Configuration of various radio systems may have a number of possible benefits. For example, small cell configuration may be useful for interference mitigation. A method, in certain embodiments, can include determining a virtual subframe index for a cell. The method can also include communicating the virtual subframe index for the cell by communicating a time division duplex configuration and a relative subframe offset.

Systems, methods, and devices for high-efficiency wireless frequency division multiplexing are provided. A method includes exchanging, at an access point, at least one frame reserving a wireless medium with at least one of a first and second wireless device. The method further includes receiving a first communication on a first set of wireless frequencies from the first wireless device. The method further includes receiving a second communication, at least partially concurrent with the first communication, on a second set of wireless frequencies from the second wireless device. The method further includes transmitting at least one acknowledgment of the first and second communication. The first set and the second set are mutually exclusive subsets of a set of wireless frequencies available for use by both the first and second wireless device.

The present invention proposes a hybrid spatial multiplexing (SM) and a space division multiple access (SDMA) technique in a frequency division duplex (FDD) massive multiple-input multiple output (MIMO) system using a two-dimensional planar array antenna, which effectively transmits a channel state information reference signal (CSI-RS) for estimating a downlink two-dimensional space channel using only a limited amount of downlink radio resources, and optimally selects and performs the SM and SDMA techniques in a two-dimensional space channel. To this end, the present invention proposes a technique which defines space resource blocks (SRB) by grouping space elements (SE) having a high spatial correlation between downlink channels in the horizontal dimension and corresponding SEs thereof in the vertical dimension, and transmits CSI-RSs for estimating channels in vertical dimension SEs corresponding to one selected horizontal SE in each SRB every transmit time interval (TTI). The present invention proposes a technique wherein user equipment (UE) estimates the spatial correlation between channels of different horizontal dimension SEs belonging to the same SRB received in different TTIs and the spatial correlation between channels of horizontal dimension SEs belonging to different SRBs received in the same TTI, and feeds information for changing the size of SRB of the corresponding UE to an optimal size back to eNodeB. The present invention proposes a technique wherein the UE estimates downlink channels through CSI-RSs transmitted from each SRB, and each UE feeds an index of a preferred SRB, a rank of the corresponding SRB in the vertical dimension, and channel quality information (CQI) back to eNodeB. When each UE determines the rank, it is possible to transmit the ranks to the fullest extent in the vertical dimension and only a single rank from each SRB in the horizontal dimension.

A method for wireless communication is provided. The method comprises transmitting a first wireless message comprising a request for a first user terminal to transmit uplink data and an indication of at least one requested operational parameter. The method also comprises receiving a second wireless message from an access point in response to the first wireless message, the second wireless message indicating whether a plurality of user terminals including the first user terminal is selected to transmit uplink data, the second wireless message indicating at least one operational parameter for transmission of uplink data based on the at least one requested operational parameter.

A base station includes a transmitter configured to transmit a downlink signal to a terminal device in a first frequency band, a receiver configured to receive an uplink signal from the terminal device in a second frequency band narrower than the first frequency band, at least a part of the second frequency band being included in the first frequency band, and a canceller circuit configured to execute a suppression process of a self-interference in which the downlink signal transmitted from the transmitter reaches the receiver and interferers with the uplink signal, wherein the canceller circuit executes the suppression process by limiting to a third frequency band including the second frequency band and not including at least a part of the first frequency band.

Methods and apparatus for multiple user uplink are provided. In one aspect, a method for wireless communication includes receiving, via a first device, a first wireless message granting permission for the first device to transmit a message during a transmission opportunity, the first wireless message being transmitted to the first device at least partially concurrently with a transmission of at least a portion of a second wireless message addressed to a second device, the first wireless message being received over a first spatial stream and the second wireless message being transmitted over a second spatial stream; and transmitting, via the first device, a third message to a third device during the transmission opportunity at least partially concurrently with a transmission of a fourth message by the second device to the third device.

Methods and apparatus for multiple user uplink are provided. In one aspect, a method for wireless communication is provided. The method includes receiving a trigger frame from an access point, the trigger frame being transmitted to two or more stations and indicating an uplink transmission opportunity. The trigger frame further includes a request for the two or more stations to concurrently transmit uplink data at a specific time. The method includes transmitting uplink data at the specific time to the access point concurrently with another of the two or more stations transmitting uplink data to the access point.

Systems and methods of wireless communication in which wireless devices are adapted to implement adaptive waveform selection are disclosed. For example, operation according to embodiments may provide for use of a waveform design that minimizes peak-to-average power ratio (PAPR), such as single-carrier frequency division multiplexing (SC-FDM), as well as a waveform design that provides higher spectral efficiency, such as orthogonal frequency division multiplexing (OFDM), for scenarios that are not power-limited and the higher PAPR is acceptable. Adaptive waveform selection may be based implicitly on one or more parameters or may be based on explicit signaling. Adaptive waveform selection may be utilized with respect to initially establishing a communication link and/or with respect to an established communication link.

A data transmission method, a device, and a transceiver are provided. The method is applied to a data transmission method for an access point. A transceiver of the access point includes m transmit paths and n receive paths. In the present invention, uplink transmission and downlink transmission can be performed simultaneously on different channels, so that a transmit path and a receive path work simultaneously, increasing usage of the transmit path and the receive path and increasing a throughput of a system.

Methods and apparatus for acknowledgment of multiple user uplink are provided. In one aspect, a method of wireless communication includes receiving a first wireless message from a first station at least partially concurrently with receiving a second wireless message from a second station, generating a first acknowledgment message in response to receiving the first wireless message, generating a second acknowledgement message in response to receiving the second wireless message, and transmitting the first acknowledgment message to the first station at least partially concurrently with transmitting the second acknowledgement message to the second station.