Abstract: A cognitive radio communication terminal including a transmission processing unit to divide data by a quiet time slot that is allocated at a first point in time of a collision detection period, to transmit at least one portion of the divided data to a reception side, and a sensing unit to determine whether at least one of a feature information and an energy of another terminal is detected in a channel with the reception side during the quiet time slot of the first point in time. Where neither the feature information nor the energy of the other terminal is detected based on a determination of the sensing unit, the transmission processing unit transmits the remaining divided data.

Abstract: Provided are a communication apparatus and method using a matrix network coding scheme. The communication apparatus includes a reception unit to receive a corrupted packet including a plurality of corrupted words, and a controller to estimate a first decoded word corresponding to the corrupted words based on the corrupted words and a generator matrix. The controller generates a second decoded word corresponding to the corrupted words based on a codebook and the estimated first decoded word. The codebook is based on the generator matrix. The controller generates a message based on a plurality of second decoded words respectively corresponding to the plurality of corrupted words.

Abstract: Provided is an apparatus and a method for transmitting power to electronic devices and of transmitting and receiving data. The method of transmitting power includes searching for a device to be charged located in an area, determining whether the found device needs charging, and transmitting power to the found device when the found device is determined to need charging. The apparatus may be mobile, and may travel towards or away from one or more devices based on whether the one or more devices need charging.

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: A receiver that generates side information associated with information that is transmitted with packet data and that is included in received packet data, and that feeds back the side information to the transmitter, is provided. The transmitter may generate and transmit additional redundant bits based on the side information.

Abstract: A wireless power transmission method is provided. The method includes exchanging information for wireless power transmission between a wireless power transmission device and a terminal, in order to determine a communication protocol.

Abstract: Provided is a communication method of a relay node for network coding, including determining one of a plurality of nodes included in a mesh network as a relay node to perform network coding; determining, by the relay node among the plurality of nodes, nodes capable of participating in the network coding; and performing the network coding with respect to the nodes capable of participating in the network coding.

Abstract: A wireless power transmission device and method are provided. An amount of power transmitted wirelessly by the wireless power transmission device may be controlled based on information to be transmitted by the wireless power transmission device, such that the information may be transmitted without using any additional device for information transmission. Additionally, an internal impedance of a terminal may be controlled based on information to be transmitted by the terminal, and a reflected wave of a transmission signal transmitted by the wireless power transmission device may be then controlled, such that the information may be transmitted without using any additional device for information transmission. Therefore, no further device may be desired, and thus a power consumption amount may be reduced, and there may be no need to match a communication part for information exchange with a transmission part for wireless power transmission.

Abstract: A communication network comprising a collaborative photography group including a plurality of cameras having synchronized photographing times, is provided. The plurality of cameras may share location information, direction angle information, and image information generated by photographing an object, and generate a three-dimensional (3D) image of the object.

Abstract: A user scheduling and transmission power controlling method in a hierarchical-cell communication system or a multi-cell communication system, and a device to perform the methods, are provided. Interference may occur between various cells in the hierarchical-cell communication system or the multi-cell communication system, and the interference may be controlled by adjusting transmission power of various cells. The various cells may determine an optimal transmission power based on a cost of a corresponding transmission power. Also, the various cells may serve various users and may propose an optimal user scheduling method.

Abstract: A frequency band setting apparatus and method are provided. The frequency band setting apparatus may include a calculation unit and a control unit. The calculation unit may calculate a basic frequency band of each of a plurality of Access Points (APs), and the control unit may divide a frequency band, which is available to the plurality of APs, into each of the calculated basic frequency bands and a common frequency band.

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 precoding method for a femtocell or a picocell and a communication system using the same is provided. The communication system may include a small base station that is able to implement a protection mode to protect a neighbor terminal from an interference regardless of whether a neighbor base station is performing a process to protect the neighbor terminal from the interference. Also, the small base station may use at least one process scheme appropriate for a current environment among various process schemes, thereby effectively protecting the neighbor terminal from the interference.

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: Provided is a communication system using various types of random beamforming technologies. Each of terminals that belong to a user group may generate a decoding matrix, based on interference caused by a neighboring base station of a serving base station. Each of the terminals may transmit, to the serving base station or the neighboring base station, information associated with a signal-to-interference plus noise ratio (SINR) or throughput based on the decoding matrix. The serving base station may select, from the terminals, at least one target terminal to communicate with the serving base station.

Abstract: A communication network applying an interference alignment scheme with a low or reduced complexity is provided. The communication network may include a plurality of transmit nodes and a plurality of receive nodes. A plurality of combinations of transmit-receive pairs may exist between the plurality of transmit nodes and the plurality of receive nodes. A communication apparatus for the communication network may select, from candidate combinations of transmit-receive pairs, a target combination to be applied with the interference alignment scheme. In particular, the communication apparatus may sequentially decrease a number of candidate combinations to select the target combination with a low complexity.

Abstract: A communication system may include a serving base station and neighboring base stations. Each of the serving base station and the neighboring base stations may have a corresponding user group. Terminals belonging to a particular user group may feed back information associated with interference channels, and reasonably generate a precoding matrix. Through this, it is possible to perform an accurate interference alignment and to enhance a throughput. In this instance, terminals belonging to the other user groups may feed back information associated with a throughput, and a corresponding base station may perform the interference alignment using a user selection resulting in decreased overhead.

Abstract: Provided is a signal transmission system including a terminal to receive a signal using an interference alignment scheme, and a transmitting base station to transmit, to the terminal, a signal where interference is aligned. The transmitting base station may select, from a plurality of terminals, a target terminal to receive the signal using the interference alignment scheme. The selected target terminal may receive the signal from the transmitting base station and receive interference signals from a plurality of interference base stations.

Abstract: An operation method of a relay node in a wireless network using a superposition coding scheme is provided. In particular, a relay node may receive a first transmission message from a first source node in a first time slot. The relay node may also receive a second transmission message from a second source node in a second time slot.

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.