Patent application number | Description | Published |
20090312030 | RELAY STATION, TERMINAL AND BASE STATION IN CELLULAR SYSTEM, AND METHOD FOR RELAYING BETWEEN TERMINAL AND BASE STATION - Disclosed are a base station, a relay station, and a terminal according to a method for designing a cellular system for improving resource usage efficiency by reducing interference between relay stations and interference between the base station and the relay station. The relay station gets control signals that terminals served by the base station transmit, and registers terminals, levels of the control signals of which are bigger than a predetermined value, to a list of the interference terminals. The relay station checks an interference resource through resource allocation information of the base station, checks an available resource corresponding to a resource except the interference resource among a resource allocated by the base station, and allocates some of the available resource to the terminal. | 12-17-2009 |
20100042666 | METHOD AND DEVICE FOR DETECTING TRANSMISSION SIGNAL WITH DIVISION DETECTION - 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. | 02-18-2010 |
20100046361 | DEVICE AND METHOD FOR TRANSMITTING AND RECEIVING PILOT SIGNAL IN WIRELESS COMMUNICATION SYSTEM - Disclosed is a pilot signal transmitting/receiving device and method in a wireless communication system. When generating a pilot signal block that is shorter than the length of a data signal, a frequency for each predetermined pilot signal block is transitioned so as to guarantee frequency domain channel estimation performance. A cyclic prefix according to the length of the transitioned pilot signal is added to the pilot signal, a data signal is time division multiplexed together with the pilot signal, and a resultant signal is transmitted through an antenna. In advance to this, a position of a subcarrier for transmitting the pilot signal and the data signal is determined, a data signal is mapped on the determined subcarrier, and in this instance, diversity on the channel for a symbol is used to map the data signal on the transmission method using one of the localized FDMA (L-FDMA) channel and the distributed FDMA (D-FDMA) channel. Therefore, the frequency resolution in the frequency domain is maintained to thus provide high-quality channel estimation performance. | 02-25-2010 |
20100248634 | METHOD OF CYCLIC DELAY DIVERSITY WITH THE OPTIMAL CYCLIC DELAY VALUE, AND TRANSMITTER PERFORMING THE SAME - Disclosed are an apparatus and method of determining an optimal cyclic delay value. The method of determining the optimal cyclic delay value includes determining a Signal-to-Interference and Noise Ratio (SINR) function depending on a diversity order; determining a channel estimation error variance function; and determining an SINR being required for a system according to the SINR function and the channel estimation error variance function. | 09-30-2010 |
20100279600 | RELAY NETWORK AND ENTITY FOR CONTINUOUS TRANSMISSION BASED ON SUPERPOSITION CODING - Disclosed is a method of using relay that may continuously transmit data without time division based on superposition coding in a communication system. When transmission of a relay-supported user signal via a base station-relay link is performed, the method of using relay based on the superposition coding reuses a resource allocated to a direct-transmission user based on the superposition coding to perform the transmission. According to example embodiments, a separate resource for the base station-relay link may not be needed, and continuous relay transmission is possible without time division, thereby substantially increasing frequency efficiency and reducing a transmission delay caused by the use of the relay. | 11-04-2010 |
20110044313 | APPARATUS AND METHOD FOR TRANSMITTING DATA USING MULTIPLE ANTENNA FOR SINGLE CARRIER FREQUENCY DIVISION MULTIPLE ACCESS SYSTEM - Disclosed is a technique in which multiple antennas are applied to a mobile communication system using a single carrier frequency division multiple access method. | 02-24-2011 |
20110081902 | METHOD OF TRANSMITTING CONTROL INFORMATION USING PHYSICAL UPLINK SHARED CHANNEL REGION IN MIMO ANTENNA SYSTEM - Provided is a method of transmitting control information using a physical uplink shared channel (PUSCH) region in a system employing a multi-input multi-output (MIMO) antenna system in which transmission is performed through a plurality of layers. A method of transmitting a channel quality indicator (CQI)/precoding matrix indicator (PMI) using a PUSCH region in a system employing a MIMO antenna system in which transmission is performed through a plurality of layers includes encoding the CQI/PMI using one channel encoder, and transmitting the encoded CQI/PMI using some or all of the layers. Accordingly, it is possible to transmit uplink control information through a PUSCH region using a plurality of layers. | 04-07-2011 |
20110090987 | APPARATUS FOR TRANSMISSION AND RECEPTION WITH TRANSMIT DIVERSITY USING CYCLIC SUBCARRIER SHIFT - Provided is a technology adopting multiple transmit antennas in a radio communication system. In a mobile communication system of a signal carrier frequency division multiple access (SC-FDMA) scheme, it is possible to transmit data using the multiple transmit antennas, while maintaining a peak to average power ratio (PAPR) to be low. Also, it is possible to provide a new transmit diversity transmission even in a general radio communication system including an orthogonal frequency division multiple access (OFDMA), a code division multiple access (CDMA) scheme, and the like. | 04-21-2011 |
20110122812 | SEAMLESS SERVICE METHOD CONTROLLED BY USER TERMINAL - Provided are a seamless service method controlled by a user terminal, the method including: storing radio access technology (RAT) information and service flow information associated with a connecting radio access network (RAN); when a new link is detected, storing RAT information associated with the new link; verifying whether a new RAN satisfying a handover initiation criterion exists; when the new RAN exists, attempting a link connection with the new RAN; being assigned with an Internet Protocol (IP) to be used in the new RAN; setting up a handover service flow using the new RAN; and receiving a service via multiple paths using a connecting service flow and the handover service flow. Through this, it is possible to provide the seamless QoS even while the handover is being performed. | 05-26-2011 |
20110176632 | METHOD OF TRANSMITTING UPLINK DM-RS MULTIPLEXED WITH DATA IN UPLINK MIMO TRANSMISSION - Provided is a multi-layer transmission method of multiplexing and transmitting data and a demodulation reference signal (DM-RS) sequence in an uplink digital Fourier transform-spread-orthogonal frequency division multiplexing (DFT-S-OFDM) transmission employing multiple-input multiple-output (MIMO). The method includes allocating one DM-RS sequence as a DM-RS sequence of a first transmission layer for uplink transmission; allocating a DM-RS sequence whose cyclic shift (CS) value having the same sequence as the DM-RS sequence of the first transmission layer is configured to differ from that of the DM-RS sequence as a DM-RS sequence of a second transmission layer; and multiplexing layer-specific data and the layer-specific DM-RS sequences according to each of the first and second transmission layers. Accordingly, an RS can be transmitted in more OFDM symbols of a slot or subframe without an increase in overhead. Consequently, it is possible to satisfy requirements of LTE-advanced that a high frequency spectrum and a high mobile velocity should be supported, and transmit and receive a DM-RS multiplexed with data while maintaining orthogonality. | 07-21-2011 |
20110182187 | WIRELESS COMMUNICATION SYSTEM AND METHOD FOR PERFORMING COOPERATIVE DIVERSITY USING CYCLIC DELAY - A wireless communication system and method of performing cooperative diversity using cyclic delay is provided. A transmitting terminal constituting the wireless communication system includes: a data transmitter configured to transmit data to each of at least one relay terminal and a receiving terminal; an error detection result receiver to receive an error detection result from a relay terminal that detects an error in the data among the at least one relay terminal; and a data retransmitter configured to retransmit data to the receiving terminal when it is determined each of the at least one relay terminal detects the error in the data based on the error detection result. | 07-28-2011 |
20120087393 | REFERENCE SYMBOL STRUCTURE FOR DFT SPREAD OFDM SYSTEM - Provided is a data transmission apparatus to transmit a reference orthogonal frequency division multiplexing (OFDM) symbol generated by frequency division multiplexing a reference symbol and a data symbol, and a data reception apparatus to estimate a channel using the reference OFDM symbol. Since the reference symbol and the data symbol are frequency division multiplexed, a Peak to Average Power Ratio (PAPR) may not increase greatly, and the transmission apparatus may transmit the reference OFDM symbol to the data reception apparatus more frequently. Accordingly, the data reception apparatus may estimate a channel accurately. | 04-12-2012 |
20120195292 | CARRIER AGGREGATION IN WIRELESS COMMUNICATION SYSTEM - Provided is a data transmission system using a carrier aggregation. The data transmission system may assign a radio resource based on a correspondence relationship between a downlink and an uplink, and may transmit data using the assigned radio resource. | 08-02-2012 |
20120269285 | METHOD FOR GENERATING AND TRANSMITTING A REFERENCE SIGNAL FOR UPLINK DEMODULATION IN A CLUSTERED DFT-SPREAD OFDM TRANSMISSION SCHEME - Disclosed is a method for generating and transmitting a reference signal in a clustered DFT-spread OFDM transmission scheme. A method for generating and transmitting a DM-RS in a clustered DFT-spread-OFDM scheme comprises: a step of generating DM-RS sequences corresponding to the number of clusters allocated for an uplink transmission; and a step of mapping the generated DM-RS sequences to the relevant DM-RS symbol positions for each cluster. Accordingly, the method for generating and transmitting a reference signal according to the present invention, in which DM-RS sequences are allocated and transmitted on a cluster basis, uses a complete DM-RS sequence for each cluster, and therefore inter-cell interference can be weakened, and problems which might occur when applied to a multi-user MIMO (MU-MIMO) scheme can be solved. | 10-25-2012 |
20120288021 | SECONDARY TRANSMITTER INCLUDED IN COGNITIVE RADIO COMMUNICATION SYSTEM AND COMMUNICATION METHOD OF THE SECONDARY TRANSMITTER - Provided is a communication method of a secondary transmitter included in a multiple-antenna based multiple input multiple output (MIMO) cognitive radio communication system, the method including: estimating an interference channel between the secondary transmitter and a primary user in each of at least one first spectrum band that is being used in a primary system; calculating an orthogonal projection matrix to cancel interference with respect to the primary user from the interference channel; calculating an effective channel between the secondary transmitter and a secondary receiver based on the to orthogonal projection matrix; and selecting an index of an optimal spectrum band from the at least one first spectrum band based on the orthogonal projection matrix and the effective channel. | 11-15-2012 |
20120289266 | COGNITIVE RADIO BASE STATION AND COMMUNICATION METHOD THEREOF IN MULTI-USER MULTIPLE-INPUT MULTIPLE OUTPUT COGNITIVE RADIO NETWORK SYSTEM - A communication method for a cognitive radio (CR) base station in a multi-user multiple-input multiple-output (MIMO) CR communication system including the CR base station and CR terminals, may include calculating, from an interference channel, an orthogonal projection matrix to be used for removing interference on a primary user through use of a zero forcing (ZF) processing scheme, and obtaining a beamforming weight vector for each of the CR terminals, through use of the orthogonal projection matrix. | 11-15-2012 |
20120320883 | METHOD FOR TRANSMITTING ACK/NACK INFORMATION TO UPLINK PHYSICAL CONTROL CHANNEL - Disclosed is a communication system which transmits Acknowledgement (ACK)/Negative Acknowledgement (NACK) information on downlink data by using an uplink control channel. The communication system individually allocates radio resources for a plurality of slots included in an uplink subframe. Consequently, uplink radio resources may be used freely, and it is even possible to flexibly handle a situation in which the amount of the ACK/NACK information is increased. | 12-20-2012 |
20130121130 | CARRIER AGGREGATION IN WIRELESS COMMUNICATION SYSTEMS - Provided is a data transmission system using a carrier aggregation. The data transmission system may assign a radio resource based on a correspondence relationship between a downlink and an uplink, and may transmit data using the assigned radio resource. | 05-16-2013 |
20130155977 | METHOD OF TRANSMITTING CONTROL INFORMATION USING PHYSICAL UPLINK SHARED CHANNEL REGION IN MIMO ANTENNA SYSTEM - Provided is a method of transmitting control information using a physical uplink shared channel (PUSCH) region in a system employing a multi-input multi-output (MIMO) antenna system in which transmission is performed through a plurality of layers. A method of transmitting a channel quality indicator (CQI)/precoding matrix indicator (PMI) using a PUSCH region in a system employing a MIMO antenna system in which transmission is performed through a plurality of layers includes encoding the CQI/PMI using one channel encoder, and transmitting the encoded CQI/PMI using some or all of the layers. Accordingly, it is possible to transmit uplink control information through a PUSCH region using a plurality of layers. | 06-20-2013 |
20130163572 | COMMUNICATION METHOD USING A PREAMBLE TO SHARE CHARACTERISTIC INFORMATION, METHOD FOR GENERATING THE PREAMBLE, AND COMMUNICATION SYSTEM TO WHICH THE METHODS ARE APPLIED - A communication method of a transmitter using a preamble in a wireless communication system, includes determining at least two subcarriers from among a plurality of subcarriers, for the preamble; mapping a subcarrier sequence and a subcarrier phase value of the preamble to the at least two subcarriers; and transmitting the preamble using the at least two subcarriers. The preamble may include a real component having a first repeated pattern in a preset time interval, and an imaginary component having a second repeated pattern in the preset time interval, and a relationship between the first repeated pattern and the second repeated pattern may indicate characteristic information of the wireless communication system. | 06-27-2013 |
20130163575 | CONTENTION BASED CHANNEL OCCUPYING METHOD IN WIRELESS NETWORK USING A PLURALITY OF CHANNELS - Disclosed is a contention based channel occupying method in a wireless network using a plurality of channels, including: acquiring, by terminals that are incapable of transmitting a data frame through primary contention, occupation channel information from a terminal that transmits the data frame through the primary contention; verifying, by the terminals, an occupiable channel based on the occupation channel information; and performing, by the terminals, secondary contention in the occupiable channel. | 06-27-2013 |
20130176960 | APPARATUS AND METHOD FOR COGNITIVE RADIO MESH NETWORK BASED ON GEOLOCATION DATABASE - A cognitive radio mesh node may include at least one directional antenna, at least one transceiver to transmit and receive data using the at least one directional antenna, and a processor to determine a channel for performing communication for a cognitive radio mesh network based on a geolocation database and to control the at least one transceiver based on the determined channel. | 07-11-2013 |
20130184025 | WHITE SPACE USE SYSTEM WITH CONNECTING COGNITIVE SIGNAL - Provided is a white space use system using a connection recognition signal, which is associated with technology that enables white space devices to search for and to use an available frequency band in a digital broadcasting system. In particular, provided is a white space use system using a connection recognition signal that enables even devices incapable of autonomously searching for an available channel to safely use a white space in interaction with white space devices. | 07-18-2013 |
20130223488 | APPARATUS FOR WIDEBAND TRANSMISSION AND RECEPTION FOR MULTIBAND - A wideband transmitting and receiving apparatus including a local oscillator (LO) synthesizer providing a constant output to a wide band is provided. The LO synthesizer may generate LO signals of different amplitudes according to channels. The LO synthesizer may store the amplitudes of the LO signals different according to the channels and compensate the amplitudes of the LO signals using the stored amplitudes. Accordingly, the LO synthesizer may output the LO signals of uniform amplitudes irrespective of the channels. | 08-29-2013 |
20130267266 | METHOD OF COMMUNICATING BETWEEN BASE STATION AND TERMINAL BASED ON INTERFERENCE ALIGNMENT IN MULTI-CELL MULTI-USER MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) INTERFERENCE CHANNEL AND METHOD AND APPARATUS OF COMMUNICATION USING INTERFERENCE ALIGNMENT AND BLOCK SUCCESSIVE INTERFERENCE PRE-CANCELLATION IN MULTI-USER MULTIPLE-INPUT MULTIPLE-OUTPUT INTERFERENCE CHANNEL - A communication method of a base station and a terminal based on interference alignment in a multi-cell multi-user multiple-input multiple-output (MIMO) interference channel and a method and apparatus of communication using interference alignment and block successive interference pre-cancellation in a multi-user MIMO interference channel. The base station may determine a precoding matrix to maximize a signal to interference and noise ratio (SINR) and a signal to leakage and noise ratio (SLNR) in the interference channel, and a terminal communicating with the base station may determine a decoding matrix to align interference. The transmitter including a multicell interference channel may calculate a rotation matrix for interference alignment, identify effective symbol vectors using the rotation matrix, and generate a transmit signal of a target transmitter to pre-cancel interference corresponding to a transmit signal of a neighboring transmitter. | 10-10-2013 |
20130336175 | METHOD AND APPARATUS FOR DUPLEX IN COGNITIVE RADIO COMMUNICATION SYSTEM - Provided is a method for duplex in a cognitive radio communication system, including: collecting radio environment information including information of usable radio resources; determining a duplex scheme for each radio resource based on the radio environment information; and allocating at least one of the radio resources to information to be transmitted and received, depending on characteristics of the information. | 12-19-2013 |
20130336180 | CARRIER AGGREGATION APPARATUS FOR EFFICIENTLY UTILIZING FREQUENCY RESOURCE OF LICENSE BAND AND SHAREABLE BANDS, AND OPERATION METHOD THEREOF - An exemplary embodiment provides a carrier aggregation apparatus including: a level assignment manager configured to perform management by classifying a license band allocated to a cognitive radio cell into a primary radio resource (PRR) level, and by classifying a shareable band obtained through a cognitive radio database or spectrum sensing into an auxiliary radio resource (ARR) level; a determiner configured to determine a quality of service (QoS) level of a communication service provided to the cognitive radio cell; and a service provider configured to allocate a frequency resource of the PRR level when the QoS level requires a first communication service, and to allocate a frequency resource of the ARR level when the QoS level requires a second communication service lower than the first communication service. | 12-19-2013 |
20140016578 | METHOD AND APPARATUS FOR ALLOCATING OPERATING CHANNEL PRIORITY BETWEEN FREQUENCY SHARING SYSTEMS - Disclosed is a method for improving the efficiency of sharing a frequency between a plurality of adjacent systems using an idle band. A method for allocating an operating channel priority between frequency sharing systems according to the present invention includes: a coarse channel priority allocating operation of collecting information about a target white space object (WSO) for priority allocation of an operating channel and information about the operating channel, and classifying the operating channel based on a predetermined criterion; and a fine channel priority allocating operation of removing the operating channel by checking an interference level of the classified operating channel. | 01-16-2014 |
20140016609 | METHOD FOR GENERATING AND TRANSMITTING A REFERENCE SIGNAL FOR UPLINK DEMODULATION IN A CLUSTERED DFT-SPREAD OFDM TRANSMISSION SCHEME - Disclosed is a method for generating and transmitting a reference signal in a clustered DFT-spread OFDM transmission scheme. A method for generating and transmitting a DM-RS in a clustered DFT-spread-OFDM scheme comprises: a step of generating DM-RS sequences corresponding to the number of clusters allocated for an uplink transmission; and a step of mapping the generated DM-RS sequences to the relevant DM-RS symbol positions for each cluster. Accordingly, the method for generating and transmitting a reference signal according to the present invention, in which DM-RS sequences are allocated and transmitted on a cluster basis, uses a complete DM-RS sequence for each cluster, and therefore inter-cell interference can be weakened, and problems which might occur when applied to a multi-user MIMO (MU-MIMO) scheme can be solved. | 01-16-2014 |
20140018117 | COEXISTENCE MANAGEMENT SYSTEM FOR MEASURING CHANNEL INFORMATION BETWEEN SPECTRUM SHARING DEVICES AND METHOD THEREOF - Provided are a coexistence management system for measuring channel information between spectrum sharing devices and a method thereof. The coexistence management system for measuring channel information between spectrum sharing devices according to the exemplary embodiment of the present invention includes: a plurality of coexistence enablers (CEs) which is provided for each of the plurality of white space objects (WSOs) having at least one measurement capability of measuring channel information on an operation channel that is being used; a coexistence manager (CM) which is linked with at least one CE within a group to confirm measurement capability of a corresponding WSO and receives channel information on the operation channel from one or more WSOs within another neighboring groups according to the confirmed result; and a coexistence discovery and information server (CDIS) which registers at least one measurement capability for each of the plurality of WSOs. | 01-16-2014 |
20140043955 | CARRIER AGGREGATION IN WIRELESS COMMUNICATION SYSTEMS - Provided is a data transmission system using a carrier aggregation. The data transmission system may assign a radio resource based on a correspondence relationship between a downlink and an uplink, and may transmit data using the assigned radio resource. | 02-13-2014 |
20140080530 | METHOD FOR CALCULATING FAIRNESS INDEX AND METHOD FOR ALLOCATING RESOURCES BASED ON THE FAIRNESS INDEX IN COEXISTENCE MANAGEMENT SYSTEM - Provided is a method of calculating a fairness index that is a criterion indicating fairness of resource allocation between coexistence managers in a coexistence management system, the method including: calculating a normalized resource allocation amount by normalizing an amount of resources allocated to a corresponding coexistence manager to an amount of resources required by the corresponding coexistence manager with respect to each of the coexistence managers; and calculating the fairness index using the normalized resource allocation amounts calculated with respect to the respective coexistence managers. | 03-20-2014 |
20140126617 | SIGNAL COMPRESSION APPARATUS AND METHOD FOR DYNAMIC COMPRESSIVE SENSING USING SPARSITY INFORMATION OF INPUT SIGNAL - Disclosed are a signal compression apparatus and method for dynamic compressive sensing, including: a signal input unit configured to simultaneously output an input signal, and generate and output a linear measurement reference signal based on the input signal; a linear transform unit configured to receive the linear measurement reference signal and variably generate a linear measurement matrix value according to the linear measurement reference signal; a signal compressor configured to output a compressed signal for the input signal based on the generated linear measurement matrix value; and a signal processor configured to reconstruct the compressed signal and perform spectrum sensing of the input signal. Accordingly, it is possible to increase signal compression efficiency of compressive sensing and improve signal reconstruction performance by using sparsity information of the input signal, and also by performing signal compression by using a compression matrix suitable for the sparsity information of the input signal. | 05-08-2014 |
20140162715 | CHANNEL INFORMATION PROVIDING METHOD, CHANNEL INFORMATION PROVIDING DATABASE SERVER, AND CHANNEL INFORMATION PROVIDING SYSTEM - The present invention provides a channel information providing method, a channel information providing database server, and a channel information providing system which receive channel quality information from a cognitive radio terminal which receives channel information based on position information and efficiently use channels using the received information. A channel information providing method which uses a database server to provide channel information to a cognitive radio terminal based on position information includes providing channel information to at least one cognitive radio terminal; receiving collected information regarding a quality of the channel from the at least one cognitive radio terminal; and determining to update the channel information provided in the providing using the information received in the receiving. | 06-12-2014 |
20140171072 | APPARATUS AND METHOD OF CALCULATING AVAILABLE CHANNELS CONSIDERING PRIORITY IN TVWS - Disclosed are an apparatus and a method of calculating available channels considering a priority in a TVWS. An apparatus for calculating available channels considering a priority in a TVWS according to the present invention includes: a communication module configured to receive a request for information on usable available channels from a TV Band Device (TVBD); an available channel calculation unit configured to calculate one or more available channels usable by the TVBD based on one or more predetermined reference parameters according to the request; a priority assignment unit configured to assign a priority to each of the calculated available channels, generate an available channel list including the available channels to which the priorities are assigned, and provide the TVBD with the generated available channel list; and a database configured to store the available channels, to which the priorities are assigned, calculated for each TVBD. | 06-19-2014 |
20140179247 | APPARATUS AND METHOD FOR CONTROLLING TRANSMITTING POWER OF WIRELESS DEVICE - Provided is an apparatus and method for controlling a transmission output of a radio device using a television (TV) band based on a frequency band, the apparatus including a frequency band selecting unit to select frequency bands to be compared, a radio wave attenuation calculation unit to calculate a radio wave attenuation for each of the selected frequency bands, and a transmission output control unit to automatically control the transmission output of the radio device using a TV band based on a difference value among the calculated attenuation values. According to an example embodiment, it is possible to extend a service area while sufficiently protecting a service being provided in the TV band, thereby realizing an efficient use of frequency resources. | 06-26-2014 |
20140185458 | METHOD FOR MANAGING ERROR IN MULTICAST OR BROADCAST TRANSMISSION AND APPARATUS THEREOF - Disclosed are a method of managing an error in wireless transmission, and an apparatus thereof, and more particularly, a method of managing an error in multicast or broadcast transmission, and an apparatus thereof. The method of managing an error in multicast or broadcast transmission disclosed in the present invention includes: receiving data multicasted or broadcasted to a plurality of receivers; determining whether the data is normally received; selecting a random resource among wireless resources through which an acknowledgement indicating whether the data is normally received is to be transmitted; and transmitting the acknowledgement indicating whether the data is normally received through the selected random resource. | 07-03-2014 |
20140198836 | METHOD AND APPARATUS FOR WIDEBAND SPECTRUM SENSING USING COMPRESSIVE SENSING - Disclosed is a method for wideband spectrum sensing using compressive sensing, the method including: acquiring a sampling signal by applying a modulated wideband converter (MWC) to a received signal; and acquiring a restoration signal corresponding to the received signal by using a compressive sensing restoration algorithm from the sampling signal, and a mixing signal multiplied by the received signal at the time of applying the MWC, as a signal transformed from a first mixing signal having a periodic waveform, includes a second mixing signal to remove a partial frequency area from the received signal through the application of the MWC. | 07-17-2014 |
20140200017 | COGNITIVE RADIO APPARATUS AND COMMUNICATION METHOD THEREOF - To perform communication in a cognitive radio network, a cognitive radio apparatus according to an exemplary embodiment includes: an estimation module configured to generate a channel estimation signal to be transmitted to a predetermined reception apparatus positioned in a predetermined channel in the case of selecting the predetermined channel from among multiple channels; a communication module configured to transmit the channel estimation signal to the predetermined reception apparatus, and to receive a channel response signal from the predetermined reception apparatus; and a control module configured to control the communication module so that at least one of a communication signal set with respect to the predetermined channel and a variable communication signal obtained by varying the communication signal is transmitted to the predetermined reception apparatus, when it is determined that the predetermined channel is positioned in a deep fading section based on the channel response signal. | 07-17-2014 |
20140357279 | METHOD FOR PERFORMING SEAMLESS GROUP HANDOVER FOR SUPPORTING PORTABLE TV BAND DEVICE BASED ON TV WHITE SPACE - An method for performing a TVBD (TV Band Device) group handover based on TV white space by an AP (Access Point), the method comprising: transmitting multiple location information corresponding to a path along which a mobile vehicle travels to an available channel information providing server; receiving multiple geo-location information from the available channel information providing server as a reply to the transmitted multiple location information; extracting operating channel set information so as to minimize a channel switching caused by the travel of the mobile vehicle, based on the multiple geo-location information; and transmitting the extracted operating channel set information to a TVBD group. | 12-04-2014 |
20150072700 | METHOD AND DEVICE FOR MANAGING BACKUP CHANNELS FOR COGNITIVE RADIO COMMUNICATION - Provided is an apparatus and method for managing a backup channel for cognitive radio communication that may group at least one device included in a cell served by a base station, and allocate backup channels for cognitive radio communication to the groups, based on location information and mobility of the groups. | 03-12-2015 |