In the present invention, disclosed is a method for uplink multi-user transmission in a wireless communication system and an apparatus therefor. Specifically, a method for performing, by a station (STA), uplink (UL) multi-user (MU) transmission in a wireless communication system comprises the steps of: receiving, from an access point (AP), a trigger frame including information for UL MU transmission; and transmitting an UL MU PPDU on the basis of the information for UL MU transmission, wherein the trigger frame is a medium access control (MAC) frame, a MAC header of the trigger frame includes a type field and a subtype field, and the type of the trigger frame may be indicated by the type field and the subtype field.

Two-way (full-duplex) wireless links in facilitating network management and improve network performance. Once aspect includes methods for network management using a high-throughput channel and a low-throughput channel. Other aspects include methods to facilitate practical realization and improve performance of some of the network information theoretic configurations, such as Space-Division Multiple Access (SDMA) in uplink and downlink, Interference Channel, and other forms of distributed collaborative signaling schemes. Another aspect includes methods to support cognitive wireless networks.

A first device transmits to a second device a first data unit which indicates a maximum number of long training field (LTF) symbols that the first device transmits and receives for a multiple input multiple output communication. The first device receives, from the second device, a second data unit which comprises a plurality of LTF symbols up to the maximum number of LTF symbols the first device receives indicated by the first data unit. A channel estimation is performed based on the plurality of LTF symbols of the second data unit up to the maximum number of LTF symbols indicated by the first data unit to recover information in one or more fields of the second data unit. For the case when the second data unit is a trigger frame, the first device generates the third data unit with a plurality of LTF symbols up to the maximum number of LTF symbols the first device transmits indicated by the first data unit and transmits the third data unit.

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.

Transmitter having multiple transmit antennas for transmitting two or more streams. The transmitter comprises an encoding circuitry configured to perform space-time block encoding to obtain for at least one of the two or more streams a pair of space-time encoded streams. Further, a mapping circuitry is configured to assign each stream of each pair of space-time encoded streams to a transmit antenna of the multiple transmit antennas for wirelessly transmitting the two or more streams. Finally, a control circuitry is configured to adjust one or more parameters of the mapping circuitry in order to achieve a defined channel characteristic between the transmitter and a receiver.

Modulated signal A is transmitted from a first antenna, and modulated signal B is transmitted from a second antenna. As modulated signal B, modulated symbols S2(i) and S2(i+1) obtained from different data are transmitted at time i and time i+1 respectively. In contrast, as modulated signal A, modulated symbols S1(i) and S1(i)′ obtained by changing the signal point arrangement of the same data are transmitted at time i and time i+1 respectively. As a result the reception quality can be changed intentionally at time i and time i+1, and therefore using the demodulation result of modulated signal A of a time when the reception quality is good enables both modulated signals A and B to be demodulated with good error rate performances.

Certain aspects of the present disclosure generally relate to wireless communications, and more specifically to increased diversity for devices with limited communications resources. An example method generally includes transmitting data as a bundled transmission to a device with limited communications resources, the bundled transmission comprising multiple bursts wherein each burst spans a plurality of transmission time intervals (TTIs) and the same data is transmitted in each burst, and taking action to increase diversity (e.g., at least one of spatial diversity, time diversity, frequency diversity, etc.) for the bundled transmission.

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.

A method for performing, by a UE, channel estimation in a wireless communication system includes: receiving, from an eNB, a control message including reference signal transmission pattern information representing a transmission pattern of a channel estimation reference signal (RS) transmitted through antenna ports; receiving the reference signal from the eNB on the basis of the received reference signal transmission pattern information; measuring a channel per antenna port of the eNB on the basis of the received reference signal; and feeding back channel state information related to the measured channel to the eNB.

Disclosed is a method for supporting uplink multiple-input and multiple-output (MIMO) in a wireless communication system. A method for transmitting data according to the present invention comprises the steps of: mapping, to first orthogonal frequency division multiplexing (OFDM) symbols within a subframe, first demodulation reference signals (DMRSs) corresponding to a first antenna port and a second DMRSs corresponding to a second antenna port; mapping, to second OFDM symbols except the first OFDM symbols within the subframe, first data corresponding to the first antenna port and second data corresponding to the second antenna port; and transmitting the subframe by using resources allocated to the uplink, wherein predetermined precodings are applied to the first data and the second data, and the predetermined precodings may be changed according to the index of the second OFDM symbols.