Abstract: Disclosed is a differential space-time block coding apparatus with a high transmission rate in a wireless communication system employing multiple transmit antennas and a method thereof. The differential space-time block coding method includes the steps of, when elements of a transmission matrix B43v are transmitted in a predetermined block (a vth block) through a predetermined transmit antenna at a predetermined time, modulating a symbol Sv of inputted binary data to a symbol Sv+1, creating a matrix S44v+1 in a block (a (v+1)th block) following the predetermined block by substituting the modulated symbol for the matrix P44, and then, in order to perform a differential encoding function, multiplying the matrix B43v by the matrix S44v+1 so as to calculate a new matrix B43v+1 to be transmitted in the (v+1)th block.

Abstract: Disclosed is a space-time coding apparatus and method to flexibly adjust diversity/multiplexing orders in a multiple-antenna system. The transmitting apparatus for the multiple-antenna system includes a space-time code controller, an encoder, a demultiplexer, and a space-time encoder. The space-time code controller generates space-time codes by determining bases according to a multiplexing order required by a receiver. The encoder modulates and encodes data destined for the receiver in accordance with a predetermined modulation level. The demultiplexer demultiplexes data received from the encoder in order to transmit the data through at least one antenna. The space-time encoder space-time-codes the demultiplexed data using the space-time codes.

Abstract: In an orthogonal frequency division multiplexing (OFDM) communication system using multiple transmit antennas, a first base sequence with a first length is segmented into a first number of second sequences to which different time offsets are applied. Subsequences of a first preamble sequence corresponding to the number of second sequences are generated. A second base sequence with a second length is segmented into a second number of third sequences to which different time offsets are applied. Subsequences of a second preamble sequence corresponding to the number of third sequences are generated. A subsequence is selected from the subsequences of the first preamble sequence and is transmitted through a transmit antenna in a first time interval. A third preset number of subsequences are selected from the subsequences of the second preamble sequence, and are mapped and transmitted to the transmit antennas in a second time interval.

Abstract: In a method for feeding back combination information of transmitted signals in a multiple-input multiple-output (MIMO) system using a multiple space-time block coding technique, mean square error values are computed in relation to the combination information pieces of the transmitted signals. An index of a combination having a minimum mean square error value from among the mean square error values is fed back.

Abstract: A method and system for transmitting and receiving resource allocation information in a communication system are disclosed, in which an Relay Station (RS) receives a resource allocation information message from a Base Station (BS), detects a first resource allocation information from the resource allocation information message, and detects a second resource allocation information intended only for the RS using the first resource allocation information.

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 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: A method and system for retransmitting data in a communication system are provided. In the retransmission method, a BS determines an automatic retransmission number for a multicast data frame according to the number of MSs of a multicast group, transmits the determined automatic retransmission number to the MSs of the multicast group, and repeatedly transmits the multicast data frame to the MSs until the number of transmissions of the multicast data frame is equal to the automatic retransmission number, irrespective of reception of information indicating whether the multicast data frame has been received from the MSs. Accordingly, resource consumption can be reduced and overhead can be decreased.

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 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: An optical recording medium for recording a predetermined subtitle code in a predetermined region in which contents are stored, and an apparatus and method to play the optical recording medium which are capable of displaying a subtitle on a screen when the contents are played. The method of playing an optical recording medium includes analyzing a stream that is read from the optical recording medium, and searching whether a predetermined subtitle code is recorded in a reserved region in a predetermined stream, storing the searched predetermined subtitle code and outputting the stored predetermined subtitle code with a command execution key, and signal-processing the predetermined subtitle code that is output with the command execution key, and displaying the signal-processed predetermined subtitle code on a screen of the played optical recording medium.

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 method and apparatus for allocating frequency resources for peer to peer (P2P) communication between terminals without a base station are provided. The method determines resources used for a direct communication between two terminals in a communication system. The method includes determining uplink frequency resources of a cellular communication system for use in the direct communication between the two terminals, determining a primary maximum transmission power to minimize interference caused by the direct communication on the cellular communication system and performing the direct communication between the two terminals by using the uplink frequency resources and a transmission power less than the determined primary maximum transmission power.

Abstract: A system and method for remotely controlling a debugging unit, which can easily and accurately control the debugging unit in real time from a remote location regardless without data loss are disclosed. The system for remotely controlling a debugging unit comprises: a first protocol converter for converting a first or a second message between User Datagram Protocol (UDP) and Transmission Control Protocol (TCP), wherein the first message contains a debugging command and the second message contains debugging results; and a second protocol converter for converting a first or a second message between UDP and TCP.

Abstract: An apparatus and method for performing Peer-to-Peer (P2P) communication in a broadband wireless communication system are provided. The apparatus includes a first calculator for calculating a maximum Transmit (Tx) power level for each band of a Mobile Station (MS) by using channel information and capability information of the MS; a second calculator for calculating a preference for each band of the MS by using information on the maximum Transmit (Tx) power level for each band and by using interference information for each band of a counterpart MS; and a selector for selecting a P2P transmission band of the MS according to the preference for each band.

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: An apparatus and method for full-diversity, full-rate space-time block coding in a transmitter using two Tx antennas are provided. An input symbol sequence is STBC-encoded in a predetermined method and transmitted through the two Tx antennas.

Abstract: A method and apparatus for transmitting common control information by a base station in a wireless communication system are provided. The base station determines whether a first system and a second system different from the first system coexist in a wireless communication system. When the wireless communication system is a coexistence system, the base station indicates information for coexistence of the first system and the second system, position and size information of a resource allocation zone where common control information for the second system can be transmitted, and information necessary for decoding of the resource allocation zone, through a first information element in a downlink subframe where resources are occupied for the first system. The base station transmits the common control information of the second system in the resource allocation zone where the common control information can be transmitted.