Methods and apparatus for orthogonal stream spatial multiplexing. In one embodiment, a method includes splitting and modulating a data stream into n MIMO RF spatial streams and coupling them to corresponding switchable polarization antenna elements controlled via orthogonal binary codes for transmission. Each transmitted stream manifests as time-varying-polarization-orthogonal to the other n−1 spatial streams. The method includes reception of the streams at their destination using corresponding antenna elements controlled by the same set of orthogonal codes. Thus, each of the n transmitted spatial streams is polarization-match-filtered, unambiguously separated and individually recovered from all the others upon reception for subsequent demodulation and MIMO spatial recombination into the original data stream. Thus, n MIMO spatial streams emanating from a common source and featuring equal amplitude and bandwidth but bearing distinct data and exhibiting mutually orthogonal time varying polarization will propagate mutually interference-free on the same frequency channel to a single destination.

Systems, methods, and apparatus cause a first wireless device to transmit to a plurality of locator devices, an extended signal including a first segment and second segment. The first segment includes an indication for each of the plurality of locator devices to listen for a change in the extended signal from the first segment to the second segment. The second segment includes an indication for each of the plurality of locator devices to rotate through a plurality of antennas to receive the second segment via the plurality of antennas. Responsive to the transmitting of the extended signal, receiving direction data from each of the plurality of locator devices.

Disclosed herein are devices, systems and methods between a between a plurality of collaborating Access Points (APs) and a receiving station (STA) operating in a wireless local area network (WLAN). The method include the steps of: transmitting, by each AP in the plurality of collaborating APs, a data frame to the receiving STA, each data frame has a preamble portion, the preamble portion including a signal (SIG) field, and the SIG field has a subfield including information representative of a total number of spatial streams transmitted by the plurality of collaborating Aps.

A communication system comprises a fixed network comprising access points for mm wave radio communication using directional beams. A wireless modem of a vehicle comprises a first search circuit searching for a beacon transmission in a first frequency channel. A first data receiver extracts data from a detected beacon signal including: an indication of a first access point transmitting the beacon signal; a first load value indicative of a loading of the first access point; and an indication of a second access point having overlapping coverage with the first access point. Another receiver extracts data from a second beacon signal transmitted by the second access point in a second frequency channel including a second load value indicative of a loading of the second access point. A controller selects a target access point dependent on the first and second load values, and initializes a link setup with the target access point.

Some embodiments of the present disclosure provide for use of a linear chirp signal as a basis for a sensing signal. Modification of the linear chirp signal by a signature function can allow a receiver of the sensing signal to determine an identity for a source of the sensing signal. Accordingly, upon processing the received sensing signal to obtain path parameter estimates, the receiver can direct a transmission of an indication of the path parameter estimates to the source of the sensing signal. Aspects of the present application relate to performing multi-node, multi-path channel estimation on the basis of processing the received sensing signal. Conveniently, the processing is performed with low complexity.

Some embodiments of the present disclosure provide for use of a linear chirp signal as a basis for a sensing signal. Modification of the linear chirp signal by a signature function can allow a receiver of the sensing signal to determine an identity for a source of the sensing signal. Accordingly, upon processing the received sensing signal to obtain path parameter estimates, the receiver can direct a transmission of an indication of the path parameter estimates to the source of the sensing signal. Aspects of the present application relate to performing multi-node, multi-path channel estimation on the basis of processing the received sensing signal. Conveniently, the processing is performed with low complexity.

An apparatus includes an antenna array having a plurality of antennas. The antenna array is configured to receive a multi-carrier signal from a multi-antenna transmitter over a radio channel. The multi-carrier signal has at least two subcarriers, and each subcarrier is mapped at the transmitter to a respective subcarrier-beamformer. The respective subcarrier-beamformers has non-identical null and beam cone directions. A processor is configured to identify a communication direction for a radio signal communication between the apparatus and the transmitter. The communication direction is identified based on one or more specular path components of the radio channel which are related to a null or to a maximum of a subcarrier-beamformer.

This disclosure relates to a transceiver element comprising receiving circuitry, down-converting circuitry, extracting circuitry and output circuitry. The receiving circuitry is configured to receive a radio frequency signal via an antenna element associated with the receiving circuitry. The radio frequency signal comprises a first received signal part and a second received signal part. The down-converting circuitry is configured to down-convert the radio frequency signal to provide a down-converted signal. The down-converted signal comprises a first down-converted signal part corresponding to the first received signal part and a second down-converted signal part corresponding to the second received signal part. The extracting circuitry is configured to extract at least the second down-converted signal part from the down-converted signal. The output circuitry is configured to provide an output signal comprising a first output signal part and a second output signal part. The first output signal part comprises at least a first intermediate signal part which comprises at least the first down-converted signal part. The second output signal part comprises at least the second down-converted signal part extracted from the down-converted signal. Corresponding transceiver, wireless communication apparatus, method and computer program product are also disclosed.

Embodiments of the present disclosure relate to methods and apparatuses for signal detection in a MIMO communication system. A receiver device according to an embodiment of the present disclosure comprises a remote unit and a baseband unit. The remote radio unit is configured to receive a first set of signals from a first number of receiving antennas, and the baseband unit comprises: an interfacing unit, configured to obtain the first set of signals from the remote radio unit; a beamforming unit, configured to generate a second set of signals associated with a second number of virtual antennas by performing receiving beamforming for the obtained first set of signals, the second number being less than the first number; and a detecting unit, configured to detect the second set of signals generated by the beamforming unit. Embodiments of the present disclosure may reduce complexity of signal detection and cost of implementation.

An adaptive array antenna system receives a desired wave arriving through K time slots each allocated to one of K transmitting stations. In the adaptive array antenna system, an adaptive control device includes a correlation matrix calculating unit, a correlation matrix storing unit, an inverse matrix calculating unit, and a weighting factor calculating unit. The inverse matrix calculating unit acquires a correlation matrix having been calculated at previous time for another time slot other than the current time slot from the correlation matrix storing unit, regards the acquired correlation matrix as an interference noise correlation matrix, and calculates an inverse matrix of the interference noise correlation matrix. The weighting factor calculating unit calculates values of a plurality of weighting factors used by a beamforming unit using the inverse matrix.