Abstract: An optimum perturbation apparatus and method in a multi-antenna, multi-user communication system are provided. In the optimum perturbation method, upon receipt of modulation symbols, channel responses are decomposed into eigenvalues and eigenvectors by Single Value Decompositin (SVD) and a distortion value of the modulation symbols is estimated using the eigenvectors and the eigenvalues to minimize noise and interference power. The modulation symbols are precoded by combining the modulation symbols with the estimated distortion value.

Abstract: An apparatus and method for determining a pilot pattern in a Broadband Wireless Access (BWA) communication system are provided. In the pilot pattern determining method, an Orthogonal Frequency Division Multiplexing (OFDM) demodulator generates frequency-domain data by fast-Fourier-transform (FFT)-processing a received signal. A pilot pattern decider calculates a coherence bandwidth and a coherence time using subcarrier values received from the OFDM demodulator, and selects one of a plurality of pilot patterns according to the ratio of the coherence bandwidth to the coherence time.

Abstract: An apparatus and method for removing interference in a transmitting end of a multi-antenna system are provided. The method includes receiving channel information for all Receive (Rx) antennas; calculating a beam-forming matrix that maximizes a Signal-to-Interference plus Noise Ratio (SINR) for each Rx antenna by using the received channel information; calculating an integer value which is in proportion to an interference signal for each Rx antenna by using the received channel information and the calculated beam-forming matrix, and performing Dirty Paper Coding (DPC) on a Transmit (Tx) signal by using the calculated integer value; and performing beam-forming by multiplying the Tx signal that has undergone the DPC by the calculated beam-forming matrix. Accordingly, a highest data rate for each user and a highest diversity can be obtained.

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: 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 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: Frame structures, a method and an apparatus for resource allocation in a wireless communication system based on a full duplex relay are provided. The method for a centralized resource allocation in the wireless communication system based on the full duplex relay includes receiving channel information from a plurality of mobile stations (MSs) and relay stations (RSs); scheduling radio resources for a link between a base station (BS) and the MS and a link between the BS and the RS using the channel quality; constituting a first radio resource region for the link between the BS and the RS and a second radio resource region for the link between the BS and the MS; and scheduling radio resource for a link between the RS and the MS by reusing the first radio resource region. The relay link resource is reused in the full-duplex relay structure, and the system capacity can be raised by minimizing the interference in the resource utilization.

Abstract: A Multiple-Input Multiple-Output (MIMO) wireless communication system is provided. A receiving end includes a selector for selecting at least one stream for a MultiUser (MU) mode; a first generator for generating per stream channel quality information for the at least one selected stream as at least one candidate for channel information for the MU mode; and a determiner for determining one per stream channel quality information of the candidates as channel information for the MU mode.

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: 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: 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: 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: An apparatus and method for cooperative relay in a multiple-antenna wireless communication system based on relay stations (RSs) are provided. The apparatus includes a serial/parallel converter for dividing data into N number of streams, a channel estimator for calculating a first transmission rate at which a RS performing the cooperative relay can perform decoding and a second transmission rate at which all relay stations performing the cooperative relay can commonly perform decoding, and determining transmission rates for each of the N-number streams, and an adaptive modulation and coding (AMC) unit for encoding and modulating the N-number streams according to their respective transmission rates.

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: In the present invention, an apparatus and a method for generating feedback information for a Maximum Likelihood (ML) detection scheme in a Multiple-Input Multiple-Output (MIMO) wireless communication system are provided. An apparatus of the invention includes a generator for generating constellation difference points by converting a constellation domain representing values of symbols into a constellation difference domain representing values of distance between symbols, a calculator for calculating per stream Symbol Error Rates (SERs) using the constellation difference points, and a determiner for determining per stream Effective Signal to Noise Ratios (ESNRs) using the per stream SER.

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 supporting a plurality of MIMO modes in a wireless communication system are provided, in which a receiver selects one of the plurality of MIMO modes according to at least one of a received signal strength, a speed of the receiver, a correlation between a transmitter and the receiver, a presence or absence of channel quality information, a precoding index, and an antenna information, a rank, and a number of users, generates feedback information in a transmission format corresponding to the selected MIMO mode, and transmits the feedback information to the transmitter using a feedback resources allocated according to the selected MIMO mode.

Abstract: An apparatus and method for supporting a multiple antenna service in a wireless communication system are provided. The apparatus includes at least one antenna, a form determining unit for determining a form of an MS, and an antenna constructing unit for constructing an antenna structure according to the form of the MS using the at least one antenna.

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 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.