Abstract:
The present invention relates to a method of performing channel sounding in a wireless LAN system. The method includes transmitting a Null Data Packet Announcement (NDPA) frame for providing notice of an NDP to be transmitted, and transmitting the NDP and receiving a feedback frame from a station (STA). The feedback frame includes channel state information created on the basis of the NDP. The NDP includes a signal field and at least one long training field (LTF) for a multiple input multiple output channel. The signal field includes a repetitive instruction subfield. The repetitive instruction subfield provides instruction on whether orthogonal frequency division multiplexing (OFDM) symbol repetition is applied to the at least one LTF.
Abstract:
Disclosed are a method and apparatus for transmitting a training field. The method for transmitting a training field in a wireless LAN system comprises the steps of: transmitting additional long training field (LTF) indication information; and transmitting a frame including the additional LTF and partitioned data fields. The additional LTF comprises a field for demodulating the partitioned data fields included in the frame, the additional LTF indication information includes information on the location of the additional LTF included in the frame, and the partitioned data field includes at least one sub-field. Accordingly, the present invention can enhance channel estimation performance.
Abstract:
Method and device for discovering a service are provided. A responding device receives a service request frame including a first service identifier indicating a service queried by the requesting device. The responding device transmits a service response frame to indicate that the queried service is currently not available and a service announce frame follows on. The responding device determines whether the queried service is accepted or not during a pre-defined time after transmitting the service response frame.
Abstract:
Disclosed are a method and an apparatus for indicating a frame type using a physical layer convergence protocol header. A method for determining a frame type using a PLCP header may comprise: a step of demodulating a frame type contained in an SIG of the PLCP header so as to acquire information indicating a physical service data unit (PSDU) of a frame; and a step of acquiring frame information required for demodulating the frame contained in the SIG dependently on the information indicating PSDU. Thus, unnecessary information may not be additionally demodulated to thereby improve demodulation efficiency and reduce unnecessary power consumption.
Abstract:
The present invention relates to a method for transmitting and receiving a frame performed by an AP in a wireless communication system. The method includes the steps of: transmitting a PST message providing instructions to transmit a frame to at least one STA; and receiving frames from a first STA and a second STA. The PST message includes first subband information indicating a first subband in which a first frame is transmitted from the first STA and second subband information indicating a second subband in which a second frame is transmitted from the second STA.
Abstract:
Provided is a method for transmitting a data unit in a wireless local area network system, according to one embodiment. The method comprises transmitting a signal field, transmitting a first data symbol for a first data field, and transmitting a second data symbol for a second data field. The signal field, the first data symbol, and the second data symbol are transmitted through a 1 MHz channel bandwidth having a band of 1 GHz or less. Two pilot tones are inserted to each of the first data symbol and the second data symbol.
Abstract:
Method and device for discovering a service are provided. A responding device receives a service request frame including a first service identifier indicating a service queried by the requesting device. The responding device transmits a service response frame to indicate that the queried service is currently not available and a service announce frame follows on. The responding device determines whether the queried service is accepted or not during a pre-defined time after transmitting the service response frame.
Abstract:
Disclosed are method and device for indicating a PLCP header transmission mode. A method for generating a physical layer convergence protocol (PLCP) of a data frame can comprise the following steps: demodulating PLCP header mode information based on a scrambling sequence of the received frame or information elements included in the received frame; and generating a data frame including the PLCP header generated based on the PCLP header mode information. The PLCP header mode information comprises at least one indication from a space time block coding mode indication, a guard interval mode indication, and a repetition mode indication. The invention is capable of improving data transmission efficiency by adaptively determining a transmission mode of a PCLP header to a channel situation.
Abstract:
In an aspect, a method of receiving a data unit, performed by an Access Point (AP), in a Wireless LAN (WLAN) system is provided. The method includes transmitting a signal protection frame, the signal protection frame comprising a group ID field indicating a Multiple Input Multiple Output (MIMO) transmission STA group including a first station (STA) and a second STA; and, a spatial stream field indicating a number of spatial streams allocated to each of member STAs included in the MIMO transmission STA group; receiving a first preamble for a first data unit from the first STA; receiving a second preamble for a second data unit from the second STA; and simultaneously receiving the first data unit from the first STA and the second data unit from the second STA.
Abstract:
Disclosed are a method and a device for transmitting a data block. The method involves generating and transmitting a physical layer protocol data unit (PPDU) that includes a short training field, a long training field and a signal field. The signal field includes a frame type field that has a length of one bit and indicates whether the PPDU includes a control medium access control (MAC) frame. The device is capable of performing the method.