Patents by Inventor Hyun-Kyu Chung

Hyun-Kyu Chung 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: 20120170619
    Abstract: A data transmission method of a source node in a cooperative communication system includes: performing a beamforming to a relay node; transmitting data to the relay node; performing a beamforming to a destination node; and transmitting data to the destination node.
    Type: Application
    Filed: July 8, 2010
    Publication date: July 5, 2012
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTIT
    Inventors: Kap-Seok Chang, Woo-Yong Lee, Kyeongpyo Kim, Hyoung-Jin Kwon, Hyun-Kyu Chung
  • Publication number: 20120169374
    Abstract: The present invention relates to a digital signal processing circuit, and more particularly, to a method and apparatus for generating a maximum value or a minimum value used for designing the digital signal processing circuit. An apparatus for obtaining a maximum value or a minimum value from N digital input signals may include N×W bit processing elements to receive an input of W bits of each of the N digital input signals, W OR operators to receive an input of N operation values output from bit processing elements, and to perform an OR operation, respectively, and W inverters to invert an output value for each of the W OR operators.
    Type: Application
    Filed: December 29, 2011
    Publication date: July 5, 2012
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Sung Woo CHOI, Woo Yong Lee, Hyun Kyu Chung
  • Publication number: 20120163217
    Abstract: The present invention relates to communication using multiple antennas, and more particularly, to an apparatus and method for adaptively adjusting, based on a channel environment, an interval and direction of multiple antennas each of a transmitter and a receiver. A communication method according to the present invention may include verifying information about a channel state based on a pilot signal transmitted for each antenna of a transmitter, adjusting intervals among antennas of a receiver based on the information about a channel state, calculating transmission capacity values according to the adjusted intervals among antennas, and setting an antenna to an antenna interval corresponding to a transmission capacity having a highest value among the transmission capacity values calculated.
    Type: Application
    Filed: December 22, 2011
    Publication date: June 28, 2012
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Kyeong Pyo KIM, Kap Seok Chang, Woo Yong Lee, Seung Joon Lee, Hyun Kyu Chung
  • Publication number: 20120155516
    Abstract: A multi-link wireless channel sounder is provided. The multi-link wireless channel sounder includes a multi-input multi-output (MIMO) antenna unit, a transmitter (TX) signal processing unit configured to transmit via the MIMO antennas one or more TX wireless channel signals to be transmitted via a wireless channel, a receiver (RX) signal processing unit configured to receive and process one or more RX wireless channel signals that are received from multiple links via the MIMO antenna unit, and a control unit configured to receive an operation mode selection signal that indicates a TX mode or an RX mode from a user and to control the TX signal processing unit or the RX signal processing unit to operate selectively in accordance with the operation mode selection signal.
    Type: Application
    Filed: December 21, 2011
    Publication date: June 21, 2012
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Myung-Don KIM, Jae-Joon PARK, Hyun-Kyu CHUNG
  • Publication number: 20120113975
    Abstract: A method of operating a network coordinator for a spatial reuse scheme includes receiving a reservation request for a time period for a data communication of a target transmitter/receiver pair that uses a directional antenna, searching for a time period reserved in advance for another transmitter/receiver pair, from a Channel Time Allocation Period (CTAP) that is a contention-free access period for the data communication, and reserving a time period for the target transmitter/receiver pair in the CTAP, so that the time period reserved for the target transmitter/receiver pair overlaps the time period reserved in advance for the other transmitter/receiver pair.
    Type: Application
    Filed: July 16, 2010
    Publication date: May 10, 2012
    Inventors: Kyeongpyo Kim, Seung Eun Hong, Woo Yong Lee, Hyun Kyu Chung
  • Patent number: 8174328
    Abstract: A dual-band wideband local oscillation signal generator includes an oscillation unit, a division unit, a poly phase filter (PPF), a switch unit, and a single side band (SSB) mixer. The oscillation unit is configured to generate a positive in-phase (IP) signal, a negative in-phase (IN) signal, a negative quadrature-phase (QN) signal, and a positive quadrature-phase (QP) signal. The division unit is configured to divide frequencies of the IP signal and the IN signal and generate an RF signal. The PPF is configured to receive the IP signal and the IN signals inputted to the division unit, and generate an LO IP signal, an LO IN signal, an LO QP signal, and an LO QN signal. The switch unit is configured to receive the generated LO signals and select a high band frequency signal or a low band frequency signal.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: May 8, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bong-Hyuk Park, Kwang-Chun Lee, Hyun-Kyu Chung
  • Patent number: 8175071
    Abstract: There is provided an intercell interference mitigation apparatus for use in a terminal having a single reception antenna in a multi-cell downlink of an OFDMA system. The apparatus includes one or more parallel interference cancellers for canceling intercell interference by respreading soft decision values of cells other than a self cell; one or more LLR creation blocks for creating channel LLRs required for the soft decision for each of subcarriers, and producing channel soft outputs; one or more soft deciders for performing a soft decision of a self user symbol of the self cell in which interferences from other users are mitigated, and producing the soft decision values; and one or more channel estimation blocks for performing iterative channel estimation by respreading symbols of the soft decision values produced from the soft deciders.
    Type: Grant
    Filed: June 5, 2009
    Date of Patent: May 8, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Junyoung Nam, Seong Rag Kim, Hyun Kyu Chung
  • Publication number: 20120106575
    Abstract: Disclosed is an apparatus and method for transmitting/receiving data using a low-density parity check (LDPC) coding scheme in a communication system. The method includes generating a multi-user data packet containing data to be transmitted to a plurality of users, encoding the multi-user data packet as a BCC and an LDPC code, and transmitting the encoded multi-user data packet to the plurality of users. In the method, the encoding of the multi-user data packet encodes MPDU subframes corresponding to each of the plurality of users in the multi-user data packet as the LDPC code, and calculates information on a length in LDPC encoding, corresponding to the encoding of the multi-user data packet as the LDPC code.
    Type: Application
    Filed: October 27, 2011
    Publication date: May 3, 2012
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Jong-Ee OH, Sok-Kyu Lee, Min-Ho Cheong, Jee-Yon Choi, Jae-Woo Park, Hyun-Kyu Chung
  • Publication number: 20120100820
    Abstract: Provided are a method for measuring a variable bandwidth wireless channel, and a transmitter and a receiver therefor. The transmitter, includes: a pre-processing unit for performing variable over-sampling and band-limited filtering on an original sequence for measuring the wireless channel according to a pre-determined digital-to-analog (D/A) operation speed and measurement bandwidth, and creating and storing a probing sequence whose frequency is up-converted into a fixed transmitting intermediate frequency; and a real-time processing unit for transmitting a probing signal that the stored probing sequence is converted according to the D/A operation speed to the wireless channel.
    Type: Application
    Filed: January 5, 2012
    Publication date: April 26, 2012
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Sung-Jun LEE, Heon-Kook KWON, Myung-Don KIM, Hyun-Kyu CHUNG, Kwang-Chun LEE
  • Publication number: 20120082142
    Abstract: Provided is a data transmission method. The data transmission method may limit a use authorization for a contention time period so that a portion of data transmission devices among a plurality of data transmission devices may transmit data during the contention time period.
    Type: Application
    Filed: October 5, 2011
    Publication date: April 5, 2012
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Yong Sun KIM, Seung Eun HONG, Woo Yong LEE, Hyun Kyu CHUNG
  • Publication number: 20120082109
    Abstract: Provided are a method of performing contention based channel access by classifying a contention period into a beamformable contention period in which a beamforming is allowed and a non-beamformable contention period in which the beamforming is interrupted so as to resolve an issue regarding channel access occurring due to an introduction of a directional antenna for handling a path loss in a wideband wireless communication system according to an embodiment of the present invention, and a method for maximizing a spatial reuse gain by managing, for each direction, information about a transmission time of a message received from a dispersion device.
    Type: Application
    Filed: October 4, 2011
    Publication date: April 5, 2012
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Seung Eun HONG, Yong Sun Kim, Woo Yong Lee, Hyun Kyu Chung
  • Patent number: 8149769
    Abstract: Provided are apparatus and method of transmitting and receiving a reception acknowledgment signal in a mobile communication system. The apparatus and method of receiving the reception acknowledgment signal includes respectively calculating a probability that the received reception acknowledgment signal is a reception success signal and a probability that the reception acknowledgment signal is a reception failure signal, by using an estimated packet error rate predicted based on a pre-set required packet error rate and determining whether the reception acknowledgment signal is the reception success signal or the reception failure signal.
    Type: Grant
    Filed: December 5, 2007
    Date of Patent: April 3, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Heesoo Lee, Hyun-Kyu Chung
  • Patent number: 8139498
    Abstract: Provided are a method and an apparatus for determining a reporting period of channel quality indicator. The method includes the steps of: a) estimating a channel gain through a channel received from a base station; b) calculating a weight by using a variable for determining a fairness value and the estimated channel gain, and estimating weight channel quality to the estimated channel gain by using the calculated weight; c) comparing the estimated weight channel quality and a threshold value; and d) feeding back estimated channel quality indicator by using wireless resources assigned for the channel quality indicator feedback only in case that the weight channel quality is higher than the threshold value.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: March 20, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bangwon Seo, Heesoo Lee, Hyun-Kyu Chung, Dongwoo Kim, In-Ho Lee
  • Publication number: 20120063410
    Abstract: Provided is a method and apparatus for setting up a channel for communication between distributed devices in a wireless communication system. A method of selecting a communication channel in a communication device of a wireless communication system may include requesting scanning of channels between the communication device and a discovery device, receiving a channel scanning response message including a Distributed Reservation Protocol (DRP) Availability Information Element (IE) assigned for each scanned channel, and selecting a channel based on the DRP Availability IE.
    Type: Application
    Filed: September 2, 2011
    Publication date: March 15, 2012
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Seung Eun HONG, Yong Sun Kim, Woo Yong Lee, Hyun Kyu Chung
  • Patent number: 8112040
    Abstract: Provided are a method for measuring a variable bandwidth wireless channel, and a transmitter and a receiver therefore. The transmitter, includes: a pre-processing unit for performing variable over-sampling and band-limited filtering on an original sequence for measuring the wireless channel according to a pre-determined digital-to-analog (D/A) operation speed and measurement bandwidth, and creating and storing a probing sequence whose frequency is up-converted into a fixed transmitting intermediate frequency; and a real-time processing unit for transmitting a probing signal that the stored probing sequence is converted according to the D/A operation speed to the wireless channel.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: February 7, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sung-Jun Lee, Heon-Kook Kwon, Myung-Don Kim, Hyun-Kyu Chung, Kwang-Chun Lee
  • Publication number: 20120025909
    Abstract: A distortion compensation apparatus and an apparatus and method for transmitting a signal are provided. The distortion compensation apparatus can extract precise distortion information by adding an additional signal to an input signal during the compensation of distortion in a nonlinear apparatus, and can linearize the nonlinear properties of the nonlinear apparatus using the distortion information. The apparatus for transmitting a signal can output a signal linearized by the same method as that used by the distortion compensation apparatus.
    Type: Application
    Filed: January 13, 2011
    Publication date: February 2, 2012
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Gweon-Do Jo, Jung-Hoon Oh, Joon-Hyung Kim, Young-Hoon Kim, Jae-Ho Jung, Hyun-Kyu Chung
  • Publication number: 20120020432
    Abstract: Disclosed are a method and apparatus for estimating a Multiple Input Multiple. Output (MIMO) channel. A signal transmission method for estimating the MIMO channel via 2N transmission antennas (N is greater than or equal to “1”) includes generating a code having a predetermined Interference Free Window (IFW), and transmitting the code via two transmission antennas.
    Type: Application
    Filed: August 8, 2008
    Publication date: January 26, 2012
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Won Sop Kim, Jae Joon Park, Myung Don Kim, Hyun Kyu Chung
  • Patent number: 8089859
    Abstract: 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.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: January 3, 2012
    Assignee: Electronics and Telecommunication Research Institute
    Inventors: Byung-Jang Jeong, Tae-Gyun Noh, Hyun-Kyu Chung
  • Publication number: 20110312370
    Abstract: An operation control method in a base station of a wireless communication system includes: checking whether or not an allowed mobile station exists in coverage of the base station and overall coverage of base stations adjacent to the base station; and controlling the base station to perform transmission/reception at a predetermined period through a first discontinuous operation, when the allowed mobile station does not exist in the coverage of the base station and the overall coverage of the adjacent base stations.
    Type: Application
    Filed: March 2, 2010
    Publication date: December 22, 2011
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Tae-Joong Kim, Kwang-Chun Lee, Jae-Heung Kim, Hyun-Kyu Chung
  • Publication number: 20110280182
    Abstract: A method for simultaneously transmitting packets to one or more users in a wireless communication system includes: generating the packets which include length information and are to be transmitted to the one or more users; and simultaneously transmitting the generated packets to the one or more users. The length information includes information representing a unit of the length information and information representing lengths of the packets according to the unit.
    Type: Application
    Filed: March 11, 2011
    Publication date: November 17, 2011
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Yun-Joo KIM, Sok-Kyu Lee, Hyun-Kyu Chung