665 results about "Diagonal matrix" patented technology

An apparatus and method for generating an encoding matrix for a low density parity check (LDPC) code having a dual-diagonal matrix as a parity check matrix are disclosed. The apparatus and method construct an information sub-matrix of the encoding matrix with a predetermined number of square matrixes according to a predetermined code rate such that each of the square matrixes has columns and rows with a weight of 1 and has a different offset value, combine the square matrixes with the dual-diagonal matrix, and perform inter-row permutation on the information sub-matrix.

A channel response matrix is obtained by performing a training process between a transmitter 401 and a receiver 402 to obtain optimal signal phases of the antenna array. Next, a singular-value decomposition (SVD) process is performed to decompose the channel response matrix into a correlation matrix and eigenvalues. Next, a diagonal matrix having square roots of the eigenvalues as its components is obtained. Next, all but one of diagonal components included in the diagonal matrix are replaced with zeros, and optimal setting of the amplitudes and phases of signals to be applied to the antenna array (antenna weight vector) for use in wireless communication between the transmitter and the receiver is obtained based on a channel response matrix that is reconstructed by using the component-replaced diagonal matrix. In this way, when wireless communication is implemented by performing beam forming, the time necessary to find and set a beam direction can be reduced.

A method of transmitting data using a generalized phase shift based proceding or an extended phase shift precoding scheme in a multiple-antenna system using a plurality of subcarrier and a transceiver for supporting the same are disclosed. A phase shift based precoding matrix may be generalized and determined by a product of a diagonal matrix for phase shift and a unitary matrix for maintaining orthogonality in spatial domain. The diagonal matrix may be extended by a product of a proceding matrix for increasing channel power and the diagonal matrix for phase shift. The design of the transceiver can be simplified or communication efficiency can be improved by generalizing and extending the phase shift based proceding.

A method for transmitting data in a multiple antenna system comprises the steps of: generating a transmission signal in plural antennas through the application of a precoding eight matrix to first and second antenna clusters including the plural antennas, and transmitting the transmission signal. The precoding weight matrix is a block diagonal matrix that is configured in a precoding weight corresponding to first and second antenna clusters respectively. The precoding weight of the first antenna cluster is selected according to a channel condition, and the precoding weight of the second antenna cluster is selected regardless of the channel condition but according to a rule.

The disclosed invention implements SVD-MIMO communication efficiently with a less number of high-load calculation required for singular value decomposition (SVD) processing for a channel matrix. A receiver derives a channel matrix H from a reference signal from a transmitter and acquires downlink transmit weights V and receive weights U^H by SVD of the channel matrix H. The receiver transmits a reference signal weighted with U* to the transmitter, where U* is a conjugate matrix for U as uplink transmit weights. The transmitter receives the reference signal weighted with U* and separates the signal into downlink transmit weights V and a diagonal matrix D, based on unitary matrix properties.

A method for transmitting/receiving data in a Multiple Input Multiple Output (MIMO) communication system is disclosed. The data transmission method includes determining a precoding matrix to be a part of a phase-shift-based precoding matrix, determining a first diagonal matrix for phase shift to be a part of the phase-shift-based precoding matrix, determining a unitary matrix to be a part of the phase-shift-based precoding matrix, precoding a transmission symbol for each resource using the phase-shift-based precoding matrix to produce precoded data, and transmitting the precoded data, wherein the phase-shift-based precoding matrix is determined by the product of the precoding matrix, a Hermitian matrix of the unitary matrix, the first diagonal matrix, and the unitary matrix.

An apparatus and method for coding an irregular Repeat Accumulate (RA) code. A repeater repeats a received information word such that the information word corresponds to weights of a first information part and a second information part of a parity check matrix in which permutation matrixes are arranged in the first information part and the second information part corresponding to the information word such that a minimum length of a cycle on a factor graph of the irregular RA code becomes a predetermined length and weights are irregular, and a dual diagonal matrix is arranged in a parity part corresponding to a parity. An interleaver interleaves a signal output from the repeater using an interleaving scheme predefined for the parity check matrix. An accumulator generates the irregular RA code by accumulating a signal output from the interleaver according to a weight of the parity part.

The invention discloses a method for estimating pulse noise in an OFDM (Orthogonal Frequency Domain Multiplexing) underwater acoustic communication system. At a receiving end, sparse estimation is performed on pulse noise on an OFDM signal in an underwater acoustic channel transmission process according to a frequency domain signal subjected to redundant Doppler frequency shift compensation, and frequency offset compensation is performed on the frequency domain signal subjected to the redundant Doppler frequency shift compensation with void subcarriers. Under the consideration of mutual interference between the pulse noise and a carrier frequency offset in underwater acoustic communication, compensation of the carrier frequency offset is added in an iteration process while the pulse noise is estimated with all subcarriers and a posteriori distribution under a framework of conventional sparse Bayesian learning, and the frequency domain signal subjected to the redundant Doppler frequency shift compensation and a measurement diagonal matrix for estimating the pulse noise are updated continuously in order to lower influences between the two types of interference. Moreover, the pulse noise is estimated by full utilization of all the subcarriers in the method, so that the spectrum efficiency and the performance of the communication system are improved.

An apparatus and method of generating a codebook. The codebook generation apparatus includes a matrix extender to generate a candidate matrix set by multiplying a base matrix and at least one diagonal matrix, wherein the at least one diagonal matrix includes elements of a constrained set as diagonal elements; and a codebook generator to generate the codebook where a minimum distance between the elements is maximized, based on the candidate matrix set. According to aspects of the present invention, it is possible to provide a precoding codebook that can reduce an amount of feedback from a terminal.

Channel state information in a closed-loop, multiple-input, multiple-output wireless networks is fed back from each mobile station to a base station by first determining a transmit covariance matrix R, and applying a singular value decomposition (SVD) R=UΣV^H, where U, V are left and right singular vector matrices, Σ is a diagonal matrix with singular values. The matrix V includes column vectors V. A beamforming vector v_max=[1 exp(jΦ)exp(j2Φ) . . . exp(jΦ)]/√{square root over (N)}] is approximated by the column vector V having a maximum magnitude, where Φ is a real number. Then, only the angle Φ is fed back using a phase modulation mapping of the components exp(jΦ) onto the associated subcarrier.

An apparatus and method for encoding low-density parity check (LDPC) codes. The method for generating a low-density parity check code formed of an information-part matrix and a parity-part matrix comprises the steps of converting the information-part matrix into an array code structure and assigning a degree sequence to each submatrix column; extending a dual-diagonal matrix corresponding to the parity-part matrix such that an offset value between diagonals has a random value; lifting the normalized dual-diagonal matrix; determining an offset value for cyclic column shift for each submatrix of the lifted normalized dual-diagonal matrix; and determining a parity symbol corresponding to a column of the parity-part matrix.

A method of determining as to whether a received signal includes an information signal is provided. The method provided includes determining a covariance matrix from a received signal and transforming the covariance matrix into a transformed covariance matrix, wherein the transformation is configured such that the transformed covariance matrix is a non-diagonal matrix in case the received signal includes the information signal, wherein the non-diagonal matrix includes non-zero non-diagonal matrix elements. The method provided further includes determining a first function using at least one of the non-zero non-diagonal matrix elements of the transformed covariance matrix, determining a second function using at least one matrix element of the transformed covariance matrix, wherein the second function is different from the first function, and determining as to whether a received signal includes an information signal based on a comparison of a value of the first function and a value of the second function.

A method is provided for puncturing a low density parity check (LDPC) code decoded by a parity check matrix that is expressed by a factor graph including a check node and a bit node, being connected to each other at an edge, and includes a parity part having a dual diagonal matrix with a single 3-weight column and the remaining columns being 2-weight columns. The method includes generating a puncturing pattern such that bits of the LDPC code are punctured in an order of a bit mapped to a column with a higher weight from among the columns constituting the parity part; and puncturing the LDPC code according to the generated puncturing pattern.

Disclosed is a method for puncturing a Low Density Parity Check (LDPC) code that is expressed by a factor graph having a check node and a variable node, connected to each other by an edge, and is decoded by a parity check matrix including a parity part having a single weight-3 column and a dual-diagonal matrix. The method includes selecting 1-step recoverable (1-SR) variable nodes with the highest quality including a variable node mapped to a weight-3 column, and setting a first puncturing priority group using the selected 1-SR variable nodes, selecting k-step recoverable (k-SR) variable nodes with the highest quality in the next step k taking into account the variable nodes selected in the current step, and setting a priority group for each individual step, puncturing an LDPC code mapped to a variable node belonging to a corresponding group according to priority of each group obtained in the preceding steps.

Time-varying and frequency-selective channels in an orthogonal frequency division multiplexing (OFDM) network are estimated by first storing, in a buffer at a receiver, a received signal corresponding to a set of pilot tones of a set of OFDM symbols, wherein the pilot tones are predetermined and inserted in frequency subcarriers and time slots of the OFDM symbol. A covariance matrix of the received signal is estimated. A diagonal matrix is estimated based on the covariance matrix and a variance of noise in the received signal. The diagonal matrix indicates delays of non-zero paths in a time domain. A channel impulse response (CIR) for each OFDM symbol is estimated using the diagonal matrix, and the received signal. Then, the CIR is transformed to the frequency domain to obtain the channel frequency response (CFR).

To realize a GDFE precoder for multi-user MIMO systems, which significantly reduces the computational cost while resulting in no capacity loss, one method comprises computing an effective UL channel matrix H_UL using one of two methods H_UL=H_DL^H, or H_UL=[(P_t/N_t)H_DL^HH_DL+I]^−1/2H_DL^H; extracting H_k from H_UL; computing a singular value decomposition of the DL channel between the BS and k^th UT, H_k, for all K UTs, H_k=U_kS_kV_k^H; extracting all singular values as s=[diag(S₁), . . . , diag(S_K)]; extracting a vector ŝ from s by choosing first utmost N_t largest non-zero singular values of s; sorting elements in ŝ in decreasing order; performing water-filling to allocate power and obtain a diagonal matrix Γ_k representing power allocations corresponding to the singular values of the k^th UT; computing an UL covariance matrix for each UT as Φ_k=U_kΓ_kU_k^H; and obtaining an overall input covariance matrix D for the equivalent UL channel.

A zero-sample classifying method based on class transfer comprises the steps of acquiring a vision characteristic of C kinds of training samples, a class semantic characteristic of the training sampleand a true label matrix; calculating a semantic similarity matrix by means of cosine similarity or Gaussian similarity through the class semantic characteristic; calculating a diagonal matrix of a class semantic similarity matrix; calling a Sylvester equation in an MATLAB toolset for obtaining a mapping matrix; inputting the vision characteristic of the training sample, the corresponding class semantic characteristic and the true label matrix into a target function, continuously adjusting the value of a model regularization parameter, calculating the least value of the target function, and finishing model training; and in a testing period, inputting the vision characteristic of the testing sample and the corresponding semantic characteristic, calculating scores of the classes, and determining the class with highest score as the predicated class of the testing sample. The zero-sample classifying method based on class transfer has advantages of sufficiently digging the semantic relationbetween different classes, realizing knowledge transfer between a known class classifier and an unknown class classifier, and realizing high convenience in application in image classification.

The invention relates to the technical field of wireless communication and specifically relates to a method, system and device for transmitting coding instruction information and determining precoding matrixes to solve a problem that decreased performance is caused when a codebook is applied directly to a three-dimension beam forming/precoding technology at present. The method includes: UE determining and sending first precoding instruction information, second precoding instruction information and third precoding instruction information, wherein the first precoding instruction information, the second precoding instruction information and the third precoding instruction information are corresponding to the precoding matrixes. A first component precoding matrix is a block diagonal matrix. A third component precoding matrix is comprised of weighted column selection vectors which include P non-zero elements, the other all being zero. Through adoption of the method, system and device for transmitting the coding instruction information and determining the precoding matrixes, performance of the three-dimension beam forming/precoding technology can be improved.

The invention discloses a differentially expressed gene identification method based on combined constraint non-negative matrix factorization. The method comprises the following steps of 1, representing a cancer-gene expression data set with a non-negative matrix X, 2, constructing a diagonal matrix Q and an element-full matrix E, 3, introducing manifold learning in the classical non-negative matrix factorization method, conducting orthogonal-constraint sparseness and constraint on a coefficient matrix G, and obtaining a combined constraint non-negative matrix factorization target function, 4, calculating the target function, and obtaining iterative formulas of a basis matrix F and the coefficient matrix G, 5, conducting semi-supervision non-negative matrix factorization on the non-negative data set X, and obtaining the basis matrix F and the coefficient matrix G after iteration convergence, 6, obtaining an evaluation vector (the formula is shown in the description), sorting elements in the evaluation vector (the formula is shown in the description) from large to small according to the basis matrix F, and obtaining differentially expressed genes, 7, testing and analyzing the identified differentially expressed genes through a GO tool. The identification method can effectively extract the differentially expressed genes where cancer data is concentrated, and be applied in discovering differential features in a human disease gene database. The identification method has important clinical significance for early diagnosis and target treatment of diseases.

A plurality of information bits are encoded using a parity-check matrix that is equivalent to a modular code matrix. The modular code matrix is a diagonal sub-matrix structure immediately above a connection layer that includes a plurality of diverse connection layer sub-matrices, all but at most one of which are below corresponding diagonal matrix structure sub-matrices. The information bits are assembled with a plurality of parity bits produced by the encoding to provide a codeword that is exported to a medium. Preferably, all the diagonal matrix structure sub-matrices are identical. Preferably, some of the parity bits are computed using only diagonal matrix structure sub-matrices.