Methods, systems, and devices for wireless communications are described. A transmitting device, which may be an example of a user equipment and/or a base station, may receive a signal from a receiving device indicating an antenna topology supported by the receiving device. The transmitting device may select, based at least in part on the antenna topology, a diversity scheme for performing a wireless transmission to the receiving device, the diversity scheme including one or more diversity types from a plurality of diversity types. The transmitting device may transmit the wireless transmission to the receiving device employing the selected diversity scheme.

A method is provided for estimating at least one characteristic of a signal received by a receiver, the signal having been transmitted in succession by a plurality of antennas in successive time segments, each segment being dedicated to one separate antenna, the signal being modulated into the form of pulses according to ultra-wideband modulation. The method includes steps of: receiving and digitizing the signal, computing the product of multiplication of each symbol of the received signal by the complex conjugate of the corresponding transmitted symbol, for each segment and for each symbol of the signal received for this segment, estimating a phase error by means of a phase-locked loop applied to the product, for each segment, determining a reference phase by means of a linear regression applied to the phase errors estimated for all of the segments, determining, for at least one pair of antennas, a phase difference between the signals transmitted by the antennas of the pair, on the basis of the difference between the reference phases computed for the segments associated with the antennas.

The described techniques relate to improved methods, systems, devices, or apparatuses that support channel state information feedback for semi-open-loop and open-loop schemes. The described techniques provide for a user equipment (UE) to determine an open-loop, semi-open-loop, or closed-loop transmission scheme for deriving channel quality information (CQI). In the case of determined open-loop transmission scheme, the UE may select a transmission scheme corresponding to a time offset value and a precoder cycling granularity value. The UE may determine one or more of a time offset value, a precoder cycling granularity value, and a precoding matrix indicator (PMI) for a channel state information (CSI) report, and generate CQI accordingly. Additionally, the UE may include the determined values in the CSI report to indicate the transmission scheme used for the CQI derivation. Based on the CQI, the base station can then determine the transmission scheme and perform link adaption accordingly.

Spatial redistributors and methods of redistributing signals in accordance with various embodiments of the invention are illustrated. One embodiment includes an array of channels configured to receive and retransmit a signal, where each of a plurality of independently operating channels in the array includes: at least one antenna element; an RF chain configured to apply at least a time delay to the received signal prior to retransmission; control circuitry configured to control the time delay applied to the received signal by the RF chain; and a reference oscillator. In addition, the array of channels is configured to redirect a signal received from a first set of directions for retransmission in a second set of directions; and the control circuitry of the channels in the array of channels coordinates the time delays applied to the received signal across the array of channels to control the wave front of the retransmitted signal.

A wireless audio system including a transmitter using multiple antenna diversity techniques for different signal types is provided. Multipath performance may be optimized, along with improved spectral efficiency of the system.

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

According to an aspect of the present invention, a method for performing a downlink (DL) multi-user (MU) transmission by an access point (AP) in a wireless communication system may include transmitting a DL MU Physical Protocol Data Unit (PPDU), where the DL MU PPDU includes a trigger frame including trigger information for an uplink (UL) MU transmission and a DL MU frame; and UL MU receiving a UL MU PPDU generated based on the DL MU PPDU, where the UL MU PPDU includes a UL MU frame based on the trigger frame and an acknowledge (ACK) frame in response to the DL MU frame.

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.

A simple block coding arrangement is created with symbols transmitted over a plurality of transmit channels, in connection with coding that comprises only simple arithmetic operations, such as negation and conjugation. The diversity created by the transmitter utilizes space diversity and either time or frequency diversity. Space diversity is effected by redundantly transmitting over a plurality of antennas, time diversity is effected by redundantly transmitting at different times, and frequency diversity is effected by redundantly transmitting at different frequencies: Illustratively, using two transmit antennas and a single receive antenna, one of the disclosed embodiments provides the same diversity gain as the maximal-ratio receiver combining (MRRC) scheme with one transmit antenna and two receive antennas. The principles of this invention are applicable to arrangements with more than two antennas, and an illustrative embodiment is disclosed using the same space block code with two transmit and two receive antennas.

The present invention relates to generating an interference pattern for controlling inter-cell interference, a method for signaling therefor, and an apparatus utilizing the method. The method for signaling an interference pattern according to the present invention may comprise the steps of: determining the length and cyclic shift offset for a first interference pattern to be allocated to a set reference resource from among interference pattern sets; generating a cell-specific sequence to which the cyclic shift offset of the first interference pattern has been applied; and allocating the first interference pattern and cell-specific sequence to a resource and transmitting same.