104 results about "Channel correlation matrix" patented technology

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.

Adaptive precoding codebooks are described. In one embodiment, the method of wireless communication includes reading at least a rank-2 baseline codebook having codewords representing precoding matrices. An adaptive codebook is generated by multiplying a first column of the codeword with a first transform matrix calculated from a channel correlation matrix, and multiplying a second column of the codeword with a second transform matrix calculated from the channel correlation matrix. The first and the second transform matrices are orthogonal.

A time division duplex using code division multiple access user equipment receives a plurality of data signals in a time slot. Each data signal experiences a similar channel response. The user equipment receives a combined signal over the shared spectrum in a time slot. The combined signal comprises the plurality of data signals. The combined signal is sampled at a multiple of a chip rate of the combined signal. The similar channel response is estimated. A channel response matrix or a channel correlation matrix is constructed based on in part the estimated channel response. A spread data vector is determined based on in part a fast fourier transform (FFT) decomposition of a circulant version of the channel response or channel correlation matrix. The spread data vector is despread to recover data from the matrix.

A method for generating channel quality feedback information in terms of quantized eigenvectors calculated from an eigenvalue decomposition that uses a channel matrix and an eigenvalue matrix to generate quantized and bounded eigenvectors. The channel correlation matrix and the eigenvalue matrix are obtained from a channel matrix formed from channel measurements of various signal parameters of signals transmitted over the communication channel. The eigenvalue decomposition uses the elements of the channel correlation matrix, the elements of the eigenvalue matrix and conditional relationships between elements of the channel correlation matrix to calculate the quantized and bounded eigenvectors. Because the elements of the quantized bounded eigenvectors can be expressed in terms of each other, not all elements of the quantized bounded vectors need be transmitted over the communication channel resulting in efficient use of the communication channel.

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.

A code division multiple access user equipment is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A column of a channel correlation matrix is determined using the estimated channel response. A spread data vector is determined using the determined column, the estimated channel response, the received combined signal and a fourier transform. Data of the data signals is estimated using the spread data vector.

The invention discloses a method, a system and a device for selecting a precoding vector and a mobile terminal. The method for selecting the precoding vector comprises that: a receiving end performs quantization treatment on a channel correlation matrix according to the stored vector quantization codebook aiming at the channel correlation matrix; the receiving end feeds back the information of the channel correlation matrix subjected to the quantization treatment to a transmitting end; and the transmitting end acquires the channel correlation matrix according to the stored vector quantization codebook aiming at the channel correlation matrix and the received information subjected to the quantization treatment, and selects the precoding vector according to the acquired channel correlation matrix. Due to the technical scheme, the amount of the quantization information fed back by the receiving end is reduced, and the amount of the quantization information fed back by the receiving end is not increased along the increase of the antenna amount of the receiving end.

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 provides a sequential multi-antenna selectable transmitting method for code-division multi-path channel. The sequential multi-antenna selectable transmitting method is used for the combined antenna selection and beam shaping of a TD-HSPA+ and comprises the steps of replacing the downlink practical wireless multi-path channel parameters with the obtained uplink channel parameters; calculating the equivalent channel related matrix of a system; selecting the transmitting antenna to join in the data transmission by a sequential way; selecting the transmitting antenna according to the second characteristic value criteria of maximum equivalent channel related array; after selecting the antenna, calculating the related array RK of the selected antenna; carrying out beam shaping according to the characteristic vector of the RK and sending data stream. The sequential multi-antenna selectable transmitting method meets the experience truth that the system performance mainly depends on the data path of the dual streams with the worst sending channel quality, sufficiently considers the common influence factor of the multipath channel is sufficiently considered, and the system performance is improved greatly. Furthermore, according to the sequential antenna selecting method, the practical complexity the simplified and the feasibility is improved.

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.

The invention discloses a method for determining a valid signal-to-noise ratio, comprising the following steps of: in an OFDM (orthogonal frequency division multiplexing) system, determining a channel correlation matrix estimation value of a measured bandwidth according to the channel estimation result of a time frequency sub-channel at a pilot frequency position in the measured bandwidth; respectively calculating channel capacity of the time frequency sub-channel of each interference type of the measured bandwidth by using the channel correlation matrix estimation value; obtaining an average equivalent channel capacity of each time frequency sub-channel on the measured bandwidth according to the channel capacity of the time frequency sub-channel of each interference type; and determining the valid signal-to-noise ratio of the measured bandwidth according to the average equivalent channel capacity of each time frequency sub-channel. The invention further discloses a device for determining a valid signal-to-noise ratio. With the method and the device provided by the invention, computational complexity for the valid signal-to-noise ratio can be reduced.

The invention discloses a method for transmitting data by space-time coding operation, including: calculating all signal power element values and all interference power element values of each equivalent channel correlation matrix according to the current channel condition; selecting an equivalent channel correlation matrix meeting set condition according to the signal power element value and the interference power element value; and carrying out space-time coding on the data to be sent by utilizing the space-time coding matrix corresponding to the selected equivalent channel correlation matrix and sending the data. By the invention, error rate of an MIMO transmission system is reduced while the signal to noise ratio is determined. The invention also discloses a device for transmitting data by the space-time coding operation.

The invention discloses an incoherent multiple-user detection method and device for non-orthogonal multi-pulse modulation. The method comprises the steps of receiving multi-user overlapped signals through the non-orthogonal multi-pulse modulation; establishing a pseudo linear model for receiving signals; passing through a group of matching filters by the receiving signals to obtain a channel related matrix; carrying out QR decomposition on the related matrix and converting the related matrix into an upper triangular matrix structure; feeding back judged user information among users, thereby eliminating multi-access interference among the users; eliminating correlation of the signals of the users through decorrelation inversion operation; and carrying out maximum judgment on the detected signals and selecting the maximum from M possible results as judgment output. According to the method and the device, the detection performance of the users with relatively low power is greatly improved by feeding back the judgment signals of the users with relatively high power. The multi-access interference among the users is eliminated effectively through judgment feedback. Even if the interference users are many, the good stability can be still achieved. The method and the device are applied to the technical field of wireless communication.

The invention is a matrix rotation based method for eliminating self-interference of a nonorthogonal space-time packet code, in view of the problem that there are self-interference items in the channel correlation matrix of nonorthogonal (or quasi-orthogonal) space-time packet code, adopting Givens rotation twice. Thus, one hand, it can effectively eliminate the self-interference items and rotates channel matrix into orthogonal matrix. During space-time transmit diversity, the maximum advantage caused by the channel matrix being an orthogonal matrix is that it can make linear decoding at receiving end, largely reducing decoding complexity. And at the same time it make the packet code corresponding to the channel matrix have an orthogonal structure, accordingly able to obtain maximum transmitting speed, partial diversity gain and receiving-end linear decoding.

The invention discloses a multi-antenna diversity combination receiving method and a device. The method is characterized in that the diversity combination step is carried out in the associated detection in advance, that is to say that diversity combination is carried out after completing matched filtering of each antenna data and calculating the channel correlation matrix corresponding to each antenna in associated detection process; and decomposition and linear equation resolving are carried out according to the combined channel correlation matrix and the combined matched filtering result to obtain a sign to be demodulated, thereby obviating the operations of decomposition and linear equation resolving for each antenna according to the matched filtering result and the channel correlation matrix of each antenna. The multi-antenna diversity combination receiving method provided by the embodiment has better diversity gain in comparison with single antenna receiving, and can remarkably reduce the calculation amount and the realization complexity of the system in comparison with the existing diversity combination receiving system under the condition of same diversity gain performance.

A method and apparatus for performing chip level equalization (CLE) using joint processing to enhance performance and system throughput using a transmitter having a plurality of transmit antennas and a receiver having a plurality of receive antennas. A channel response matrix is formed between the transmit antennas and the receive antennas to generate a joint channel correlation matrix between the transmit antennas and the receive antennas using a block-FFT (B-FFT) decomposition of the channel response matrix. Estimates of transmitted chip sequences from each of the transmit antennas are generated using minimum mean square error (MMSE) and the joint channel correlation matrix are combined. The combined estimate of the transmitted chip sequences are despread to recover transmitted data.