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.

Systems and methods for port selection in a wireless communication system are disclosed. In embodiment, a method performed by a radio access network (RAN) node for mapping Sounding Reference Signal (SRS) ports to transmission layers comprises obtaining a channel matrix, H, for one subcarrier or a group of subcarriers for a particular User Equipment (UE) and transforming the channel matrix, H, using a Singular Value Decomposition (SVD) of the channel matrix to thereby provide a transformed channel matrix. The method further comprises computing beamforming weights using the transformed channel matrix. Embodiments of a RAN node are also disclosed.

A transmission method using a massive MIMO (Multiple-Input and Multiple-Output) scheme with an arrangement 108 of N.sub.mN.sub.b antenna elements at the transmitter, arranged in N.sub.m sets of N.sub.b antenna elements or N.sub.b sets of N.sub.m antenna elements based on SC-FDE (Single-Carrier with Frequency Domain Equalization) schemes with large constellations that is compatible with low-cost, highly-efficient, nonlinear amplifiers 106, while allowing spatial multiplexing gains.

The transmission structure of this transmission method decomposes in 103 the modulated symbols from 102 associated to a given constellation as the sum of N.sub.m polar components that are modulated as N.sub.m BPSK (Binary Phase Shift Keying) signals. Each of these BPSK signals can be regarded as an OQPSK (Offset Quadrature Phase Shift Keying) signal in the serial format that is specially designed to have good tradeoffs between reduced envelope fluctuations and a compact spectrum.

This invention presents methods for MU-MIMO wireless communication systems comprising a BS with plural of antennas placed as a linear array or planar array, plural of UEs, for conducting two-level signal processing at the BS to reduce the system implementation complexity, i.e., the RF precoding/combination and the baseband precoding/detection, for the BS to obtain the second-order statistical information of the channel matrix of each UE to computing the RF precoding matrix through a much smaller number of pilots than that of the transceiving antennas at the BS, where the second-order statistical information of the channel matrix can be obtained through the uplink reference signals or downlink reference signals plus uplink feedback.

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 MIMO beamforming method comprises receiving at a base station information regarding a difference between an ideal beamforming matrix and an averaged beamforming direction, using the information to construct a beamforming matrix at the base station, and performing a beamforming operation using the reconstructed beamforming matrix. Alternatively, the method comprises computing at a subscriber station an averaged beamforming direction, computing at the subscriber station a quantization index corresponding to a differential matrix in a differential codebook, and transmitting the quantization index across a wireless channel of the wireless network. The differential codebook may be constructed by identifying a codebook center and transforming a predefined codebook that is stored in a memory of a component of the wireless network.

A communicating method for an antenna array communication system, a user equipment and a base station are provided. The communicating method includes the following steps. A plurality of beams which are formed by a plurality of antennas is transmitted by a base station, and some of the beams is selected by a user equipment. A beam set of the selected beams for the user equipment is configured by the base station. A pre-coding information is fed back to the base station according to the configured beam set by the user equipment.

A method allows reconfigurable multi-element antennas to select the antenna configuration in MIMO, SIMO and MISO communication system. This selection scheme uses spatial correlation, channel reciprocal condition number, delay spread and average Signal to Noise Ratio (SNR) information to select the antenna radiation pattern at the receiver. Using this approach, it is possible to achieve capacity gains in a multi-element reconfigurable antenna system without modifying the data frame of a conventional wireless communication system. The capacity gain achievable with this configuration selection approach is calculated through numerical simulations using reconfigurable circular patch antennas at the receiver of a MIMO system that employs minimum mean square error receivers for channel estimation. Channel capacity and Bit Error Rate (BER) results show the improvement offered relative to a conventional antenna selection technique for reconfigurable MIMO systems.

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.

According to one example embodiment, a method is provided including initializing a first recurrent neural network with a first vector; iteratively training a weight matrix for one or more layers of the first recurrent neural network, wherein W(t) is the weight matrix of the layer of the first recurrent neural network corresponding to iteration t, and wherein W(t) is based at least on a channel covariance matrix; the first vector; and an output from a previous layer of the first recurrent neural network corresponding to iteration, t1: and determining a first eigenvector based on a converged output from the first recurrent neural network, wherein the first eigenvector is used to perform beamforming for multiple input multiple output reception and/or transmission.