Patent application number | Description | Published |
20110045862 | APPARATUS AND METHOD FOR COMMUNICATION IN COGNITIVE RADIO NETWORK - A CR apparatus for performing communication in a CR network includes: a communication unit configured to measure a channel estimation signal, transmit measured channel state information to a master device, and, when a QP of a reference channel arrives, make a communication channel transition to a candidate channel and perform communication; and a channel information management unit configured to receive and manage the channel state information measured by the communication unit and channel information comprising a candidate channel, into which a channel transition is to be made during a QP of the reference channel, received from the master device and control channel transition of the communication unit based on the channel information. | 02-24-2011 |
20110103320 | CONTENTION-BASED DATA COMMUNICATION APPARATUS AND METHOD - Provided is a contention-based data communication apparatus and method that may notify that a radio resource is to be used using a search signal prior to transmitting a communication frame, and may transmit data based on a priority when a search signal received from another communication apparatus is detected. | 05-05-2011 |
20110149889 | METHOD AND DEVICE FOR COMMUNICATION BETWEEN DEVICES WITH DIFFERENT TRANSMISSION COVERAGE - Provided is a large range management device (LRMD) of managing a communication between a plurality of small range devices (SRDs) and a plurality of large range devices (LRDs), the SRDs and the LRDs being located in a single cell and having different transmission coverage, the LRMD including an access slot allocation unit to allocate an SRD access slot to a radio resource for a downlink, to enable a first SRD to request an association from a network, a selection unit to select a communication relay device for relaying relay data of the first SRD, a relay slot allocation unit to allocate at least one SRD relay slot to a radio resource for an uplink, to enable the communication relay device to relay the relay data to a second SRD or another LRD, and a receiving unit to receive the relay data based on the at least one SRD relay slot | 06-23-2011 |
20110167321 | APPARATUS AND METHOD OF TRANSMITTING AND RECEIVING DATA FOR IMPROVING TRANSMISSION RATE - A data transmitter and receiver for improving a data rate, and more particularly, to an apparatus and method of transmitting and receiving an orthogonal frequency division multiplexing (OFDM) symbol in which a pilot signal is added to a data signal is provided. The apparatus includes a transmitter including: a pilot adder to add a pilot signal to a data signal; and a guard interval inserting unit to insert a guard interval to the data signal with the added pilot signal, and a receiver including: a guard interval removal unit to remove a guard interval in a received time domain signal; a fast Fourier transform (FFT) unit to transform the time domain signal in which the guard interval is removed to a frequency domain signal; a channel estimator to estimate a channel value from the time domain signal in which the guard interval is removed; an equalizer to equalize the frequency domain signal based on the estimated channel value; and a pilot signal removal unit to remove the pilot signal in the equalized frequency domain signal. | 07-07-2011 |
20110200129 | METHOD OF TRANSMITTING AND RECEIVING ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) SIGNAL USING MULTIPLE ANTENNAS, AND TRANSMITTER AND RECEIVER THEREOF - Provided is a transmitter for transmitting an orthogonal frequency division multiplexing (OFDM) signal using multiple antennas, including: a subgroup generator to divide data symbols of a frequency domain into a plurality of subgroups; an inverse fast Fourier transform (IFFT) unit to perform an IFFT with respect to each of the subgroups so as to generate partial signals of a time domain corresponding to the plurality of subgroups, respectively; a candidate OFDM signal generator to generate at least two candidate OFDM signals using a combination of the partial signals so that each of the partial signals is transmitted to one of transmit antennas; and a selector to select one of the at least two candidate OFDM signals. | 08-18-2011 |
20110243089 | HYBRID BEACONING METHOD - Provided is a hybrid beaconing method in which a centralized beaconing scheme and a distributed beaconing scheme are combined. In the hybrid beaconing method, a beaconing scheme is converted according to a network condition, and a centralized beaconing scheme or a distributed beaconing scheme is used to maintain an optimum network status | 10-06-2011 |
20120100883 | TRANSMISSION POWER CONTROL METHOD AND DEVICE FOR COGNITIVE RADIO DEVICE - A method and an apparatus for controlling transmit power of a CR device are provided. The method includes acquiring CR environment information regarding a licensed user or an unlicensed user occupying an adjacent channel or an adjacent cell of the CR device; determining a transmit power value of the CR device using the CR environment information; and generating transmit power control information including the transmit power value. The method and apparatus guarantee reliable communication of the CR device and minimize interference with the licensed user. | 04-26-2012 |
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 |
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 |
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 |
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 |