Abstract: A packet buffering apparatus and method in a multi-hop relay system supporting hop-by-hop retransmission are provided. In the buffering apparatus and method, a first buffer buffers a user packet until the user packet is successfully transmitted to a next node, and a second buffer buffers the user packet until the user packet is successfully transmitted to an MS, after the user packet is successfully transmitted to the next node. Accordingly, time delays and transmission costs are reduced.

Abstract: Disclosed is a system and method for transmitting/receiving a signal in a communication system. In the system and method, a base station transmits data to a first relay station, which is connected directly thereto from among relay stations belonging to a first relay station group, through a first frame interval, and transmits data to a second relay station, which is connected directly thereto from among relay stations belonging to a second relay station group, through a second frame interval subsequent to the first frame interval. In the first frame interval or the second frame interval where no data is received from the base station, each of the first and second relay stations transmits data to a next relay station connected directly thereto within the same relay station group, and communicates data with a mobile station in direct communication therewith.

Abstract: In the MS apparatus for performing scheduling, a reception module receives any number information through a specific downlink channel in a first time unit from each of neighbor BSs. A scheduling module determines, among the neighbor BSs, a BS which is to transmit and receive data using a downlink data transmission region and an uplink data reception region, respectively, in a second time unit according to a previously set rule based on the number information. A transmission module transmits a signal, indicating that data transmission and reception using the downlink transmission region and uplink data reception region, respectively, in the second time unit are not possible, to the other neighbor BSs excluding the determined BS among the neighbor BSs.

Abstract: Provided is a handover method of a wireless communication system using a hierarchical cellular scheme. In the method, signal quality of a serving node is measured, so that whether to start scanning for a handover is determined. When the scanning for the handover starts, signal qualities of a serving cell including the serving node and one or more neighbor cells are measured through a first preamble including a first identifier for distinguishing a cell. An intra-cell handover or an inter-cell handover is selected using the signal qualities of the serving cell and the neighbor cells. Therefore, a terminal can easily distinguish between the inter-cell handover and the intra-cell handover, and an overhead during a handover can be reduced because an intra-cell handover procedure is simplified.

Abstract: An apparatus and method for simultaneous transmission scheduling in a multi-hop cellular system are provided, in which a base station presets simultaneous transmission relay station set information and transmits the simultaneous transmission relay station set information to relay stations managed by the base station, and an relay station receives the simultaneous transmission relay station set information from the base station, determines, upon receipt of a data frame from the base station, a state of the relay station preset in relation to a receiving relay station for the data frame by comparing an ID of the receiving relay station included in the data frame with the simultaneous transmission relay station set information, and operates according to the preset state.

Abstract: An apparatus and method for receiving data in a communication system. A Mobile Station (MS) receives a Base Station (BS) signal and a Relay Station (RS) signal, measures strengths of the received BS signal and RS signal, determines whether the BS signal acts as interference to the RS signal depending on the measured strengths of the RS signal and the BS signal, and transmits the determination result to an RS in communication with the MS. The RS allocates resources using resource allocation information for the BS signal that acts as interference, and the MS receives data using the resource allocation scheme allocated from the RS.

Abstract: A method and apparatus for transmitting and receiving data in a Base Station (BS) of a communication system are provided. A controller determines a location of a Mobile Station (MS), and determines a transmission/reception scheme for data transmission and reception to/from the MS according to the location of the MS. A transceiver transmits and receives data to/from the MS using the determined transmission/reception scheme. Preferably, the MS is located in any one of a cell's inner region and a cell's outer region, the cell's inner region has a radius which varies according to interference between adjacent cells, and the cell's outer region is a region defined by excepting the cell's inner region from the entire cell region.

Abstract: An apparatus and method for avoiding interference between a base station and a relay station when using full duplex relay in a multi-hop relay wireless communication system are provided. An operation of a mobile station includes measuring an strength of a receive signal from a base station and an strength of a receive signal from an relay station, calculating a receive signal strength ratio of base station to relay station by dividing the strength of the receive signal from the base station by the strength of the receive signal from the relay station, determining if interference occurs using the receive signal strength ratio, and transmitting a control message representing if interference occurs.

Abstract: A system and method for transmitting and receiving signals in a communication system are provided, in which a BS communicates with a first MS located within an inner area of a cell during first and second time periods in TDD and communicates with a second MS located within an outer area of the cell during the first time period in FDD, and an RS detects signals transmitted between the BS and the second MS during the first time period and transmits the detected signals simultaneously to the BS and the second MS during the second time period.

Abstract: An apparatus and a method for mitigating interference of a neighbor cell in a multihop relay wireless communication system are provided. The method includes constituting a subframe for a link affected by interference of a neighbor cell over a first frequency band of the frame, and constituting a subframe for a link causing interference to a neighbor cell over a second frequency band of the frame. Therefore, the interference between the neighbor cells can be reduced and the amount of the resources allocated to the links can be freely adjusted.

Abstract: A method and apparatus for reducing an uplink feedback overhead in a wireless communication system includes scheduling DownLink traffic. The method includes determining a transmission period, and allocating UpLink feedback resources considering the DL traffic transmission period.

Abstract: In the MS apparatus for performing scheduling, a reception module receives any number information through a specific downlink channel in a first time unit from each of neighbor BSs. A scheduling module determines, among the neighbor BSs, a BS which is to transmit and receive data using a downlink data transmission region and an uplink data reception region, respectively, in a second time unit according to a previously set rule based on the number information. A transmission module transmits a signal, indicating that data transmission and reception using the downlink transmission region and uplink data reception region, respectively, in the second time unit are not possible, to the other neighbor BSs excluding the determined BS among the neighbor BSs.

Abstract: An apparatus and method for transmitting/receiving resource allocation information in a communication system are provided. In the method of transmitting resource allocation information, at least one of a plurality of FDD UL FA resources is divided into a plurality of segment regions, and first resource allocation information is transmitted to mobile stations through a plurality of TDD DL FA resources. The first resource allocation information indicates, among the plurality of segment regions, each of segment regions corresponding to the TDD down link FA resources.

Abstract: An apparatus and method for simultaneous transmission scheduling in a multi-hop cellular system are provided, in which a base station presets simultaneous transmission relay station set information and transmits the simultaneous transmission relay station set information to relay stations managed by the base station, and an relay station receives the simultaneous transmission relay station set information from the base station, determines, upon receipt of a data frame from the base station, a state of the relay station preset in relation to a receiving relay station for the data frame by comparing an ID of the receiving relay station included in the data frame with the simultaneous transmission relay station set information, and operates according to the preset state.

Abstract: A method for receiving multicast service data by a terminal in a communication system. The method includes receiving a pilot from a base station, measuring channel state information using the received pilot, and transmitting the channel state information to the base station; receiving a frame from the base station, and determining whether there is an error in the received frame; when no error has occurred in the received frame, determining whether the number of frames consecutively received without error is greater than or equal to a predetermined number; and when the number of frames consecutively received without error is greater than or equal to the predetermined number, transitioning to a non-feedback state where the terminal transmits no channel state information to the base station. The frame includes multicast service data.

Abstract: An apparatus and method for avoiding interference between a base station and a relay station when using full duplex relay in a multi-hop relay wireless communication system are provided. An operation of a mobile station includes measuring an strength of a receive signal from a base station and an strength of a receive signal from an relay station, calculating a receive signal strength ratio of base station to relay station by dividing the strength of the receive signal from the base station by the strength of the receive signal from the relay station, determining if interference occurs using the receive signal strength ratio, and transmitting a control message representing if interference occurs.

Abstract: An apparatus and method for receiving data in a communication system. A Mobile Station (MS) receives a Base Station (BS) signal and a Relay Station (RS) signal, measures strengths of the received BS signal and RS signal, determines whether the BS signal acts as interference to the RS signal depending on the measured strengths of the RS signal and the BS signal, and transmits the determination result to an RS in communication with the MS. The RS allocates resources using resource allocation information for the BS signal that acts as interference, and the MS receives data using the resource allocation scheme allocated from the RS.

Abstract: Disclosed is a system and method for transmitting/receiving a signal in a communication system. In the system and method, a base station transmits data to a first relay station, which is connected directly thereto from among relay stations belonging to a first relay station group, through a first frame interval, and transmits data to a second relay station, which is connected directly thereto from among relay stations belonging to a second relay station group, through a second frame interval subsequent to the first frame interval. In the first frame interval or the second frame interval where no data is received from the base station, each of the first and second relay stations transmits data to a next relay station connected directly thereto within the same relay station group, and communicates data with a mobile station in direct communication therewith.

Abstract: A method and apparatus for reducing an uplink feedback overhead in a wireless communication system are provided. The method includes scheduling DownLink traffic and determining a transmission period, and allocating UpLink feedback resources considering the DL traffic transmission period.

Abstract: Provided is a handover method of a wireless communication system using a hierarchical cellular scheme. In the method, signal quality of a serving node is measured, so that whether to start scanning for a handover is determined. When the scanning for the handover starts, signal qualities of a serving cell including the serving node and one or more neighbor cells are measured through a first preamble including a first identifier for distinguishing a cell. An intra-cell handover or an inter-cell handover is selected using the signal qualities of the serving cell and the neighbor cells. Therefore, a terminal can easily distinguish between the inter-cell handover and the intra-cell handover, and an overhead during a handover can be reduced because an intra-cell handover procedure is simplified.