Abstract: An apparatus and method for beamforming in a multi-antenna system are provided. The method includes assuming at least one codeword comprised in a codebook as a precoding weight of a reference receive end and generating post-processing weights of at least two receive ends, confirming a codeword maximizing a sum rate using the post-processing weights, generating preceding weights of the receive ends using the codeword maximizing the sum rate, and precoding a transmit signal using the generated precoding weights and transmitting the precoded transmit signal to each receive end.

Abstract: A method for transmitting and receiving data in a communication system. The method generates a frame for mapping each of multiple communication service modes of a base station providing the multiple communication service modes to a user terminal, in units of subframes each having a time interval and a frequency band. The method includes estimating a communication service mode supporting an optimal service among the multiple communication service modes provided by the base station supporting the multiple communication service modes, and sending to the base station a random access message for access to the base station over a shared channel.

Abstract: An apparatus and a method for generating a frame for communication using beamforming in a wireless communication system are provided. A method for transmitting a signal in a transmitting stage includes determining a beam change time of a region for transmitting information in a frame, and transmitting the information to a receiving stage over the region for transmitting the information by considering the beam change time. The frame includes a plurality of regions divided based on a type of the information transmitted to the receiving stage, and the plurality of the regions includes different beam change times.

Abstract: A method and apparatus for selecting an antenna in a communication system is provided. The apparatus includes a mobile station for determining a set of transmit antennas by considering statistical channel information, for determining a subset of the transmit antennas, which can increase a diversity gain and reduce an effect of a spatial correlation, from among the determined set of the transmit antennas by considering the statistical channel information and instantaneous channel information, for generating antenna selection information by using the determined subset of the transmit antennas, and for feeding back the generated antenna selection information to a base station.

Abstract: A method and system for using frequency resources in a communication system are provided. In the method and system, a total frequency band is divided into at least two frequency subbands and there is a guard interval between frequency subbands. A first frequency subband includes a TDD UL frequency subband and a TDD DL frequency subband. A second frequency subband includes an FDD UL frequency subband. A BS sets a frequency band between the TDD UL frequency subband and an FDD UL frequency subband as an additional UL frequency subband, and receives a signal from an MS in the additional UL frequency subband.

Abstract: A method and an apparatus for operating a moving network in a mobile communication system are provided. A method of a Base Station (BS) for operating a Moving Network (MN) includes determining an operation mode of the MN in a cell by collecting information of the cell, and transmitting the determined operation mode to the MN. The operation mode includes at least one of an Operation ON mode in which the MN maintains links to Mobile Stations (MSs) in a service coverage area of the MN, and an Operation OFF mode in which the MN turns off the links to the MSs in the service coverage area of the MN.

Abstract: An apparatus and a method for transmitting data according to distributed scheduling by guaranteeing fairness and considering system throughput at same time in a wireless communication system are provided. The method for operations of a terminal for transmitting the data include determining a Proportional Fairness (PF) value, determining a link class of a link to a peer terminal using the PF value, determining a variable which is used to determine whether the terminal wins or loses a contention according to the link class, and transmitting a request message requesting channel occupation based on the contention according to the variable.

Abstract: An apparatus and a method for canceling interference using a space-frequency block coding in a multi-antenna system. The method includes confirming a code for coding to minimize a Pairwise Error Probability (PEP) of a transmit signal of which the PEP is maximized according to a time variation; and coding the transmit signal with the code and transmitting the coded signal via at least two antennas. Accordingly, the interference cancellation can be accomplished while lowering the complexity of the receiver without degrading the spectral efficiency.

Abstract: An apparatus and a method for transiting an operation mode of a femto base station in a wireless communication system are provided. The method includes, in a sleep mode, confirming whether operation transition request information is received from at least one terminal; and when receiving the operation transition request information from the terminal, entering an active mode. Thus, the power consumption of the femto base station can be reduced and the interference caused by the operation of the femto base station can be mitigated.

Abstract: A method for mitigating interference at a small base station in a hierarchical cell structure is provided. In the method, the small base station checks a sub-frame allocated to macro user equipment by using a downlink signal received from a macro base station when an interference candidate user equipment list is received. The interference candidate user equipment list contains information on the macro user equipment adjacent to a femto cell controlled by the small base station. Then the small base station allocates other sub-frame to femto user equipment located in the femto cell by avoiding the sub-frame allocated to the macro user equipment.

Abstract: An apparatus and a method for detecting a femto Base Station (BS) of a Mobile Station (MS) in a wireless communication system including a macro BS and a femto BS are provided. The method includes receiving a request, from the macro BS, to monitor an UpLink (UL) signal of an MS permissible by the femto BS to access, and monitoring the UL signal of the MS permissible to access.

Abstract: A cluster-based cooperative communication system and method is provided for mitigating inter-cell interference effectively. A cluster-based cooperative communication method of a mobile station includes receiving allocation of a resource of a weighted subband mapped to one of preset cooperative base station clusters, the selected cooperative base station cluster having a group including a serving base station of the mobile station and dominant interfering base stations found by channel estimation, and communicating with the serving base station in cooperation with the dominant interfering base stations.

Abstract: A Maximum Likelihood (ML) detection apparatus and method in a wireless communication system are provided, in which a Euclidean distance are calculated using at least one of channel matrix information, noise power information and modulation order information of each stream, Pairwise Error Rate (PER) are calculated using the Euclidean distance, an error probability of the each stream is calculated using the PER, the error probability of the each stream is ordered and sorted, and ML detection is performed using a result of the ordering and sorting.

Abstract: A method and apparatus for establishing a Peer-to-Peer (P2P) connection between Mobile Stations (MSs) in a wireless communication system are provided. A method of operating a transmitting MS for establishing the P2P connection between the MSs in the wireless communication system includes when a location of a receiving MS is not known, requesting a Base Station (BS) to transmit a message instructing MSs to prepare for P2P setup, and thereafter, broadcasting to neighbor MSs a message requesting P2P-related information, receiving the P2P-related information from each of the neighbor MSs, generating a list of MSs capable of P2P communication using the received P2P-related information, and establishing a P2P connection by selecting the receiving MS from the list of MSs with which P2P communication is desired. Accordingly, in an environment where the location of the receiving MS is not known, the receiving MS can be found and thus the P2P connection can be established.

Abstract: A method and apparatus for allocating a Peer-to-Peer (P2P) resource in a relay-based wireless communication system are provided. The method includes receiving relay link resource information, determining whether a current link is a multi-hop link by using the relay link resource information, and if the current link is the multi-hop link, allocating a corresponding relay link resource as the P2P resource by determining a serving station. Accordingly, P2P communication can be achieved without having to use additional P2P-dedicated resources.

Abstract: A method for providing a service in a communication system is provided. A Base Station (BS) supporting a plurality of communication service modes allocates communication resources for each of the plurality of communication service modes according to a ratio determined in accordance with a communication service mode preferred by a terminal. The BS transmits a combination of resources allocated for each of the plurality of communication service modes to the terminal. The communication service mode preferred by the terminal is determined using at least one of channel condition of the terminal, moving velocity, preferred communication mode, required performance, billing system, and user preference.

Abstract: According to one embodiment, a method of a base station configured to select a precoding mode in a mobile communication system. When channel estimate information is received from at least one terminal, the channel estimate information is collected, so that user grouping is performed according to one precoding scheme from among multiple precoding schemes. Individual user scheduling is performed according to each precoding scheme, so that a service candidate group set is generated. The selected precoding scheme is maximized according to a transmission capacity of a service candidate group set for each precoding scheme. Data is then transmitted to a determined candidate group set using the determined precoding scheme.

Abstract: A method for mitigating interference at a small base station in a hierarchical cell structure is provided. In the method, the small base station checks a sub-frame allocated to macro user equipment by using a downlink signal received from a macro base station when an interference candidate user equipment list is received. The interference candidate user equipment list contains information on the macro user equipment adjacent to a femto cell controlled by the small base station. Then the small base station allocates other sub-frame to femto user equipment located in the femto cell by avoiding the sub-frame allocated to the macro user equipment.

Abstract: A collaborative Hybrid Automatic Repeat reQuest (HARQ) in a broadband wireless communication system using a relay station is provided. A transmitting end includes a distance estimator for estimating a distance to a relay station; a controller for determining whether to execute a collaborative HARQ using the estimated distance to the relay station; and a transmitter for, when the execution of the collaborative HARQ is determined and a retransmission request is received from a receiving end, sending a retransmission packet according to a multiple antenna signal processing scheme by constituting a virtual multiple antenna group with the relay station.

Abstract: An apparatus and a method for interference cancellation in a transmitting end of a multi-antenna system are provided. A precode is generated which maximizes a diversity gain of one or more receive antennas using channel information of the receive antennas to be serviced. Transmit powers of the receive antennas are updated by taking into account a power loss and a shaping loss according to a dirty paper coding. Transmit signals are precoded by updating the precode according to the updated transmit powers. The dirty paper coding is performed on the precoded transmit signals to be transmitted to the receive antennas.