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 method for receiving a signal, includes a useful signal, interfering signals and noise, and for suppressing interfering signals in a multi-channel receiver, comprising steps of: (a) reception, frequency transposition and digital conversion of the received signal; (b) estimation of a correlation matrix of the received signals; (c) estimation of the variance of the noise; (d) initial estimation of the arrival directions of the useful and interfering signals; (e) initialization of the powers of the useful and interfering signals; (f) iterative computation: of the current directional vectors of the useful and interfering signal; of the powers of the useful and interfering signals; of the amplitude/phase errors of assumed directional vectors with respect to the current directional vectors; and of the arrival directions of the useful and interfering signals; (i) suppression of the interfering signals from the signal received in step (a).

This disclosure provides methods, devices and systems for obtaining and providing channel feedback. In some implementations, a beamformee provides channel feedback to a beamformer that enables the beamformer to construct and independently precode two or more different sets of spatial streams for transmission to the beamformee. The independent precoding of the different sets of spatial streams ensures that the decodings of the different sets of spatial streams may be decoupled from one another at the beamformee. To provide the channel feedback, the beamformee partitions a channel estimate into two or more sub-estimates prior to performing a channel decomposition. In some implementations, the beamformee determines null-space-based projections of the sub-estimates before performing the channel decomposition. The determination of the null-space-based projections enables the beamformee to perform independent decompositions of the multiple channel sub-estimates to determine multiple respective feedback matrices, which are then assembled to provide the channel feedback to the beamformer. The channel feedback is then reconstructed and disassembled by the beamformer to perform the independent precoding of the different sets of spatial streams.

A method for indicating a combination between a codeword and a layer in a MIMO communication, system, a layer mapping method, and a data transmission method using the same are disclosed. A minimum number of codeword-layer mapping combinations from among all available combinations based on the' numbers of all codewords and all layers are pre-defined in consideration of a ratio of a codeword to a layer, a reception performance of a receiver, and reduction of combinations, so that a data transmission method using the predefined combinations is implemented. If a. specific one codeword is mapped to at least two layers, a diversity gain can be acquired.

Disclosed are a method and device for beamforming, for use in performing beamforming by means of combining location information of a user equipment, thus ensuring improved broadcast beam coverage performance, and preventing the problem of large power loss resulting from an insufficient broadcasting beamforming weight amplitude value being employed to ensure all coverage ranges in a cell. Provided in the present application, the method for beamforming comprises: determining location information of a user equipment, and performing beamforming on the basis of the location information of the user equipment.

Disclosed is a signal source estimation method and apparatus performing the same, the signal source estimation method including acquiring first reception signals received by first receivers, among signals radiated from signal sources, selecting second receivers receiving reception signals to be used to estimate the signal sources, from among the first receivers based on the first reception signals, and detecting the number of signal sources based on second reception signals received by the second receivers.

Precoding is a technique that may be used in wireless communications when antenna spacing in a multiple-input multiple-output (MIMO) system is smaller than optimum spacing conditions. A precoding system and method are disclosed herein that distributes power among streams to trade-off increased data throughput and complexity of interference cancellation. Distributing power among streams may increase data throughput compared to singular value decomposition (SVD) precoding, but interference may be reduced compared to other methods that result in relatively high interference.

In order to make it possible to prevent occurrence of an interference among terminal apparatuses when a base station forms a beam toward a terminal apparatus by beam-forming to transmit a downlink signal, and to improve reception quality at a terminal apparatus. A base station of the present disclosure includes a memory storing instructions and one or more processors configured to execute the instructions to: perform channel estimations respectively on a plurality of terminal apparatuses; and determine a transmission layer of a target terminal apparatus by comparing angular profiles respectively obtained on the basis of channel estimates on the target terminal apparatus and at least one comparable terminal apparatus out of the plurality of terminal apparatuses and performing a path exclusion process to exclude, from transmission layers of the target terminal apparatus, a path that falls within a certain angular range around a path angle indicated by an angular profile of the at least one comparable terminal apparatus.

A wireless communication system non-collaborative, multiple input, multiple output (MIMO) space division multiple access (SDMA) system determines subscriber station combining and weighting vectors that yield a high average signal-to-interference plus noise ratio (SINR). Each subscriber station independently transmits information to a base station that allows the base station to determine a weight vector w.sub.i for each subscriber station using the determined combining vector of the subscriber station. The i.sup.th combining vector corresponds to a right singular vector corresponding to a maximum singular value of a channel matrix between a base station and the i.sup.th subscriber station. Each subscriber station transmits signals using a weight vector v.sub.i, which corresponds to a left singular vector corresponding to a maximum singular value of a channel matrix between the i.sup.th subscriber station and the base station. The base station uses the weight vector w.sub.i to determine the signal transmitted by the i.sup.th subscriber station.

Precoding is a technique that may be used in wireless communications when antenna spacing in a multiple-input multiple-output (MIMO) system is smaller than optimum spacing conditions. A precoding system and method are disclosed herein that distributes power among streams to trade-off increased data throughput and complexity of interference cancellation. Distributing power among streams may increase data throughput compared to singular value decomposition (SVD) precoding, but interference may be reduced compared to other methods that result in relatively high interference.