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 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 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: 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 method of setting a packet transmission path in a wireless communication network and a network apparatus using the same are provided. A method of setting a packet transmission path includes setting N?1 routing regions including at least one node between a source node and a destination node based on a predetermined N number of hops, N denoting an integer greater than or equal to two, and determining a node in each of the routing regions as a relay node based on a channel gain.

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: 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 are examples of methods of a vehicular moving relay in a communication system including the vehicular moving relay, a moving terminal, and a macro base station. Also provided is an example of a terminal. The vehicular moving relay may repeatedly transmit data to a vehicular moving terminal without requesting a handover from a macro base station to the vehicular moving relay, using a unique code that is allocated to the vehicular moving terminal from the macro base station.

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 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 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.

Abstract: A cognitive radio communication device and method are provided. The cognitive radio communication device includes a reception unit to receive reference signals from a first communication device, a frequency division unit to divide operating frequency bands of the first communication device into a plurality of sub frequency bands, a first sensing unit to sense each of the plurality of sub frequency bands using the reference signals to estimate whether the first communication device uses each of the plurality of sub frequency bands, and to determine an unused frequency band group including at least one sub frequency band not used by the first communication device based on the estimated result, and a transmission unit to transmit data to a second communication device using the sub frequency band included in the unused frequency band group.

Abstract: An apparatus and a method of performing radio communication are provided. The radio communication apparatus may determine a channel capacity of a radio channel based on a sensing duration to sense the radio channel and a false alarm probability, determine a sensing duration value and a false alarm probability value that maximize the channel capacity, and sense the radio channel based on the determined sensing duration value and the false alarm probability value.

Abstract: A pilot signal power control apparatus to determine a power level of a pilot signal of a primary network to indicate an availability of a wireless resource of thereof to a secondary user of a secondary network according to a cognitive radio technology, the pilot signal power control apparatus and an operation method thereof, the pilot signal power control apparatus including: a prediction unit to predict a noise increase and/or a sensing probability, the noise increase occurring in a primary user of the primary network due to a channel estimation error, and the sensing probability being a probability that a secondary user senses the pilot signal of; a channel capacity calculation unit to calculate a channel capacity of the primary user based on the predicted noise increase and/or sensing probability; and a power level determination unit to determine the power level of the pilot signal using the calculated channel capacity.

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: A method and apparatus for controlling transmission power in a wireless network area is provided. A target base station may control transmission power in cooperation with a neighboring base station and, thus, a satisfaction with a Quality of Service (QoS) of target terminals may be improved. Additionally, the target base station may determine whether to control the transmission power in cooperation with the neighboring base station, based on a possible improvement in satisfaction with the QoS of the target terminals.

Abstract: A communication method of a macro base station including reporting information about a broadcast channel section in order to identify a femtocell in 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 in the broadcast channel section. The macro base station generates a list of the neighboring femto base stations and information about the neighboring femto base stations based on the position information of the mobile terminal, and transmits the list 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: 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: 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.