Patent application number | Description | Published |
20090016293 | METHOD FOR SENSING SPECTRUM AND ARRANGING QUIET PERIOD IN COGNITIVE RADIO SYSTEM, CUSTOMER PREMISE EQUIPMENT, BASE STATION AND SUPERFRAME STRUCTURE USING THE SAME - Provided are methods of spectrum sensing and assigning quiet periods in a cognitive radio system in order to increase the reliability of detection regarding whether an incumbent user appears in his/her frequency channel, customer premises equipment (CPE), a base station, and the structure of a super frame for performing the methods. The spectrum sensing method includes communicating with a base station (BS) and performing spectrum sensing for frequency channels having quiet periods (QPs) during the QPs of the frequency channels used in the cognitive radio system, wherein the QPs of the frequency channels do not overlap each other | 01-15-2009 |
20090039943 | MIXER AND TRANSCEIVER HAVING THE MIXER - Provided are a mixer and a transceiver having the mixer. The mixer includes: an local oscillation (LO) differential signal generator converting an input LO signal into a differential signal; and a mixing unit receiving the LO differential signal as a first input and a first signal having a first frequency as a second input and performing differential amplification on the LO differential signal and the first signal to output a second signal having a second frequency. | 02-12-2009 |
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 |
20090161610 | METHOD OF FREQUENCY CHANNEL ASSIGNMENT USING EFFECTIVE SPECTRUM SENSING IN MULTIPLE FREQUENCY ASSIGNMENT SYSTEM - Provided is a method of assigning a frequency channel using efficient spectrum sensing in a multiple Frequency Assignment (FA) system. The method includes a channel sensing process, wherein abase station (BS) of a secondary user classifies multiple frequency channels licensed to a primary user into a plurality of channel states by changing a sensing period according to the types of classified channel state sets, and manages the sensed channel states as frequency channel state set information; a channel state set broadcasting process, wherein the BS transmits the frequency channel state set information manage d in the channel sensing process to secondary user terminals using a broadcast message; and a channel assigning process, wherein if the BS receives a channel assignment request message from a new secondary user terminal which has received the broadcast message, the BS assigns an unused frequency channel from among frequency channels licensed to the primary user to the new secondary user terminal using the frequency channel state set information. Accordingly, a frequency channel can be assigned to a secondary user requesting channel assignment using frequency channel state set information without a primary user experiencing interference noise. | 06-25-2009 |
20090190537 | METHOD, APPARATUS FOR DYNAMIC RESOURCE ALLOCATION METHOD IN OFDMA-BASED COGNITIVE RADIO SYSTEM AND FORWARD LINK FRAME STRUCTURE THEREOF - Provided are a dynamic resource allocation method and apparatus in an Orthogonal Frequency Division Multiple Access (OFDMA)-based cognitive radio system and a downlink frame structure of the method and apparatus. The method includes a base station (BS) selecting one of an Adaptive Modulation and Coding (AMC) subchannel allocation scheme, in which a subchannel comprising at least one bin comprising a first plurality of continuous subcarriers in a frequency domain, is allocated, and a diversity subchannel allocation scheme, in which a subchannel comprising a second plurality of scattered subcarriers in the frequency domain is allocated, according to a level of frequency selectivity of an unused idle frequency band; and the BS allocating at least one subchannel to a terminal according to the selected subchannel allocation scheme. Accordingly, downlink throughput in the cognitive radio system can be increased. | 07-30-2009 |
20090196362 | TRANSMISSION METHOD AND APPARATUS FOR ALLOCATING SUBCHANNEL AND FORMING STATIONARY BEAM TO MAXIMIZE TRANSMISSION EFFICIENCY IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING/MULTIPLE ACCESS BASED WIRELESS COMMUNICATION SYSTEM - Provided are a transmission method and apparatus for allocating a subchannel and forming a stationary beam to maximize transmission efficiency in an OFDMA based wireless communication system. The method includes determining the subchannel for the equipment of each user based on the channel state of the equipment of each user, determining a beam index for the equipment of each user, based on location information and direction of arrival information of the equipment of each user, generating an OFDM symbol by mapping a modulation symbol corresponding to the equipment of each user to the determined subchannel, and transmitting the generated OFDM symbol to a wireless space by forming a beam following the determined beam index. Using the method, the equipment of each user can be allocated with an advantageous subchannel, can remove an interference signal at low cost, and can increase total throughput of an OFDMA system downlink. | 08-06-2009 |
20090219909 | METHOD FOR SWITCHING AND MANAGING FREQUENCY ACCESS IN COGNITIVE RADIO SYSTEM, BASE STATION AND SUBSCRIBER STATION USING THE SAME - Provided are a channel switching method for effectively performing channel switching in a cognitive radio system while protecting an incumbent user, a method of managing a frequency channel, and a base station and customer premises equipment (CPE) using the methods. In the channel switching method performed by the base station, a currently unavailable first frequency channel is detected from among at least one uplink/downlink frequency channel which is set as a communication channel with the CPE; a channel switching request message requesting switching from the first frequency channel to a second frequency channel is transmitted to the CPE; and the first frequency channel is switched to the second frequency channel when a channel switching report message reporting that channel switching is to be performed in response to the channel switching request message is received from the CPE. | 09-03-2009 |
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 |
20100040080 | METHOD OF AND APPARATUS FOR ALLOCATING SUB-CHANNELS IN ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS (OFDMA) SYSTEM - A method and apparatus for allocating subchannels in an orthogonal frequency division multiple access (OFDMA) system is provided. In the method and apparatus, mixed bands in each of which adjacent subcarriers and distributed subcarriers are mixed are used to form a band of a basic physical resource. Accordingly, diversity subchannels each comprised of distributed subcarriers distributed over the whole band and band subchannels each comprised of adjacent subcarriers adjacent to parts of the band are formed in a single OFDMA symbol, thereby simultaneously and flexibly allocating subchannels to users. | 02-18-2010 |
20100087216 | RELAY STATION FOR CELL INFORMATION EXCHANGE BETWEEN ADJACENT BSs OVER AIR LINKS IN CELLULAR SYSTEMS - The present invention relates to relay customer premises equipment (RCPE) for exchanging operational information and coexistence information of each cell between adjacent cells in a cellular system. The present invention enables effective control between multiple cells by directly transmitting operational information and coexistence information between cells over air links. | 04-08-2010 |
20100151799 | TRANSCEIVER USING MILLIMETER-WAVE - Provided is a transceiver using a millimeter-wave (MM-wave). The transceiver determines output power of a transmitting signal according to a receiving signal of a receiving end in the same device so that a possible loss value occurring in the air may be predicted. By doing so, performance of a whole link budget may be enhanced, and the transmitting signal may be rapidly controlled. | 06-17-2010 |
20100161545 | DATA INTEGRATION APPARATUS AND METHOD - Provided are a data integration apparatus and method using a weight factor. The data integration apparatus receives sensing information from at least one sensing device, the sensing information including a value indicating the existence of signals and confidence estimated parameters indicating the degree of confidence for the value indicating the existence of signals, and then generates the weighting factor based on the confidence estimated parameters. Then, the value indicating the existence of signals and the weighting factor are used to produce characteristic values of each sensing device and to finally determine the existence of signals. | 06-24-2010 |
20100172316 | RESOURCE ALLOCATION METHOD FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING ACCESS SYSTEM - A resource allocation method for an orthogonal frequency division multiplexing access (OFDMA) system is provided. The resource allocation method includes dividing a frequency band occupied by a predetermined number of OFDM symbols into a plurality of subbands and determining the number of diversity subchannels, each of which comprises at least two time-frequency resources respectively included in different subbands, and the number of subband selective subchannels, which comprise time-frequency resources that are not included in the diversity subchannels; and generating the diversity subchannels and the subband selective subchannels according to the determined numbers and allocating a physical channel comprised of a generated subchannel to a user in a cell. Accordingly, diversity is enhanced without reducing the freedom of selection of a subband. | 07-08-2010 |
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 |
20100240407 | Method and System for Managing Channel Set for Dynamic Channel Allocation - Provided are a method and an apparatus for managing a channel set in a cognitive radio (CR) communication system. A CR communication system for dynamically allocating frequencies or channels manages vacant channels regularly so as to set an appropriate priority to usage of the vacant channels such that a channel set can be managed efficiently. | 09-23-2010 |
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 |
20100283550 | MULTI-OUTPUT OSCILLATOR USING SINGLE OSCILLATOR AND METHOD OF GENERATING MULTIPLE OUTPUTS USING THE SAME - Provided are a multi-output oscillator using a single oscillator, and a method of generating multiple outputs. The multi-output oscillator includes: an oscillator outputting the single frequency; a multiplier multiplying the single frequency to output a first frequency; a first frequency divider dividing the single frequency by a first division factor; a first mixer outputting a second frequency by mixing an output of the first frequency divider and an output of the multiplier; a second frequency divider dividing the single frequency by a second division factor; a second mixer mixing the output of the second frequency divider and the output of the first mixer to output a third frequency; and a third mixer mixing the output of the second frequency divider and the output of the multiplier to output a fourth frequency. | 11-11-2010 |
20100284355 | HANDSHAKING METHOD, AND TRANSMISSION POWER DETERMINING METHOD AND APPARATUS THEREOF FOR PARALLEL TRANSMISSION OF MULTIPLE STREAMS IN SINGLE RADIO CHANNEL - Provided are a transmission power determining method and an apparatus thereof for parallel transmission of a plurality of streams. In a wireless communication system, the transmission power determining method and apparatus determine a transmission power suitable for allowing the plurality of streams to be simultaneously and reliably transmitted in a mutually permissible interference range, and use a Hidden Handshaking (HHS) procedure to determine the transmission power. By doing so, it is possible to perform reliable channel allocation and to reliably transmit the plurality of streams. | 11-11-2010 |
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 |
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 |
20110241956 | CASSEGRAIN ANTENNA FOR HIGH GAIN - Provided is a high gain Cassegrain antenna. The antenna includes a feed unit that radiates radio waves, a subreflector that faces a radiation surface of the feed unit and reflects the radiated radio waves, and a main reflector that has a plurality of hole scatterers of different depths facing the subreflector and reflecting again the radio waves reflected from the subreflector. Accordingly, it is possible to manufacture a high-gain broadband antenna at low costs. | 10-06-2011 |
20110249589 | CHANNEL SENSING SCHEME USING NATURAL QUIET PERIOD IN COGNITIVE RADIO SYSTEM - Provided is a method of sensing an operating channel by using a natural quiet period in a cognitive radio system. A requested QP is reduced by using a natural QP needed for communication that is intrinsic to a communication system, not by using a QP for cognitive radio. | 10-13-2011 |
20110289175 | METHOD FOR RESERVING RESOURCES ON A CENTRALIZED NETWORK - A resource reservation method between a master device and a slave device or between slave devices in a centralized network. In resource reservation between slave devices, optimal resources may be allocated by performing link measurement between the slave devices before allocating the resources. | 11-24-2011 |
20120307782 | METHOD OF FREQUENCY CHANNEL ASSIGNMENT USING EFFECTIVE SPECTRUM SENSING IN MULTIPLE FREQUENCY ASSIGNMENT SYSTEM - A method of assigning a frequency channel using efficient spectrum sensing in a multiple Frequency Assignment system includes a channel sensing process, wherein a base station of a secondary user classifies multiple frequency channels licensed to a primary user into a plurality of channel state sets according to usage states, periodically senses channel states by changing a sensing period according to the types of classified channel state sets, and manages the sensed channel states as frequency channel state set information; a channel state set broadcasting process; and a channel assigning process. Accordingly, a frequency channel can be assigned to a secondary user requesting channel assignment using frequency channel state set information without a primary user experiencing interference noise. | 12-06-2012 |
20140376493 | 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. | 12-25-2014 |