18 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 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.

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 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 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 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 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 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 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 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.

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.

The disclosure inter alia relates to a user equipment. The user equipment may comprise means for obtaining a precoding matrix for precoding an uplink data stream to be transmitted to a network node by the user equipment using three antenna ports. The uplink data stream may comprise at most three uplink layers, wherein each of the at most three uplink layers is to be transmitted to the network node using the three antenna ports. The precoding matrix may be obtainable based on performing at least the following: obtaining a 3N×3N discrete Fourier transform, DFT, matrix with a matrix order parameter N, wherein N is an arbitrary natural number, wherein the 3N×3N DFT matrix comprises 3N rows forming 3N-2 sub-matrices, with each of the 3N-2 sub-matrices consisting of three consecutive rows of the 3N×3N DFT matrix, wherein each of the 3N-2 sub-matrices comprises 3N column vectors forming N groups of column vectors, with each group n of the N groups of column vectors comprising the ꞃ tℎ, (N + ꞃ) tℎ, and (2N + ꞃ) tℎ column vector of the respective sub-matrix, with n∈{1,...,N}; determining a 3×3 matrix based on a sub-matrix of the 3N-2 sub-matrices, the 3×3 matrix consisting of three column vectors comprised by a respective group of the N groups of column vectors comprised by the sub-matrix; determining the precoding matrix based on the 3×3 matrix. The user equipment may further comprise means for generating, based on the uplink data stream and the precoding matrix, a precoded uplink data stream. The user equipment may further comprise means for transmitting the precoded uplink data stream to the network node using the three antenna ports.

The disclosure inter alia relates to a user equipment. The user equipment may comprise means for obtaining a precoding matrix for precoding an uplink data stream to be transmitted to a network node by the user equipment using three antenna ports. The uplink data stream may comprise at most three uplink layers, wherein each of the at most three uplink layers is to be transmitted to the network node using the three antenna ports. The precoding matrix may be obtainable based on performing at least the following: obtaining an oversampled 3×3N discrete Fourier transform, DFT, matrix with an oversampling factor N, wherein N is an arbitrary natural number, wherein the oversampled 3×3N DFT matrix comprises 3N column vectors forming N groups of column vectors, with each group n of the N groups of column vectors comprising the n th , (N + n) th , and (2N + n) th column vector of the oversampled 3×3N DFT matrix, with n ∈ {1,..., N}; determining a 3×3 matrix consisting of three column vectors comprised by a respective group of the N groups of column vectors; determining the precoding matrix based on the 3×3 matrix. The user equipment may further comprise means for generating, based on the uplink data stream and the precoding matrix, a precoded uplink data stream. The user equipment may further comprise means for transmitting the precoded uplink data stream to the network node using the three antenna ports.