Abstract: Provided are a method of performing contention based channel access by classifying a contention period into a beamformable contention period in which a beamforming is allowed and a non-beamformable contention period in which the beamforming is interrupted so as to resolve an issue regarding channel access occurring due to an introduction of a directional antenna for handling a path loss in a wideband wireless communication system according to an embodiment of the present invention, and a method for maximizing a spatial reuse gain by managing, for each direction, information about a transmission time of a message received from a dispersion device.

Abstract: A method of allocating time for a communication device includes receiving a request for allocation of a second time period related to a second communication link, after allocating a first time period related to a first communication link, and reserving the portion of the second period overlapping the first period, wherein the first link is generated between first and second communication devices, and the second link is generated between third and fourth communication devices. A further aspect of the method includes identifying the first period reserved in advance, and receiving the request for allocating the second period, and allocating the second period to spatially overlap the first time period. A further aspect of the method includes identifying an existing reservation for the first period of the first link, receiving a new reservation for the second period, and allocating the second period to spatially overlap the first period.

Abstract: Disclosed is a method for adjusting a transmission time point of at least one second terminal in a wireless network by a first terminal. In the method for adjusting a transmission time point of a terminal, a transmission time point of the second terminal is set, a first frame including information regarding the transmission time point is transmitted to the second terminal, a first response frame transmitted according to the transmission time point from the second terminal is received, and the transmission time point is adjusted according to an arrival time of the first response frame.

Abstract: A preamble generation method of a station includes: generating a base sequence for channel estimation; generating an antenna channel estimation sequence for at least one or more antennas of the station; generating a preamble by allocating at least one or more modified sequences to frequency domains for at least one or time periods. The modified sequences are generated by using the base sequence, the antenna channel estimation sequence, and a control sequence for estimating at least one or more channels.

Abstract: A scheduling method of giving a chance for transmission to a plurality of terminals in the same time period, and a device therefor are provided. The scheduling method includes: transmitting first scheduling information to terminals in a network, the first scheduling information defining transmitting/receiving terminals and a transmission time period; receiving channel measurement information including inter-terminal interference information from the terminals in the network; and generating second scheduling information defining transmission time periods and a plurality of transmitting/receiving terminals that do not interfere with each other by using the channel measurement information.

Abstract: The present invention relates to communication using multiple antennas, and more particularly, to an apparatus and method for adaptively adjusting, based on a channel environment, an interval and direction of multiple antennas each of a transmitter and a receiver. A communication method according to the present invention may include verifying information about a channel state based on a pilot signal transmitted for each antenna of a transmitter, adjusting intervals among antennas of a receiver based on the information about a channel state, calculating transmission capacity values according to the adjusted intervals among antennas, and setting an antenna to an antenna interval corresponding to a transmission capacity having a highest value among the transmission capacity values calculated.

Abstract: A source station for synchronization of transmission and reception of data in a cooperative communication system includes a first receiver to receive, from a destination station, a first request frame including information regarding a first point in time when a first response frame is to be transmitted; a first transmitter to transmit the first response frame to the destination station, at the first point in time; a second transmitter to transmit, to a relay station, a second request frame including information regarding a second point in time when a second response frame is to be transmitted; a second receiver to receive the second response frame transmitted by the relay station at the second point in time; and a time estimator to estimate a first propagation delay time between the source station and the relay station, based on a time in which the second response frame is received.

Abstract: A communication method of a coordinator in a wireless networks system that uses a reservation-based media access control (MAC). The communication method includes receiving, from a source device, a frame that requests a reservation resource for a relay device, to enable a frame that the source device transmits to a destination device to be relayed via the relay device, and allocating the reservation resource for the relay device, in response to the request.

Abstract: A method for simultaneously transmitting packets to one or more users in a wireless communication system includes: generating the packets which include length information and are to be transmitted to the one or more users; and simultaneously transmitting the generated packets to the one or more users. The length information includes information representing a unit of the length information and information representing lengths of the packets according to the unit.

Abstract: A method of operating a network coordinator for a spatial reuse scheme includes receiving a reservation request for a time period for a data communication of a target transmitter/receiver pair that uses a directional antenna, searching for a time period reserved in advance for another transmitter/receiver pair, from a Channel Time Allocation Period (CTAP) that is a contention-free access period for the data communication, and reserving a time period for the target transmitter/receiver pair in the CTAP, so that the time period reserved for the target transmitter/receiver pair overlaps the time period reserved in advance for the other transmitter/receiver pair.

Abstract: A wireless transmitter which performs reconfiguration for high mobility and high throughput includes: an operation mode decision unit configured to decide an operation mode depending on mobility, a required data rate, and wireless link performance; a clock generation unit configured to generate a plurality of clock signals; a selection unit configured to select necessary clock signals among the plurality of clock signals generated by the clock generation unit according to the operation mode decided by the operation mode decision unit; and at least one or more digital modulation units configured to modulate transmitted data by adjusting a signal bandwidth of a frequency domain and a transmission time of a time domain using the clock signals selected by the selection unit.

Abstract: Provided is a method and apparatus for setting up a channel for communication between distributed devices in a wireless communication system. A method of selecting a communication channel in a communication device of a wireless communication system may include requesting scanning of channels between the communication device and a discovery device, receiving a channel scanning response message including a Distributed Reservation Protocol (DRP) Availability Information Element (IE) assigned for each scanned channel, and selecting a channel based on the DRP Availability IE.

Abstract: Provided is a communication method of a coordinator in a wireless networks system that uses a reservation-based media access control (MAC). The communication method includes receiving, from a source device, a frame that requests a reservation resource for a relay device, to enable a frame that the source device transmits to a destination device to be relayed via the relay device, and allocating the reservation resource for the relay device, in response to the request.

Abstract: A method for simultaneously transmitting packets to one or more users in a wireless communication system includes: generating the packets which include length information and are to be transmitted to the one or more users; and simultaneously transmitting the generated packets to the one or more users. The length information includes information representing a unit of the length information and information representing lengths of the packets according to the unit.

Abstract: Provided are machine type communication (MTC) gateway user equipment (MGUE) and an MTC data relay method of the same. The MGUE includes a first radio matching unit configured to process a signal having a first frequency band characteristic and provide radio access matching with a base station, a second radio matching unit configured to process a signal having a second frequency band characteristic and provide radio access matching with at least one MTC device, a radio access switching processor configured to convert data respectively output by the first radio matching unit and the second radio matching unit and provide the converted data, and a controller configured to find an identifier of at least one MTC device related to MTC control information received from the first radio matching unit and control the second radio matching unit to transmit the MTC control information to the MTC device.

Abstract: A method for generating a data frame in a wireless communication system includes generating a plurality of first headers having information about the number of segments of a payload, generating a plurality of second headers having information about a transmission mode and a length of predetermined segments among segments of the payload, generating a third header having a transmission mode and a length of remaining segments of the payload; generating a fourth header having supplementary information of the payload and error information of the supplementary information and the first to third headers or error information of the supplementary information and the third header; and generating a data frame with the first to fourth headers sequentially allocated.

Abstract: Provided are a pilot transmitting apparatus and method capable of selectively using an OFDMA scheme and an SC-FDMA scheme. The pilot transmitting apparatus includes a pilot inserter for inserting a pilot signal in a modulated symbol and inserting a cyclic prefix code for the inserted pilot signal, an FFT processor for receiving symbols with a pilot inserted thereto from the pilot inserter and performing an FFT process on the received symbols, an IFFT processor for receiving the transformed data from the FFT processor and performing an IFFT process on the transformed data, a mapping processor for mapping the output of the FFT processor to input positions of the IFFT processor to load the frequency domain transformed data on predetermined sub-carriers, and a cyclic prefix inserter for inserting a cyclic prefix code for the output of the IFFT processor.

Abstract: Provided is an apparatus for allocating a sequence to a synchronization channel for a node identification (ID), the apparatus including: a base node sequence generator to generate a base sequence that is a sequence for a node ID of a base node; a relay node sequence generator to generate a relay sequence that is a sequence for a node ID of a relay node by transforming the base sequence; a baseband signal generator to generate a baseband signal by mapping the base sequence or the relay sequence to a frequency domain and a time domain; and a transmitter to transmit the baseband signal.

Abstract: Disclosed is a radio-frequency front-end apparatus that can be used in wireless communication systems performing transmission/reception by using a single antenna. The radio-frequency transceiving front-end apparatus using passive elements in a wireless communication system includes: a transmitting unit's hybrid coupler configured to divide and output a transmission signal into two outputs having a phase difference of 90°; a first circulator configured to receive a first output of the hybrid coupler through a first terminal thereof and output the received first output through a second terminal thereof; a second circulator configured to receive a second output of the hybrid coupler through a first terminal thereof and output the received second output through a second terminal thereof; and an output unit's hybrid coupler configured to receive transmission signals from the second terminal of the first circulator and the second terminal of the second circulator, and combine and output the received signals.

Abstract: A source station for synchronization of transmission and reception of data in a cooperative communication system includes a first receiver to receive, from a destination station, a first request frame including information regarding a first point in time when a first response frame is to be transmitted; a first transmitter to transmit the first response frame to the destination station, at the first point in time; a second transmitter to transmit, to a relay station, a second request frame including information regarding a second point in time when a second response frame is to be transmitted; a second receiver to receive the second response frame transmitted by the relay station at the second point in time; and a time estimator to estimate a first propagation delay time between the source station and the relay station, based on a time in which the second response frame is received.