit signal, and constructing a discrete Fourier transform matrix based on the distance unit signal; determining a window function, processing each time point of the distance unit signal according to a sliding window, and determining a signal in a local time window; constructing a local harmonic wavelet basis matrix according to the discrete Fourier transform matrix and the window function; constructing an optimization model according to the local harmonic wavelet basis matrix and the signals in the local time window; introducing an auxiliary variable and a dual variable to iteratively update the optimization model to obtain a final harmonic wavelet coefficient; and calculating local energy distribution based on the harmonic wavelet coefficient, constructing a time-frequency matrix through the local energy distribution, and reconstructing the target image according to the time-frequency matrix to obtain a final ISAR image. According to the invention, resolution can be improved, cross term interference is reduced, and imaging precision is high.

The present disclosure relates to machine vision systems and methods for performing optical flow calculations. Machine vision systems in accordance with many embodiments of the invention use GPU tensor processing cores to perform one-dimensional Discrete Fourier Transform (DFT) calculations using real DFT matrices, enabling efficient separable window correlation for optical flow. In one embodiment, the machine vision system includes: a camera; a processor; a processor comprising tensor processing cores; and a memory containing instructions. Executing the instructions using the processors causes the machine vision system to: obtain a pair of sequential images from the camera; identify windows in the images; perform optical flow calculations using separable window correlation, wherein the separable window correlation calculations comprise performing one-dimensional discrete Fourier transform (DFT) calculations using the tensor processing cores, and wherein the one-dimensional DFT calculations are performed on the tensor processing cores using real DFT matrices; and output optical flow information.

The present application provides a communication method and a communication system. The communication method, applied to a transmitter, includes: collecting a bitstream; modulating and converting the bitstream and obtaining a frequency domain signal matrix; multiplying the frequency domain signal matrix with an inverse approximate Discrete Fourier Transform (DFT) matrix and obtaining a time domain signal matrix; post-processing the time domain signal matrix and obtaining a time domain signal, and sending the time domain signal to a receiver connected with the transmitter. The communication method, applied to a receiver, includes: receiving a time domain signal from a transmitter connected with the receiver; pre-processing the time domain signal and obtaining a time domain signal matrix; multiplying the time domain signal matrix with an approximate DFT matrix and obtaining a frequency domain signal matrix; demodulating and converting the frequency domain signal matrix and obtaining a bitstream.

The method for super-resolution direction of arrival estimation of uniform linear array based on inverse beamforming comprises the following steps: step (1): constructing a narrowband single snapshot echo signal model of the linear array, realizing the signal model of direction of arrival estimation, and forming a beam; step (2): constructing a discrete Fourier transform matrix F N Inverse beamforming observation model; Step (3): Construct the discrete Fourier transform matrix F P Inverse beamforming observation model; Step (4): Construct the downsampling matrix Θ, N actual array data y NP Considered as the full sampling data y of P virtual array elements using Θ P The result of downsampling; Step (5): Based on the inverse beamforming observation model at point P, use Θ, F P and y NP , constructing a P (P>N) point inverse beamforming super-resolution observation model; step (6): constructing a super-resolution optimization model based on the weighted L1 norm, using MATLAB's CVX toolbox to solve the optimization model, and finally achieving direction of arrival super-resolution estimation. The present invention achieves direction of arrival super-resolution estimation of linear arrays.

The application discloses a UV image blur detection method based on DFT matrix integer approximate decomposition, which performs integer approximate decomposition on a matrix on the basis of setting a numerical range constraint and a sparsity constraint when the DFT matrix is used for image discrete Fourier transform. The matrix is decomposed into a form of a series of sparse and element value limited matrix multiplication, so as to reduce the matrix multiplication calculation times, thereby optimizing the calculation complexity and reducing the calculation cost. The spectrum image obtained by performing the discrete Fourier transform on the UV image of the water surface floating colorless chemical based on the method is subjected to high-pass filtering, the average amplitude intensity is calculated, the blur value is compared with a set threshold value, whether the UV image of the water surface floating colorless chemical is blurred can be determined, and thus the blur detection function is realized.

The embodiment of the application provides a communication method and device, relates to the field of communication, and more types of waveforms are introduced for communication or sensing by setting waveform parameters, so that flexible configuration of different waveforms can be realized. In the method, a first device determines a second signal according to a third signal and a first pre-processing matrix selected from a first pre-processing matrix set, so as to determine a first signal according to the second signal. By setting the first pre-processing matrix set to include a unit matrix and at least one first type of matrix, or to include a DFT matrix and at least one first type of matrix, the first type of matrix is not a square matrix, or neither a unit matrix nor a DFT matrix, more types of waveforms can be introduced for communication or sensing. Different pre-processing matrices are configured to realize flexible configuration of different waveforms, so that different service requirements in the communication or sensing scene can be met.

The application relates to a kind of discrete fourier transform implementation method and equipment based on matrix operation unit, the method comprises: DFT matrix is transformed arrangement and generates the DFT matrix of transformed arrangement, the DFT matrix of transformed arrangement and input data matrix are copied to equipment global memory in host end;Start computing kernel, input data matrix and the DFT matrix of transformed arrangement are read to the data on-chip cache from global memory, input data matrix and DFT matrix are multiplied by calling matrix operation unit, and the operation result of discrete fourier transform is obtained;Host end copies result data from equipment global memory to host memory, and releases computing resource.The application directly adopts matrix multiplication operation to calculate DFT, does not need additional complex imaginary-real separation combination operation, can reduce global memory access frequency, improves the execution efficiency of entire complex matrix multiplication operation, improves equipment DFT calculation efficiency.

A communication device providing CSI feedback in a wireless communication system includes a transceiver to receive downlink reference signals and downlink signals including a reference signal configuration. A processor estimates an explicit CSI in the frequency domain. The processor selects a Doppler-delay-beam precoder matrix for a composite Doppler-delay-beam three-stage precoder, which is based on one or more codebooks includingone or more transmit-side spatial beam components,one or more delay components, andone or more Doppler-frequency components.The processor calculates a CQI and / or a PMI and / or a rank indicator, RI, using the explicit CSI and the composite Doppler-delay-beam three-stage precoder, and reports the CSI feedback including the CQI, and / or the PMI and / or the RI. The one or more delay and / or Doppler-frequency components are defined by one or more sub-matrices of a DFT matrix or an oversampled DFT matrix.

The application relates to a multi-dimensional fast Fourier transform acceleration method based on matrix operation in the field of computing power optimization. The method comprises the following steps: S1, applying for a computing resource, copying computing data to device global memory on the host side, generating a DFT matrix and an input data matrix; S2, reading the DFT matrix data and the input data matrix from the global memory to a register and a shared memory; S3, using multi-thread parallelism to complete the calculation task of matrix element multiplication of the input data matrix and a rotation factor matrix, and obtaining intermediate calculation result data; S4, calling a matrix operation unit to perform matrix multiplication on the intermediate calculation result data obtained in the step S3 and the DFT matrix, and outputting final calculation result data; and S5, copying the final calculation result data from the device global memory to the host memory on the host side, and releasing the computing resource. The application adopts matrix operation to calculate multi-dimensional FFT, and uses a high-performance matrix operation unit of a GPU to accelerate the calculation, so that the FFT calculation efficiency on the GPU is improved.

A receiver processes a radio signal received via a radio channel from a transmitter employing a plurality of antenna ports, determines complex precoder coefficients and delays of one or more space-delay precoders for one or more transmission layers and antenna ports at the transmitter so as to achieve a predefined property for a communication over the radio channel, and feeds back, explicitly or implicitly, delays and the complex precoder. The space-delay precoder has a dual-stage structure having a spatial codebook matrix including spatial beamforming vectors, a frequency-domain codebook matrix, and a combining element per layer for complex scaling or combining one or more of the vectors selected from the spatial and / or frequency-domain codebook matrices. The frequency-domain codebook matrix is defined by a sub-matrix of a DFT matrix, which the sub-matrix of the DFT matrix is associated with a range of delay values.

The application discloses a large-scale MIMO uplink semi-blind channel estimation method based on independent component analysis and compressed sensing, which comprises the following steps: using a windowed least square channel estimation of a transmission pilot to perform channel preliminary estimation; performing discrete Fourier transform matrix conversion on the channel preliminary estimation result to an angle domain; using a compressed sensing recovery method to acquire angle domain features and a user number of a target user channel according to the channel preliminary estimation result in the angle domain; performing blind source separation of independent component analysis according to the user number to obtain each user channel including the target user channel with ambiguity; and using the angle domain features of the target user channel to eliminate the ambiguity of the target user channel to obtain an estimation result of the target user. The method combines the advantages of the compressed sensing technology and the independent component analysis technology, combines the two together, and greatly improves the channel estimation performance.

The present invention discloses a satellite target ISAL vibration phase compensation method based on improved phase gradient autofocusing, comprising: performing distance compression on an echo signal to obtain heterodyne data; compensating the heterodyne data using a PGA algorithm, and forming a marker vector using the compensated data; cyclically shifting each distance unit in the heterodyne data, and adaptively windowing the cyclically shifted data; performing phase gradient estimation on the windowed data according to the marker vector to obtain a phase gradient value; constructing a characteristic matrix, a phase error estimation matrix, and a signal-to-noise ratio weighting matrix for each azimuth unit according to the phase gradient value; constructing a phase error compensation matrix and a discrete Fourier transform matrix according to the characteristic matrix, the phase error estimation matrix, and the signal-to-noise ratio weighting matrix; and compensating the heterodyne data according to the phase error compensation matrix and the discrete Fourier transform matrix to obtain a compensation result. The present invention achieves highly intelligent, efficient, and high-precision compensation.

Signal processing methods based on compressed sensing (CS) theory, intended to solve storage space and communication limitations in a Nyquist sampling framework, have attracted increased attention in recent years. In conventional harmonic detection, sparse bases are typically represented by a discrete Fourier transform (DFT) matrix. Harmonic non-synchronous sampling inevitably leads to spectral leakage and fence effect. To address this issue, we present an improved CS model for harmonic detection in power systems. A windowing technique is introduced in the compression sampling process. The fixed-point continuation algorithm combined with interpolation technique is used to directly extract harmonic parameters from the sparse coefficients without reconstructing the original signal. The proposed harmonic detection method, using an improved CS model, can achieve an accuracy comparable to that of the windowed interpolation FFT algorithm.