Patents by Inventor Sang-Jung Ra

Sang-Jung Ra 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: 20200322121
    Abstract: A method and an apparatus for estimating synchronization of a broadcast signal in a time domain using a synchronization estimation signal through steps of: performing a correlation operation using a correlation window on a plurality of synchronization estimation signals separated to a plurality of paths and outputting a plurality of correlated signals; delaying the plurality of correlated signals to output a plurality of delayed signals; and estimating the synchronization using the plurality of delayed signals are provided.
    Type: Application
    Filed: April 3, 2020
    Publication date: October 8, 2020
    Inventors: Myung-Sun BAEK, Sang-Jung RA, Byungjun BAE, Yong Seong CHO, Hyoung Kyu SONG, Won-Seok LEE
  • Patent number: 10425906
    Abstract: Disclosed herein are an apparatus and method for detecting an upstream RF signal based on a preamble. The apparatus for detecting an upstream RF signal based on a preamble includes an analog-to-digital converter unit for receiving an RF analog signal and converting the same into an RF digital signal; a down-converter unit for converting the RF digital signal into a baseband digital signal; a packet detection unit for performing packet detection by performing an operation on the baseband digital signal and preset differential preamble signals; and a timing calculation unit for generating timing information of a terminal device based on the baseband digital signal and time information generated through the packet detection.
    Type: Grant
    Filed: November 21, 2017
    Date of Patent: September 24, 2019
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Sang-Jung Ra, Jin-Hyuk Song, Ho-Sook Lee, Dong-Joon Choi, Joon-Young Jung, Nam-Ho Hur
  • Patent number: 10193687
    Abstract: Disclosed are a method for acquiring synchronization in a cable network, and a physical (PHY) transmitter and PHY receiver. The method for acquiring synchronization in a cable network according to an embodiment includes receiving, by a PHY receiver, a signal from a PHY transmitter, and acquiring, by the PHY receiver, channel synchronization when a symbol in which a channel preamble exists is detected from the received signal and a position of a frequency in which a channel subcarrier exists is detected from the detected symbol by performing a cross correlation operation on the received signal and the channel preamble.
    Type: Grant
    Filed: February 24, 2017
    Date of Patent: January 29, 2019
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jae Hwui Bae, Sang Jung Ra, Jin Hyuk Song, Dong Joon Choi, Nam Ho Hur
  • Patent number: 10110275
    Abstract: A method of estimating an integer frequency offset and compensating for the integer frequency offset by an estimated error is provided. A frequency offset estimation method may include receiving a reception signal including PLC data and a physical layer link channel (PLC) preamble, detecting first position information on a position of a subcarrier of the PLC preamble in a frequency axis from the reception signal through a cross-correlation between the PLC preamble and the reception signal, detecting second position information on the position of the subcarrier of the PLC preamble defined in a transmission end by restoring the PLC data, and calculating a frequency offset by comparing the first position information with the second position information.
    Type: Grant
    Filed: July 21, 2017
    Date of Patent: October 23, 2018
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Jae Hwui Bae, Sang-Jung Ra, Jin Hyuk Song, Joon Young Jung, Dong Joon Choi, Namho Hur
  • Publication number: 20180167902
    Abstract: Disclosed herein are an apparatus and method for detecting an upstream RF signal based on a preamble. The apparatus for detecting an upstream RF signal based on a preamble includes an analog-to-digital converter unit for receiving an RF analog signal and converting the same into an RF digital signal; a down-converter unit for converting the RF digital signal into a baseband digital signal; a packet detection unit for performing packet detection by performing an operation on the baseband digital signal and preset differential preamble signals; and a timing calculation unit for generating timing information of a terminal device based on the baseband digital signal and time information generated through the packet detection.
    Type: Application
    Filed: November 21, 2017
    Publication date: June 14, 2018
    Inventors: Sang-Jung Ra, Jin-Hyuk Song, Ho-Sook Lee, Dong-Joon Choi, Joon-Young Jung, Nam-Ho Hur
  • Publication number: 20180102808
    Abstract: A method of estimating an integer frequency offset and compensating for the integer frequency offset by an estimated error is provided. A frequency offset estimation method may include receiving a reception signal including PLC data and a physical layer link channel (PLC) preamble, detecting first position information on a position of a subcarrier of the PLC preamble in a frequency axis from the reception signal through a cross-correlation between the PLC preamble and the reception signal, detecting second position information on the position of the subcarrier of the PLC preamble defined in a transmission end by restoring the PLC data, and calculating a frequency offset by comparing the first position information with the second position information.
    Type: Application
    Filed: July 21, 2017
    Publication date: April 12, 2018
    Inventors: Jae Hwui BAE, Sang-Jung RA, Jin Hyuk SONG, Joon Young JUNG, Dong Joon CHOI, Namho HUR
  • Publication number: 20170324541
    Abstract: Disclosed are a method for acquiring synchronization in a cable network, and a physical (PHY) transmitter and PHY receiver. The method for acquiring synchronization in a cable network according to an embodiment includes receiving, by a PHY receiver, a signal from a PHY transmitter, and acquiring, by the PHY receiver, channel synchronization when a symbol in which a channel preamble exists is detected from the received signal and a position of a frequency in which a channel subcarrier exists is detected from the detected symbol by performing a cross correlation operation on the received signal and the channel preamble.
    Type: Application
    Filed: February 24, 2017
    Publication date: November 9, 2017
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Jae Hwui BAE, Sang Jung RA, Jin Hyuk SONG, Dong Joon CHOI, Nam Ho HUR
  • Publication number: 20170279648
    Abstract: Disclosed is a an apparatus for reducing a reducing a peak to average power ratio (PAPR) for layer division multiplexing (LDM) in an orthogonal frequency division multiplexing (OFDM) system, the apparatus may include a peak remover configured to detect a peak power value of a subcarrier signal that is input and generate a peak removal signal that decreases the detected peak power value, and a processor configured to perform constellation remapping on a first signal generated by combining the subcarrier signal and the peak removal signal and then generate a second signal into which additional data is inserted.
    Type: Application
    Filed: January 11, 2017
    Publication date: September 28, 2017
    Inventors: Jin Hyuk SONG, Sang Jung RA, Jae Hwui BAE, Dong Joon CHOI, Nam Ho HUR
  • Publication number: 20170048094
    Abstract: An apparatus and a method of channel estimation and equalization based on pilot signals, which acquire a channel estimation vector and effectively perform channel equalization by using scattered pilots and continuous pilots in a communication system to which an OFDM symbol is applied, such as a DOCSIS 3.1 Down stream PHY system using multiple carriers.
    Type: Application
    Filed: July 15, 2016
    Publication date: February 16, 2017
    Inventors: Jae Hwui BAE, Sang Jung RA, Jae Ho LEE, Dong Joon CHOI, Nam Ho HUR
  • Patent number: 9154293
    Abstract: Disclosed are a method and apparatus for estimating symbol timing in a non-synchronized OFDM system. The present invention includes synchronizing a frame of a received signal, estimating the symbol timing of each symbol of the frame based on the synchronization, compensating for the symbol timing using a phase difference attributable to a Symbol Timing Offset (STO), variably changing within a Cyclic Prefix (CP) interval due to the frequency offset of a sampling clock and thermal noise, and performing channel equalization using a preamble based on output including corrected phase rotation.
    Type: Grant
    Filed: December 5, 2013
    Date of Patent: October 6, 2015
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Jae Ho Lee, Yang Su Kim, Sang Jung Ra, Han Seung Koo, Dong Joon Choi, Nam Ho Hur
  • Patent number: 9059886
    Abstract: In an orthogonal frequency division multiplexing (OFDM) wireless communication system, when path delay information is received from a reception apparatus through a return path after data transmission, a length of a cyclic prefix included in a transmitted signal is adjusted on the basis of a delay value included in the path delay information.
    Type: Grant
    Filed: June 19, 2014
    Date of Patent: June 16, 2015
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jae-Ho Lee, Sang-Jung Ra, Dong Joon Choi, Namho Hur
  • Publication number: 20150156045
    Abstract: In an orthogonal frequency division multiplexing (OFDM) wireless communication system, when path delay information is received from a reception apparatus through a return path after data transmission, a length of a cyclic prefix included in a transmitted signal is adjusted on the basis of a delay value included in the path delay information.
    Type: Application
    Filed: June 19, 2014
    Publication date: June 4, 2015
    Inventors: Jae-Ho LEE, Sang-Jung RA, Dong Joon CHOI, Namho HUR
  • Publication number: 20150139339
    Abstract: A broadcasting transmitting apparatus splits a piece of broadcast content into an audio signal and a video signal, encodes the audio signal to generate an audio bit string, encodes the video signal to generate a video bit string, multiplexes the audio bit string and the video bit string, and modulates the multiplexed bit strings into a symbol. The encoded audio bit string is allocated to some bits of the symbol, and the encoded audio bit string is allocated to the remaining bits of the symbol.
    Type: Application
    Filed: June 19, 2014
    Publication date: May 21, 2015
    Inventors: Sang-Jung RA, Joon Young JUNG, Jae-Ho LEE, Dong Joon CHOI, Namho HUR
  • Patent number: 9027071
    Abstract: An apparatus for combining a broadcasting channel may include a channel detector to detect a vacant Radio Frequency (RF) broadcasting channel used by a photoelectric converter that converts a first broadcast program as an optical signal to a first RF signal, a broadcast receiving interface to receive at least one second broadcast program, a broadcast modulator to generate a second RF signal by modulating the second broadcast program using the vacant RF broadcasting channel, and a channel combiner to combine a broadcasting channel used for the first RF signal and the vacant RF broadcasting channel.
    Type: Grant
    Filed: April 23, 2013
    Date of Patent: May 5, 2015
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yang Su Kim, Han Seung Koo, Jae Ho Lee, Sang Jung Ra, Dong Joon Choi, Nam Ho Hur
  • Publication number: 20140286468
    Abstract: Disclosed are a method and apparatus for estimating symbol timing in a non-synchronized OFDM system. The present invention includes synchronizing a frame of a received signal, estimating the symbol timing of each symbol of the frame based on the synchronization, compensating for the symbol timing using a phase difference attributable to a Symbol Timing Offset (STO), variably changing within a Cyclic Prefix (CP) interval due to the frequency offset of a sampling clock and thermal noise, and performing channel equalization using a preamble based on output including corrected phase rotation.
    Type: Application
    Filed: December 5, 2013
    Publication date: September 25, 2014
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Jae Ho LEE, Yang Su Kim, Sang Jung Ra, Han Seung Koo, Dong Joon Choi, Nam Ho Hur
  • Publication number: 20130283331
    Abstract: An apparatus for combining a broadcasting channel may include a channel detector to detect a vacant Radio Frequency (RF) broadcasting channel used by a photoelectric converter that converts a first broadcast program as an optical signal to a first RF signal, a broadcast receiving interface to receive at least one second broadcast program, a broadcast modulator to generate a second RF signal by modulating the second broadcast program using the vacant RF broadcasting channel, and a channel combiner to combine a broadcasting channel used for the first RF signal and the vacant RF broadcasting channel.
    Type: Application
    Filed: April 23, 2013
    Publication date: October 24, 2013
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Yang Su KIM, Han Seung KOO, Jae Ho LEE, Sang Jung RA, Dong Joon CHOI, Nam Ho HUR
  • Publication number: 20130129021
    Abstract: Provided is an automatic gain controlling device that may prevent deterioration in performance of an orthogonal frequency division multiplexing (OFDM) receiver, on a cable network that performs communication by an orthogonal frequency division multiplexing (OFDM) scheme using high-order quadrature amplitude modulation (QAM), the automatic gain controlling device including a power computing unit to compute a power of a signal received by the OFDM receiver, and a gain controller to control a gain of the received signal based on the computed power of the received signal.
    Type: Application
    Filed: July 17, 2012
    Publication date: May 23, 2013
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Jae Ho LEE, Yang Su KIM, Han Seung KOO, Sang Jung RA, Dong Joon CHOI, Nam Ho HUR
  • Publication number: 20110154393
    Abstract: An Internet Protocol Television (IPTV) Set-Top Box (STB) is provided to efficiently use a time gap caused by a channel switching. The IPTV STB may request a network switch to perform a channel switching operation so that a national service broadcast stream of a second channel is received, when a channel selection signal for the second channel is received while a national service broadcast stream of a first channel is received. Additionally, the IPTV STB may transmit a local service broadcast stream received from a broadcast stream receiver to a display device.
    Type: Application
    Filed: September 23, 2010
    Publication date: June 23, 2011
    Applicant: Electronics and Telecommunications Research Institute
    Inventor: Sang-Jung RA
  • Patent number: 7504884
    Abstract: Provided is an automatic gain control (AGC) apparatus of a cable modem. The apparatus includes: a gain controller for measuring a power level of digital input signals transmitted from outside, accumulating the measured values of the digital input signals for a predetermined period, acquiring an average size of the signals, and calculating an error value between the average signal size and a predetermined signal size; an amplitude control unit for receiving error values adjusted by the gain controller and controlling an amplitude of the signal; a low pass filter for receiving the signal outputted from the amplitude control unit and performing low pass filtering on the signal; and a signal size control unit for receiving the signal obtained from filtering of the low pass filter and controlling the signal size.
    Type: Grant
    Filed: August 21, 2006
    Date of Patent: March 17, 2009
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sang-Jung Ra, O-Hyung Kwon, Soo-In Lee
  • Publication number: 20070139113
    Abstract: Provided is an automatic gain control (AGC) apparatus of a cable modem. The apparatus includes: a gain controller for measuring a power level of digital input signals transmitted from outside, accumulating the measured values of the digital input signals for a predetermined period, acquiring an average size of the signals, and calculating an error value between the average signal size and a predetermined signal size; an amplitude control unit for receiving error values adjusted by the gain controller and controlling an amplitude of the signal; a low pass filter for receiving the signal outputted from the amplitude control unit and performing low pass filtering on the signal; and a signal size control unit for receiving the signal obtained from filtering of the low pass filter and controlling the signal size.
    Type: Application
    Filed: August 21, 2006
    Publication date: June 21, 2007
    Inventors: Sang-Jung Ra, O-Hyung Kwon, Soo-In Lee