Patents by Inventor Chang-Joo Kim

Chang-Joo Kim has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20100260106
    Abstract: 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.
    Type: Application
    Filed: December 10, 2008
    Publication date: October 14, 2010
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Sung-Hyun Hwang, Jung-Sun Um, Gwangzeen Ko, Myung-Sun Song, Chang-Joo Kim
  • Patent number: 7809524
    Abstract: There is an apparatus for predicting wave propagation characteristic of a multiple antenna system, including: a transmission position calculator for calculating transmission positions of multiple transmitting antennas; a wave propagation path searcher for searching for a wave propagation path for each of a plurality of image antennas generated for each of said multiple transmitting antennas; a reflection electric field calculator for calculating a partial reflection electric field on the searched propagation path; and a received power calculator for calculating a received power based on the calculated partial reflection electric field.
    Type: Grant
    Filed: July 30, 2008
    Date of Patent: October 5, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Ho-Kyung Son, Heon-Jin Hong, Chang-Joo Kim
  • Publication number: 20100250221
    Abstract: A method and apparatus for modeling radio propagation is provided. In the method, when a wall having a thickness is modeled as a line having no thickness, an error in a shade area is minimized by considering the thickness of a wall while maintaining simplicity in a ray-tracing method.
    Type: Application
    Filed: February 27, 2008
    Publication date: September 30, 2010
    Inventors: Jong Ho Kim, Young Keun Yoon, Heon Jin Hong, Chang-Joo Kim
  • Publication number: 20100238086
    Abstract: A double-ridged horn antenna having a higher-order mode suppressor includes a pair of upper and lower ridges arranged opposite to each other, each of the upper and lower ridges having an inner surface to guide electromagnetic waves and an outer surface arranged opposite to the inner surface; upper and lower flares fixedly attached to respective outer surfaces of the upper and lower ridges; left and right flares coupled to the upper and lower flares to form a rectangular cone structure; and metal conductors symmetrically positioned between the upper and lower ridges and the left and right flares.
    Type: Application
    Filed: February 22, 2010
    Publication date: September 23, 2010
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Jung-Ick Moon, Soon-Soo Oh, Joung-Myoun Kim, Soon-Ik Jeon, Chang-Joo Kim
  • Publication number: 20100238077
    Abstract: The present invention relates to an apparatus and method for receiving an antenna measuring signal, and a system of measuring an antenna. In particular, the present invention relates to an apparatus and method for receiving an antenna measuring signal that can remove a measurement error caused by motion of an antenna cable, and a system for measuring an antenna. According to the apparatus and method for receiving an antenna measuring signal and the system and method for measuring an antenna according to the present invention, it is possible to remove a coupling effect of an RF cable of a receiving antenna side while measuring antenna characteristics, thereby minimizing a measurement error of the antenna.
    Type: Application
    Filed: October 1, 2008
    Publication date: September 23, 2010
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: In Kui Cho, Je Hoon Yun, Soon-Soo Oh, Jung Ick Moon, Joung Myoun Kim, Soon Ik Jeon, Chang-Joo Kim
  • Publication number: 20100207827
    Abstract: An antenna radiation pattern measurement device that measures a radiation pattern of an AUT by using a source antenna includes a control unit, an analysis unit, and a measurement unit. The control unit controls driving of the source antenna and the AUT. The analysis unit measures an electric field value from a radio frequency (RF) signal that is transmitted from one of the source antenna and the AUT and received by the other antenna. In addition, the measurement unit controls the control unit and the analysis unit and measures a radiation pattern of the AUT by using the electric field value.
    Type: Application
    Filed: September 19, 2008
    Publication date: August 19, 2010
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Soon-Soo Oh, Yong-Heui Cho, In-Kui Cho, Je Hoon Yun, Soon Ik Jeon, Chang-Joo Kim
  • Publication number: 20100202401
    Abstract: 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.
    Type: Application
    Filed: June 11, 2008
    Publication date: August 12, 2010
    Inventors: Sung-Hyun Hwang, Jung-Sun Um, Myung-Sun Song, Chang-Joo Kim, Gwangzeen Ko
  • Publication number: 20100205234
    Abstract: A method and apparatus for detecting a signal using a cyclo-stationary characteristic value is provided. A method of detecting a signal using a cyclo-stationary characteristic value includes: calculating cyclo-stationary characteristic values with respect to a cyclic frequency domain of an input signal; multiplying the calculated cyclo-stationary characteristic values with each other; and detecting the signal from the input signal based on the result of the multiplication.
    Type: Application
    Filed: August 21, 2008
    Publication date: August 12, 2010
    Inventors: Sunmin Lim, Sang-Won Kim, Changhyun Park, Myung Sun Song, Gwangzeen Ko, Chang-Joo Kim
  • Patent number: 7768362
    Abstract: There is provided a comb polarizer suitable for millimeter band applications including: a waveguide having an aperture side formed of two separable half waveguides, and a comb shaped conductive unit having a plurality of cogs interposed between two half waveguides for transforming a linear polarized signal to a circular polarized signal.
    Type: Grant
    Filed: August 7, 2007
    Date of Patent: August 3, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Soon-Young Eom, Je-Hoon Yun, Soon-Ik Jeon, Chang-Joo Kim, Yury Borlsovich Korchemkin
  • Publication number: 20100177645
    Abstract: There is a provided a method for managing a multiple frequency assignment using a terminal's RX performance in an orthogonal frequency division multiple access (OFDMA) wireless regional area network (WRAN) system, including: a) measuring a bit energy/noise power spectral density (Eb/No) and a received signal strength indicator (RSSI) which are received in the terminal; b) informing the measured Eb/No and RSSI of a base station; c) calculating a round trip delay (RTD) in the base station; d) determining a terminal performance level based on the measured Eb/No, RSSI and the calculated RTD; and e) determining a frequency channel and modulation scheme based on the determined performance level.
    Type: Application
    Filed: August 8, 2007
    Publication date: July 15, 2010
    Inventors: Bub-Joo Kang, Chang-Joo Kim, Myung-Sun Song, Gwang-Zeen Ko, Sung-Hyun Hwang, Hyung-Rae Park
  • Publication number: 20100172316
    Abstract: 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.
    Type: Application
    Filed: October 30, 2006
    Publication date: July 8, 2010
    Inventors: Sung-Hyun Hwang, Myung-Sun Song, Chang-Joo Kim, Yun-Hee Kim, Jae-Yun Won
  • Publication number: 20100156523
    Abstract: An electromagnetic-wave suppression structure in a multilayer PCB or package structure is supplied with a power to be used therein by a power distribution network including a power plane and a ground plane. The multilayer PCB and package includes: an electromagnetic-wave suppression structure including an electromagnetic band-gap; and the electromagnetic-wave suppression structure is formed at a specific portion(s) of the power plane and/or the ground plane to suppress noises.
    Type: Application
    Filed: October 14, 2009
    Publication date: June 24, 2010
    Inventors: Jong Hwa KWON, Dong-Uk SIM, Sang Il KWAK, Je Hoon YUN, Chang-Joo KIM
  • Publication number: 20100156695
    Abstract: An electromagnetic absorber using resistive material includes a ground plane of a conductive material; a dielectric layer formed on the ground plane; and a pattern layer in which specific unit cell patterns made of a resistive material are periodically arranged on the dielectric layer. The electromagnetic absorber is applied to an electronic toll collection system, a transportation device, a building structure, an electronic device and an anechoic chamber.
    Type: Application
    Filed: August 12, 2009
    Publication date: June 24, 2010
    Inventors: Dong-Uk SIM, Jong Hwa KWON, Sang Il KWAK, Je Hoon YUN, Chang-Joo KIM
  • Publication number: 20100134370
    Abstract: A probe and an antenna reduces the multiple reflection of electromagnetic waves. The probe includes: a waveguide; and a resonance unit entirely or partially disposed in the inside of the waveguide and comprising a conductor.
    Type: Application
    Filed: December 2, 2009
    Publication date: June 3, 2010
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Soon-Soo Oh, Jung-Ick Moon, Joung-Myoun Kim, Soon-Ik Jeon, Chang-Joo Kim
  • Publication number: 20100111017
    Abstract: Provided is a method and apparatus of generating signals for initial ranging in an Orthogonal Frequency Division Multiple Access (OFDMA) system. The method, includes: generating a plurality of ranging symbols by cyclic-shifting sample data of a ranging symbol in one OFDMA symbol period as much as a value obtained by multiplying a cyclic prefix size by a symbol index; generating a ranging signal by copying a rear part corresponding to the cyclic prefix size in the sample data with respect to each of the ranging symbols and inserting the copied rear part in front of the sample data as a cyclic prefix.
    Type: Application
    Filed: April 21, 2008
    Publication date: May 6, 2010
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Jung-Sun Um, Sung-Hyun Hwang, Chang-Joo Kim, Myung-Sun Song
  • Publication number: 20100109964
    Abstract: Provided is a shaped-beam antenna having a multi-layered conductive element array surrounded by a dielectric ring. The shaped-beam antenna includes: a planar excitation element having a radiation structure according to a required polarization; a multi-layered conductive element array disposed on the planer excitation element, wherein the multi-layered conductive element array is formed by layering conductive elements at an arbitrary interval; and a dielectric ring surrounding the multi-layered conductive element array at a predetermined separation distance therefrom. Accordingly, it is possible to reduce the entire size of the shaped-beam antenna and manufacturing costs thereof.
    Type: Application
    Filed: February 26, 2008
    Publication date: May 6, 2010
    Inventors: Soon-Young Eom, Je-Hoon Yun, Soon-Ik Jeon, Chang-Joo Kim
  • Publication number: 20100109957
    Abstract: Provided are an antenna radiation performance measuring apparatus and a method for designing the same. The apparatus includes a chamber configured to include a transmit antenna radiating electromagnetic wave, a receive antenna receiving the electromagnetic wave, and an electromagnetic wave absorber absorbing the electromagnetic wave, and a reflector disposed on one side of the chamber between the transmit antenna and the receive antenna, inclined at a predetermined angle, and configured to reflect an electromagnetic wave radiated in a direction to the one side from the transmit antenna.
    Type: Application
    Filed: November 2, 2009
    Publication date: May 6, 2010
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Jung-Ick MOON, Soon-Soo OH, Joung-Myoun KIM, Soon-Ik JEON, Chang-Joo KIM
  • Publication number: 20100087216
    Abstract: 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.
    Type: Application
    Filed: September 9, 2009
    Publication date: April 8, 2010
    Inventors: Gwangzeen KO, Chang Joo KIM, Myung Sun SONG, Sung Hyun HWANG, Sung Jin YOU, Jung Sun UM
  • Publication number: 20100069125
    Abstract: Provided are a transceiver and a transceiving method for use in an ultra wide band system for frequency sharing. The transceiver for use in an ultra wide band system for reducing interference that can be generated by an external system includes an external signal detector which detects an external signal generated from the external system, and a transmission signal controller which determines a power level of a transmission signal to be transmitted by the transceiver based on a power level of the detected external signal, in the case where an external signal using the same frequency channel as the ultra band system is detected, wherein the ultra wide band system and the external system are in a frequency sharing environment.
    Type: Application
    Filed: June 13, 2007
    Publication date: March 18, 2010
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Young-Keun Yoon, Heon-Jin Hong, Chang-Joo Kim
  • Publication number: 20100039334
    Abstract: There is provided to a method for measuring antenna characteristics operating in an out-of-operational frequency range of a chamber, in the chamber having a predetermined operational frequency range, including the steps of: a) measuring reflected wave characteristics of the out-of-operational frequency range generated within the chamber; b) measuring the characteristics of a measurement target antenna operating in the out-of-operational frequency range of the chamber; and c) measuring final characteristics of the measurement target antenna by compensating the characteristic data of the measurement target antenna measured in the step b) for reflected wave data measured in the step a).
    Type: Application
    Filed: September 21, 2007
    Publication date: February 18, 2010
    Inventors: Young-Bae Jung, Soon-Ik Jeon, Chang-Joo Kim