Abstract: Disclosed herein are an apparatus and a method for receiving uplink data to determine whether to use a reception beam group in reception of the uplink data on the basis of a preamble for a random access or a CQI included in a feedback.

Abstract: Disclosed are a load modulation-based beamspace MIMO transmission method and apparatus. The beamspace MIMO transmission apparatus may include a plurality of impedance loading circuits each including a plurality of imaginary impedance devices, a beamspace MIMO control unit calculating loading values of the plurality of imaginary impedance devices, corresponding to a spatial multiplexing orthogonal frequency division multiplexing (OFDM) sample, and an RF chain unit generating a first signal having a predetermined carrier frequency.

Abstract: A method for cooperative beamforming communication, is described including negotiating, at a first access point, a cooperative transmit beamforming with a second access point having an overlapped basic service set (OBSS) area with the first access point, and transmitting, from the first access point, a clear-to-send (CTS) signal to the second access point. The method, upon detecting at the first access point a completion of transmission of the CTS signal, performs at the first access point the cooperative transmit beamforming with the second access point during a time duration of the cooperative transmit beamforming and after a predetermined time interval has elapsed.

Abstract: When a plurality of terminals share the same resources in a wireless communication system, and when control information such as acknowledgement/negative acknowledgement (ACK/NAK) information or scheduling information is transmitted, a method of efficiently performing code division multiplexing (CDM) is required to distinguish the plurality of terminals. In particular, it is necessary to develop a method by which a code sequence of CDM can be selected and used according to each cell condition. Provided is a method of forming a signal in a wireless communication system in which a plurality of terminals commonly share frequency and time resources. The method includes the operations of receiving condition information in a cell; selecting one of a plurality of time domain orthogonal sequences having different lengths, according to the condition information; and allocating the selected time domain orthogonal sequence to a control signal symbol block.

Abstract: There are provided an antenna apparatus and a method of handover using the antenna apparatus. The antenna apparatus may comprise a plurality of antenna elements forming a plurality of beams in a predetermined service area. The plurality of antenna elements are arranged in a plurality of rows, and a number of antenna elements included in an uppermost row of the plurality of rows is smaller than a number of antenna elements included in a downmost row of the plurality of rows, and differences between center angles of beams formed by the antenna elements included in the downmost row are larger than differences between center angles of beams formed by the antenna elements included in the uppermost row.

Abstract: A method of searching a cell in a mobile station of a communication system in which a plurality of cells are grouped into a plurality of cell groups, each cell group including at least two cells, includes: detecting a primary synchronization signal and a secondary synchronization signal from a received signal; and identifying a cell based on a combination of the primary synchronization signal and the secondary synchronization signal. The secondary synchronization signal is related to the cell group to which the mobile station belongs and the primary synchronization signal is related to the cell to which the mobile station belongs within the cell group.

Abstract: Disclosed are a frame transmission method and a communication device performing the same. The communication device may transmit a null data packet (NDP)-announcement (NDP-A) including information on a plurality of communication devices participating in interference alignment and transmit an NDP including a common signal field and a common training field commonly applied to the plurality of communication devices.

Abstract: A base station configures beam identifiers for a plurality of transmission beams. The base station configures virtual beam identifiers for the plurality of transmission beams based on the maximum number of transmission beams from the plurality of transmission beams that may spatially overlap one another, and the beam identifiers. The base station allocates resources using the virtual beam identifiers.

Abstract: A method of and an apparatus therefor searching a cell in a mobile station of a communication system in which a plurality of cells are grouped into a plurality of cell groups, and each cell group includes at least two cells. The method includes detecting a primary synchronization signal and a secondary synchronization signal from a received signal, and identifying a cell based on a combination of the primary synchronization signal and the secondary synchronization signal. The secondary synchronization signal is related to the cell group to which the mobile station belongs and the primary synchronization signal is related to the cell to which the mobile station belongs within the cell group.

Abstract: Disclosed is a random access method for a machine type communication (MTC) terminal. The random access method performed by a terminal includes performing a cell search, determining a radio environment based on time taken to perform the cell search, and performing different random access procedures depending on the determined radio environment. Accordingly, coverage of the MTC terminal that is in a poor radio environment may be enhanced, thereby performing normal communication with a base station.

Abstract: Methods for wireless communications based on relay and apparatuses for the same are disclosed. The method for a terminal to transmit signals comprises receiving scheduling information from a base station connected to the terminal; generating uplink data based on the scheduling information; performing punctuation on a data symbol positioned in a region through a downlink synchronization signal is transmitted in the generated uplink data; and transmitting the punctured uplink data. Therefore, the terminal may acquire synchronization signal easily, and perform neighbor cell search correctly based on the acquired synchronization signal.

Abstract: A base station in a mobile communication system determines the number of slots that are to be used to transmit a synchronization signal in a period of the synchronization signal depending on the number of neighbor cells, allocates a synchronization signal region in which the synchronization signal is to be transmitted to a first slot of the determined number of slots depending on a cell identifier of a serving cell, and allocates a reserved region in which no signal is transmitted to slots other than the first slot among the determined number of slots so as to correspond to a position of the synchronization signal region.

Abstract: A base station allocates a first frequency resource and a first time resource for first information that is included in a first physical channel and second information that is included in a second physical channel. The base station multi-transmits the first physical channel and the second physical channel through spatial multiplexing.

Abstract: A method and apparatus for scheduling a beam in a mobile communication system are provided. A terminal receives signals through a plurality of switching beam directions, and receives a plurality of beams that are transmitted while performing beam switching in a transmission time interval (TTI) unit by a base station. The terminal selects a signal having largest intensity among received signals, and transmits an uplink scheduling request signal in a beam direction corresponding to the selected signal.

Abstract: A transmitter generates a first precoding vector for a first virtual antenna port among a plurality of virtual antenna ports using a first sequence having a constant magnitude and a discrete Fourier transform (DFT) vector sequence in a time domain and a frequency domain. The transmitter generates a plurality of second precoding vectors for the remaining virtual antenna port, except for the first virtual antenna port of the plurality of virtual antenna ports by circular shifting the first precoding vector. The transmitter maps a plurality of first data streams for the plurality of virtual antenna ports to a plurality of physical antenna ports using the first precoding vector and the plurality of second precoding vectors.

Abstract: Provided is a wireless communication method performed at an access point to enhance the transmission efficiency in a wireless local area network (WLAN) system, the method including scheduling a transmission time of an enhanced traffic indicator map (TIM) frame based on a type of a station, and transmitting a second beacon including the enhanced TIM frame to the station at a point in time aside from a transmission point in time of a first beacon.

Abstract: Provided is a data communication method performed at a transmission node, the method including collecting a node list including nodes communicable with the transmission node, exchanging the node list with each of the communicable nodes, determining an allowance of a space recycling transmission to a reception node by determining that the transmission node is a corresponding node as an exposed node in response to an occurrence of a clear-to-send (CTS) timeout, and transmitting data to the reception node based on a result of determining the allowance of the space recycling transmission.

Abstract: Disclosed are a load modulation-based beamspace MIMO transmission method and apparatus. The beamspace MIMO transmission apparatus may include a plurality of impedance loading circuits each including a plurality of imaginary impedance devices, a beamspace MIMO control unit calculating loading values of the plurality of imaginary impedance devices, corresponding to a spatial multiplexing orthogonal frequency division multiplexing (OFDM) sample, and an RF chain unit generating a first signal having a predetermined carrier frequency.

Abstract: A method and apparatus for generating pilot signals in a mobile communication system and a method of estimating a frequency offset using the same are provided. In an environment in which a terminal moves at a high speed, pilot signals are disposed at a first interval in a first range of a transmission frame forming a single transmission unit. Furthermore, pilot signals are disposed at a second interval in a second range of the transmission frame. A frequency offset is estimated based on the pilot signals.

Abstract: Disclosed is a method and apparatus for communication in a millimeter band communication system. In a case in which a first terminal obtains a list including members of a cooperative group in which terminals receive a service with the same beam as a first terminal's beam, the first terminal informs a second terminal, corresponding to a member of the list, of communication link failure when the failure occurs, and requests a cooperative service. After that, the first terminal receives information on the service from a base station through the second terminal.