| Patent application number | Description | Published |
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| 20100260106 | NETWORK COMMUNICATION METHOD AND NETWORK DEVICE USING PREAMBLE - Provided are a network communication method and a network device using a preamble. According to the network communication method and the network device, network coexistence is easily achieved by using network identification transmitted in the preamble, and an unknown terminal, which has a low reception signal to noise ratio (SNR) and has not yet been connected to an existing network, is easily connected to the existing network. | 10-14-2010 |
| 20100265871 | BEACON RE-BROADCASTING APPARATUS, BEACON RE-BROADCASTING METHOD, AND INITIAL ACCESS REQUEST METHOD IN WIRELESS NETWORK - Provided are a beacon re-broadcasting apparatus, a beacon re-broadcasting method, and an initial access request method in a wireless network. In the re-broadcasting apparatus and method, a beacon frame including beacon information for communications in the wireless network and information on an echo beacon slot allocated for beacon re-broadcasting among time slots of a superframe is received from a management device for managing the wireless network in which a plurality of terminals communicated with each other through the superframe including time-divided time slots, and the beacon information is re-broadcasted during the echo beacon slot. Accordingly, the beacon information can be received in various environments, and the beacon information can be received to an adjacent network in addition to the corresponding network. Therefore, frequency resources can be shared and effectively used between networks, and convenience and efficiency in network operation can be maximized. | 10-21-2010 |
| 20100272039 | METHOD OF MANAGING MULTIPLE CHANNELS IN SINGLE NETWORK AND NETWORK MANAGEMENT DEVICE - Provided are a method of managing multiple channels in a single network, and a network management device, also referred to as a network management system. According to the method and the network management device, all devices in one network that operate by using multiple channels share core information, and are effectively controlled. | 10-28-2010 |
| 20100290416 | CHANNEL SWITCHING APPARATUS AND METHOD OF A BASE STATION AND CHANNEL SWITCHING APPARATUS AND METHOD OF A TERMINAL BASED ON THE COGNITIVE RADIO SYSTEM - In a cognitive radio system, when communication in an operational channel is determined to be discontinued due to that an incumbent user (IU) entering the operational channel that is currently being used or due to that an excessive interference occurring in the operational channel, the operational channel is switched to a pre-arranged channel. However, since some parameters are different between the operational channel and the pre-arranged channel, an initialization procedure has to be performed to allow the cognitive radio system to be adapted to those some parameters. Since an initialization technique aiming for this situation is not developed yet, a conventional cognitive radio system uses a general initialization technique used to initially operate a system. However, the general initialization technique has to allow the system to be adapted to many parameters so that it takes a relatively long initialization time. A channel switching apparatus and method thereof of a base station, which allocates a slot for data exchange with each of a plurality of terminals in a frequency channel that is not used by the IU and thus performs communication, include transmitting a channel switching message for requesting to switch to a backup channel when a signal of the IU is sensed in the frequency channel; transmitting a beacon frame via the backup channel, wherein the beacon frame comprises allocation information about slots which are in the frequency channel and which are respectively allocated to each of the plurality of terminals; and allocating the slot for data exchange with each of the plurality of terminals to the backup channel according to the allocation information, and communicating with each of the plurality of terminals. By doing so, frequency resources between each of networks can be efficiently used, and convenience and efficiency with respect to network operation can be maximized. | 11-18-2010 |
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| 20090135713 | METHOD FOR USING FLEXIBLE BANDWIDTH IN OFDMA-BASED COGNITIVE RADIO SYSTEM, BASE STATION AND SUBSCRIBER STATION USING THE SAME - Provided are a method for using a flexible bandwidth in an orthogonal frequency division multiple access (OFDMA)-based cognitive radio system, and a base station (BS) and a subscriber station using the method. The method includes: allocating a channel band from among unused channel bands having a bandwidth that is a natural number times a bandwidth resolution to customer premises equipment (CPE), wherein the bandwidth resolution is a predetermined bandwidth smaller than a bandwidth of a broadcast channel band, and transmitting an OFDMA-based signal comprising band allocation information indicating information regarding the allocated channel band. | 05-28-2009 |
| 20100202401 | METHOD AND APPARATUS OF HYBRID BURST MAPPING IN OFDMA SYSTEMS - Provided are a method of adaptively allocating appropriate hybrid bursts according to terminal attributes including terminal position, channel state, and service type in an orthogonal frequency-division multi-access (OFDMA) system, and an upstream-MAP information element (US-MAP IE) structure supporting the method. The method includes dividing an upstream subframe into a plurality of zones depending on the number of OFDMA symbols and allocating bursts of a zone to a terminal according to the terminal attributes. Bursts are formed by allocating slots along a time axis in the upstream subframe, and are formed by allocating slots along a frequency axis in a downstream subframe. | 08-12-2010 |
| 20110129026 | METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING DATA USING FREQUENCY DIVERSITY SCHEME - Provided are a transmitter and a receiver. The transmitter combines N data signals received from an encoded bit stream to generate N symbols; maps the N symbols to subcarriers that are spaced more than a coherent bandwidth apart; and receives and moves the N symbols, which are mapped to the subcarriers that are spaced more than a coherent bandwidth apart, to their own positions. The receiver demodulates N pieces of data using the N symbols received from the transmitter in a manner similar to that used by the transmitter. | 06-02-2011 |
| 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 |
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| 20090274174 | METHOD OF GENERATING PILOT PATTERN FOR ADAPTIVE CHANNEL ESTIMATION IN OFDMA SYSTEMS, METHOD OF TRANSMITTING/RECEIVING USING THE PILOT PATTERN AND APPARATUS THEREOF - Provided is a method of generating a pilot pattern capable of perform adaptive channel estimation, and a method and apparatus of a base station and a method and apparatus of a terminal using the pilot pattern. The pilot pattern selects pilot symbol positions based on distances from pilots of previous orthogonal frequency division multiple access (OFDMA) symbols to a subcarrier position of a current OFDMA symbol in the frequency domain and the time domain, so that a low pilot density is maintained so as to effectively transmit data, and stable channel estimation performance can be obtained even in a bad channel environment. In addition, the minimum burst allocation size is determined according to the channel environment between the base station and the terminal, guaranteeing channel estimation performance suitable for the channel environment, and improving granularity, channel estimation latency, and channel estimation memory size. | 11-05-2009 |
| 20110116411 | METHOD OF GENERATING PILOT PATTERN FOR ADAPTIVE CHANNEL ESTIMATION IN OFDMA SYSTEMS, METHOD OF TRANSMITTING/RECEIVING USING THE PILOT PATTERN AND APPARATUS THEREOF - Provided is a method of generating a pilot pattern capable of perform adaptive channel estimation, and a method and apparatus of a base station and a method and apparatus of a terminal using the pilot pattern. | 05-19-2011 |
| 20110116516 | METHOD OF GENERATING PILOT PATTERN FOR ADAPTIVE CHANNEL ESTIMATION IN OFDMA SYSTEMS, METHOD OF TRANSMITTING/RECEIVING USING THE PILOT PATTERN AND APPARATUS THEREOF - Provided is a method of generating a pilot pattern capable of perform adaptive channel estimation, and a method and apparatus of a base station and a method and apparatus of a terminal using the pilot pattern. | 05-19-2011 |
