Abstract: A data transmission system that determines data transmission power using a virtual cell is provided. A base station may receive transmission data from a plurality of cooperative base stations positioned around the base station, and model terminals receiving an interference signal from the base station and the plurality of cooperative base stations into a virtual cell. The base station may calculate the influence of the interference signal transmitted to the terminal, using the virtual cell, and determine a transmission power for a plurality of frequency bands based on the interference signal.

Abstract: A method of determining an optimal transmission mode and a data frame structure for determining an optimal transmission mode in a data transmission system using a relay, are provided. Any one of a base station, a relay, and a mobile station determines an optimal transmission mode from among a plurality of transmission modes, and the base station transmits the determined optimal transmission mode by enabling the determined optimal transmission mode to be included in the system information duration of the data frame, so that the overall relay system can transmit data according to the optimal transmission mode.

Abstract: Provided is an apparatus and method for transmitting/receiving signals in a communication system. A base station allocates a quasi-dedicated control channel (QDCCH) to a first mobile station (MS), and allocates the QDCCH allocated to the first MS, to a second MS for a preset time. An MS receives a QDCCH allocated from the base station. If there is data to transmit to the base station, the MS determines whether the QDCCH is allocated to another MS different from the MS. If it is determined that the QDCCH is allocated to the MS itself, the MS transmits the data to the base station over the QDCCH.

Abstract: Provided is a data transmission system that may determine a multiple input multiple output dynamic spectrum management (MIMO-DSM) operation mode of a base station based on information associated with a data transmission route and a computational capability of each base station. A terminal may generate feedback information based on a cooperation level between base stations and may transmit the generated feedback information to a serving base station. The serving base station may select terminals that may receive data from among a plurality of terminals through a MIMO-DSM algorithm and a user scheduling based on the feedback information.

Abstract: A terminal apparatus for forwarding/sharing a data service is provided. The terminal apparatus for forwarding/sharing the data service includes a service receiver to receive the data service from a service provision apparatus; a connector to perform a connection with a corresponding terminal; and a service forwarding unit to forward the data service to the corresponding terminal via the connection with the corresponding terminal.

Abstract: A common operating set including a plurality of cells may be set, and common radio resources may be allocated to enable the plurality of cells to perform a multi-cell common operation. Unique uplink radio resources may be allocated to each of terminals in the common operating set within the common radio resources, and each of the terminals may transmit corresponding uplink feedback information to a plurality of base stations based on corresponding unique uplink radio resources. Accordingly, each of the base stations may recognize information associated with a wireless environment between each of terminals and a corresponding base station.

Abstract: Provided is a method, and an apparatus and communication system to perform the method, of detecting a victim terminal and performing an interference coordination in a multi-cell environment. The multi-cell environment may include a heterogeneous cell environment including a small cell and a macro cell. The method includes determining whether a macro terminal is located within a cell coverage of a small base station, and adjusting the cell coverage according to the determination.

Abstract: System and methods for intercell coordination are provided. The system includes a macro terminal and a macro base station that allocate a radio resource for a sounding signal and determine a pattern of a sounding signal, in advance. The macro base station provides a femto base station included in the system with information about the pattern of the sounding signal, and the information about the radio resource of the sounding signal. The femto base station may receive the sounding signal from the macro terminal based on the information, and thus, the femto base station may determine whether the macro terminal exists and may determine a channel between the macro terminal and the femto base station.

Abstract: A communication system with an improved network access structure for inter-cell cooperation is provided. The communication system includes a central unit and at least one radio access unit. The at least one radio access unit may form at least one virtual cell by merging or separating cells of radio access units according to a distribution of terminals, statuses of channels, an amount of traffic, and the like.

Abstract: A user scheduling and transmission power controlling method in a hierarchical-cell communication system or a multi-cell communication system, and a device to perform the methods, are provided. Interference may occur between various cells in the hierarchical-cell communication system or the multi-cell communication system, and the interference may be controlled by adjusting transmission power of various cells. The various cells may determine an optimal transmission power based on a cost of a corresponding transmission power. Also, the various cells may serve various users and may propose an optimal user scheduling method.

Abstract: A system and method for distributed control of spectrum power in a multi-cell communication system are provided. A plurality of cells included in a multi-cell communication system may be grouped into a plurality of groups. Cells included in a first group may iteratively calculate spectrum powers to perform dynamic spectrum management (DSM) scheme in calculation sub-frames. The cells included in the first group may also perform a user scheduling. Spectrum powers determined by cells included in a second group and user scheduling results of the cells in the second group may be held static.

Abstract: A wireless data transmission method and apparatus are provided for compensating a distortion due to a clipped amplitude when an amplitude of a signal is clipped to reduce a peak to average power ratio (PAPR) in a wireless communication system using an orthogonal frequency division multiplexing (OFDM) scheme and a transmit diversity method using an orthogonal coding. The wireless data transmission apparatus includes a coding unit which Space-Time block codes a first data stream into a plurality of second data streams, the plurality of second data streams being orthogonal to each other; an inverse Fourier transform unit which performs an inverse Fourier transform of each of the Space-Time block coded second data stream and generates a plurality of time domain signals; and a plurality of amplitude clipping units which clips an amplitude of each of the plurality of generated time domain signals.

Abstract: A system and method for transmitting resource allocation information in a wireless communication system is provided. A transmitter transmits resource allocation information mapped to a current time interval in a first region to a receiver, and transmits resource allocation information mapped to a next time interval in a second region. When receiving the resource allocation information of the second region, the receiver notifies the transmitter whether the resource allocation information has been received. The transmitter receives notification that the resource allocation information of the second region has been received and transmits resource allocation information mapped to a subsequent time interval in the second region.

Abstract: A method of reporting channel state information by a Mobile Station (MS) in a mobile communication system is disclosed. The method includes measuring a state of a downlink channel for the entire frequency band, determining a first Modulation and Coding Scheme (MCS) level corresponding to the measured channel state, and reporting the determined MCS level to a Base Station (BS).

Abstract: An apparatus and method for exchanging frequency bands used by a plurality of base stations are provided. A base station for exchanging frequency bands includes a receiving unit to receive first quiet time duration information of an adjacent base station, a frequency band measuring unit to determine first frequency band measuring information with respect to a first frequency band used by the adjacent base station based on the first quiet time duration information, a frequency band exchange-determining unit to determine whether to exchange frequency bands with each other based on the first frequency band measuring information, and a transmitting unit to transmit data to a terminal using the first frequency band according to the determined result.

Abstract: Provided are a signal transmission method and a network apparatus to control interference in a radio communication network. A terminal may transmit to the network apparatus, signal quality information associated with a radio channel formed between the terminal and a corresponding base station. The corresponding base station may output a signal received by the plurality of terminals, based on the signal quality information.

Abstract: Disclosed are an apparatus and method for loading small and medium caliber cartridges with pressable plastic bonded explosives (PBXs). A plurality of pellets are pre-formed to have a high density, and are loaded into a small and medium caliber cartridge one by one. Accordingly, a high and uniform density is obtained. And, when manufacturing small and medium caliber cartridges, the pressable PBXs are anticipated to be massively loaded into the small and medium caliber cartridges in the future.

Abstract: A femtocell base station apparatus may sense a wireless propagation environment around the femtocell base station apparatus to obtain wireless propagation environment information, transmit first control information including the wireless propagation environment information to at least one master base station adjacent to the femtocell base station apparatus, receive second control information from the at least one master base station, and control data communication performed between the femtocell base station apparatus and a mobile terminal based on the second control information.

Abstract: A method of compressing uplink control information in a wireless communication system where an MSS scans neighbor BSs upon request from a serving BS and transmits neighbor BS information to the serving BS. In the method, the serving BS broadcasts a neighbor advertisement message including the BS ID of at least one neighbor BS about which the serving BS wants to acquire information, and the BS ID of the at least one neighbor BS. The MSS then scans a channel from the at least one neighbor BS and transmits a scanning result along with a BS index of the at least one neighbor BS to the serving BS.

Abstract: A sliding-type apparatus for absorbing front shock energy is disclosed. The sliding-type apparatus of the present invention includes a driver panel (130), which is provided on the front surface of a driver's cab defined by a front part protective shell (110) of a railway vehicle so as to be movable backwards, and a bottom shock absorber (150), which is provided under the lower surface of the driver panel (130). The sliding-type apparatus further includes a front shock absorber (170), which is provided on the front surface of the driver panel (130), and a driver panel shock absorber (190), which is provided at a position towards which the driver panel is moved backwards. Thus, when a railway vehicle is involved in a collision, the several shock absorbers are consecutively collapsed to efficiently absorb shock energy. Furthermore, the driver panel is moved backwards without being deformed by the shock energy. Therefore, the safety of the driver is ensured.