Abstract: A method for transmitting a sounding reference signal in a MIMO wireless communication system and an apparatus therefor are disclosed. The method for transmitting sounding reference signals (SRSs) in a MIMO wireless communication system comprises receiving sounding reference signal parameters from a base station; receiving information of the number of sounding reference signals which will be transmitted at a transmission time instant from the base station; if a plurality of sounding reference signals are provided, generating the sounding reference signals corresponding to each of the plurality of antennas by using the sounding reference signal parameters; and transmitting the generated sounding reference signals to the base station through their corresponding antennas at a specific transmission instant.

Abstract: The present application discloses a method in which a base station transmits a reference signal sequence in a wireless communication system. In detail, the method comprises the steps of: generating a pseudo-random sequence using a first m-sequence and a second m-sequence; generating the reference signal sequence using the pseudo-random sequence; and transmitting the reference signal to a mobile station via antenna ports different from one another. The second m-sequence has an initial value containing parameters for discriminating reference signal sequences among users.

Abstract: A method for transmitting a reference signal for channel measurement (CSI-RS) to a user equipment; a base station therefore; a method for receiving a CSI-RS; and the user equipment therefore are discussed. The method for transmitting a CSI-RS according to one embodiment includes transmitting CSI-RS pattern information for indicating a pattern of time-frequency resource to be nulled, hereinafter referred to as null CSI-RS pattern, and CSI-RS subframe information for indicating in which subframe the null CSI-RS pattern occurs; and nulling a time-frequency resource corresponding to the null CSI-RS pattern in a subframe corresponding to the CSI-RS subframe information, hereinafter referred to as null CSI-RS subframe, based on the CSI-RS pattern information and the CSI-RS subframe information. The CSI-RS subframe information includes information indicating a periodic interval with which the null CSI-RS subframe occurs. The periodic interval corresponds to a plurality of subframes.

Abstract: A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

Abstract: According to one embodiment, a method for a wireless local area includes: generating a medium access control (MAC) protocol data unit (MPDU) to be transmitted to a target station; generating a physical layer convergence procedure (PLCP) protocol data unit (PPDU) by attaching a PLCP preamble to the MPDU; selecting a transmission channel; and transmitting the PPDU to the target station over the transmission channel. Selecting the transmission channel includes: performing clear channel assessment (CCA) on a first channel to determine whether the first channel is idle; and only after it is determined that the first channel is idle, selecting the first channel and at least one idle second channel as the transmission channel. The PLCP preamble includes channel allocation information indicating a bandwidth of the transmission channel.

Abstract: A method is provided for transmitting a signal by a station in a wireless local area network (WLAN). The station obtains a transmission opportunity (TXOP) indicating a time duration used for transmission of a plurality of data units. The station transmits, during the TXOP, an initial data unit of the plurality of data units. The initial data unit comprises a control field indicating a transmit bandwidth of the initial data unit. The station selects a transmit bandwidth of a non-initial data unit of the plurality of data units to be narrower than the transmit bandwidth of the initial data unit. The station transmits, during the TXOP, the non-initial data unit. The non-initial data unit comprises a control field indicating the transmit bandwidth of the non-initial data unit.

Abstract: A method and a transmitting station for transmitting data in a wireless local area network are discussed. The method according to an embodiment includes generating a physical layer convergence procedure (PLCP) protocol data unit (PPDU), the PPDU including a Very High Throughput Signal (VHT-SIG) field and a PLCP Service Data Unit (PSDU); and transmitting the PPDU to a receiving station. The VHT-SIG field includes a class type and identification information, the class type indicates that the PPDU is transmitted by an access point (AP) or a non-AP station, the identification information includes a partial identifier formed from a Basic Service Set Identifier (BSSID), and the partial identifier has a length shorter than a length of the BSSID.

Abstract: A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

Abstract: A method for transmitting data in a wireless local area network, the method comprising: receiving, by a receiving station, a physical layer protocol data unit (PPDU) from a transmitting station, the PPDU including a signal-A field, the signal-A field including a bandwidth in which the PPDU is received, decoding the PPDU, wherein, when the PPDU is used for single-user (SU) transmission, the PPDU is decoded with assuming that the PPDU does not include a signal-B field, and, when the PPDU is used for multi-user (MU) transmission, the PPDU is decoded with assuming that the PPDU include the signal-B field, and wherein the signal-B field includes a modulation and coding scheme (MCS) used for the receiving station.

Abstract: A method and apparatus for allowing a UE to transmit uplink signals using a MIMO scheme are disclosed. In order to maintain good Peak power to Average Power Ratio (PAPR) or Cubic Metric (CM) properties when the UE transmits uplink signals using the MIMO scheme, the UE uses a precoding scheme based on a precoding matrix established in a manner that one layer is transmitted to each antenna in specific rank transmission.

Abstract: According to one embodiment, a method for a wireless local area includes: generating a medium access control (MAC) protocol data unit (MPDU) to be transmitted to a target station; generating a physical layer convergence procedure (PLCP) protocol data unit (PPDU) by attaching a PLCP preamble to the MPDU; selecting a transmission channel; and transmitting the PPDU to the target station over the transmission channel. Selecting the transmission channel includes: performing clear channel assessment (CCA) on a first channel to determine whether the first channel is idle; and only after it is determined that the first channel is idle, selecting the first channel and at least one idle second channel as the transmission channel. The PLCP preamble includes channel allocation information indicating a bandwidth of the transmission channel.

Abstract: A method is provided for transmitting a data frame by a station in a wireless local area network. The station obtains a transmission opportunity (TXOP) for a bandwidth, the TXOP indicating an interval of time during which the station has a right to initiate frame exchange sequences onto wireless medium. The station sets a transmit bandwidth parameter of a non-initial physical layer protocol data unit (PPDU) of a plurality of PPDUs to be transmitted during the TXOP based on a transmit bandwidth parameter of a preceding PPDU of the plurality of PPDUs. The transmit bandwidth parameter of the non-initial PPDU is set to be same or narrower than the transmit bandwidth parameter of the preceding PPDU. A bandwidth indicated by the transmit bandwidth parameter of the non-initial PPDU or the preceding PPDU includes at least one of 20 MHz, 40 MHz and 80 MHz. The station transmits the non-initial PPDU during the TXOP.

Abstract: A method of transmitting a data frame by a transmitter in a WLAN system is provided. The method includes generating a data block including at least one data units respectively transmitted through at least one or more spatial streams to at least one receiver, transmitting first control information to the at least one receiver, transmitting second control information to each receiver, and transmitting the data block to the at least one receiver. The first control information includes a length indicator for the data block, a MIMO indicator indicating whether the data block is for SU-MIMO or MU-MIMO, and a spatial stream indication field including information about the number of the spatial streams. The second control information includes a FEC coding field indicating an encoding scheme applied to the data unit and an MCS field indicating an MCS applied to the data unit.

Abstract: A method of link adaptation performed by an access point supporting multi user (MU) multiple input multiple output (MIMO) in wireless local area network system is provided. The method includes transmitting, to a first station, a physical layer convergence procedure (PLCP) protocol data unit (PPDU) containing a modulation and coding scheme (MCS) request (MRQ) and receiving, from the first station, a MCS feedback (MFB) in response to the MRQ, wherein the first station is one of destination stations of MU-MIMO transmission performed by the access point, and the MFB includes a recommended MCS value computed, by the first station, on the assumption that the first station, as a member of the destination stations, receives data transmitted over at least one spatial stream allocated to the first station in MU-MIMO transmission.

Abstract: A method and apparatus for allowing a UE to transmit uplink signals using a MIMO scheme are disclosed. In order to maintain good Peak power to Average Power Ratio (PAPR) or Cubic Metric (CM) properties when the UE transmits uplink signals using the MIMO scheme, the UE uses a precoding scheme based on a precoding matrix established in a manner that one layer is transmitted to each antenna in specific rank transmission.

Abstract: Provided is a method of receiving a physical layer convergence procedure (PLCP) protocol data unit (PPDU) by an access point (AP) in a wireless local area (LAN) system. The method includes: allocating a first transmission channel bandwidth to a first station (STA) which is multiple input multiple output (MIMO)-paired with the AP; allocating a second transmission channel bandwidth to a second STA which is MIMO-paired with the AP; transmitting to the first STA and the second STA a sync trigger for determining a time point at which the first STA transmits a first PPDU and a time point at which the second STA transmits a second PPDU; and receiving simultaneously the first PPDU and the second PPDU from the first STA and the second STA.

Abstract: A method of transmitting a training signal in a Wireless Local Area Network (WLAN) system includes generating one or more first training signals for a first destination station and one or more second training signals for a second destination station by applying a mapping matrix P to a training signal generation sequence, mapping the first training signals and the second training signals to a plurality of antennas according to an antenna mapping matrix, and performing Inverse Fast Fourier Transform (IFFT) on each of the first training signals and the second training signals mapped to the plurality of antennas and transmitting the training signals through the plurality of antennas.

Abstract: A method and apparatus for allowing a UE to transmit uplink signals using a MIMO scheme are disclosed. In order to maintain good Peak power to Average Power Ratio (PAPR) or Cubic Metric (CM) properties when the UE transmits uplink signals using the MIMO scheme, the UE uses a precoding scheme based on a precoding matrix established in a manner that one layer is transmitted to each antenna in specific rank transmission.

Abstract: A method and a radio apparatus for signal transmission in a Wireless Local Area Network (WLAN) system are discussed. The method according to an embodiment includes generating first and second very high throughput (VHT) fields including first and second control information, respectively; and transmitting a physical layer protocol data unit (PPDU) including the first and second VHT fields to at least one target station. The first VHT field includes an indicator indicating whether the PPDU is to be transmitted by using a single-user multiple input multiple output (SU-MIMO) scheme or a multi-user multiple input multiple output (MU-MIMO) scheme.

Abstract: A method is provided for transmitting a data frame by a station in a wireless local area network. The station obtains a transmission opportunity (TXOP) for a bandwidth, the TXOP indicating an interval of time during which the station has a right to initiate frame exchange sequences onto wireless medium. The station sets a transmit bandwidth parameter of a non-initial physical layer protocol data unit (PPDU) of a plurality of PPDUs to be transmitted during the TXOP based on a transmit bandwidth parameter of a preceding PPDU of the plurality of PPDUs. The transmit bandwidth parameter of the non-initial PPDU is set to be same or narrower than the transmit bandwidth parameter of the preceding PPDU. A bandwidth indicated by the transmit bandwidth parameter of the non-initial PPDU or the preceding PPDU includes at least one of 20 MHz, 40 MHz and 80 MHz. The station transmits the non-initial PPDU during the TXOP.