According to one embodiment, a wireless communication device includes a transmitter configured to transmit a first frame including first information required for uplink multi-user transmission without receiving a transmission request for the first information; and a receiver configured to receive a second frame.

Methods, systems, and devices are described for hierarchical communications and low latency support within a wireless communications system. An eNB and/or a UE may be configured to operate within the wireless communications system which is at least partially defined through a first layer with first layer transmissions having a first subframe type and a second layer with second layer transmissions having a second subframe type. The first subframe type may have a first round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, and the second layer may have a second RTT that is less than the first RTT. Subframes of the first subframe type may be multiplexed with subframes of the second subframe type, such as through time division multiplexing. In some examples symbols of different duration may be multiplexed such that they different symbol durations coexist.

Disclosed herein are apparatuses, systems, and methods using or implementing dynamic beamforming in control channels, by transmitting downlink control channels to user equipment (UEs) in a number of orthogonal frequency division multiplexing (OFDM) symbols of a downlink subframe. A first OFDM symbol of the number of OFDM symbols can be transmitted using first beamforming parameters in a first direction, and a second OFDM symbol of the number of OFDM symbols can be transmitted using second beamforming parameters different from the first beamforming parameters and in a second direction different from the first direction. The number of OFDM symbols used, as well as other parameters, can be dynamically adjusted in subsequent subframes. Other embodiments are described.

User equipment (UE) applies a first code division multiplex access (CDMA) code to a baseband signal to generate a first signal, and a second CDMA code to the baseband signal to generate a second signal. The UE then transmits the first signal to a receiving device via a first antenna, and the second signal to the receiving device via a second antenna. The receiving device receives the first and second signals as a combined signal at an antenna, and extracts the first signal from the combined signal using the first CDMA code, and extracts the second signal from the combined signal using the second CDMA code. The CDMA codes may be real-valued or complex-valued. In some embodiments, the UE may separate the baseband signals into first and second portions, and transmit the first portion as part of the first signal and the second portion as part of the second signal.

Methods, systems, and devices are described for hierarchical communications and low latency support within a wireless communications system. An eNB and/or a UE may be configured to operate within the wireless communications system which is at least partially defined through a first layer with first layer transmissions having a first subframe type and a second layer with second layer transmissions having a second subframe type. The first subframe type may have a first round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, and the second layer may have a second RTT that is less than the first RTT. Subframes of the first subframe type may be multiplexed with subframes of the second subframe type, such as through time division multiplexing. In some examples symbols of different duration may be multiplexed such that different symbol durations coexist.

According to one embodiment, a wireless communication device includes a transmitter configured to transmit a first frame including first information required for uplink multi-user transmission without receiving a transmission request for the first information; and a receiver configured to receive a second frame.

Various aspects described herein relate to techniques for using orthogonal demodulation reference signals (DMRSs) for downlink control channels in wireless communications systems. In an aspect, a method for a user equipment (UE) includes receiving one or more DMRSs over a multi-symbol downlink control channel. The method may further include identifying a time-first control channel element (CCE)-to-resource element group (REG) mapping for the multi-symbol downlink control channel, and identifying an orthogonal DMRS of the one or more DMRSs based on the time-first CCE-to-REG mapping, and decoding the multi-symbol downlink control channel based on at least the identified orthogonal DMRS.

The present invention presents a method by which a base station notifies a terminal of information on a tone into which interference caused by surrounding cells greatly flows, and by which a terminal uses the information so as to efficiently remove the interference caused by the surrounding cells and to demodulate data channels, such that the method improves reception performance. Particularly, when the surrounding cells transmit cell-specific reference signals, the base station transmits, to the terminal, location information of the cell-specific reference signals transmitted by the surrounding cells, and the terminal demodulates the received data except for a data channel tone in which cell-specific reference signals of the surrounding cells greatly cause interference. The present invention can improve data reception performance by efficiently removing the interference caused by the surrounding cells.

A method, wireless device, and network node for increasing the capacity on a control channel when using Frequency Division Multiplexing (FDM) of data and DMRS are disclosed. According to one aspect, a wireless device (WD) is configured to perform intra-symbol frequency division multiplexing of data subcarriers and demodulation reference signal, DMRS, subcarriers. The WD is also configured to apply intra-symbol orthogonal cover codes, OCCs, to the data subcarriers. The WD is further configured to apply intra-symbol cyclic shifts to the DMRS subcarriers.

Apparatus, computer readable medium, and methods for initiating uplink multi-user medium access in high-efficiency wireless local-area networks (WLANs) are disclosed. A station is disclosed comprising circuitry configured to generate a trigger frame comprising one or more resource allocations. Each of the resource allocations may include an indication of whether the resource allocation is an orthogonal frequency division multiple access (OFDMA) resource allocation or a multiple-user multiple-input multiple-output (MU-MIMO) resource allocation. An identity either of an OFDMA group or an MU-MIMO group may be included. Each resource allocation may include an indication of a bandwidth for the OFDMA resource allocation or a bandwidth for the MU-MIMO resource allocation. Each OFDMA resource allocation may include one or more indications of an address of one or more HE stations and one or more indications of an OFDMA sub-channel resource allocation for the corresponding HE station.