109 results about "Spatial covariance matrix" patented technology

Adaptive antenna array techniques for use in an orthogonal frequency division multiplexed spread-spectrum multi-access (OFDM-SSMA) cellular wireless system or other type of wireless communication system. A base station of the system includes an antenna array and a base station receiver. The base station receiver implements an adaptive antenna gain algorithm which estimates a spatial covariance matrix for each of K mobile stations communicating with the base station. The spatial covariance matrix for a given one of the mobile stations is determined at least in part based on a unique hopping sequence of the mobile station, and provides a correlation between signals received from the mobile station at different antenna elements within the antenna array. An average spatial covariance matrix for a set of received signals is also generated. The individual spatial covariance matrices and the average spatial covariance matrix are processed to generate an estimate of an interference matrix for the K mobile stations, and the estimate of the interference matrix is further processed to generate array responses for each of the mobile stations. The array response for a given mobile station is processed to determine an antenna weighting which is applied to a signal received from the given mobile station in order to facilitate detection of a corresponding transmitted symbol.

A method constructs descriptors for a set of data samples and determines a distance score between pairs of subsets selected from the set of data samples. A d-dimensional feature vector is extracted for each sample in each subset of samples. The feature vector includes indices to the corresponding sample and properties of the sample. The feature vectors of each subset of samples are combined into a d×d dimensional covariance matrix. The covariance matrix is a descriptor of the corresponding subset of samples. Then, a distance score is determined between the two subsets of samples using the descriptors to measure a similarity between the descriptors.

A multi-user receiver which uses at least two antenna elements and in which the influence of interference is reduced, the receiver comprises: means (200) for pre-filtering a wideband antenna signal, the pre-filtering means being determined on the basis of a spatial covariance matrix estimate, which spatial covariance matrix estimate is obtained from wideband antenna signals by sampling, arranging sampled values into a signal vector and by multiplying the signal vector by its conjugate transpose vector, means (210, 218) for removing the whitening from signals of predetermined users by using an inverse matrix of the matrix used in the whitening filter, means (202, 204, 206, 208, 210) for performing multi-path combining and multi-antenna combining.

A multi-user receiver which uses at least two antenna elements and in which the influence of interference is reduced, the receiver comprises: means (200) for pre-filtering a wideband antenna signal, the pre-filtering means being determined on the basis of a spatial covariance matrix estimate, which spatial covariance matrix estimate is obtained from wideband antenna signals by sampling, arranging sampled values into a signal vector and by multiplying the signal vector by its conjugate transpose vector, means (210, 218) for removing the whitening from signals of predetermined users by using an inverse matrix of the matrix used in the whitening filter, means (202, 204, 206, 208, 210) for performing multi-path combining and multi-antenna combining.

A method is provided for tracking a non-rigid object in a sequence of frames of a video. Features of an object are extracted from the video. The features include locations of pixels and properties of the pixels. The features are used to construct a covariance matrix. The covariance matrix is used as a descriptor of the object for tracking purposes. Object deformations and appearance changes are managed with an update mechanism that is based on Lie algebra averaging.

The invention discloses a method of shaped-beam, relating to the shaped-beam technique, aiming at developing the poor performance of the current shaped-beam in a multi-path environment. The method adopts the technical proposal of: A. processing channel estimation to the user signals received by an antenna array and calculating space covariance matrix and all the characteristic values of the received signals, or determining all the maximums of a spatial power spectrum of the received signals according to the space covariance matrix; B. determining all the directions of arrival of the user signals according to the spatial power spectrum or the characteristic values of the space covariance matrix; and C. using one or a plurality of the directions of arrival as the direction of shaped-beam and processing shaped-beam to the signals sent to a user terminal. A device for realizing the method is also disclosed. The invention processing shaped-beam to each effective multi-path direction develops the receiving quality of signals of the user terminal and better copes with the multi-path environment change.

A method constructs descriptors for a set of data samples and determines a distance score between pairs of subsets selected from the set of data samples. A d-dimensional feature vector is extracted for each sample in each subset of samples. The feature vector includes indices to the corresponding sample and properties of the sample. The feature vectors of each subset of samples are combined into a d×d dimensional covariance matrix. The covariance matrix is a descriptor of the corresponding subset of samples. Then, a distance score is determined between the two subsets of samples using the descriptors to measure a similarity between the descriptors.

The invention belongs to the technical field of image detection and relates to a method for tracing a covariance matrix based on grayscale restraint, which comprises the following steps: selecting a rectangular area of a image as a target model to trace; calculating a grayscale value of each point of the target model; extracting the characteristic vector of each point of the target model; calculating the covariance matrix of the target model; after the length and the width of a subsequent frame are respectively amplified by taking the target model as a center, obtaining a tracing window, selecting a candidate target and checking whether the candidate target meets the grayscale restraint or not; and calculating a difference value of the covariance matrix of the candidate target which meetsthe grayscale restraint and the target model, wherein the candidate target area with the minimal difference value is the position of a traced target. The invention has the advantages of more accuratetarget positioning, higher tracing speed and higher instantaneity.

The method comprises: a) respectively making channel estimation for the expected signal and the interference signal in those signals received from current antenna array to get the channel array impulse responses respectively corresponding to the expected signal and the interference signal; b) in term of obtained channel impulse response, calculating its own space covariance matrix of either the expected signal or the interference signal; c) in term of the relation between the expected signal and interference signal, getting a new interference signal space covariance matrix; d) in term of the expected signal space covariance matrix and the new interference signal space covariance matrix, calculating beam-forming weight coefficient of current antenna array.

Channel covariance feedback is disclosed for enhanced full-dimension multiple input, multiple output (eFD-MIMO) systems. Channel state information (CSI) reference signal (CSI-RS) feedback operations are implemented using spatial covariance feedback of a covariance estimate. After obtaining a set of orthogonal basis vectors, a user equipment (UE) measures the CSI-RS from a base station and determines the spatial covariance matrix from the signal. The UE may then compress the spatial covariance matrix into a lower-dimension covariance estimate matrix using the orthogonal basis vectors. The lower-dimension matrix along with element-wise quantization allows for feedback of spatial covariance for eFD-MIMO systems without excessive feedback overhead.

The invention discloses a method for estimating an elevation angle of an intelligent antenna multi-subarray system, comprising the following steps: each antenna subarray estimates a channel of a received user terminal signal, computes a space covariance matrix of the received user terminal signal and then determines all maximal values of a space power spectrum of the received user terminal signal according to the space covariance matrix; taking one maximal value of the maximal values of the space power spectrum, which is greater than a threshold value, as an effective value, and determining the elevation angle of the signal sent by a user terminal by the effective value; and reporting the elevation angle determined by the antenna subarray with maximal average single-channel receiving power to a network side. The invention is easy to realize, and an elevation value of the reported elevation angle is more accurate.

The invention discloses a method for detecting an interference source of a TD-SCDMA (Time Division-Synchronization Code Division Multiple Access) system, comprising the following steps of: when no user exist in a target cell, receiving the receiving signals of all chips outside the target cell on preset upstream time slots in preset subframes in a detection carrier frequency by utilizing each receiving antenna of a base station for the target cell, and calculating the average power of the received receiving signals of all chips; determining whether the interference source exists or not according to the average power, if so, determining a covariance matrix in an interference signal space of each preset subframe and a covariance matrix in interference signal average space of all preset subframes; determining the space power spectrum of the interference signals by utilizing the covariance matrix of the average space and the preset direction vector, wherein a direction corresponding to a peak value in the space power spectrum is the direction of the interference source, and the peak value is an interference power. The method can be applied to positioning the interference source on account of the interference outside the cell of the TD-SCDMA system.