Abstract: A distortion compensation apparatus and an apparatus and method for transmitting a signal are provided. The distortion compensation apparatus can extract precise distortion information by adding an additional signal to an input signal during the compensation of distortion in a nonlinear apparatus, and can linearize the nonlinear properties of the nonlinear apparatus using the distortion information. The apparatus for transmitting a signal can output a signal linearized by the same method as that used by the distortion compensation apparatus.

Abstract: A group service providing method and apparatus suitable for use in a wireless communication system. A group registration method for providing a group service to a master terminal and a slave terminal, the group registration method may comprise receiving and storing subscriber profile information of the master terminal from an associated communication network server in response to a group service registration request from the master terminal; generating a group related to the group service registration request and a group key corresponding to the generated group and transmitting to the master terminal a group generation completion message including the group key; receiving and storing subscriber profile information of the slave terminal dependent on the master terminal from the communication network server; and transmitting the group key to the slave terminal with reference to the subscriber profile information of the slave terminal.

Abstract: The method includes performing a wired back-to-back test by forming M wired paths connecting one of the N transmission antennas with the M reception antennas through M cables, separating ith digital data corresponding to an ith receiver wired path from the plurality of digital data stored in the receiver wherein i is a natural number greater than 1 and smaller than M, extracting a time delay by decimating the separated ith digital data and performing sliding correlation on the decimated data, and extracting attenuation and phase characteristics of the ith receiver wired path by extracting samples after the time delay among the decimated samples.

Abstract: A reception apparatus including: a detection unit detecting extrinsic information based on a tentative symbol decision signal, a channel estimation signal, a noise variance estimation signal, and a received signal that are obtained from a previous iteration process; a Cyclic Redundancy Check (CRC) aided channel decoding unit outputting an interleaved bit or a posteriori information thereof based on the extrinsic information; a tentative symbol decision unit determining a tentative transmission symbol based on an output of the CRC aided channel decoding unit; a channel estimation unit estimating a channel based on an output of the tentative symbol decision unit; and a noise variance estimation unit estimating a noise variance based on the output of the tentative symbol decision unit and an output of the channel estimation unit is provided.

Abstract: Disclosed is a radio-frequency front-end apparatus that can be used in wireless communication systems performing transmission/reception by using a single antenna. The radio-frequency transceiving front-end apparatus using passive elements in a wireless communication system includes: a transmitting unit's hybrid coupler configured to divide and output a transmission signal into two outputs having a phase difference of 90°; a first circulator configured to receive a first output of the hybrid coupler through a first terminal thereof and output the received first output through a second terminal thereof; a second circulator configured to receive a second output of the hybrid coupler through a first terminal thereof and output the received second output through a second terminal thereof; and an output unit's hybrid coupler configured to receive transmission signals from the second terminal of the first circulator and the second terminal of the second circulator, and combine and output the received signals.

Abstract: The present invention relates to a digital signal processing circuit, and more particularly, to a method and apparatus for generating a maximum value or a minimum value used for designing the digital signal processing circuit. An apparatus for obtaining a maximum value or a minimum value from N digital input signals may include N×W bit processing elements to receive an input of W bits of each of the N digital input signals, W OR operators to receive an input of N operation values output from bit processing elements, and to perform an OR operation, respectively, and W inverters to invert an output value for each of the W OR operators.

Abstract: A method for simultaneously transmitting packets to one or more users in a wireless communication system includes: generating the packets which include length information and are to be transmitted to the one or more users; and simultaneously transmitting the generated packets to the one or more users. The length information includes information representing a unit of the length information and information representing lengths of the packets according to the unit.

Abstract: Disclosed is a digital pre-distortion device which includes a pre-compensation lookup table which outputs a first input value and a second input value adjacent to an input signal, a first distortion value corresponding to the first input value, and a second distortion value corresponding to the second input value; and a function generator which generates a pre-distortion function based on the first and second input values and the first and second distortion values and generates a pre-distortion value corresponding to the input signal from the pre-distortion function.

Abstract: Provided is a transmission/reception apparatus and method for transmitting a frame in an ultra wideband radio communication system, which may enable a protocol version to be included in a fixed-length physical layer protocol (PHY) header so that interaction between systems using different protocol versions may be realized, and may enable information about a modulation and coding scheme to be included in a variable-length PHY header to thereby overcome a decoding delay problem occurring due to a Reed Solomon code.

Abstract: The present invention relates to a multi-antenna radio channel measurement system and method for a two-way radio channel measurement, including: Control & Console Software to select a radio measurement mode, generate a probing signal for measurement, receive input parameters to be measured, and deliver the parameters to a baseband unit; a baseband unit (BBU) to set a transmission/reception frequency band and bandwidth and set a timing using the selected radio measurement mode and the received input parameters; a timing unit to synchronize a time with another radio channel measurement system to generate a transmission/reception synchronization signal, and provide the transmission/reception synchronization signal to the BBU; a transceiver unit (TRXU) to up-convert the probing signal for measurement and down-convert the reception channel signal; and a radio frequency (RF) front-end unit (RFFU) to switch to a suitable antenna according to a timing control signal of the BBU.

Abstract: The present invention relates to a method and device for detecting a transmission signal on the basis of a received signal by applying a division and detection algorithm. An embodiment of the invention provides a method of detecting a transmission signal including: obtaining a unitary matrix and an upper triangular matrix by performing a sorted QR-decomposition algorithm with respect to a matrix indicating a channel state; calculating a vector y by multiplying a transpose matrix of the unitary matrix by the received signal Y; dividing the upper triangular matrix R into a plurality of sub-upper triangular matrices and dividing the calculated vector y into a plurality of sub-vectors so as to correspond to the divided plurality of sub-upper triangular matrices; and detecting a lattice point corresponding to each of the divided sub-vectors using the divided plurality of sub-upper triangular matrices.

Abstract: Provided are machine type communication (MTC) gateway user equipment (MGUE) and an MTC data relay method of the same. The MGUE includes a first radio matching unit configured to process a signal having a first frequency band characteristic and provide radio access matching with a base station, a second radio matching unit configured to process a signal having a second frequency band characteristic and provide radio access matching with at least one MTC device, a radio access switching processor configured to convert data respectively output by the first radio matching unit and the second radio matching unit and provide the converted data, and a controller configured to find an identifier of at least one MTC device related to MTC control information received from the first radio matching unit and control the second radio matching unit to transmit the MTC control information to the MTC device.

Abstract: Provided are a method of controlling a multi-user multiple input multiple output (MIMO) system and a transmitter/receiver used in the method. In the method, it can be determined whether feedback information is fed back according to the feedback information type rather than being indiscriminately provided to a transmitter, and then only a necessary feedback information type is transmitted, thereby increasing system capacity while reducing feedback load.

Abstract: A method and apparatus of accessing a channel in a wireless local area network is provided. A destination station receives a request to send (RTS) frame to allocate a network allocation vector from a source station over a first bandwidth and transmits a clear to send (CTS) frame over a second bandwidth to the source station in response to the RTS frame. The second bandwidth is dynamically determined when a first parameter has a predetermined value.

Abstract: A terminal receives a map scheduling interval that is set to be greater than a multicast and broadcast service map transmission cycle by a base station from the base station, and receives a multicast and broadcast service map from the base station according to the received map scheduling interval.

Abstract: A reception apparatus including: a detection unit detecting extrinsic information based on an output of a tentative symbol decision unit, an output of a channel estimation unit, and an output of a noise variance estimation unit that are obtained from a previous iteration process; a Cyclic Redundancy Check (CRC) aided channel decoding unit outputting an encoded and interleaved bit, or a posteriori information thereof based on the extrinsic information; the tentative symbol decision unit determining a tentative transmission symbol based on an output of the CRC aided channel decoding unit; the channel estimation unit estimating a channel based on an output of the tentative symbol decision unit or a pilot symbol; and the noise variance estimation unit estimating a noise variance or an initial noise variance based on the output of the tentative symbol decision unit and the output of the channel estimation unit is provided.

Abstract: Disclosed are a cooperation communication method and system using feedback signals. The cooperation communication method includes transmitting a packet to a base station by a terminal, determining, by the terminal, whether decoding of the transmitted packet is successfully performed using a feedback signal from the base station, and re-transmitting the packet to the base station by the terminal according to whether decoding of a packet of an adjacent terminal within a prescribed distance from the terminal is successfully performed.

Abstract: A communication method of a source device according to an embodiment includes detecting a status of a first link directly connected from the source device to a destination device or a status of a second link connected from the source device to the destination device via a relay device, selecting any one of the first link and the second link based on a result of the detection, and transmitting data using the selected link.

Abstract: Provided is a communication method of a coordinator, the method including: receiving a relay search request frame for requesting a search for at least one relay station between a destination station and a source station; and transmitting, in response to the relay search request frame, a relay search response frame including a list of the at least one relay station so that the source station selects a target relay station from the at least one relay station.

Abstract: A portable apparatus including: a Radio Frequency (RF) unit to control a frequency of a signal to be measured, to broadcast the signal to be measured through multiple transmission antennas, to control a frequency of a received signal, and to send the received signal to the baseband unit, the received signal being received through multiple receiving antennas; and a baseband unit to generate and transmit, to the RF unit, the signal to be measured, to measure wireless channels for each of the multiple transmission antennas and wireless channels for each of the multiple receiving antennas based on the received signal output from the RF unit, to calculate a correlation for each of the multiple transmission antennas, and to calculate a correlation for each of the multiple receiving antennas based on the wireless channels for each of the multiple transmission and receiving antennas.