310 results about "Unitary matrix" patented technology

Using a transformation based at least in part on a non-simple orthogonal or unitary matrix, data may be transmitted over a data bus in a manner that is resilient to one or more types of signal noise, that does not require a common reference at the transmission and acquisition points, and / or that has a pin-efficiency that is greater than 50% and may approach that of single-ended signaling. Such transformations may be implemented in hardware in an efficient manner. Hybrid transformers that apply such transformations to selected subsets of signals to be transmitted may be used to adapt to various signal set sizes and / or transmission environment properties including noise and physical space requirements of given transmission environments.

A method for feeding back transmitter beamforming information from a receiving wireless communication device to a transmitting wireless communication device includes a receiving wireless communication device receiving a preamble sequence from the transmitting wireless device. The receiving wireless device estimates a channel response based upon the preamble sequence and then determines an estimated transmitter beamforming unitary matrix based upon the channel response and a receiver beamforming unitary matrix. The receiving wireless device then decomposes the estimated transmitter beamforming unitary matrix to produce the transmitter beamforming information and then wirelessly sends the transmitter beamforming information to the transmitting wireless device.

Precoding methods and method for performing precoding and methods of transmitting feedback information for precoding or transmitting a signal using a multi-codebook and method of transceiving precoding information in a multi-antenna system, where a signal transmitting method in a multi-antenna system, and more particularly, a method of transceiving precoding matrix information for a multi-input multi-output (MIMO) system is disclosed. The present invention proposes a method of performing communications using an expanded unitary matrix generated from shifting a phase of a base unitary matrix. The present invention is applicable to single user MIMO, multi-user MIMO, beam forming, etc.

A process for beamforming data to be transmitted in a MU-MIMO communication system comprising a base station and a selected set of User Equipments (UE) communicating with said base station; said data being precoded by said base station in accordance with a beamforming matrix complying with a precoding matrix under the form of: (formula 1) Where—M is the number of transmit antennas—D is a diagonal unitary matrix of the form D=diag (formula 2)—P is a permutation matrix interchanging only the last M−1 rows. —A is a general Hadamard matrix. and that the signaling information transmitted by the base station to the UE comprises at least a first and a second index which are representative of D, P and A.

The present invention provides an algebraic approach to quantum circuit design based on using a GSVD (Generalized Singular Value Decomposition) to map a unitary matrix, representing a desired quantum computation, into a product of block diagonal unitary matrices, each of which can then be mapped into equivalent circuit fragments. The invention describes a number of rules allowing such circuits to be compactified.

The method contains the following steps. First, in a MCM system with N sub-carriers, the baseband signal blocks Xj, j=1, 2, . . . ,B are supplemented with zeros and processed with LN-point IFFT, respectively, to obtain L-time oversampled time-domain signal blocks xj, j=1,2, . . . ,B. Then, xj undergoes Q Time Domain Circular Shifts or Frequency Domain Circular Shifts to obtain Q signal blocks {tilde over (x)}j(i<sub2>j< / sub2>), ij=1,Λ,Q. Subsequently, a B×B unitary transform is performed against ( x1,{tilde over (x)}2(i<sub2>2< / sub2>), . . . ,{tilde over (x)}B(i<sub2>B< / sub2>)). After the unitary transform, for each (i2, . . . ,iB) a combination having B time-domain signal blocks is obtained as follows: ({tilde over (y)}1(i<sub2>2< / sub2>, . . . ,i<sub2>B< / sub2>),{tilde over (y)}2(i<sub2>2< / sub2>, . . . ,i<sub2>B< / sub2>), . . . ,{tilde over (y)}B(i<sub2>2< / sub2>, . . . ,i<sub2>B< / sub2>)=( x1,{tilde over (x)}2(i<sub2>2< / sub2>), . . . ,{tilde over (x)}B(i<sub2>B< / sub2>)) cU where U is the B×B unitary matrix, and c is an arbitrary constant (c≠0). Finally, the total QB-1 combinations are compared against each other to select a best candidate for transmission that could produce the lowest peak value, or the smallest PAPR, or the lowest clipping noise power.

A method and apparatus are provided for feedback for closed-loop transmitting with multiple transmit antenna elements and multiple receive antenna elements. A base station includes a codebook containing sets of weightings for the multiple transmit antenna elements, with each set of weightings identified by an index and the codebook known to the base station and a served mobile station (MS). The base station pre-codes pilot signals using a precoding matrix, preferably a unitary matrix, to produce pre-coded pilot signals, which precoding matrix may or may not be known to the MS and which precoding matrix may or may not be included in the codebook. The base station then transmits the pre-coded pilot signals to the MS via the multiple transmit antenna elements and, in response, receives an index to a set of weightings in the codebook for use in a subsequent transmission of a data stream.

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.

The present invention relates to methods and apparatus for establishing a precoding codebook for a Multiple Input Multiple Output (MIMO) wireless communication system. The precoding codebook includes a plurality of codebook entries. Each codebook entry includes four sets of vectors for four respective corresponding transmission ranks. The vectors may be predetermined, or generated from source unitary matrices. In addition, the codebook is fully nested.

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 UH 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.

The embodiment of the invention discloses a precoding method which comprises the steps that: a first codebook and a second codebook are arranged at a base station and a user terminal, the second codebook is a set of unitary matrices generated by vectors in the first codebook and by making use of channel matrices, vectors that ensure that the user terminal obtains the maximum coding gain are respectively selected for every user terminal in the first codebook and corresponding CQI values are calculated; the base station determines the user terminal to be precoded and chooses a unitary matrix from the second codebook according to the vectors in the first codebook and corresponding CQI values corresponding to the user terminal to be precoded or chooses a unitary matrix from the second codebook and determines the user terminal to be precoded according to vectors in the first codebook and the corresponding CQI values corresponding to every user terminal; the unitary matrices or submatrices thereof are used as precoding matrices to carry out precoding towards the user terminal to be precoded. The embodiment of the invention also discloses a precoding system, and failure of matching among a plurality of user terminals can be avoided by the method and the system of the invention.

A communication node relays a transmission signal transmitted from a desired source node to a target destination node among multiple source nodes and multiple destination nodes. The communication node includes a first unitary matrix estimation unit that estimates a first unitary matrix by performing singular value decomposition involving one or more channel matrices between the relay node and the source nodes other than the desired source node; a second unitary matrix estimation unit that estimates a second unitary matrix by performing singular value decomposition involving one or more channel matrices between the relay node and the destination nodes other than the target destination node; and a transmission unit configured to transmit a relaying signal generated by multiplying a received signal by the first and second unitary matrices toward the target destination node.

The present invention relates to a beamforming method and apparatus. A beamforming method for use in a base station for transmitting a plurality of streams through a plurality of antennas includes: receiving feedback information including information on a first codeword selected from a codebook including a plurality of codewords from each of a plurality of user terminals; grouping the plurality of user terminals by use of the feedback information from each user terminal; determining a user terminal to which a plurality of streams will be assigned of the plurality of user terminals, and determining a second codeword to be used for beamforming from the codebook by use of the feedback information of each user terminal and grouping information; and multiplying data to be transmitted through the plurality of steams by the second codeword and a unitary matrix.

An apparatus for generating a precoding matrix codebook includes a matrix group generator to generate a first group of unitary matrices based on a vector-based codebook for precoding of a multiple input multiple output (MIMO) communication scheme; a matrix group extender to extend the first group of unitary matrices to generate a second group of unitary matrices; and a matrix group selector to select a group of columns corresponding to a communication rank from each of the unitary matrices that are elements of the second group so that the columns are optimized based on a distance between the columns corresponding to the communication rank.

A method for transmitting and receiving a precoded signal in a Multi-Input Multi-Output (MIMO) communication system is provided. In the method, a preceding matrix is selected from a codebook including one or more preceding matrices of each rank, each of the preceding matrices including a unitary matrix modified by an antenna selection element. A signal for transmission is then precoded by applying the selected preceding matrix to the signal for transmission and the precoded signal is transmitted through a selected antenna.

The invention discloses a pre-coding method, a system and a device in a MIMO system. The method, the system and the device which are related to by the invention can be applied in the orthogonal space-time coding circumstance. The inventive method adopts a non-unitary matrix for pre-coding, and the non-unitary matrix is obtained by judging the obtained optimal pre-coding vector construction. The inventive system includes a transmitter and a receiver, wherein, the transmitter includes a code list, a pre-coding matrix construction unit and a pre-coding unit; the receiver includes a channel estimation unit, the code list and a judgement unit. The simulation and the analysis show that, compared with the prior art, the usage of the inventive proposal can lower the bit error rate and reduce the complexity of decoding simultaneously in the situation of the same signal-to-noise ratio.

A transmitting MIMO wireless device transmits a training sequence to a receiving MIMO wireless device. The receiving MIMO wireless device estimates a channel response based upon the training sequence, determines an estimated transmitter beamforming unitary matrix and a transmit path quality matrix, and then transmits some / all of these parameters to the transmitting MIMO wireless device. The transmitting MIMO wireless device receives these components and determines a modulation to be employed for each of a plurality of data streams. The transmitting MIMO wireless device transmits a data frame to the receiving MIMO wireless device that includes a short training sequence, a long training sequence, a signal field with demodulation control signals, and a data payload for each of multiple data streams. According to one embodiment of the signal field, the signal field indicates a number of data streams of the data frame and a modulation employed for each data stream. The signal field may include additional information, such as whether beamforming is employed for the data frame.

A flat non-porous unitary solid surface product, and a method for the manufacture thereof, the product comprised of: (a) a flat non-porous unitary matrix made of polymethylmethacrylate, polyvinyl chloride, polycarbonate, or combinations thereof; and (b) a visible decorative object that is permanently fixated in the matrix, wherein the decorative object extends to least one edge of the matrix. Surfaces of the flat non-porous unitary matrix may be coated or treated to provide a dry-erase surface or projection screen.

A method of transmitting data using a generalized phase shift based precoding 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 precoding 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 precoding.

Disclosed is a method for wireless signal transmission of signals from an array of two or more antennas, in which each signal to be transmitted is selected from a constellation of unitary space-time signals. Each unitary space-time signal is a unitary matrix, in which each column represents a respective antenna, each row represents a respective time interval, and each element represents a complex amplitude to be transmitted by a given antenna during a given time interval. In specific embodiments of the invention, the matrices of the signal constellation form a non-Abelian group having a positive diversity product, or a coset of such a group. In other embodiments, the signal constellation is a subset of such a group, and its multiplicative closure forms a finite non-Abelian group having a positive diversity product. In still other embodiments, the signal constellation is an extension of any of the preceding types of constellations, formed by adding one or more further elements that do not belong to and are not derived from the group or group subset.

Aspects of a method and system for an alternating delta quantizer for limited feedback MIMO pre-coders may comprise quantizing a change in channel state information in a MIMO pre-coding system onto at least a first and a second codebook, each of which comprises one or more unitary matrices, using a cost function; feeding back, in an alternating manner, an index to an element of at least the first codebook or the second codebook, associated with the quantizing, from a receiver to a transmitter in said MIMO pre-coding system, and generating the at least first and second codebook based on at least the channel state information. The channel state information may be a matrix V and the cost function may be defined by the following relationship:f(A)=(1N∑j=1Najj2)where A is a matrix of size N by N and aij is element (i,j) of matrix A.

The invention provides a method for self-adaptively pre-coding in a multi-input and multi-output system on the basis of a codebook and a device thereof, wherein the method comprises: obtaining a switching threshold value or a switching threshold value list which are corresponding to the correlation of a sending or receiving space according to the prior value which is obtained by tests under different conditions, selecting one or a plurality of following switches according to the switching threshold value or the switching threshold value list and through combining the correlation of the sending or receiving space: switch between a single user mode and a multi-user mode through combining user number information, switch between a unitary matrix pre-coding mode and a zero-forcing shaped-beam pre-coding mode, switch between a discrete Fourier transformation codebook and Grassmannian codebook and switch between a big codebook and a small codebook which are carried out according to the user number information. The method of the invention can switch MIMO modes, pre-coding methods, codebooks and the codebook size according to environmental changes, and can adopt preferentially.

A signal detection apparatus and method using a modified stack algorithm in a Multi-Input Multi-Output (MIMO) system are provided. The signal detection method includes sorting signals received via antennas and channel coefficients for respective users in descending order, decomposing a channel matrix composed of the sorted channel coefficients into a unitary matrix and an upper-triangular matrix, determining the number of candidate symbol-sequences using the decomposed upper-triangular matrix, obtaining a signal vector for the antennas by using the sorted signals received via respective antennas and the unitary matrix, wherein the signal vector is proportional to the upper-triangular matrix, and detecting the determined number of candidate symbol-sequences by using a modified stack algorithm while expanding a stack structure for the obtained signal vector.

The present invention relates to a method and device for detecting a transmission signal on the basis of a received signal by applying a division and detection algorithm. An embodiment of the invention provides a method of detecting a transmission signal including: obtaining a unitary matrix and an upper triangular matrix by performing a sorted QR-decomposition algorithm with respect to a matrix indicating a channel state; calculating a vector y by multiplying a transpose matrix of the unitary matrix by the received signal Y; dividing the upper triangular matrix R into a plurality of sub-upper triangular matrices and dividing the calculated vector y into a plurality of sub-vectors so as to correspond to the divided plurality of sub-upper triangular matrices; and detecting a lattice point corresponding to each of the divided sub-vectors using the divided plurality of sub-upper triangular matrices.

The invention provides a precoding transmission method for a multi-input and multi-output system, which comprises: a mobile station supposes an emission matrix as a unitary matrix, an MMSE receiver is used for signal combination, an equative channel is calculated, CQI and CDI are obtained and are fed back a base station; according to a channel direction index and channel quality information fed by the mobile station, the base station obtains a zero-forcing precoding emission matrix or a regulated zero-forcing precoding emission matrix corresponding to partial or total possible user combination, carries out multiuser scheduling operation and determines the scheduled user combination; and the base station utilizes the zero-forcing precoding emission matrix or the regulated zero-forcing precoding emission matrix corresponding to the scheduled user combination to carry out precoding and emission; and a scheduled user carries out MMSE receiving. The method reduces error of channel feedback, therefore effectively promoting the utilization ratio of frequency spectrum of the system.

A transmitting device Fourier-transforms symbols in a transmission symbol sequence, maps the Fourier-transformed symbols to subcarriers, inverse-Fourier-transforms the mapped symbols, and transmits the inverse-Fourier-transformed symbols from multiple transmitting antennas. A receiving device Fourier-transforms received signals, extracts signal components mapped to the subcarriers, and estimates the symbols transmitted via the subcarriers by applying a QR decomposition algorithm to the extracted signal components. The receiving device obtains a unitary matrix QH such that the product of the unitary matrix QH, a weight matrix W determining a correspondence between the transmission symbol sequence and the subcarriers, and a channel matrix H becomes a triangular matrix R, and estimates candidates of the symbols transmitted from the transmitting antennas based on the unitary matrix QH and the triangular matrix R.

An antenna-selection preprocessing method of multi-user MIMO system down link includes setting up model of multi-user MIMO system down link to confirm coding mode and channel transmission matrix, confirming base of preprocessing matrix of each user by channel transmission matrix between base station and each user, utilizing said channel transmission matrix and said base to confirm optimum unitary matrix of each user preprocessing matrix, converting said model to be equivalent vector form and using linear zero-approach means to realize signal detection.

The invention provides a method and a device for estimating rank indication and precoding matrix indication in a precoding system. The method comprises the following steps: A. calculating a self-correlation matrix A of a channel matrix H: A=H<H>H; B. carrying out singular value decomposition on the matrix A: A=VsigmaV<H>, wherein V is a unitary matrix, and sigma is a diagonal matrix; C. confirming a rank of the matrix H according to a matrix sigma and generating rank indication according to the rank of the matrix H; D. confirming a precoding matrix according to the rank of the matrix H and a matrix V<H> and generating precoding matrix indication according to the precoding matrix. The invention can effectively reduce the complexity of an algorithm for estimating the rank indication and the recoding matrix indication by a terminal and improve the performance of the precoding system.