A mechanism for mutually coupling multiple antennas for transmission in a wireless communication environment, wherein, for a received or transmitted radio signal a precoding matrix is created that includes artificial mutual antenna coupling coefficients and processing the received or transmitted radio signal using the created precoding matrix.

Fiber, cable, and wireless data channels are typically impaired by reflectors and other imperfections, producing a channel state with echoes and frequency shifts in data waveforms. Here, methods of using OTFS pilot symbol waveform bursts to automatically produce a detailed 2D model of the channel state are presented. This 2D channel state can then be used to optimize data transmission. For wireless data channels, an even more detailed 2D model of channel state can be produced by using polarization and multiple antennas in the process. Once 2D channel states are known, the system turns imperfect data channels from a liability to an advantage by using channel imperfections to boost data transmission rates. The methods can be used to improve legacy data transmission modes in multiple types of media, and are particularly useful for producing new types of robust and high capacity wireless communications using non-legacy OTFS data transmission methods.

The disclosure relates to a method performed in a network node for transmitting data in a wireless network. The network node is configurable for controlling a multiple input multiple output antenna system. The method comprises beamforming user specific data streams to one or more communication devices, UE.sub.1, . . . , UE.sub.K, wherein the beamforming is based on respective channel information available for each of the one or more communication devices, UE.sub.1, . . . , UE.sub.K, precoding control information streams using a transmit diversity scheme; and transmitting the beamformed user specific data streams and the precoded control information streams in a same transmission resource. The disclosure relates to a network node, method in communication device, communication device and computer programs and computer program products.

Distortion caused by spurious components in a determined channel impulse response (CIR) is reduced. In an OFDM (orthogonal frequency-division multiplexing) system pilot signals are applied to different subcarriers of different symbols in accordance with a pilot transmission scheme. Channel estimates are determined by time-interpolation for some of the data slots of the received signal which do not already include a pilot signal. For each of a sequence of symbols, a respective Inverse Fast Fourier Transform is performed on the pilot signals and interpolated channel estimates in the data slots of that symbol, thereby determining a sequence of estimated CIRs for the sequence of symbols. Spurious channel components will vary across the sequence of estimated CIRs, whereas the true channel peaks will tend not to significantly vary across the sequence of estimated CIRs. Therefore the sequence of estimated CIRs can be filtered (e.g. with a low-pass filter) to attenuate the spurious components, thereby determining a CIR for the signal for which the distortion caused by the spurious components is reduced.

Methods and apparatuses are provided to cancel a near-field reflected self-interference component. The method includes: obtaining a radio frequency receive signal by using a main receive antenna; performing interference cancellation processing on the radio frequency receive signal according to the radio frequency reference signal to generate a first processed signal; performing near-field reflected self-interference channel estimation according to a digital baseband reference signal corresponding to the radio frequency reference signal and according to a first digital signal obtained by sampling the first processed signal to obtain a near-field reflected self-interference component parameter; performing near-field reflected self-interference signal reconstruction according to the near-field reflected self-interference component parameter and the radio frequency reference signal to obtain a near-field reflected self-interference signal; and performing interference cancellation processing on the first processed signal according to the near-field reflected self-interference signal to obtain a second processed signal.

A network-wide interference cancellation scheme estimates channel impulse responses related to Self Interference and the Mutual Interference, then reduces both the Self Interference and the Mutual Interference in the receiver of an Full Duplex device. Full Duplex gains may be capitalized upon and translated into system gain. The scheme is based on an extended Multiple-Input-Multiple-Output (MIMO) treatment of the whole Full Duplex network. The network-wide interference cancellation may be seen to be feasible when a unique pilot signal design and training structure are in place network-wide.

To provide a wireless communication device, a system, a method, and a program capable of accurately demodulating an orthogonal time frequency space (OTFS) signal with a small amount of calculation while maintaining an OTFS signal of a high data rate. A wireless communication device according to the present disclosure includes a reception unit configured to perform channel estimation using a first reference signal, perform phase correction mainly using a second reference signal, and demodulate a received orthogonal time frequency space (OTFS) signal using results of the channel estimation and the phase correction.

A delay estimation method for a multiple input multiple output communications system, includes: calculating, by a receiver, a channel response matrix of a Multiple input multiple output MIMO communications system, where there are n transmit channels and m receive channels in the MIMO communications system, n2, m2, and the channel response matrix includes channel responses of n*m sub-channels; calculating, by the receiver, an integer delay, relative to a reference sub-channel, of each of the n*m sub-channels according to the channel response matrix, where the reference sub-channel is any sub-channel in the n*m sub-channels; calculating, by the receiver, fraction delays of the n*m sub-channels according to the channel response matrix; and separating out, by the receiver, delays of the m receive channels according to delays of the n*m sub-channels.

A device comprises a memory that stores instructions executed by one or more processors to obtain a plurality of received signals transmitted by a user equipment from a plurality of antenna elements in a cellular network. A plurality of complex channel values are calculated in an angle domain for a horizontal arrival angle and a vertical arrival angle per a received ray in a plurality of received rays in response to the plurality of received signals. A frequency-offset estimation is calculated and applied to the plurality of complex channel values. The plurality of offset complex channel values are transformed to a plurality of channel values in a time domain. A time-offset estimation is calculated and applied to the plurality of channel values. An expected value of the plurality of channel values is obtained to obtain a power angle delay profile for the geographical location of the user equipment.

Wireless communication wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. An encoding operation encodes and outputs transmitting data (bit string) and a bit converting operation converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into 1 0. A modulating operation modulates the bit string inputted from the bit converting operation by using a single modulation mapper and a plurality of data symbols are generated.