A power-allocation method for scalable video transmission over MIMO system includes: encoding a video sequence into L layers; performing MCSs to the layers and estimating bit error rate or symbol error rate respectively for each of the layers after MCSs procedure based on channel quality feedbacks from the receiver side; performing power allocations of L sub-problems and obtaining candidate power allocation solution of each of the sub-problems respectively based on bit error rate or symbol error rate of each of the layers and derivative of bit error rate or symbol error rate of each of the layers; and choosing one of the candidate power allocation solution with the largest quality of experiences as the power allocation of the scalable video transmission over MIMO system. This invention considers transmission-error-rate of PHY layer and video coding structure of APP layer and optimizes quality of experiences at user end with cross-layer design.

A method of transmission over multiple wireless channels in a multiple antenna system includes storing channel modulation matrices at a transmitter; receiving quantized channel state information at the transmitter from plural receivers; selecting a transmission modulation matrix using the quantized channel state information from the stored channel modulation matrices; and transmitting over the multiple channels to the plural receivers using the selected transmission modulation matrix. In another embodiment, the method includes storing, at one or more receivers, indexes of modulation matrices generated by a capacity enhancing algorithm; upon a selected one of the one or more receivers receiving a transmission from the transmitter, the selected receiver selecting a modulation matrix from the stored modulation matrices that optimizes transmission between the transmitter and the selected receiver; the selected receiver sending an index representing the selected modulation matrix; and receiving the index at the transmitter from the selected receiver.

A method includes: The receive end receives 2N channels of signals through N first antennas, where the 2N channels of signals are respectively from N second antennas of the transmit end. When transmission performance of any one of the 2N channels of signals is less than a first threshold, the receive end respectively receives, from two second antennas, two channels of signals whose polarization directions are orthogonal. When transmission performance of the two channels of signals is both greater than a second threshold, the receive end receives the 2N channels of signals through the N first antennas.

Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

A communication device for providing an explicit channel state information, CSI, feedback in a wireless communication system includes a transceiver to receive, from a transmitter a radio signal via a radio time-variant frequency MIMO channel, the radio signal including downlink reference signals according to a reference signal configuration, and downlink signals including the reference signal configuration, and a processor. The processor estimates the CSI using measurements on the downlink reference signals of the radio channel according to the reference signal configuration over one or more time instants/slots, constructs a frequency-domain channel tensor using the CSI estimate, performs a higher-order principal component analysis, HO-PCA, on the channel tensor, identifies a plurality of dominant principal components of the channel tensor, thereby obtaining a compressed channel tensor, and reports to the transmitter the explicit CSI including the dominant principal components of the channel tensor.

A method and network node for management of beams radiated by a phased array antenna of a network node to comply with regulatory or other constraints are provided. According to one aspect a network node is configured to selectively transmit radio frequency beams in a plurality of directions on a plurality of layers to a plurality of wireless devices. The network node includes processing circuitry configured to direct and beams to a first set of directions while suppressing energy radiated in a second set of directions according to algorithms that modify a precoder to achieve a distribution of radiated energy without computationally burdensome optimization algorithms.

According to the present disclosure, there are provided methods and devices for estimating a high-dimensional MIMO channel by expressing the MIMO channel in the form of a flow function to determine a change from an input state to an output state. This may be considered similar to a manner in which fluid dynamic problems are solved. Instead of using linearization to estimate all of the coefficients of a matrix representing a MIMO channel, a receiver may determine the MIMO channel rank by detecting leading modes in a subspace of the entire MIMO channel matrix.

Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

Embodiments of this application provide a communication method and apparatus. In the method, a network device receives first information from a terminal device, where the first information includes information about a first location and a movement speed of the terminal device, and the first location is a location of the terminal device. The network device predicts, based on the first information, a second location at which the terminal device performs channel estimation, and determines a first channel covariance matrix, where the first channel covariance matrix is a channel covariance matrix of a downlink channel corresponding to the second location, and the first channel covariance matrix is for determining downlink channel state information. The network device sends the first channel covariance matrix to the terminal device.