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1.发明授权公开(公告)号：US10904043B2
公开(公告)日：2021-01-26
申请号：US15931821
申请日：2020-05-14
Inventor： Hun Sik Kang , Sang Rok Moon , Seung Woo Lee , In Ki Hwang , Sun Hyok Chang
Abstract: An optical transmission method for processing a signal based on direct detection includes setting, by an equalizer, an adaptive equalization coefficient by performing an equalization process during a training symbol field section in a frame of a received signal, performing, by a channel estimator, channel estimation to perform an equalization process of a soft output maximum likelihood sequence equalizer (MLSE) during the training symbol field section, driving the soft output MLSE, and compensating for, by the soft output MLSE, distortion of the received signal during a data symbol field section in the frame on the basis of the adaptive equalization coefficient and an estimated result value of a channel, and recovering, by an error corrector which allows soft-decision processing to be performed, the received signal by performing error correction on the received signal in which the distortion is compensated for.
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2.发明公开公开(公告)号：US20240348340A1
公开(公告)日：2024-10-17
申请号：US18633199
申请日：2024-04-11
Inventor： Seung-Woo LEE , Sang Rok Moon
IPC: H04B10/524 , H04B10/58
CPC classification number: H04B10/524 , H04B10/58
Abstract: Proposed is a technology for compensating for the performance of a transmitter using a pre-distortion method in an optical communication system, wherein a signal sending apparatus may include a transceiver, and at least one controller operably connected to the transceiver, wherein the at least one controller is configured to receive a digital signal, to modulate the digital signal into a PAM signal, to provide the PAM signal to a signal receiving apparatus, to obtain a distortion coefficient value from the signal receiving apparatus, to perform a nonlinear pre-distortion on PAM signals on the basis of the distortion coefficient value, and to provide a result signal generated on the basis of the nonlinear pre-distortion to the signal receiving apparatus.
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公开(公告)号：US10523323B2
公开(公告)日：2019-12-31
申请号：US16207287
申请日：2018-12-03
Inventor： Hun Sik Kang , Sang Rok Moon , Seung-Woo Lee , Sun Hyok Chang , In Ki Hwang
IPC: H04B10/54 , H04B10/2513 , H04B10/079
Abstract: A method and apparatus for compensation of a chromatic dispersion through an optical compensation and an electronical compensation in optical communication. An optical communication method receives an optical signal, estimates a first transmission length based on a null component included in a frequency spectrum of the optical signal, optically compensates for a chromatic dispersion of the optical signal based on the first transmission length, estimates a second transmission length based on a null component included in a frequency spectrum of the compensated optical signal, and electronically compensates for a residual chromatic dispersion of the compensated optical signal based on the second transmission length.
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公开(公告)号：US12177045B2
公开(公告)日：2024-12-24
申请号：US18126137
申请日：2023-03-24
Inventor： Seung-Woo Lee , Sang Rok Moon , Joon Ki Lee
IPC: H04L25/03 , H04L25/497
Abstract: A method of equalization for high-speed processing and an equalizer thereof are proposed. The method of equalization includes determining a filter coefficient applied to a transmitter equalizer provided with a 2-tap precoder according to an approximate channel response characteristic, generating a pre-equalization signal by removing precursor ISI of a transmission feedback signal by the precoder to which the filter coefficient is applied, so as to output the pre-equalization signal as a transmitting signal, and receiving a transmission signal and generating an equalization signal by removing postcursor ISI of the received transmission signal by a receiver equalizer provided with a feedback filter having auxiliary coefficients for compensating for a difference between an overall channel response of the transmission signal and a channel response based on the precoder.
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公开(公告)号：US11515902B2
公开(公告)日：2022-11-29
申请号：US17514849
申请日：2021-10-29
Inventor： Sang Rok Moon , Minkyu Sung , Eon-sang Kim , Won Kyoung Lee , Seung-Hyun Cho
Abstract: Disclosed is a method and apparatus for phase error compensation having tolerance to a cyclic slip. The method includes determining first phase error candidates based on symbol phases of a first block of a received signal, determining an initial estimation error according to the first phase error candidates, determining second phase error candidates based on symbol phases of a second block of the received signal, determining a final estimation error according to the initial estimation error and the second phase error candidates, and compensating for a phase of the received signal according to the final estimation error.
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Patent Agency Ranking
6.发明授权公开(公告)号：US10027437B2
公开(公告)日：2018-07-17
申请号：US15471064
申请日：2017-03-28
Inventor： Sang Rok Moon , Changyo Han
IPC: H04B10/08 , H04J14/04 , H04B10/079
Abstract: A mode-multiplexing control method, and a transmission apparatus and reception apparatus for the same, the mode-multiplexing control method performed by the transmission apparatus, the mode-multiplexing control method including measuring data traffic, determining a transmission mode count to be used based on the measured data traffic, and transmitting data to a reception apparatus through an optical line in transmission modes corresponding to the determined transmission mode count.
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公开(公告)号：US12177047B2
公开(公告)日：2024-12-24
申请号：US18111275
申请日：2023-02-17
Inventor： Won Kyoung Lee , Sang Rok Moon , Joon Ki Lee , Seung-Hyun Cho
Abstract: A method and apparatus for compensating an in- and quadrature-(IQ) imbalance are disclosed. The method and apparatus for compensating an in- and quadrature-(IQ) imbalance provide a technique for compensating a signal distortion caused by imperfect element features and various noises on a transmission link in terahertz wireless communication and improving transmission performance.
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公开(公告)号：US12166531B2
公开(公告)日：2024-12-10
申请号：US18096638
申请日：2023-01-13
Inventor： Joon Young Huh , Sae Kyoung Kang , Hun Sik Kang , Sang Rok Moon , Joon Ki Lee
IPC: H04B10/00 , H04B10/572 , H04B10/58 , H04J14/00
Abstract: Disclosed herein is an optical transmitter for generating a vestigial sideband (VSB) optical signal. The optical transmitter includes: a modulator configured based on a photonic integrated chip (PIC); an optical fiber block; and a lensed thin film filter implemented between the modulator configured based on the PIC and the optical fiber block. The PIC includes at least one grating coupler, and the lensed thin film filter is disposed so that an angle of an optical signal emitted from a first grating coupler of the PIC coincides with an angle of incident (AOI) of the lensed thin film filter to design the first grating coupler and the lensed thin film filter.
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公开(公告)号：US11799553B2
公开(公告)日：2023-10-24
申请号：US17695346
申请日：2022-03-15
Inventor： Eon-Sang Kim , Sang Rok Moon , Minkyu Sung , Seung-Hyun Cho
IPC: H04B10/50 , H04B10/079 , H04B10/69
CPC classification number: H04B10/504 , H04B10/0797 , H04B10/6911
Abstract: Provided are an apparatus and method of generating a terahertz (THz) signal using a directly-modulated laser. An apparatus of generating a THz signal includes a first directly-modulated laser configured to output a local oscillator (LO) signal, a second directly-modulated laser configured to receive a baseband signal used as data and optically modulate the baseband signal, a band-pass filter configured to filter a spectral component of the baseband signal optically modulated and outputted through the second directly-modulated laser by using a specific frequency bandwidth, a coupler configured to couple the baseband signal filtered through the band-pass filter and the LO signal to each other, and a uni-travelling-carrier photodiode (UTC-PD) configured to generate a THz signal by beating the baseband signal and the LO signal coupled to each other.
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公开(公告)号：US11408822B2
公开(公告)日：2022-08-09
申请号：US17131063
申请日：2020-12-22
Inventor： Sun Hyok Chang , Sang Rok Moon
IPC: G01N21/3586 , G01N21/39 , G02F1/39
Abstract: A method of generating a terahertz wave and apparatuses performing the method are disclosed. According to an example embodiment, a method of generating a terahertz wave includes outputting a laser comb by modulating a laser output from a laser source based on a linearly modulated frequency of an output that is output from a frequency source, and generating a terahertz wave based on a first comb line and a second comb line selected from the laser comb.
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