Abstract: The present invention relates to a method for marking the surface of a rubber stopper with a character or numeral by irradiating the surface of the rubber stopper with a laser beam. According to the method of the present invention, there are advantages in that when a mark is made on a rubber stopper, foreign matter is not produced, deformation of the rubber stopper does not occur, and the mark is not erased or spread.

Abstract: A method for assigning a single frequency sub-channel to a plurality of MSs (Mobile Stations) in an OFDM (Orthogonal Frequency Division Multiplexing) system utilizing SDM (Spatial Division Multiplexing) with multiple transmit/receive antennas. In the method, a BS (Base Station) can effectively assign a pilot channel to estimate a downlink channel. The BS divides the single frequency sub-channel into a plurality of spatial channels, and sequentially assigns the plurality of spatial channels to the MSs having the maximum communication capacity, thereby transmitting signals of the MSs through the single frequency sub-channel.

Abstract: An adaptive subchannel and bit allocation method in a wireless communication system. A mobile station analyzes channel quality information of a subchannel at a predetermined period and determines a feedback band index with a maximum decision criterion. The mobile station feeds back the determined feedback band index with the maximum decision criterion to a base station. The base station generates band allocation information using the feedback information from the mobile station, and transmits the band allocation information to the mobile station. The mobile station transmits AMC information using the band allocation information received from the base station. The base station estimates a channel using the AMC information transmitted from the mobile station and allocates bits to the allocated band according to the channel estimation result.

Abstract: Dynamic frequency selection based on CR is provided. A CR BS detects an interference-free and unused frequency band. When sensing a new BS that has great signal strength and requires the frequency band during communications in the frequency band, the CR BS releases the frequency band and dynamically selects another frequency band to avoid interference.

Abstract: A transmitter in a multiple input multiple output (MIMO) communication system is provided. The transmitter includes a multiplexer for multiplexing an input bit stream into a plurality of bit streams, and outputting the bit streams in parallel; a bit-order rearranger for reordering bits constituting the bit streams, which are output from the multiplexer in the same time period, and outputting the reordered bits as reordered bit streams; and a modulator for modulating the parallel reordered bit streams output from the bit-order rearranger according to their associated modulation schemes, and transmitting the modulated symbols via their associated antennas.

Abstract: An explicit outband signaling method for detecting sharable resources for management of public resources in a wireless network supporting Cognitive Radio (CR) technology. To this end, the invention transmits state information for the current channel to a CR system in order to enable communication of the CR users, whose communication with the CR system is impossible due to an influence of an incumbent system, thereby allowing the CR system to stop the use of the interference channel, and to provide a corresponding service with another channel.

Abstract: A communication initialization method at a MAC layer in a CR wireless communication system is provided. The use or non-use of a frequency band is sensed over a broadband with a minimized sensing time in a non-interfering manner with existing communication systems.

Abstract: A cooperative diversity method and apparatus that can minimize interference and maximize an efficiency of a transmission channel between terminals of a cooperative diversity pair, the method including: determining a pair of terminals to be a cooperative diversity pair according to a spectrum sensing result of a cognitive radio (CR); selecting a subchannel through which data is exchanged between the pair of terminals; and transmitting the data between the pair of terminals through the selected subchannel.

Abstract: A resource management method in a Cognitive Radio communication system where at least two Base Stations of heterogeneous networks provide a connection service to Mobile Stations within their service areas is provided. In the method, at least one BS having candidate resources broadcasts its candidate resource information on the downlink of a system information channel. At least one BS lacking in resources searches the downlinks of system information channels from neighbor heterogeneous networks, selects an offer BS among the BSs having candidate resources, and rents resources from the selected offer BS by negotiations.

Abstract: A method for transmitting to one cell a frame including broadcast channels in a cellular wireless communication system in which a base station supports a plurality of physical channels corresponding to the broadcast channels. The base station generates the frame and transmits the generated frame to a mobile station. The frame includes separate broadcast channels for the respective physical channels. A position, in the frame, of a first broadcast channel for a physical channel capable of supporting a mobile station having the worst channel state is fixed in all of transmission frames. The first broadcast channel includes positional information of the remaining broadcast channels except for the first broadcast channel. The mobile station detects only an address of a broadcast channel for a physical channel allocated thereto from the first broadcast channel among broadcast channels belonging to the frame.

Abstract: A method of partitioning resources in a CR wireless communication system and a system supporting the same are provided. A new BS receives radio resource status information from a prior BS using a particular frequency band, and requests resource partitioning to the prior BS using a new uplink subchannel defined for communications between BSs. Resource negotiation messages are exchanged over a channel defined between the two BSs so as to efficiently partition resources between the BSs.

Abstract: A transmitter and a receiver are disclosed herein that support transmit antenna diversity using space-time block coding in a wireless communication system. The transmitter produces symbol combinations containing, as their elements, input symbols, the inversions and conjugates of the symbols, and symbols obtained by rotating the phases of the symbols once, forms a matrix having symbols in at least two columns orthogonal to each other with the symbol combinations, and transmits the matrix. The receiver detects symbols that minimize maximum likelihood (ML) decoding metrics over all possible symbols using channel gains from transmit antennas to a receive antenna. Also, the receiver selects candidate symbols among all possible symbols according to the characteristics of transmitted modulation symbols and detects symbols that minimize the ML decoding metrics.

Abstract: A communication method and apparatus for a distributed network system where a cognitive radio (CR) technology is used. A communication method of a distributed network system where the CR technology is used includes transmitting adjacent channel information, from at least one first neighbor node adjacent to a source node, first adjacent channel information of the at least one first neighbor node using a pulse signal according to a request of the source node; by transmitting, from at least one second neighbor node adjacent to a destination node, second adjacent channel information of the at least one second neighbor node to the destination node using a pulse signal according to a request of the destination node; and exchanging data between the source node and the destination node using a channel that is not currently used, according to the transmitted adjacent channel information.

Abstract: A communication method and apparatus of a cognitive radio (CR) environment using a relaying system while not interfering with a communication system having a priority right to use a frequency band, the communication method including: listening to fundamental channel (FCH) information and/or downlink/uplink (DL/UL) map information of a frame transmitted in the relaying system; obtaining a transmission signal of the relaying system using the FCH information and/or the DL/UL map information; orthogonally encoding data to be transmitted in the CR environment based on the obtained transmission signal; and transmitting the orthogonally encoded data via a determined channel that is used in the relaying system. Accordingly, aspects of the present invention can retrieve radio resources unused in the CR environment more easily.

Abstract: A method and apparatus of controlling a transmission power of a cognitive radio (CR) environment, the method including: sensing an incumbent user that uses a same channel as the CR environment; detecting signal quality information of the sensed incumbent user; calculating, using the detected signal quality information, a maximum transmission power value that corresponds to a maximum transmission power that may be transmitted by a CR base station in the CR environment; and controlling a communication of the CR environment to be performed within the calculated maximum transmission power value.

Abstract: A differential STBC transmitting/receiving apparatus in a multiple antenna system using eight or less transmit antennas is provided. In the differential STBC transmitting apparatus, a symbol mapper receives binary data and generates a number of symbols from the binary data, each symbol having a number of bits. A space-time block encoder generates an STBC by encoding the symbols. A differential processor differentially encodes the STBC through feedback and delay. A distribution matrix processor substitutes the differentially coded STBC into a distribution matrix preset according to the number of transmit antennas, and outputs the differential STBC code of the distribution matrix to the transmit antennas.

Abstract: A signaling method between a cognitive radio (CR) base station and a CR terminal in a CR environment, and a channel division method used for the signaling method, includes: detecting a channel usage of an incumbent system, which communicates with a CR base station; sensing an outband channel to communicate with the CR base station; receiving an EOS, which is broadcasted from the CR base station via the outband channel according to a predetermined period; and transmitting a sensing report signal with respect to the channel to the CR base station.

Abstract: The present invention relates to a transmitter and a transmission method in communication system using three Tx antennas in order to maximize STFBC coding gain. An input symbol sequence is transmitted through a plurality of Tx antennas in a predetermined method.

Abstract: A multiple-input multiple-output (MIMO) communication system is provided for communication between a transmission apparatus having a plurality of transmission antennas and a reception apparatus having a plurality of reception antennas. The reception apparatus performs singular value decomposition (SVD) on channel information for a channel established to the transmission apparatus, and feeds back the SVD-decomposed channel information to the transmission apparatus. The transmission apparatus receives the SVD-decomposed channel information from the reception apparatus, performs QR decomposition on the received SVD-decomposed channel information, and sets multiple transmission antennas to be allocated to the channel, thereby performing beamforming.

Abstract: A pilot designing method in an uplink OFDMA system is provided. In the uplink OFDMA system, communications are carried out in a frame divided into time-frequency lattices, and each time-frequency lattice includes a plurality of data symbol periods and a plurality of pilot symbol periods intermittently arranged with respect to the data symbol periods. The frame is divided into a plurality of blocks. The blocks are allocated to the terminals. A predetermined allocated pilot time-frequency lattice is shared between adjacent terminals.