64 results about "R-matrix" patented technology

Precoding mitigates or removes interference signals (especially crosstalk) among multiple users with interconnected transmitters in vectored DSL systems and the like. Efficient implementation is provided of the R matrix in RQ factorization that characterizes multi-user downstream vector channels (such as DMT VDSL one-sided or two-sided transmission channels). A set of precoder coefficients can vary with each tone used by each user and depend upon the encoding order of users selected for each tone. In adaptive operation, the coefficients of the R and Q matrices can be updated when changes occur to the transmission environment. Variable modulo arithmetic mitigates the power-enhancement problem, and the base of modular arithmetic also can vary with each user within a single precoder for a single tone. The user order of preceding need not be the same on each tone, and the modular arithmetic progression may thus also be different on each tone because multi-user situations create an unusual situation for precoding in that the modulo arithmetic used for each user can be different (thus imposing a larger power increase) and because digital duplexed or synchronized DMT systems can separately implement a precoder for each tone. Further, the precoding process terminates each DMT symbol, after processing up to the total number of users. An optional dither signal, known to both transmitter and receiver, can be added at the transmit side and removed at the receiver side to smooth the precoding process and ensure that aberrations in the transmitted constellation size and characteristics are consistent despite any unusual variations in the feedback signal that exits the feedback filter matrix G before being subtracted from the user signal of interest. Some embodiments use a “subtraction only” mode while other embodiments use a dither signal and/or modulo arithmetic, though embodiments of the present invention do not require use of identical constellations by both transmitter and receiver.

A method for antenna subset selection by joint processing in RF and baseband in a multi-antenna systems. L_t input data streams are generated in a transmitter for either diversity transmission or multiplexing transmission. These streams are modulated to RF signals. These signals are switched to the t branches associated with the t transmit antennas, and a phase-shift transformation is applied to the RF signals by a t×t matrix multiplication operator Φ₁, whose output are t≧L_t RF signals. These signals are transmitted over a channel by t antennas. The transmitted signals are received by r antennas in a receiver. A phase-shift transformation is applied to the r RF signals by a r×r matrix multiplication operator Φ₂. L_r branches of these phase shifted streams are demodulated and further processed in baseband to recover the input data streams.

The invention provides a method and a device for feeding back channel state information in an MIMO (Multi-input Multi-output) system. The method comprises the step that terminal UE feeds back CSI (Channel State Information) to a base station eNodeB, wherein the CSI comprises codebook index information; the codebook index information comprises a first type of codebook index set I and a second type of codebook index set J; the combination of the first type of index set I and the second type of index set J is used for indicating a pre-coding matrix U; the pre-coding matrix U is an Nt*r matrix; in the matrix, Nt represents the total number of ports or the total number of antennas, and r represents the number of transmission layers; the pre-coding matrix U is at least composed of Q*r basic vectors with the dimensional degree of Nt/Q; Q is not less than 2, r is not less than 1 and both Q and R are positive integers; and column extraction of the basic vectors is carried out from a matrix B, the matrix B is composed of M columns of Nt/Q dimension vectors, and M is a positive integer.

The invention provides a network MIMO system and a signaling processing method thereof. The network MIMO system comprises a super honeycomb and a receiver, wherein the super honeycomb comprises a plurality of base stations; the receiver is used as a user device of a user and comprises a quantification unit, a precoding selector and a channel quality indicator counter, the quantification unit quantifies channel state information into elements t in a codebook based on the preset codebook, the precoding selector computes indexes of the elements t in the codebook, which is used as a precoding matrix index, the CQI counter counts channel quality indicators, the user devices send the precoding matrix index and the channel quality indictors to the base stations, wherein the elements t in the codebook are expressed by the following formula: t=Q*diag[wi]*uj, wi is elements in the codebooks among the base stations and is expressed by a p*r matrix, p is the number of the base stations of a stronglink found by the user device k, u and Q are shown in the formula, and L(i to k) expresses the large attenuation from the base station I to the user device k.

A method for an associative memory array includes storing each column of a matrix in an associated column of the associative memory array, where each bit in row j of the matrix is stored in row R-matrix-row-j of the array, storing a vector in each associated column, where a bit j from the vector is stored in an R-vector-bit-j row of the array. The method includes simultaneously activating a vector-matrix pair of rows R-vector-bit-j and R-matrix-row-j to concurrently receive a result of a Boolean function on all associated columns, using the results to calculate a product between the vector-matrix pair of rows, and writing the product to an R-product-j row in the array.

The invention discloses an MIMO signal detection method and a device that are applied in a system with two receiving antennas. The method includes the following steps: storing the respective size relationship between all constellation points corresponding to modulation modes adopted by the system and the Euclidean distance of positions on a constellation diagram in advance; conducting sequencing QR decomposition on channel matrix and demodulating a first layer of signal points from a receiving signal according to elements at the lower right corner of R matrix; according to the size relationship of the Euclidean distance corresponding to the modulation mode adopted by the first layer of signal points, finding out the first layer of K constellation points with the minimum Euclidean distancefrom the position of the first layer of signal points on the constellation diagram; and searching a second layer of constellation points based on every found constellation point of the first layer, selecting a search path with the minimum Euclidean distance from all search paths where the first layer of constellation points is located and determining the signal detection result according to the first layer of constellation points and the second layer of constellation points on selected K search paths. The application of the method and the device can ensure signal detection performance and simultaneously reduce the complexity of MIMO signal detection.

Provided are a receiving apparatus for a multiple input multiple output (MIMO) system and a method thereof. The receiving apparatus includes a QR decomposing unit for calculating a single (Q) matrix vector and an upper triangle (R) matrix vector for a receiving signal vector; a first symbol estimation unit for estimating predetermined symbols using the calculated Q matrix vector and R matrix vector; a log likelihood ratio (LLR) calculating unit for calculating log likelihood ratios of unit bits for the estimated symbols; an interference removing unit for receiving a decoded signal that is decided using the calculated log likelihood ratios and removing interference from the receiving signal vector; and a second symbol estimation unit for linearly estimating remaining symbols for the interference removed signal.

An apparatus for detecting a symbol in a space division multiplexing system and a method thereof are disclosed. The apparatus includes: a QR decomposing unit for performing a QR decomposition on a channel matrix H to decompose the channel matrix H to a Q matrix and a R matrix; a first symbol detecting unit for detecting a first symbol from a receive signal vector by using the result of the QR decomposition; a candidate symbol deciding unit for deciding the detected first symbol and Nc−1 symbols adjacent to the detected first symbol on a constellation as candidate symbols, wherein the Nc is an positive integer number; a candidate vector detecting unit for detecting Nc candidate transmit symbol vectors from the detected Nc candidate symbols; and a transmit symbol vector deciding unit for deciding an optimized transmit symbol vector among the detected Nc candidate transmit symbol vectors.

A wireless receiving apparatus capable of efficiently removing interference signals in a multicarrier communication. In a mobile station (200) incorporating this wireless receiving apparatus, a selecting part (205) selects a plurality of the same symbols in accordance with a mapping pattern established at the time of generating OFDM symbols in a base station. A correlation value calculating part (207) determines correlation values between the subcarriers of the same symbols to generate an R-matrix, and further determines an inverse matrix of the R-matrix. An MMSE processing part (208) performs an MMSE processing to determine a weight (W) from both a P-vector received from a channel estimating part (206) and the inverse matrix of the R-matrix received from the correlation value calculating part (207). Multipliers (209-1 to 209-N) multiply each of the symbols selected by the selecting part (205) by the weight determined by the MMSE processing part (208). A combining part (210) combines the symbols as multiplied by the weight.

The invention aims to provide a multi- AUV synthetic location method based on combination of ant colony and extended Kalman filtering. The method comprises the steps of firstly establishing an AUV kinematic model, then conducting linearization on the AUV model, adopting a modified ant colony algorithm to conduct optimum estimations on a Q matrix and a R matrix; wherein the adoption of the modified ant colony algorithm specifically comprises the steps of at first adopting the ant colony algorithm to conduct transversal for the first time to obtain a large amount of solutions; adopting a particle swarm optimization to search a global optimum value; adopting again the ant colony algorithm to set the current solution as an initial start point of the ant colony, then choosing part of the most superior ants according to virtue or defect degrees of solutions obtained by the ants in the ant colony, and conducting weighted average to release pheromone according to virtue or defect degrees of quality of the solution; finally applying solved Q,R to an EKF, and thus location of AUV is achieved. According to the multi-AUV synthetic location method based on combination of ant colony and extended Kalman filtering, an intelligent algorithm and EFK are ingeniously combined, the problems that a noise matrix is uncertain, and hard to choose are solved, and filtering precision of EKF is improved; meanwhile, the application of combination of ant colony and extended Kalman filtering in a multi-AUV location system can sharply improve precision of the AUV location.

An LDPC decoding method and apparatus of LDPC decoding a codeword formed by c code bits transmitted through a channel include receiving the codeword and a p×c parity check matrix formed of 0 and 1 values, comparing the codeword with each of p rows of the parity check matrix, the rows formed with c elements, generating an R matrix by obtaining a first minimum value that is a minimum value among elements that are not 0 in each row, a second minimum value that is a second smallest value in the same row, and a location of the first minimum value, and outputting a decoded codeword formed by c code bits by determining one code bit by adding elements of each column of the R matrix.

The invention provides a sphere decoding detection method based on an ultra large scale integrated circuit, comprising the following steps of: A. carrying out QR decomposition to a channel matrix; B. multiplying conjugate transpose of a Q matrix and received signals to obtain an equalizing signal Rho; C. setting the searching node number Ki of an ith layer; D. determining sphere decoding expression according to an R matrix and Rho, carrying out table-looking-up sequencing to the nodes of the 1st layer and reserving K1 of nodes with minimum Euclidean distances; E. respectively executing searching of the ith layer, carrying out table-looking-up sequencing in nodes according to the sphere decoding expression to the Ki-1 of nodes reserved by the ith-1st layer, calculating weights of subnodes of the Ki-1 of nodes, then carrying out divide-and-conquer sequencing to subnodes of the Ki-1 of nodes by adopting VLSI according to the result of table-looking-up sequencing and reserving Ki of nodes with minimum weights; and F. outputting decoding result when searching the last layer. The sphere decoding detection method can effectively reduce the operation complexity of sphere decoding.

Circuitry speeds up the QR decomposition of a matrix. The circuitry can be provided in a fixed logic device, or can be configured into a programmable integrated circuit device such as a programmable logic device. This implementation performs Gram-Schmidt orthogonalization with no dependencies between iterations. QR decomposition of a matrix can be performed by processing entire columns at once as a vector operation. Data dependencies within and between matrix columns are removed, as later functions dependent on an earlier result may be generated from partial results somewhere in the datapath, rather than from an earlier completed result. Different passes through the matrix are timed so that different computations requiring the same functional units arrive at different time slots. After the Q matrix has been calculated, the R matrix may be calculated from the Q matrix by taking its transpose and multiplying the transpose by the original input matrix.

Provided is a method and apparatus for lattice reduction with reduced computational complexity. The apparatus and method include calculating an R matrix using sorted QR decomposition, and conducting an R-value test using an R-value based on diagonal elements of the R matrix and a threshold value. The R matrix is an upper triangular matrix. The apparatus and method further execute a loop comprising a size reduction and a conditional update of a basis vector corresponding to a column element of the R matrix in response to the R-value being greater than or equal to the threshold value. The apparatus and method conduct another R-value test based on the R matrix comprising the updated basis vector in response to the basis vector being updated.

Circuitry for performing QR decomposition of an input matrix includes multiplication/addition circuitry for performing multiplication and addition/subtraction operations on a plurality of inputs, division/square-root circuitry for performing division and square-root operations on an output of the multiplication/addition circuitry, a first memory for storing the input matrix, a second memory for storing a selected vector of the input matrix, and a selector for inputting to the multiplication/addition circuitry any one or more of a vector of the input matrix, the selected vector, and an output of the division/square-root circuitry. On respective successive passes, a respective vector of the input matrix is read from a first memory into a second memory, and elements of a respective vector of an R matrix of the QR decomposition are computed and the respective vector of the input matrix in the first memory is replaced with the respective vector of the R matrix.

Provided is a QR decomposition apparatus and method that can reduce the number of computers by sharing hardware in an MIMO system employing OFDM technology to simplify a structure of hardware. The QR decomposition apparatus includes a norm multiplier for calculating a norm; a Q column multiplier for calculating a column value of a unitary Q matrix to thereby produce a Q matrix vector; a first storage for storing the Q matrix vector calculated in the Q column multiplier; an R row multiplier for calculating a value of an upper triangular R matrix by multiplying the Q matrix vector by a reception signal vector; and a Q update multiplier for receiving the reception signal vector and an output of the R row multiplier, calculating an Q update value through an accumulation operation, and providing the Q update value to the Q column multiplier to calculate a next Q matrix vector.

A detection process for a receiver of a wireless communication system based on Multiple-In-Multiple-Out antennas, the process involving: —a preprocessing which only depends on the channel H, said preprocessing involving: —A QRD decomposition (61) for the purpose of decomposing said channel H into two Q and R matrices, with Q^HQ=I and R being upper triangular; —a lattice reduction (62) for the purpose of generating (formula AA, formula BB) and a permutation matrix T; —a loading phase (63, 64, 65) comprising a linear LRA-Minimum-Mean-Square-Error equalization applied on said symbols y in accordance with the result of said lattice reduction for the purpose of generating a value (formula CC). The process is characterized by the fact that it further involves the steps of: —Performing a neighborhood search with a search center being equal to the result (formula CC) of said lattice reduction; —Determining the -BKest symbols in accordance with a Partial Euclidean Distance (PED) defined in accordance with the following formula (formula DD)—detecting each layer and with the result of said detection performing an update of the search center so as to perform detection of the next layer; —multiplying the estimated value (formula EE) by said matrix T plus quantizing it onto the original constellation so as to generate the estimated value (formula FF).

The invention provides a method for identifying the clouds and sky of a sky image based on an improved k-means clustering algorithm. The method comprises the steps of extracting red channel values R, green channel values G, blue channel values B from the sky image to form a red channel value R matrix, a green channel value G matrix, a blue channel value B matrix and an R/B*100 matrix, and extracting a characteristic matrix; determining an initial clustering number and an initial clustering center; based on the improved k-means clustering algorithm, clustering according to the initial clustering center, thus obtaining a new clustering center; and clustering according to the new clustering center, determining the type of an area to which each pixel point belongs according to the clustering result, and drawing a cloud and sky identification image. According to the method for identifying the clouds and sky of the sky image based on the improved k-means clustering algorithm, the extracting effect is stable; the three color components are used as a whole for clustering, and the R/B*100 column vector with high cloud and sky contrast ratio is also added, so that compared with the method of using a global threshold to perform cloud and sky identification on a gray level image only, the method for identifying the clouds and sky of the sky image based on the improved k-means clustering algorithm is greatly improved in adaptive capacity in image identification and can solve the problem of poor adaptation in the prior art.

The invention relates to a sequence QR decompose method and MIMO checking method, wherein it comprises that: a, selecting one frequency unit form several frequency units, processing QR decompose on the channel characteristic matrix, to obtain relative Q matrix, R matrix and sequence, while said sequence is used as initial sequence of present frequency unit near the frequency unit; b, based on the diagonal amplitude of present R matrix, judging if present position and next position exchanged initial sequence can reduce code error transmission; c, if it can reduce the error code transmission, exchanging present position and next position, to obtain the sequence result; d, via said result, processing QR decompose on the channel characteristic matrix, to obtain Q and R matrixes. The invention has low complexity and better sequence property.

An embodiment of an apparatus for encoding. For this embodiment of the apparatus, an encoder block is coupled to receive input data. The encoder block has an R-matrix block. The R-matrix block is configured to: exclusively OR combinations of subsets of data bits of the input data to generate (n−1) parity bits for n a positive integer greater than zero; and exclusively OR a combination of all of the data bits and all the (n−1) parity bits to generate an (n) parity bit 9-to-7.

Provided are a receiver of a Multiple Input Multiple Output (MIMO) system, QR decomposition and multi-dimensional detection used in the receiver. The receiver includes: a QR decomposing unit for performing a QR decomposing operation in cycles 1 to n_T-n−1, and performing a column exchanging operation in cycles n_T-n to n_T as QR decomposition where n and T are an integer number; and a multi-dimensional detecting unit for receiving a first R matrix R_y and a second R matrix R_z from the QR decomposing unit, calculating a first distance value for detecting an m^th symbol for the first R matrix and a second distance value for detecting an m^th symbol for the second R matrix, and simultaneously detecting an m^th symbol and an (m−1)^th symbol using the first distance value and the second distance value.

The invention provides a maximum likelihood detection method and a device in a multi-input multi-output system. The method comprises the following steps: A. carrying out QR decomposition on a channel matrix to obtain a first Q matrix and a first R matrix; B. carrying out QR decomposition on rows of the channel matrix after exchanging the sequence so as to obtain a second Q matrix and a second R matrix; C. selecting the R matrix with the absolute valves of diagonal elements of being arranged according to the sequence from small to large from the first R matrix and the second R matrix as a quenching R matrix; D. by receiving signals, exchanging R matrix and sequencing the Q matrix corresponding to the R matrix, calculating demodulated signals; and E. carrying out maximum likelihood searching according to the demodulated signals. The invention can effectively reduce the algorithm complexity of MIMO detection when the number of the receiving antennas is 2.