Abstract: Provided are a method of transmitting a dedicated reference signal (DRS), a method of receiving a DRS, and a feedback method of a terminal. The method of transmitting a DRS includes determining a DRS transmitting resource for at least one terminal which is a target of transmission, and transmitting the DRS using the determined transmission resource and notifying the terminal of information about layer used by the terminal. The method of receiving a DRS includes determining a DRS receiving resource, receiving information about layer used by a terminal from a serving cell base station, and receiving the DRS for the terminal using the determined reception resource and the information about layer. Accordingly, a terminal can find the position and sequence of its DRS. In particular, in the case of multi-user multiple input multiple output (MU-MIMO) or joint scheduling, it is possible to prevent or remove signal interference using the DRS of another terminal.

Abstract: The present invention relates to an adaptive transmitting device using limited feedback information in a mobile communication system, and a method thereof. According to an exemplary embodiment of the present invention, when the base station transmits a pilot signal to the terminal, the terminal generates channel information by using the pilot signal, generates additional channel information from the channel information, and transmits the channel information and the additional channel information to the base station. The base station determines band allocation, power allocation, and modulation methods for each use by using received feedback information, and transmits modulated traffic data to the terminal according to the determined methods.

Abstract: A semiconductor device includes a channel region extending in a vertical direction perpendicular to a substrate and having a nitrogen concentration distribution, a plurality of gate electrodes arranged on a side wall of the channel region and separated from each other in a vertical direction, and a gate dielectric layer disposed between the channel region and the gate electrodes. The nitrogen concentration distribution has a first concentration near an interface between the channel region and the gate dielectric layer.

Abstract: Disclosed is a method for controlling uplink transmit power in a mobile communication system. A mobile communication includes a first base station and a second base station which are located in two mutually adjacent cells, respectively, at least one base station of the first and second base stations which generate a subframe offset of transmit power (SOTP), and transmits a subframe offset of transmit power generated by at least one base station of the first and second base stations to at least one terminal which belongs to a corresponding cell. Accordingly, it is possible to reduce signaling times for transmit power control, and to accurately control transmit power.

Abstract: A method of managing a terminal and controlling an interference in a small base station is provided. The small base station, including: an access preamble control unit to assign a unique preamble for each terminal registered in the small base station; a transmitting/receiving unit to receive a random access request message from each of the terminals through the unique preamble, to transmit a reply message to each of the terminals, and to receive information about each of the terminals and a Radio Resource Control (RRC) connection request Message from each of the terminals in response to the reply message; and a terminal verification unit to verify whether each of the terminals is a registered terminal using the information about each of the terminals.

Abstract: A three-dimensional (3D) semiconductor memory device includes an electrode separation pattern, a stack structure, a data storage layer, and a channel structure. The electrode separation pattern is disposed on a substrate. A stack structure is disposed on a sidewall of the electrode separation pattern. The stack structure includes a corrugated sidewall opposite to the sidewall of the electrode separation pattern. The sidewall of the electrode separation pattern is vertical to the substrate. A data storage layer is disposed on the corrugated sidewall. A channel structure is disposed on the charge storage layer.

Abstract: Cell and terminal discovery methods are disclosed. A discovery method performed in a terminal may include transmitting a trigger signal; receiving a discovery signal from at least one cell which receives the trigger signal; measuring the discovery signal; and reporting a measurement result of the discovery signal to a serving cell. Therefore, cell and terminal discoveries may be performed efficiently in cellular mobile communication systems.

Abstract: The present invention relates to a multi-input and multi-output communication method in a large-scale antenna system. An MIMO transmission method according to the present invention includes: obtaining statistical channel information on at least one terminal, dividing terminals into a plurality of classes and a plurality of groups based on the statistical channel information, wherein the groups depend on the classes; determining a group beam-forming matrix for each of the divided groups; performing a group beamforming transmission by group based on the group beam-forming matrix to obtain instantaneous channel information; and scheduling terminals based on the instantaneous channel information. Thus, it is possible to decrease the complexity in a scheduling and precoding calculation without an increase in the amount of wireless resources that are required for providing feedback for a reference signal and channel status information.

Abstract: Provided are an uplink transmission method and downlink transmission method in a mobile communication network including a relay. In the uplink and downlink transmission methods, frame structures and transmission timings of a backhaul downlink and a backhaul uplink are determined in consideration of at least one of a time for the relay to switch between transmission and reception and a signal transmission time. Accordingly, in a wireless communication system including a relay, it is possible to effectively perform data transmission and reception between the relay and a base station.

Abstract: Disclosed are a coordinator based device-to-device communication method and an apparatus for the same. The communication method may comprise transmitting a synchronization signal and system information to a plurality of terminals; configuring wireless links with the plurality of terminals based on a random access procedure; receiving a scheduling message for a D2D communication from a first terminal among the plurality of terminals; allocating, to the first terminal, a transmission resource to be used for the first terminal to transmit data based on the scheduling request message; and allocating, to a second terminal performing the D2D communication with the first terminal among the plurality of terminals, a reception resource to be used for the second terminal to receive the data transmitted from the first terminal.

Abstract: Disclosed are methods and apparatuses for public safety communication. A method comprises transmitting a groupcast setup request message to a base station; receiving an uplink grant message including information on groupcast resources in response to the groupcast setup request message from the base station; and transmitting data to be transmitted to receiving terminals belonging to a group to which the transmitting terminal belongs to the base station through the groupcast resources. Therefore, public safety communication can be efficiently performed in a wireless communication system.

Abstract: The MAC frame in a wireless communication system includes a terminal ID allocated to each of multiple terminals. At least one connection ID is allocated to each terminal having the terminal ID, and sub-carrier allocation information is allocated to each connection having the connection ID. The sub-carrier allocation information includes a sub-carrier allocation status for each sub-carrier, and the number of allocated information bits for each sub-carrier. The sub-carrier allocation status and the number of allocated information bits for each sub-carrier can be allocated, by sub-carriers, to the sub-carrier allocation information using a same number of bits; or the information on the sub-carrier allocation status is first allocated to the sub-carrier allocation information and the number of allocated information bits for each sub-carrier is allocated.

Abstract: Disclosed is a communication method using a large-scale antenna in a multi-cell environment. The method comprises classifying a plurality of terminals in a cell of the base station into a least one cell center group and at least one cell edge group according to their positions; transmitting downlink pilot signals to each group; receiving a first Precoding Matrix Indicator (PMI) for the cell and a second PMI for interference signal from a cell adjacent to the cell from each terminal belonging to the at least one cell edge group; and generating information on interferences between multi-cells based on the first PMI and the second PMI. Therefore, information exchange for interference control between base stations can be minimized.

Abstract: Disclosed is a method for network synchronization acquisition in a wireless network. A synchronized node transmits a first synchronization reference signal, a second synchronization reference signal, and a beacon according to a predetermined period. A non-synchronized node receives the first synchronization reference signal, the second synchronization signal, and the beacon from at least one transmitting node. Then, the non-synchronized node acquires network synchronization temporarily based on the first synchronization reference signal, decodes the beacon, and checks whether at least one transmitting node exists or not. Then, the non-synchronized node requests a network synchronization forwarding service or a time adjustment, and acquires synchronization based on the provided network synchronization forwarding service.

Abstract: A communication system which transmits data using a relay is disclosed. The communication system efficiently divides and allocates wireless resources allocated to a data transmission system to reception and transmission links between a base station and a relay, reception and transmission links between the base station and a terminal, and reception and transmission links between the relay and the terminal.

Abstract: A semiconductor device includes a channel region extending in a vertical direction perpendicular to a substrate and having a nitrogen concentration distribution, a plurality of gate electrodes arranged on a side wall of the channel region and separated from each other in a vertical direction, and a gate dielectric layer disposed between the channel region and the gate electrodes. The nitrogen concentration distribution has a first concentration near an interface between the channel region and the gate dielectric layer.

Abstract: Provided is a data transmission apparatus to transmit a reference orthogonal frequency division multiplexing (OFDM) symbol generated by frequency division multiplexing a reference symbol and a data symbol, and a data reception apparatus to estimate a channel using the reference OFDM symbol. Since the reference symbol and the data symbol are frequency division multiplexed, a Peak to Average Power Ratio (PAPR) may not increase greatly, and the transmission apparatus may transmit the reference OFDM symbol to the data reception apparatus more frequently. Accordingly, the data reception apparatus may estimate a channel accurately.

Abstract: Disclosed is a method for configuring dual connectivity. A method for configuring dual connectivity, performed in a base station, may comprise receiving measurement information about a neighbor cell of the terminal from the terminal; obtaining information for configuring dual connectivity from the terminal or the base station; determining whether to configure dual connectivity based on the measurement information and the information for configuring dual connectivity; and when the dual connectivity is to be configured, transmitting a message instructing to configure the dual connectivity to the terminal.

Abstract: According to example embodiments of inventive concepts, a method of fabricating a semiconductor device includes: forming a preliminary stack structure, the preliminary stack structure defining a through hole; forming a protection layer and a dielectric layer in the through hole; forming a channel pattern, a gapfill pattern, and a contact pattern in the through hole; forming an offset oxide on the preliminary stack structure; measuring thickness data of the offset oxide; and scanning the offset oxide using a reactive gas cluster ion beam. The scanning the offset oxide includes setting a scan speed based on the measured thickness data of the offset oxide, and forming a gas cluster.

Abstract: A three-dimensional (3D) semiconductor memory device includes an electrode separation pattern, a stack structure, a data storage layer, and a channel structure. The electrode separation pattern is disposed on a substrate. A stack structure is disposed on a sidewall of the electrode separation pattern. The stack structure includes a corrugated sidewall opposite to the sidewall of the electrode separation pattern. The sidewall of the electrode separation pattern is vertical to the substrate. A data storage layer is disposed on the corrugated sidewall. A channel structure is disposed on the charge storage layer.