A method, system and device are provided for using an indexed list of linearly independent, predetermined vectors Vref = {v1 ref ,..., VM ref }and channel knowledge H, G from each transmitter to compute and feedback equivalent channel matrix information Hi, j eq to its affiliated transmitter based on the assigned/determined rank of the receiver. With this information, each transmitter selects L i receivers and constructs a transmitted signal by applying a selected precoding matrix to the mixed rank data, thereby eliminating interference to the rest of the receivers in the network.

Mixed rank downlink multi-user interference alignment scheme

A method for operating a receiver having multiple receive antennas to process a signal from a first affiliated transmitter and align interference from a second interfering transmitter includes providing a codebook of predefined matrices. Each predefined matrix has an identifier associated therewith. A first channel matrix and a second channel matrix are assembled for the first and the second transmitters. An equivalent direct channel matrix is determined from the first and second channel matrices, and predetermined reference vectors are selected from a plurality of predetermined vectors. A predefined matrix is selected from the codebook based upon the equivalent direct channel matrix and an identifier for the predefined matrix is fed back to the first transmitter. A signal is received and decoded using a combining matrix derived from the predetermined reference vectors and an inverse of the second channel matrix, thereby reducing interference from the interfering transmitters.

Codebook based downlink multi-user interference alignment scheme

The invention discloses a beamforming method for polarized antenna array consisting of a plurality of antenna elements, applied to single layer beamforming or dual layer beamforming, which includes the steps: determining (201) first beamforming weights for phase compensation among the antenna elements within each polarization direction; determining (202) second beamforming weights for phase compensation between equivalent channels of two polarization directions; and calculating (203) hybrid beamforming weights as product of the first beamforming weights and the second beamforming weights. A beamforming apparatus for polarized antenna array is also provided in the invention as well as a radio communication device and a system thereof. With the invention, the single-layer and dual-layer beamforming weights are determined for the cross-polarized antenna array without requiring full channel knowledge or the aid of PMI. Computation complexity is lowered and full power amplifier utilization can be achieved.

Beamforming method, apparatus for polarized antenna array and radio communication device and system thereof

A method, system and device are provided to enable one or more users to receive mixed-rank data from two transmitters by using an indexed list of linearly independent, predetermined vectors {V1 ref,..,VM ref} and channel knowledge H1, H2 from first and second transmitters to compute equivalent channel matrix information Hi eq based on the assigned or determined rank of the receiver. With this information, each transmitter selects Li receivers and constructs a transmitted signal by applying a selected precoding matrix to the mixed rank data, thereby eliminating interference to the rest of the receivers in the network so that a receiver can receive transmitted signals from both transmitters.

Mixed rank downlink compound multi-user interference alignment scheme

Time-divided transmission method capable of avoiding interference for D2D multi-casting communication system

The invention discloses a linear precoding method in a multiuser multi-input and multi-output (MIMO) system, which comprises the following steps: determining the interference channel transmission matrix HK in the system of each user according to the channel estimation results, wherein, k is user index, k is in the range from 1 to K, and K is the user number served by the system base station simultaneously in the same band range; carrying out the QR decomposition to the conjugate transposed matrix HK of a random user's interference channel transmission matrix HK, and forming the user's linear precoding matrix Tk according to the QR decomposition result; and carrying out the linear precoding to each user's emission signal sk respectively by utilizing the formed linear precoding matrix Tk.

Linear pre-coding method in multi-user MIMO system

The invention provides a beam shaping method, which is characterized in that the method comprises dividing all antennas on the side of a base station into two groups in advance through the modes of remote antenna and or polarization grouping, distributing antennas of the same group in equal distance, and conducting the descending beam shaping through utilizing all antennas after divided. The method can be applied to bring the space diversity gain for a system, thereby further increasing the system performances compared with an existing beam shaping mode, and improving the signal-to-noise rateof user receiving signals.

Wave beam shaping method

The invention discloses a successive interference cancellation method in a multiple input and multiple output system, comprising QR ordering and decomposition are carried out on a channel transmission matrix based on householder transformation to obtain an upper triangular matrix R, and according to the matrix R, precoding successive interference cancellation is executed on all the transmit signals, or the successive interference cancellation is executed on the received signal. As the matrix R is the upper triangular matrix, the successive interference cancellation can be sequentially executed on all the transmit signals by utilizing the characteristics of the upper triangular matrix, thus avoiding determining the successive detection sequence in a way using VBLAST for matrix inverse or pseudo-inverse, and further simplifying the computational complexity of the successive interference cancellation and improving the performance of signal detection.

Dafei Wang

Papers

Linear pre-coding method in multi-user MIMO system

Wave beam shaping method

Method for eliminating serial interference in multi-input multi-output system