150 results about "Main diagonal" patented technology

A communication device is configured to encode and/or decode low density parity check (LDPC) coded signals. Such LDPC coded signals are characterized by LDPC matrices having a particular form. An LDPC matrix may be partitioned into a left hand side matrix and the right hand side matrix. The right hand side matrix can be lower triangular such that all of the sub-matrices therein are all-zero-valued sub-matrices (e.g., all of the elements within an all-zero-valued sub-matrix have the value of “0”) except for those sub-matrices located on a main diagonal of the right hand side matrix and another diagonal that is adjacently located to the left of the main diagonal. A device may be configured to employ different LDPC codes having different LDPC matrices for different LDPC coded signals. The different LDPC matrices may be based generally on a common form (e.g., with a right hand side matrix as described above).

The invention belongs to the technical field of wireless communication and discloses a standard-orthogonalization-based hybrid pre-coding method for a large-scale MIMO system. Analog pre-coding design is based on equal-gain transmission. The phase of a main diagonal element of a baseband equivalent channel matrix is set to zero to obtain the maximum antenna array gain so as to reduce the total energy consumption and complexity of a transmitter. The design of a digital pre-coding matrix is based on standard orthogonalization and singular value decomposition. By mapping a desired user to other user null space, the interference between users is completely eliminated and the maximum spectral efficiency is obtained. A numerical result shows that the performance of the hybrid pre-coding method, when equipped with a small number of radiofrequency links, approaches that of an all-digital pre-coding solution that requires the same number of radiofrequency links as the antennas, and can obtain high spectral efficiency with low implementation complexity.

The invention relates to a background noise spectrum fluctuation characteristic-based wideband array signal processing method. The processing method includes the following steps that: a frequency domain covariance matrix can be estimated accurately through the accumulation of a plurality of times of snap-shotting, and the frequency domain covariance matrix is also the foundation for obtaining exact solutions of a diagonal load reduction coefficient and a post-positioned weighted coefficient at follow-up stages; eigen-decomposition is performed on the frequency domain covariance matrix, so that the diagonal load reduction coefficient can be solved, and the main diagonal element of the frequency domain covariance matrix is multiplied by the load reduction coefficient, so that a new frequency domain covariance matrix can be obtained; MVDR beam forming is performed on the frequency domain covariance matrix which has been subjected to load reduction, so that the space energy spectra of each frequency point can be obtained; and finally, weighted summation is performed on the space energy spectra of each frequency point through using an optimal band weighted coefficient, so that a final spatial energy spectrum can be obtained. With the background noise spectrum fluctuation characteristic-based wideband array signal processing method of the invention adopted, detection performance for a weak target can be improved, and multi-target distinguishing performance can be improved. Compared with a conventional beam forming device and an MVDR beam forming device, the background noise spectrum fluctuation characteristic-based wideband array signal processing method has better detection performance.

The invention discloses a beam forming device based on sparse signals and a method of the device. The beam forming device comprises an array element receiving antenna, a multi-input analog adder, an analog multiplier, a pseudorandom sequence generator, an integrator and an A/D convertor, wherein weight coefficients of the multi-input analog adder are submitted to random Bernoulli distribution. After sampling, data reconstruction steps are as follows: 1), main diagonal elements are taken, and sampling data of (K1+1)th row are constructed; 2), the main diagonal elements are taken, and sampling data of (K1+2)th row are constructed; 3); sampling data of left (K2-2) rows are constructed sequentially; and the data of all the rows are summed. According to the beam forming device and the method, a compressed sampling technology is adopted, so that broadband signals can be sampled at a low sampling rate; an airspace projection measurement matrix selects a random Bernoulli array, a phase shifter and a multiplier are not required; a multi-channel structure and a sampling data reconstruction manner are used during time-domain observation projection; and more sampling data comprising a large amount of information can be acquired by the aid of fewer channels.

The invention relates to a steel sheet wall of a building structure and particularly relates to vibration-control partition hole-arrangement energy-consumption steel sheet wall for an architectural structure. The wall comprises an inner filling steel sheet, a connecting part, a steel column and a steel beam, wherein built-in holes are arranged in sections in the inner filling steel sheet; non built-in hole arrangement areas are arranged in two main diagonals of the inner filling steel sheet, the inner filling steel sheet is divided into four triangular areas through the two main diagonals, the built-in holes in the areas are arranged triangularly, at most two built-in holes of the inner filling steel plate are arranged vertically, and at most three built-in holes of the inner filling steel plate are arranged transversely. According to the wall, the seismic performance of the steel sheet shear wall is improved effectively, the steel sheet shear wall and an energy consumption device are integrated, the elastic distribution is reasonable, and the wall is applied to energy consumption and shock absorption of a steel structure and a reinforced concrete structure, and the wall has the advantages of being high in bearing performance, high in resistant-lateral rigidity and energy consumption performance and the like. The wall has good seismic performance, ductility and hysteretic energy consumption performances and is an excellent seismic energy consumption component.

The invention is concerned with the multi-antenna multiplying sending, receiving equipment and the frequency domain equilibrium method based on GMC, includes computation WMMSE=sigmas2...H[sigmas2......H+sigman2I]-1, including the following steps: 1) recodes [sigmas2......H+sigman2I]-1 as ...', sets ...' include M*M number of small matrix, and each matrix is the diagonal matrix; 2) decomposes ...' as the sum of the semi-diagonal matrix along the main diagonal and the semi-diagonal matrix along the anit-diagonal; 3) transforms the ...' counter-process into the contrary operation of the diagonal matrix or the block diagonal matrix in order to compute WMMSE; WMMSE is the MMSE method multiply matrix, sigmas is the signal energy, ... includes M*M number of N*N diagonal matrix, M is the number of the emissive antenna, N is the length of FFT, sigman is the noise energy, ...' is process parameter. The predigest equalizer of the invention makes the complex of contrary operation of the matrix algorithm from O((MN)3) to O(M3N) in the MMSE equilibrium, and reduces the cost of the system.

The invention belongs to the technical field of wireless communication, and discloses a method for designing a hybrid precoder/combiner based on matrix decomposition, which comprises the design of a precoder and a combiner in an analog domain and a digital domain. The design of the analog precoder is based on equal-gain transmission, and the interference between users is eliminated by zeroing theelements on the non-main diagonal of the baseband equivalent channel matrix. The simulation combiner is designed to obtain the maximum antenna array gain, and the orthogonal basis is selected by DFT for each user. The design of digital precoder and combiner is based on matrix block diagonalization. The interference between users is eliminated by matrix QR decomposition, and the stream of each useris parallelized by LDLH decomposition, so as to obtain the maximum spectral efficiency. Numerical results show that the hybrid precoding/combining algorithm can achieve higher spectral efficiency with lower implementation complexity.

The invention relates to a displacement JPEG (joint photographic experts group) double-compression tampering blind detection method based on a condition symbiotic probability matrix. The method comprises the steps: firstly, carrying out differential and thresholding treatment of horizontal, vertical, main diagonal and secondary diagonal directions on an amplitude matrix of a discrete cosine transform coefficient quantified by a JPEG; then modeling the four thresholding differential matrixes by the condition symbiotic probability matrix; selecting an element of the condition symbiotic probability matrix as characteristic data, and carrying out dimension reduction treatment on the characteristic data by principal component analysis; and finally, judging whether an image block is subjected to displacement JPEG double-compression through a support vector machine technology. An experiment shows that the method has obvious advantages compared with the existing algorithm when the image block is small, so that the practicability of the displacement JPEG double-compression tampering detection is greatly improved, and good foundation is established for further development of the digital image forensics field.

The invention relates to a method for reducing data loss, said method comprising a first computational step for processing given data on at least two main diagonals of a parity-check matrix representing an error-correcting coding scheme, respectively The associated data information entity (D) of the redundant set is used to calculate the intermediate result (T) of each redundant information entity (R) of the redundant set. The method also comprises a second calculation step for calculating the information content of the corresponding redundant information entity (R) from the corresponding intermediate result (T).

The invention belongs to the field of array signal processing, and provides a correlated/coherent signal directions of arrival estimation method based on covariance low-dimension iterative sparse reconstruction. The method comprises establishing a low-dimension covariance sparse reconstitution model through the Khatri-Rao product, and estimating a main diagonal element on the signal covariance matrix; (2) expanding the sparse reconstruction dictionary according to the non-zero main diagonal element position, estimating the non-diagonal elements of the signal covariance matrix again by means ofa sparse reconstruction algorithm; (3) updating the sparse reconstruction model according to the non-diagonal elements, re-estimating the main diagonal elements of the signal covariance matrix by means of the sparse reconstruction algorithm; and repeating the steps (2) and (3), estimating the directions of arrival of the signal according to the final main diagonal element of the signal covariancematrix. According to the method, the degree of freedom caused by the geometrical distribution of the special array can be fully utilized, the calculation complexity can be effectively reduced, and good estimation precision can be obtained.

The invention relates to an inverse beamforming method. The method comprises the following steps: discrete fourier transform is performed on a received signal to obtain a frequency domain value of the signal; a cross-spectral matrix is calculated for receiving a towed line array according to the frequency domain value; correction is performed on main diagonal elements of the cross-spectral matrix; Toeplitz averaging is performed on the corrected cross-spectral matrix to convert the corrected cross-spectral matrix into one-dimensional distribution data having the spatial distribution characteristic; phase compensation is performed on the one-dimensional distribution data in the theta angle, and then the summing process is performed to obtain a power spectrum in the theta angle; spatial scanning is performed on the power spectrum in the range from 0 degree to 179 degrees to obtain a spatial spectrum P'(f) at the current signal frequency f; and P is made to be equal to the sum of P and P'(f), and f is made to be equal to f+1, and when f is less than or equal to fmax, the above steps are repeated, or else the operation is finished, so that the broadband inverse beamforming process is completed.

The present invention relates to an antenna system (15) comprising at least two antenna radiating elements (RE1, RE2,..., REN) and respective reference ports (R1, R2,..., RN), the ports being defined by a symmetrical antenna scattering NxN matrix (S). The system (15) further comprises a compensating network (11) connected to the reference ports (R1, R2,..., RN). The compensating network (11) is arranged for counteracting coupling between the antenna radiating elements (A1, A2..., AN). The compensating network (11) is defined by a symmetrical compensating scattering 2Nx2N matrix (Sc) comprising four NxN blocks, the two blocks on the main diagonal containing all zeros and the other two blocks of the other diagonal containing a unitary NxN matrix (V) and its transpose (Vt). The product between the unitary matrix (V), the scattering NxN matrix (S) and the transpose (Vt) of the unitary matrix (V) equals an NxN matrix (s) which essentially is a diagonal matrix. The present invention also relates to a method for calculating a compensating scattering 2Nx2N matrix (Sc) for a compensating network (11) for an antenna system according to the above, and also to a compensating network (11) for an antenna system according to the above.

The invention relates to a coprime array-to-uniform linear array conversion-based DOA (Direction of Arrival) estimation method and device. The method includes the following steps that: array element positions are arranged in an ascending order according to a coprime array model, differencing processing is performed on any two array element positions, so that a delay set is obtained, and a difference set table is formed; the difference set is traversed, all coordinates requiring delay are found out in a sparse covariance matrix, corresponding covariance function values are subjected to statistical averaging, autocorrelation function values requiring delay are calculated; a Toepltz matrix is constructed according to the autocorrelation function values, element values on diagonals parallelto the main diagonal of the Toepltz matrix are identical; and a spatial spectrum search function is constructed based on the MUSIC algorithm, the Toepltz matrix is solved, when a spatial spectrum search vector is consistent with a signal steering vector, a correct DOA estimation value is found out. The device includes an external RAM, a digital signal processor, and an output driving and display circuit. The method and device of the present invention do not require a multiplier and are simple in operation, can achieve the same effect as a spatial smoothing matrix, and can greatly reduce the degrees of freedom.

A communication device (alternatively, device) includes a processor configured to support communications with other communication device(s) and to generate and process signals for such communications. In some examples, the device includes a communication interface and a processor, among other possible circuitries, components, elements, etc. to support communications with other communication device(s) and to generate and process signals for such communications. In some examples, a device encodes information using a low density parity check (LDPC) code to generate an LDPC coded signal and transmits the LDPC coded signal to another communication device. in other examples, a device receives an LDPC coded signal from another communication device and decodes the LDPC coded signal using an LDPC matrix. The LDPC matrix includes a left hand side matrix and a right hand side matrix (e.g., having CSI (Cyclic Shifted Identity) sub-matrices on a main diagonal and another diagonal adjacently located to the main diagonal).

The invention provides a channel estimation method and a channel estimation device in an orthogonal frequency division multiple access system. The method mainly comprises the following steps: acquiring time-varying information of a frequency domain transmission function of each subcarrier in a sub-channel through linear interpolation processing according to an estimation value of a main diagonal element of a frequency domain transmission matrix of the sub-channel, wherein the sub-channel linearly changes in a time frequency interval of a pilot frequency; and converting the time-varying information of the frequency domain transmission function of each subcarrier in the sub-channel according to a predetermined conversion relation to obtain estimation values of all elements in the frequency domain transmission matrix of the sub-channel. The method and the device can effectively estimate disturbance among the sub-carriers according to time variation of a time-varying frequency domain response function of a tracking channel of a linear model within a symbol in a frequency domain so as to acquire a relatively accurate channel frequency domain transmission matrix.

The invention discloses a cable-stayed flexible photovoltaic bracket unit and a photovoltaic bracket. The bracket unit comprises two oppositely arranged upright posts, a stabilization cable and a plurality of main diagonal cables are arranged between the two upright posts, and the two ends of the stabilization cable are respectively connected to the lower parts of the upright posts on the corresponding ends; all main diagonal cables are divided into two groups, each group at least comprises one main diagonal cable, the upper ends of all main diagonal cables of each group are connected to the upper parts of the upright posts on the corresponding ends, the lower ends of the two groups of main diagonal cables are connected with a cross beam, and connection points are uniformly arranged alongthe length direction of the cross beam, and the cross beam is horizontally arranged; and a plurality of slings are equidistantly arranged between the cross beam and the stabilization cable along the vertical direction, the upper ends of all slings are connected with the cross beam, and the lower ends of all slings are connected with the stabilization cable. By adoption of an optimized self-balancing prestressed cable system, the vertical stiffness of the structure is improved, and the vibration problem under the wind load is solved, thereby significantly improving the spanning capability of the photovoltaic bracket, further reducing the floor space, and having relatively high adaptability on complex terrain areas.

A method for blind identification of an (n, k and m) system convolutional code belongs to the technical field of blind identification of channel codes and comprises the following steps: after to-be-identified data is read by a computer, an identification matrix with the row number of 180 and the line number of 170 is established; row simplification is performed to the matrix through the method of gaussian elimination; for the simplified matrix, the code length, the information bit length and the data starting point are identified according to the arrangement rule of elements 0 and elements 1 in the main diagonal of the matrix, and then an appearing regular matrix is found according to the positions of obtained regular elements; the regular matrix is extracted from the simplified identification matrix to obtain a check matrix; a generator matrix is obtained through extraction according to the relation between the check matrix and the generator matrix. A specific implementation process of blind identification of the (n, k and m) system convolutional code is given in the method, so that programming operation can be realized advantageously, the identification speed is high, and the method is simple. The identification rate can reach 100% under the condition that no error code exists in the (n, k and m) system convolutional code.

The invention discloses a variable step size color image blind watermarking method based on matrix Schur decomposition in combination with the advantage of high robustness of a frequency domain digital watermarking algorithm. According to the invention, the complexity of Schur decomposition in a frequency domain is lower than that of other matrix decomposition methods; and Schur decomposition is carried out on the image blocks to obtain an upper triangular matrix, main diagonal elements of the upper triangular matrix are the characteristic values of the image blocks, and according to the method, the sum of the characteristic values is quantized to complete embedding and blind extraction of the color digital watermarks. According to the invention, the color image digital watermark can be embedded into the color host image; The method has the advantages of being high in robustness, high in safety and large in capacity, has the advantages of being good in watermark concealment, solves theproblem that a large-capacity color image digital watermark is low in safety, and is suitable for the occasion of high-safety large-capacity digital media copyright protection.

The invention discloses a full reference image quality assessment method in consideration of gradient direction difference. The method comprises the following steps: firstly carrying out graying treatment on a reference image and a distortion image to obtain a luminance component and eliminating color information; carrying out two-dimensional average low-pass filtering on a luminance component, carrying out 1/2 spatial down-sampling on width and height to obtain a corresponding image with width and height being half of the size of an original image; calculating gradient intensity of the reference image and the distortion image after down sampling in the horizontal direction, the vertical direction, the main diagonal direction and the minor diagonal direction at each pixel position by using a Prewitt gradient operator; calculating the difference of the gradient intensity of the reference image and the distortion image in the four directions at the each pixel position and counting to obtain a maximum value of the difference of the gradient intensity in four directions at each pixel position; finally accessing the overall image quality by using counting average of the maximum value of the difference of the gradient intensity at all the pixel positions.

The invention discloses a focused acoustic array imaging method and system, and the method comprises the steps: obtaining echo data of an imaging region through employing a single-array-element transmission and all-array collection mode, transmitting and traversing all array elements, and obtaining all echo data as full-matrix data; calculating a delay index table of the whole imaging area; taking a main diagonal line of the full matrix data as a reference, and calculating to obtain a reference image according to the delay index table; calculating a focused image by using secondary diagonal data of the full-matrix data according to the delay index table and echo data corresponding to the secondary diagonal, and superposing the focused image with the reference image; and continuing to gradually move towards the two sides until the superposed focused image meets the image quality requirement. According to the focused acoustic array imaging method and system, the focusing imaging real-time processing speed is increased, the target image with the better signal-to-noise ratio can be obtained according to needs, the acoustic array imaging result is greatly improved, and the acoustic array detection performance is improved.

The invention discloses a frequency domain GFDM (Generalized Frequency Division Multiplexing) low-complexity minimum mean square error receiving method and a receiver. The method comprises the following steps: initializing an all-zero large matrix, and then dividing the large matrix into a plurality of sub blocks phi(i,j); performing two-dimensional Fourier transformation on the previous K/2+1 subblocks on a primary diagonal line and the previous K/2 sub blocks on a secondary diagonal line, and then determining two-dimensional Fourier transformation results of all the other sub blocks phi(i,j) according to a symmetric relation; performing inverse transformation on the two-dimensional Fourier transformation results (as shown in the specification), and performing IDFT (Inverse Discrete Fourier Transformation) anti-diagonalization operation on each sub block (as shown in the specification) in an inverse transformation result to obtain an anti-diagonalization result psi(i,j); and acquiring a demodulation output signal (as shown in the specification) according to the anti-diagonalization result psi(i,j), a matrix (as shown in the specification), an N-point discrete Fourier transformation matrix FN and a GFDM receiving block. The receiver comprises a GFDM sending module for performing constellation labeling, series-parallel conversion and GFDM modulation on a signal; a modulated signal enters a frequency selectivity channel, and a channel delay and noise are added; and an MMSE (Minimum Mean Square Error) receiving module demodulates the signal, and finally acquires a demodulatedreceived signal.

The invention discloses a signal compressive sensing method based on a block diagonal measurement matrix structure. The method comprises the following steps: first obtaining a pseudo-random sequence of which the period Q = 2q - 1 by a linear feedback shift register, wherein q refers to the grade of the shift register, and one sequence with a Q length is selected at random and marked as L; then, constructing an M*N all-zero matrix phi, wherein N = C * M, C is an integer which is greater than or equal to 1, and N = Q + 1; next, treating the matrix phi as C M*M square matrixes, wherein elements on the main diagonal line of each square matrix are sequentially the element values of the L, so that the matrix phi is defined as the measurement matrix; then, utilizing the obtained measurement matrix phi to project an original high-dimensional signal x to a low-dimensional space y, and reconstructing an original signal x by the y to realize the compressive sensing of the signal. The signal compressive sensing method has the advantages of excellent reconstructing effect and easiness in hardware implementation.

The invention relates to a non-conformal measurement near field acoustic holography sound field rebuilding method, and relates to the technical field of acoustics. The method includes the steps that spherical wave function q(x,y) in a common wave superposition method (see the formula in the description) is replaced by a compound ray wave function with principal value directivity, by means of the method, when the holographic plane and a sound source shape are under the non-conformal condition, namely a planar array, a spherical array, a cylindrical surface array and other regular shape arrays are adopted in a holographic measurement plane, and a sound source is in an any shape, a system matrix is still in the good state of main diagonal domination, magnitude equivalence and approximate symmetry, numerical value inversion can be directly conducted on the system matrix efficiently and accurately, approximate solutions of ill-posedness problems can be obtained without using a regularization method or using the regularization method less, some variables of virtual equivalent sources are analyzed and prolongated to a complex space from a traditional real space, appropriate virtual damp is added, and therefore unique solution is obtained in the full wave number field.

The invention discloses a massive MIMO linear detection hardware architecture and a method under correlated channels. The massive MIMO linear detection hardware architecture comprises a lower triangular pulse multiplication module, a noise addition module, a diagonal matrix inversion module, a vector multiplier, an iteration module, and a detection module. The iteration module comprises a principal diagonal addition module and a coefficient adjustment module. A channel response matrix sequentially passes through the lower triangular pulse multiplication module and the noise addition module, and then enters the diagonal matrix inversion module and the vector multiplier. The vector multiplier removes principal diagonal elements from the matrix output by the noise addition module, and multiplies the matrix by a matrix solved in the diagonal matrix inversion module. The massive MIMO linear detection hardware architecture and the method are applicable to a matrix inversion algorithm under wider channel conditions, and have the advantages of low computational complexity, high accuracy and good flexibility. Moreover, the channel adaptability and throughput of the linear detection architecture are improved greatly.

The invention discloses a permuter read-write method. The method comprises the following steps: opening an internal memory space for a permuter and expressing the space with a rectangle; when writing operation is conducted, writing input code elements of the permuter into an internal memory unit in the direction of a main diagonal of the rectangle; and when reading operation is conducted, sequentially reading out the code elements of the permuter along an auxiliary diagonal of the rectangle.

The invention belongs to the technical field of mobile communication, and particularly relates to a phase shift optimization method for an IRS auxiliary downlink multi-user communication system, which comprises the following steps of: establishing an IRS auxiliary communication system model of a mobile user, and calculating the phase shift of the IRS auxiliary communication system model based on a relationship between a mean square error matrix of an optimal decoding matrix and channel capacity; constructing a channel capacity optimization model of the IRS auxiliary communication system by taking channel capacity maximization as a target; solving an optimal decoding matrix, an auxiliary matrix and a precoding matrix in the channel capacity optimization model, and constructing an IRS phase shift optimization model according to the channel capacity optimization model and a known matrix thereof; solving the IRS phase shift optimization model by adopting a Riemannian trust region method to obtain an optimal phase shift, and setting the optimal phase shift as a main diagonal element of an IRS phase shift matrix. According to the method, under the condition that throughput is not lost, complexity is greatly reduced, and the channel capacity obtained through the method is larger than that obtained through a traditional method under the same condition.