Abstract: An apparatus and method for supporting Peer-to-Peer (P2P) communications in a broadband wireless communication system are provided. A frame used by the terminal in P2P communications includes a plurality of P2P contention channels overlapping with a region for cellular communications and at least one P2P dedicated channel allocated by a base station only for the P2P communications. The method includes establishing a P2P connection with a correspondent terminal through the at least one P2P dedicated channel, and exchanging P2P communication data with the correspondent terminal through at least one of the plurality of P2P contention channels.

Abstract: A handover apparatus and method in a communication system having a macro BS and a plurality of micro BSs in one cell are provided. A handover apparatus includes a macro BS for generating a plurality of messages, each messages respectively corresponds to one of a plurality of group areas defined by grouping service areas of the micro BSs and includes information about BSs to which MSs of the group area can perform handover. The macro BS also generates group area information indicating locations of the group areas, broadcasts the plurality of messages and the group area information to the cell, and manages handover of MSs based on the plurality of messages and the group area information.

Abstract: An apparatus and method for generating an effective Signal to Noise Ratio (SNR) per stream in a Multiple Input Multiple Output (MIMO) wireless communication system is disclosed. The apparatus includes a selector, a calculator, a generator, and a decider. The selector selects effective streams among whole streams. The calculator calculates a relative SNR rate between the effective streams. The generator generates an equation having as a solution an SNR of a first effective stream. The decider decides an SNR per effective stream using the solution of the equation and the relative SNR rate.

Abstract: Disclosed is a data transmission/reception method and system for minimizing intercarrier interference (ICI) in a communication system using a multicarrier. The data transmission method by a transmitter includes grouping transmission signals in units of a predetermined number of transmission signals when the transmitter has received the transmission signals, multiplying each group of the transmission signals by a transmission coding matrix, and transmitting the transmission signals multiplied by the transmission coding matrix to a receiver.

Abstract: An apparatus and method for supporting Peer-to-Peer (P2P) communications in a broadband wireless communication system are provided. A frame used by the terminal in P2P communications includes a plurality of P2P contention channels overlapping with a region for cellular communications and at least one P2P dedicated channel allocated by a base station only for the P2P communications. The method includes establishing a P2P connection with a correspondent terminal through the at least one P2P dedicated channel, and exchanging P2P communication data with the correspondent terminal through at least one of the plurality of P2P contention channels.

Abstract: A multi-hop relay wireless communication system is provided. A base station (BS) includes a communication unit for receiving information on a received signal level and information on an interference node from mobile stations (MSs), and a scheduler for classifying a type of each MS by using the received signal level information and the interference node information and for performing differentiated scheduling according to the MS type.

Abstract: A method and system for determining a communication mode in a communication system are provided. The system and method include determining whether a first MS and a second MS are located within a preset area where P2P communications are available, estimating a first expected performance that can be achieved when the first and second MSs operate in a cellular communication mode, estimating a second expected performance that can be achieved when the first and second MSs operate in a P2P communication mode if the first and second MSs are located within the predetermined area, and selecting one of the cellular communication mode and the P2P communication mode as a communication mode between the first and second MSs by comparing the first expected performance with the second expected performance.

Abstract: A Multiple Input Multiple Output (MIMO) single carrier wireless communication system is provided. The system includes a coder for performing block coding on symbols, an extender for collecting the block-coded symbols during one transmit (Tx) signal duration and for performing repetitive extension on the collected symbol vectors by an interval required in a frequency domain, an inserter for inserting ‘0’ to the repetitively extended symbol vectors so that the vectors are mutually orthogonal in a time domain, and a combiner for multiplying the ‘0’-inserted symbol vectors by a phase component so that the vectors are mutually orthogonal in the frequency domain and thereafter for combining the symbol vectors to generate a Tx signal for each antenna.

Abstract: An apparatus and method for supporting Peer-to-Peer (P2P) communications in a broadband wireless communication system are provided. A frame used by the terminal in P2P communications includes a plurality of P2P contention channels overlapping with a region for cellular communications and at least one P2P dedicated channel allocated by a base station only for the P2P communications. The method includes establishing a P2P connection with a correspondent terminal through the at least one P2P dedicated channel, and exchanging P2P communication data with the correspondent terminal through at least one of the plurality of P2P contention channels.

Abstract: A system and method for transmitting resource allocation information by a base station in a communication system is provided. The method includes generating first MAP messages for user terminals, each of which includes an identifier of a corresponding user terminal and corresponds to resource allocation information on a first band, in an order of user terminals, generating a second MAP message, which corresponds to resource allocation information for a user terminal allocated resources of only a second band, and generating third MAP messages, which correspond to resource allocation information on the second band, for user terminals allocated resources of both the first band and the second band, among the user terminals, in the order of user terminals allocated resources of both the first band and the second band, transmitting the first MAP message through the first band, and transmitting the second and third MAP messages through the second band.

Abstract: A method and system for performing P2P communications in a communication system are provided, in which a first MS transmits a request signal requesting P2P communications with a second MS and a unique identification number of the second MS to a BS, receives from the BS a CID of the second MS allocated by the BS and transmission information required for initial synchronization of the P2P communications in response to the request signal, acquires synchronization with the second MS using the CID of the second MS and the transmission information, and establishes a P2P connection with the second MS.

Abstract: Methods and apparatuses for efficiently using radio resources in a wireless communication system based on a relay station are provided. An operating method of a relay station (RS) for efficiently using radio resources in a wireless communication system based on the RS. The method includes setting a call with a sending terminal; checking whether a receiving terminal of the sending terminal travels in the same RS cell, in a different RS cell of the same base station (BS) cell, or in a different cell of a neighbor BS; and checking a destination address of a data and relaying the data to the receiving terminal according to a result of the checking.

Abstract: An apparatus and method for pilot transmission in a wireless communication system are provided. The method includes generating a precode and a postcode for coordinated beamforming using channel information of one or more streams for transmitting signals to one or more receive ends, selecting one or more streams to be allocated pilots, updating the precode according to a reference point for representing an effective channel of non-selected streams orthogonal to an effective channel of the selected streams, and precoding signals transmitted through the streams.

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 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: 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: A method and apparatus for transmitting signals in a multi-hop wireless communication system are provided. A first BS transmits a signal including a first common information codeword and a first private information codeword. A second BS transmits a signal including a second common information codeword and a second private information codeword. A first RS joint-decodes the first common information codeword and the second common information codeword and decodes the first private information codeword. A second RS joint-decodes the first common information codeword and the second common information codeword and decodes the second private information codeword.

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 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: 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.