104 results about "Channel correlation matrix" patented technology

Methods for a transmitter station and a receiver station to perform beamforming in a wireless communication system, and a transmitter station and a receiver station to perform the corresponding method, are provided. The method for the transmitter station to perform beamforming in the wireless communication system includes estimating and tracking a long-term averaged and normalized channel correlation matrix between the transmitter station and a receiver station, determining beamforming coefficients based on the tracked long-term averaged and normalized channel correlation matrix, and communicating with the receiver station using the determined beamforming coefficients, wherein the receiver station also estimates and tracks the long term averaged and normalized channel correlation matrix, and determines beamforming coefficients based on the tracked long-term averaged and normalized channel correlation matrix.

A wireless communication system including receiving and base stations. The receiving station includes a detector that measures a downlink channel correlation matrix for multiple antennas of a base station. The detector computes an antenna weight increment vector normal to an antenna weight vector for multiple beams from the multiple antennas of the base station. The detector quantizes the antenna weight increment vectors to produce a respective quantized antenna weight increment vector. The receiving station includes a transmitter that sends the quantized antenna weight increment vectors to the base station. The base station includes a beamformer selector that receives from the receiving station and re-orthogonalizes the quantized antenna weight increment vector for each of the multiple beams. The base station includes a weight vector modifier that modifies the antenna weight vector for the multiple beams by adding an increment proportional to the respective re-orthogonalized quantized antenna weight increment vector.

The invention discloses a pre-coding method and a pre-coding device. The pre-coding method comprises that: a transmitting end acquires channel information of a plurality of antennas to two users respectively, and acquires channel related matrixes according to the channel information; the transmitting end acquires generalized characteristic vectors of the channel related matrixes; the transmittingend determines transmitting pre-coding vectors of the two users according to the generalized characteristic vectors, acquires receiving vectors of the two users according to the transmitting pre-coding vectors, and acquires equivalent channel matrixes corresponding to the two users according to the receiving vectors and the channel information respectively; and the transmitting end acquires powerscaling matrixes, feedback matrixes and feed-forward matrixes corresponding to the two users according to the equivalent channel matrixes respectively, and performing THP on the two users according to the receiving vectors, the power scaling matrixes, the feedback matrixes and the feed-forward matrixes. According to the technical scheme, the number of the antennas collocated by the two users cannot be limited.

The invention discloses a channel correlation-based user group partition method under D2D. The method comprises the following steps: (1) enabling users to measure a pilot frequency transmitted by a base station, and feeding back channel correlation matrixes and receiving signal intensities by means of an uplink; (2) obtaining the estimated positions of all the users according to an MUSIC (multiple-signal-classification) method and an RSS (receive-signal-strength) method, and adopting a binary group to indicate user positions; (3) carrying out clustering processing on the user by using a K-means method. The user group partition method provided by the invention can complete the partition of a two-step pre-coded user group of a cellular network and the discovery of a D2D cluster at the same time by utilizing cellular channel correlation matrix information, thus avoiding a complicated operation of directly utilizing channel correlation information to process medium and high-dimension matrix subspace division and projection; the method has the characteristics of being simple and efficient.

A high-order Multiple-Input-Multiple-Output (MIMO) transmitter implementing a covariance-based precoding scheme that exploits transmit channel correlation and a method of operation thereof are provided. In one embodiment, covariance-based precoding is performed at the high-order MIMO transmitter based on feedback from a remote high-order MIMO receiver regarding a covariance-based precoding matrix. The covariance-based precoding matrix is, or is derived from, a transmit channel correlation matrix determined by the high-order MIMO receiver for the high-order MIMO transmitter. The covariance-based precoding provides a beam-forming effect when there is a relatively high degree of transmit channel correlation, thereby improving performance of the high-order MIMO transmitter. Further, because changes in the transmit channel correlation occur relatively slowly over time, feedback overhead requirements are substantially reduced as compared to that required for traditional MIMO precoding schemes.

The invention discloses a low complexity channel estimation method in a large scale MIMO system. The method comprises the following steps of firstly, establishing an optimization estimation problem of a channel covariance matrix; and secondly, according to an iteration relation of covariance estimation, using a Sherman-Morrison theorem to convert matrix inversion into a matrix and vector product form so that a method complexity is reduced. In the method, approximation estimation is performed on a channel correlation matrix and the Sherman-Morrison theorem is used to convert the matrix inversion in a MMSE method into the matrix and vector product so that a calculating complexity in the MMSE method is greatly reduced and a low performance loss is possessed.

Methods for a transmitter station and a receiver station to perform beamforming in a wireless communication system, and a transmitter station and a receiver station to perform the corresponding method, are provided. The method for the transmitter station to perform beamforming in the wireless communication system includes estimating and tracking a long-term averaged and normalized channel correlation matrix between the transmitter station and a receiver station, determining beamforming coefficients based on the tracked long-term averaged and normalized channel correlation matrix, and communicating with the receiver station using the determined beamforming coefficients, wherein the receiver station also estimates and tracks the long term averaged and normalized channel correlation matrix, and determines beamforming coefficients based on the tracked long-term averaged and normalized channel correlation matrix.

The invention discloses a method for judging the mode of down space division multiple access of a time division duplex system, which includes the steps: the operation of channel estimation is carried out to a special physical channel for up adjoint to obtain the channel impulse response matrix of each user; the normalized spatial correlation matrix of each user is calculated; the eigenvalue of each spatial channel correlation matrix is analyzed so as to gather out and take the corresponding eigenvector of each eigenvalue of maximum as the forming weight of each user; the spatial correlation measure of every two users is calculated according to the forming weight of each user; and any user and the user with the spatial correlation measure less than a preset value are classified into the same set, and the actuating codes of the users in the same set are multiplexed by the mode of space division multiple access. The method can judge whether the users can adopt the SDMA mode to carry out the operation of data down-load or not according to the space division properties of the users, and the TDD HSDPA system can effectively utilize spatial information to increase the throughput of data transmission of the system and can increase the capacity of the system.

The embodiment of the disclosure provides a channel feedback method and device based on hybrid beamforming. The method comprises the following steps: estimating a physical channel correlation matrix of a long-time broadband; feeding back the physical channel correlation matrix of the long-time broadband to a base station; estimating a short-time narrow-band equivalent channel after analog beamforming; and feeding back the short-time narrow-band equivalent channel to the base station based on an adaptive codebook. The embodiment of the disclosure also provides a corresponding channel feedback method and a corresponding device. According to the channel feedback solution based on hybrid beamforming provided by the embodiment of the disclosure, the feedback overhead can be significantly reduced, the number of RF channels in the system can be reduced, and the system performance which is better than a traditional pure digital beamforming scheme can be obtained with the same feedback overhead.

The invention relates to a method for obtaining a communication channel correlation coefficient in an uplink MIMO (Multiple Input Multiple Output). The method comprises the following steps of: obtaining a communication channel response matrix of emission signal pilot data, carrying out an autocorrelation to obtain an autocorrelation matrix of the communication channel response matrix, accumulating autocorrelation matrixes of all pilot frequencies and averaging the accumulation to obtain a correlation matrix of an MIMO communication channel; carrying out noise power compensation on the obtained correlation matrix of the MIMO communication channel; carrying out eigenvalue decomposition on the compensated correlation matrix of the MIMO communication channel, and calculating a condition number of the correlation matrix of the MIMO communication channel based on the obtained eigenvalue as a correlation coefficient of the MIMO communication channel. The invention also provides a system for obtaining the correlation coefficient of the communication channel in the uplink MIMO. By using the technical scheme of the invention, the correlation matrix of the MIMO communication channel can be obtained by calculating the correlation matrix of the communication channel of pilot frequency data in uplink MIMO data, and then a condition number is obtained by carrying out the matrix eigenvalue decomposition to obtain the correlation coefficient of the MIMO communication channel.

An apparatus and method of applying a superfast algorithm to a pilot-based channel estimation process includes receiving a signal comprising information bits transmitted in a wireless channel, executing the pilot-based channel estimation process having p structures for a vector of pilot structures and an upper bound N for a channel spread, determining a result of a matrix inversion of a channel correlation matrix for an error channel estimation offline without performing a matrix inversion, storing pilot information of the received signal for channel recovery in a transform domain, representing the Toeplitz inverse by a FFT representation, detecting and estimating nonzero taps of a channel impulse response of the wireless channel, obtaining a non-structured minimum mean-square-error (MMSE) estimate as a first estimate of locations of the nonzero taps, and replacing the non-structured MMSE estimate by an estimate computed by a tap detection algorithm.

A method and device for generating and feeding back high rank adaptive codebook in multiple input multiple output system are disclosed in the embodiments of the invention. The method for generating high rank adaptive codebook includes: using different levels of a long time channel correlation matrix to transform different row vectors in high rank basic codebook, so as to aim at the directions of different eigenvectors of the long time channel correlation matrix; and using the transformed row vectors to construct the high rank adaptive codebook. The method of the invention has well system performance gain and no any additional feedback cost.

The invention discloses a beam forming method for a compact planar array Massive MIMO system. The beam forming method comprises the following steps: constructing a high-frequency sparse channel model on the basis of not considering a mutual coupling effect; performing asymptotic analysis on the high-frequency sparse channel model to obtain an asymptotic equivalence formula of a channel correlation matrix; based on an asymptotic equivalence formula, establishing an optimization model by taking maximization of the minimum receiving SINR values of all users as a target; carrying out equivalent transformation and solving on the optimization model to obtain a beam forming weight vector; based on the beamforming weight vector, performing beamforming processing on the user data, and performing signal transmission. According to the method, an asymptotic equivalence formula of a channel correlation matrix is derived through asymptotic analysis of a high-frequency sparse channel, and on the basis, a beamforming optimization problem is established by taking maximization of a user receiving signal to interference plus noise ratio as a target, so that the robustness of system performance to mutual coupling damage is ensured while the user sum rate is improved.

The embodiment of the invention discloses a technical scheme of a grouping decoding method based on partial interference elimination and a receiver. The grouping decoding method based on partial interference elimination comprises the following steps: carrying out triangular decomposition on a correlation matrix of a channel, inverting the decomposed matrix, extracting a submatrix related to a group of signals from the inverted matrix aiming at each group of which the transmitting signals are divided into, acquiring a receipt signal vector and an equivalent channel matrix corresponding to the group after between-group interference is eliminated according to the matrix after orthogonal decomposition of the submatrix, and detecting the transmission vector of the group of the signals by utilizing a multiple input and multiple output detection method according to the receipt signal vector and the equivalent channel matrix corresponding to the group after the between-group interference is eliminated. The technical scheme lowers the realization complexity of grouping decoding and saves the processing resources of the receiver.

A signal processing method, receiver and equalizing method are provided. The receiver comprises an estimator estimating a channel coefficient matrix from a received signal, a first calculation unit determining a channel correlation matrix based on the channel coefficient matrix a converter converting the channel correlation matrix into a circulant matrix. A second calculation unit determines equalization filter coefficients by applying a first transform to the real parts of a first subset of the terms in the first column of the circulant matrix and by applying a second transform to the imaginary parts of a second subset of the terms in the first column of the circulant matrix. An equalizer equalizes the received signal by using the determined equalization filter coefficients.