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 is a cell search method for supporting discontinuous transmission and reception of small cell base stations. A cell search method performed by a base station, in an environment that a plurality of small cell base stations perform discontinuous transmission and reception, may comprise transmitting information about small cell base stations whose current transmission and reception mode is in active state; receiving, from a terminal, measurement results on the small cell base stations included in the information about small cell base stations; estimating small cell base stations located around the terminal based on the measurement results; and transmitting, to the estimated small cell to stations, an instruction to change their transmission and reception modes. Therefore, power consumption of the small cell base stations may be reduced with maintaining terminal performances for searching small cells.

Abstract: A cell search method is disclosed. In an environment that a plurality of small cells are located around a macro cell, a macro base station may allocate a terminal-specific signal distinguishing a terminal from other terminal to the terminal which establishes a connection with the macro base station, and share information of the terminal-specific signal with a plurality of small cell base stations. When a cell search is triggered, the terminal may transmit the allocated terminal-specific signal, and the plurality of small cell base stations perform measurements on the received terminal-specific signal and then report the measured results to the macro base station. The macro base station may configure a candidate set of small cells for the terminal based on the measurement results reported from the plurality of small cell base stations, and transmit the candidate set to the terminal.

Abstract: Provided are a method and system for handing over a mobile terminal between a macro base station and a vehicular base station to secure a communication service of a movable mobile terminal in a wireless communication system supporting a vehicular base station such as a vehicular relay station. The mobile terminal may be handed over by selecting a network or a vehicular base station suitable to a mobility and type of communication.

Abstract: Provided is an access point grouping method to be performed in a high speed mobile environment and a communication system using the access point grouping method. A system capacity may be improved by grouping users having different movement speeds with respect to various channel environments classified based on existence of an LOS channel, and by performing beamforming. Channel information with respect to a user moving at a high speed may not be required, and thus overhead may be reduced.

Abstract: An operation method of a radio communication station is provided. The operation method of a radio communication station, the operation method including: transmitting a basic pilot signal to at least one terminal located in a coverage of a preoccupied system; and transmitting a cognitive radio (CR) pilot signal.

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 method of a serving micro base station is provided. The method includes a handover of a vehicular mobile terminal based on uplink broadcast information including a unique access code allocated to the vehicular mobile terminal within a multi-cell group. The multi-cell group includes a macro base station and a plurality of micro base stations within a cell coverage of the macro base station. The handover is performed based on a determined preparation level of the handover that is based on the uplink broadcast information.

Abstract: Provided is a communication method of a base station and a target terminal. Resources used for a channel feedback may be reduced by determining a wireless resource based on information about a channel and information about a mobility of the target terminal in each of at least one route, and by feeding back channel state information.

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: 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 method and apparatus for improving a mobile problem caused by a narrow handover region in a boundary region between virtual cells constructed by a plurality of small base stations are provided. A plurality of Virtual Cells (VCs) include a plurality of Distributed Base Stations (DBSs) whose VCs cooperatively communicate with each other. An Intermediate Distributed Base Station (I-DBS) is located in a region where adjacent at least two VCs among the plurality of VCs are superimposed, and belongs to a different VC according to a time division scheme.

Abstract: A technology that can adaptively control an access mode according to a shared band or an unlicensed band used by an adjacent communication system. An access mode controlling apparatus includes a band recognition unit to recognize a usage rate of an unlicensed band or a shared band that is used by an adjacent communication system of a target communication system; a mode determination unit to determine, as an access mode, any one of a contention access mode and a contention-free access mode, based on the usage rate of the unlicensed band or the shared band; and an information transmitter to transmit mode information associated with the determined access mode to member nodes or a base station of the target communication system.

Abstract: Communication methods of a macro base station which collects position information about a mobile micro base station and that is served by the macro base station, predicts a channel between the macro base station and the micro base station, and performs a handover between the macro base station and the micro base station based on a state of the predicted channel is provided.

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: Provided is a communication method of a vehicular access point, a vehicular user equipment, and a macro base station for a user present in a vehicle capable of effectively forming an operational relationship between the vehicular access point and the macro base station using a plurality of operational modes. The plurality of operational modes may be differentiated based on an operation of the vehicular access point and the macro base station, and are capable of transitioning the vehicular access point from an active state to an idle state by a triggering with respect to the vehicular access point.

Abstract: A communication method of a macro base station including reporting information about a broadcast channel section in order to identify a femtocell in a macrocell of the macro base station set in a downlink broadcast channel of the macrocell, is provided. The macro base station receives position information of a mobile terminal and a request for information about neighboring femto base stations from the mobile terminal, when the mobile terminal identifies an accessible femto base station among the at least one femto base station in the broadcast channel section. The macro base station generates a list of the neighboring femto base stations of the mobile terminal and information about the neighboring femto base stations based on the position information of the mobile terminal, and transmits the list of the neighboring femto base stations and the information about the neighboring femto base stations to the mobile terminal.

Abstract: Communication methods of a macro base station which collects position information about a mobile micro base station and that is served by the macro base station, predicts a channel between the macro base station and the micro base station, and performs a handover between the macro base station and the micro base station based on a state of the predicted channel is provided.

Abstract: An apparatus and a method for configuring and managing/controlling a cluster, which is a set of Base Stations (BSs) for transmitting signals cooperatively, are provided. The method includes broadcasting cluster set information indicating information about a plurality of clusters including a serving BS to a User Equipment (UE), receiving a report of information about Received Signal Strength Indicators (RSSIs) of control signals transmitted from BSs included in the plurality of clusters from the UE, and assigning any one of the plurality of clusters to a cluster for servicing the UE based on the information about the RSSIs of the control signals.

Abstract: A mobile station which connects to a base station having a plurality of relays belonging thereto is provided. The mobile station includes a receiving unit which receives a first preamble signal from a first relay and receives a second preamble signal from a second relay, the first relay belonging to a first cluster including an N1 number of relays and the second relay belonging to a second cluster including an N2 number of relays, a control unit which selects the first cluster as an access cluster to connect to the base station, based on the first preamble signal and the second preamble signal, and a transmission unit which transmits an access request message to the first relay, wherein the access request message is transmitted to the base station via the first relay.