122 results about "Zero matrix" patented technology

A method of generating a codebook for a multiple-input multiple-output (MIMO) system is provided. The codebook generation method includes: assigning a single-polarized preceding matrix to diagonal blocks among a plurality of blocks arranged in a block diagonal format in which a number of diagonal blocks corresponds to a number of polarization directions of transmitting antennas; and assigning a zero matrix to remaining blocks excluding the diagonal blocks.

A regular quasi-cyclic matrix is prepared, a conditional expression for assuring a predetermined minimum loop in a parity check matrix is derived, and a mask matrix for converting a specific cyclic permutation matrix into a zero-matrix based on the conditional expression and a predetermined weight distribution is generated. The specific cyclic permutation matrix is converted into the zero-matrix to generate an irregular masking quasi-cyclic matrix. An irregular parity check matrix in which the masking quasi-cyclic matrix and a matrix in which the cyclic permutation matrices are arranged in a staircase manner are arranged in a predetermined location.

The invention provides an encoding method of an LDPC (Low Density Parity Check) code. The encoding method comprises the following steps of: adjusting elements of a modular matrix Hbm by using an expanding factor zf to generate an adjusted modular matrix Hbmf; expanding by using the modular matrix Hbmf to generate a check matrix H, wherein the expanding mode is as follows: sub-matrixes Pi and j in the check matrix H expand according to the value of the modular matrix Hbmf, and each of the sub-matrixes Pi and j is a full zero matrix, a unit matrix or a unit matrix for left and right cyclic shifting according to a line direction; and encoding input information U by using the check matrix H and outputting encoding information V. The invention also provides an encoder of the LDPC code. According to the technical scheme proposed by the invention, through increasing the quantity of zero elements of the modular matrix Hbm, the processing complexity and the implementation complexity of the encoding and the decoding of the LDPC code can be reduced, and the processing speed of the encoding and the coding can be improved.

The invention discloses a maximizing and speed rate pre-coding method for a simultaneous wireless information and power transfer system. The maximizing and speed rate pre-coding method for the simultaneous wireless information and power transfer system includes that acquiring all the channel state information through a base station, and building an optimizing model aimed to optimize information users and speed rate. The operation for the iterative optimization of pre-coding matrix includes steps that (1) initializing, to be specific, converting a target function into a convex function through first approximation, wherein at the moment, the information user maximization and speed rate problem is a convex problem under the constraints of sending power and energy user receiving power; setting a sending signal covariance matrix as a zero matrix to solve the problem; (2) iterating, to be specific, substituting the sending signal covariance matrix obtained through solving the optimization problem into the target function, and continuing to solve till realizing information user and speed rate convergence. The theory proves that the maximizing and speed rate pre-coding method for the simultaneous wireless information and power transfer system is globally optimal in performance, compared with an existing method, the maximizing and speed rate pre-coding method for the simultaneous wireless information and power transfer system converts the problem into the convex problem through gradual convex approximation to solve. By means of the pre-coding method, the information user and speed rate of the simultaneous wireless information and power transfer system can be effectively improved.

The invention relates to a method for acquiring a colorful digital holographic image. The method is technically characterized in that a black and white type area array CCD and multiple recording wavelength lens-free fourier transform hologram recording optical path are used for respectively shooting a single-color digital hologram of an object to be recorded under the irradiation of red, green and blue laser; after the zeroing treatment of the acquired single-color digital holograms is carried out to acquire the corresponding zeroed digital holograms, the median filtering pretreatment is respectively carried out to acquire the corresponding median filtering pretreatment holograms, then the inverse fast fourier transform operation is carried out, and the acquired red, green and blue single-color digital holograms are respectively inputted into a three-layer zero matrix to acquire a colorful digital holographic image of the object to be recorded. According to the method, the position of a reproduced image on a value reconstruction image plane is fixed by the distance between the recorded object on an object plane and a reference point light source during the recording and is not changed with the recording distance. In addition, the method has less constraint on the horizontal size of the object to be recorded and has a larger space-bandwidth product.

The invention relates to a counting method based on pedestrian head and shoulder multi-target detecting and tracking. The method comprises the steps that a positive sample data set and a negative sample data set of a pedestrian head and shoulder image are constructed, HOG feature vectors of the data sets are extracted, moving foregrounds are extracted through a Gaussian mixture model, the minimum envelope rectangle of the foregrounds is taken as a detection region, pedestrian head and shoulder targets are detected through a multi-scale slide window and a trained SVM classifier, a target matching matrix is initialized into a zero matrix, a pedestrian counter is initialized, the number of the target people passing through the area is counted, and for a target in a tracking list TraList, if the center position of the target is located out of a tracking area, the target is deleted, and the pedestrian counter is updated. According to the method, the pedestrian volume in the specific area is counted through a computer vision technology, the method is used for pedestrian counting, the problems that traditional pedestrian counting is low in efficiency and accurate rate are solved, the digital and intelligent level of pedestrian counting is increased, and the method is a multi-win project capable of bringing the economic benefit and social security and is suitable for multiple indoor and outdoor scenes.

According to a quasi-cyclic low density parity check code basis matrix construction method, node distribution acquired through optimization of a density evolution algorithm is used, then a stretch factor Z is set, the circle length of the LDPC code check matrix and external message scale of the circle are jointed optimized, finally, a QC-LDPC code basis matrix with excellent performances is generated through extension. Each element in the basis matrix is corresponding to one Z*Z dimensional all-zero matrix, a unit matrix or a cyclic shift matrix of the unit matrix. But in construction of high code rate QC-LDPC code, the contradiction of limitation of matrix row number and maximum line number usually occurs, namely, the maximum line number is greater than the row number. To solve the problem, the invention provides construction of the basis matrix through a method increasing line number through superposition of a plurality of cyclic shift matrixes, namely, multiple cyclic shift matrixes are embedded in a single block matrix. The "superposition" operation is binary addition, the constructed basis matrix not only guarantees the cycle performance of the QC-LDPC code, but also meets the requirement of optimization of codon performance through increase of minimum code distance.

A method of encoding/decoding using an LDPC code is disclosed, by which performance is enhanced and by which complexity is reduced. In encoding/decoding using an LDPC code defined by an (n−k)^xn parity check matrix H, the present invention includes the step of performing the encoding/decoding input source data using the parity check matrix H including H_p and H_d to Meet H=[H_d|H_p] (where H_d has (n−k)×k dimensions, H_p has (n−k)×(n−k) dimensions), wherein if the H_p comprises a plurality of z^Xz sub-matrices, each of the sub-matrices is an identity matrix or a zero matrix and wherein a column weight of each column of the H_p is at least 2.

The invention relates to a block encoder and an encoding method of a polarization code, and belongs to the technical field of encoding devices. According to the block encoder and the encoding method of the polarization code, the problems of high algorithm complexity and relatively low processing speed existing in the prior art are solved. The block encoder comprises an input encoding module, a generator matrix module and a multiplier module; and each module is provided with multiple exclusive-OR gates and multiple time delay units. The encoding method comprises the steps of grouping to-be-encoded input information sequences; constructing a generator matrix of the polarization codes; and generating an encoding result. The principle of the block encoder and the encoding method of the polarization code is that a matrix GN is compressed, a position containing F<Kronecker product k> is replaced by 1, a K*K zero matrix is replaced by zero, the compressed matrix is the generator matrix F< Kronecker product (n-k)> of the encoder; K information bits are input to the information sequences per each clock; and a result of corresponding encoding operation for a matrix GK is output after the result is subjected to selection and exclusive-OR operation. According to the block encoder and encoding method of the polarization code, K-bit data can be input at each clock, and N-bit data can be output after 1+N/K clocks, so that encoding delay is reduced, and the encoding efficiency is improved.

The invention discloses an LDPC code constructing method based on coding cooperative communication; the method comprises the following steps: 1. choose a basis matrix W (1) based on finite field multiplicative inverse; the multiplicative inverse of a certain element in the basis matrix is multiplied with each row of the basis matrix, so as to generate a multiplicative identity in the basis matrix; 3.the basis matrix is expanded, so as to obtain an expansion matrix containing diagonal line; 4. the submatrix above the diagonal line is substituted by zero matrix, so as to obtain a quasi-cyclic matrix which is provided with a lower triangular type and has a nested structure; the invention can flexibly construct the quasi-cyclic matrix with the nested structure, which is suitable for CC proposal, while reducing the code construction complexity, the complexity of a coder of a trunk node and a destination node is reduced; in addition, the code in the invention does not have short link characteristic, and the performance of the code is promoted obviously compared with the traditional decode and forward, DF proposal.

The invention discloses a novel structured irregular repeat accumulator (S-IRA)-type LDPC codeword, a corresponding coder, a decoder and a coding method. The codeword has a structure of H=[H'1piP'], H'1 is an information bit matrix, P' is a parity check bit matrix, piP' is to carry out row transformation on the parity check bit matrix, the information bit matrix H'1 comprises multiple cyclic sub matrixes pi,j, and each cyclic sub matrix can only be a unit cyclic shift matrix or an all-zero matrix. By adopting the technical scheme of the invention, through extensive simulation, a LDPC codeword information bit matrix structure more applicable to HSS decoding algorithm compared with the prior art is found out, a coder and a decoder using the LDPC code are found out, and the parity check bit matrix is further matched and improved, and performance of the LDPC code is enhanced. The invention also discloses a coding method corresponding to the above S-IRA structure, and a coder.

The invention discloses a method for optimizing image lattice quality and a device thereof. The method comprises the steps as follows: a halftone amplitude modulation screening threshold value matrix T is obtained, and node quantity CT in the halftone amplitude modulation screening threshold value matrix T is confirmed; CT/2 data items are taken out from T sequentially; after CT/2 data items are taken out each time, the following steps are implemented: T/2 data items are put into a corresponding position for inputting a threshold value matrix H according to a position coordinates in T of T/2 data items; maximum MH in H is counted; a value at the corresponding position of a zero matrix which has same size as T is set as 1 to obtain a human visual filter matrix G; filtering operation is carried out on the G to obtain a temporary matrix G'; the threshold value matrix H and element value at the corresponding position in the human visual filter matrix G are updated and output according the position coordinates of a minimum value of all elements at the position corresponding to T/2 data items in G'; and the value of MH is updated, until T/2 data items in the threshold value matrix H are processed and output. The invention carries out human eye filter treatment on the image lattice and obtains good image output effect.

The method comprises: in the first, constructing a composite matrix H with a three diagonal line structure; then using the a zero matrix N and a i-1 time shift matrix I (i-1) to replace the elements in the composite matrix H to get (0, 1) matrix H' which is used as the check matrix of low density code; the constructed low density code namely is the quasi-cyclic low density code of the three diagonal line structures. The invention has excellent error-correcting performance and low encoding complexity.

A regular quasi-cyclic matrix is generated in which specific regularity is given to cyclic permutation matrices. A mask matrix capable of supporting a plurality of encoding rates is generated. A specific cyclic permutation matrix in the regular quasi-cyclic matrix is converted into a zero-matrix using a mask matrix corresponding to a specific encoding rate to generate an irregular masking quasi-cyclic matrix. An irregular parity check matrix with an LDGM structure is generated in which the masking quasi-cyclic matrix and a matrix in which the cyclic permutation matrices are arranged in a staircase manner are arranged in a predetermined location.

A coding device includes: an inspection matrix generating module that generates a block inspection matrix; and a coding module that generates and outputs a code word from an input message by the inspection matrix. The inspection matrix generating module includes: a degree-allocation unit that prescribes function values of the block inspection matrix by the coefficients of a self-reciprocal polynomial expression; a weight distribution determination unit that prescribes the number of components that are non-zero matrices among the components of each block of the block inspection matrix using a mask pattern; a first degree-altering unit that considers the sum of the components of the k_r-th row block of the block inspection matrix as a cyclic permutation matrix; and a second degree-altering unit that prescribes the row-block number of components that are non-zero matrices among the components of each row block excluding said k_r-th row block of the clock inspection matrix.

The invention relates to a construction method for a special structure protograph QC-LDPC code based on a Pascal's triangle, and belongs to the technical field of channel coding research. The method utilizes the Pascal's triangle to construct a matrix, and specifically comprises the following steps of constructing a weight matrix of the protograph, namely a base matrix Hbase; performing anticlockwise rotation by using the Pascal's triangle structure to acquire an S matrix; filling elements in the S matrix into the weight matrix Hbase of the protograph according to a rule to acquire a base matrix H of the protograph; extending the protograph base matrix H via a zero matrix and a unit matrix to acquire a check matrix, and providing a fast iterative coding algorithm of the codon according tothe structure of H. The base matrix has a quasi bidiagonal structure, avoids four rings and can achieve fast coding, is reduced in coding complexity, and has better iterative decoding performance without significant error floors.

The invention relates to a method for achieving security data transmission by utilizing a compressive sensing theory. Currently, the compressive sensing theory has not been applied to guaranteeing security of data transmission between a source end and a destination end in a data communication process. The source end is encrypted by a random projection matrix and a random vector, and the destination end is decrypted by the sub-matrix of the left zero matrix of the random projection matrix to re-construct data to be transmitted. Mutual information attribute in an information theory is used to prove that the data transmission method disclosed by the invention has perfect security, i.e., the method is safe to a ciphertext-only attack. The method is not only applicable to a point-to-point communication, but also applicable to multipoint-to-point communication and multipoint-to-multipoint communication. Especially when computing power of the data source end and the destination end is asymmetric (in such application fields as internet of things, wireless sensor network and the like), the method has greater advantages.

The invention relates to a method and system for conducting compression and query on a sparse matrix. According to the method, a k2-tree method is improved on the aspects of rank operation change and common matrix and non-zero matrix processing. Firstly, a sparse matrix to be processed is preprocessed to obtain a sparse matrix A of a square matrix with a unit value 0 or1; then, a k2-tree algorithm is adopted to obtain arrays T (tree) and L (leaves), the Rank array interval fixing digits are stored according to information in the T (tree) to obtain Rank (tree), V (leaves) and rank (leaves) values are obtained according to the L (leaves) and an original corresponding sparse matrix, and stored values in the sparse matrix A can be queried after coordinates of query units are input. The sparse matrix can be effectively compressed, query speed is higher, and more storage space is saved.