In an ISS process, the initiator sends a first SSW frame in different sector directions by sequentially using an antenna in m antennas, where m is not less than 1 and is less than or equal to N; and in an RSS process, the initiator receives a second SSW frame in a parallel (e.g., simultaneous) omnidirectional manner by using M antennas, where the second SSW frame is sent by a responder in different sector directions, each second SSW frame carries information used to indicate a first SSW frame with best quality in the ISS process, and the M antennas include at least the m antennas, and determines an optimal transmit beam in the ISS process based on the received second SSW frame.

There is provided mechanisms for transmitting a two-port reference signal from an analog antenna array of an antenna arrangement. The analog antenna array comprises antenna elements of two polarizations. All antenna elements of each polarization are connected to a respective physical antenna port. A method comprises generating two virtual antenna ports, one for each of the two ports of the reference signal. The method comprises feeding the reference signal from the two virtual antenna ports to the two physical antenna ports via a virtualization network. The method comprises transmitting, via the antenna elements, the reference signal from the two physical antenna ports over a composite beamwidth in different spatial coverage per polarization for each of the two physical antenna ports whereby the transmitted reference signal, over the composite beamwidth, varies between having rank 1 and rank 2.

Presently disclosed are systems and methods for beamforming training in WLANs. In various embodiments, there are unified MIMO beamforming training procedure, which includes a training period in which an initiator transmits multiple unified training frames for performing a transmit-beamforming training of the initiator and a receive-beamforming training of one or more responders; a feedback period in which each responder replies with a beamforming-feedback response; and an acknowledgement period during which the initiator transmits respective acknowledgement frames to the one or more responders from which responses were received. Rules for restricted random access in various slots of the feedback period may be implemented, to address response contention between multiple qualifying responders.

There is provided mechanisms for transmitting a two-port reference signal from an analog antenna array of an antenna arrangement. The analog antenna array comprises antenna elements of two polarizations. All antenna elements of each polarization are connected to a respective physical antenna port. A method comprises generating two virtual antenna ports, one for each of the two ports of the reference signal. The method comprises feeding the reference signal from the two virtual antenna ports to the two physical antenna ports via a virtualization network. The method comprises transmitting, via the antenna elements, the reference signal from the two physical antenna ports over a composite beamwidth in different spatial coverage per polarization for each of the two physical antenna ports whereby the transmitted reference signal, over the composite beamwidth, varies between having rank 1 and rank 2.

Presented in the present specification are a method whereby a station performs beamforming training in a wireless LAN (WLAN) system, and a device for same. In particular, presented in the present specification are a method whereby a station performs beamforming training for frequency division multiple access (FDMA) transmission, and a device for same. The method according to the present specification comprises the steps of: transmitting a beamforming setup frame including beamforming training operation information and identification information on one or more second stations corresponding to one FDMA group; performing FDMA beamforming training by using multiple transmission sectors simultaneously on the basis of the beamforming training operation information; receiving a feedback result of the performed FDMA beamforming training from the one or more second stations; and transmitting a selection frame including channel allocation information for each station and FDMA transmission configuration information determined on the basis of the received feedback result.

Methods and apparatuses for multiple input-multiple output (MIMO) channel access are provided herein. A method performed by a station may include receiving, from an access point (AP), a frame including information indicating a broadcast address. The frame may further include a control trailer including information indicating that a multi-user multiple input-multiple output (MU-MIMO) frame is to be transmitted by the AP and information indicative of a designation of a plurality of STAs, the plurality of STAs including the STA. The frame may solicit response frames from at least the designated plurality of STAs. The method may further include transmitting a response frame to the indicated broadcast address and receiving the MU-MIMO frame from the AP.

Provided is a transmitter which improves the flexibility of SRS resource allocation without increasing the amount of signaling for notifying the cyclic shift amount. In the transmitter, with regard to each basic shift amount candidate group having a basic shift amount from 0 to N−1, a transmission control unit (206) specifies the actual shift amount imparted to a cyclic shift sequence used in scrambling a reference signal transmitted from each antenna port, said specification being performed based on a table in which cyclic shift amount candidates correspond to each antenna port, and based on setting information transmitted from a base station (100). With regard to basic shift amount candidates for shift amount X, the table differentiates between an offset pattern comprising offset values for cyclic shift amount candidates corresponding to each antenna port and an offset pattern corresponding to basic shift amount candidates of X+N/2.

A method and apparatus for generation of orthogonal training signals for transmission in an antenna array are described. In this embodiment, a set of P training signals is generated. The generation of the P training signals includes generating a first set of Zadoff-Chu sequences, where the first set of sequences is based on a first reference Zadoff-Chu sequence and (P−1) first subsequent Zadoff-Chu sequences, where each one of the first subsequent Zadoff-Chu sequences is a cyclic shift of the first reference Zadoff-Chu sequence. A second set of sequences is generated based on a second reference Zadoff-Chu sequence and (P−1) second subsequent sequences that are cyclic shift of the second reference sequence. The P training signals are determined based on the first set of sequences and the second set of sequences. The training signals are then transmitted through a plurality of transmit paths of a base station towards a wireless network.

According to an aspect, a wireless node selects a set of reference signal antenna ports for use in transmitting data to other wireless nodes in a given transmit time interval, from a plurality of sets of reference signal antenna ports that are available for use and that include reference signal antenna ports having different reference signal densities in the frequency and/or time dimension. The wireless node sends a message to a second wireless node indicating a reference signal assignment and including an indication of the selected set of reference signal antenna ports.

A communication system using beamforming transmission in a millimeter wave spectrum in an environment. A memory with data including values indicative of link attributes associated with beam signal measurements with states of devices and states of environments. The states of the devices for each device including types of user behavior, locations and poses in each environment. The states of the environments for each environment including, locations of physical objects and types of behavior of ambient users. Control circuitry performs beam training with a target device in environment to measure beam signal values and environmental responses for different beams transmitted over the different beam angles. Selects, in response to the beam training, at least one dominant angle for a beamforming communication with the target device. Estimates, one of a state of the target device or a state of the environment, corresponding to environmental responses for different beams estimated during the beam training.