• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.3
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• pp.285-285
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• 1999

This paper describes a Frequency Shift Keying (FSK) modulator and demodulator and the experimented underwater data ommunication equipment to transfer the analog echo signal in real-time from an underwater vehicle to the mother ship. The system consists of an echo signal transfer unit equipped to the vehicle and an ultrasonic receiver equipped on the ship. The former includes an ultrasonic transceiver unit of 180kHz for echo detection and a continuous wave transmitter of 50kHz with a FSK modulator for echo transmission to the ship. The latter includes an ultrasonic receiver of 50kHz and the FSK demodulator. The results of experiment are as follows. 1. The characteristics of the FSK modulating and demodulating circuits designed with the use of C-MOS IC 4046 was good and confirmed its usefulness in underwater data communication system.2. The prototype ultrasonic transceiver unit shows profitable driving power while the pulse duration was short less than 3 msec, but it was found that the driving power is not sufficient while the long pulse duration or continuous wave is used. The gain of the ultrasonic receiver was 80 dB and the receiving bandwidth 700Hz (at - 3 dB point).3. It was found that the system designed by the author has some possibility to use in underwater echo transfer.4. At the FSK modulator, the widths of voltage and frequency which represent linearity were 3.5 V, 1600Hz, respectively, at the FSK demodulator 2.6 V, 700Hz, respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.1
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• pp.7-13
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• 2011

A mixed-mode QPSK demodulator for 60-GHz wireless personal area network application is demonstrated. In this work, mixed-mode QPKS demodulation scheme achieving low power consumption and small area is employed. The prototype chip realized by 60-nm CMOS Logic process can demodulate up to 4.8-Gb/s QPSK signals at 4.8-GHz carrier frequency. At this carrier frequency, the demodulator core consumes 54 mW from 1.2-V power supply while the chip area is $150{\times}150{\mu}m^2$. Using the fabricated chip, transmission and demodulation of 1.7-GSymbol/s QPSK signal in 60-GHz link is demonstrated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.3
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• pp.212-217
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• 2016

The S-band receiver for Low Earth Orbit satellite is designed and fabricated as engineering model. Demodulator is implemented by using FPGA for extension of demodulator method. The receiver consists of RF Block, Digital demodulator and Power stage and has a Doppler tracking function to compensate a frequency shift that occur on the operation. The measured results of fabricated receiver show BER of less than $1.0{\times}10^{-6}$ at -110dBm RF input power and equipped a frequency tracking of ${\pm}100KHz$ relative to the center frequency. TID test was satisfied with the results of the test criterion is 10krad.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8C
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• pp.771-778
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• 2003

A mobile station in a cell receives interference signals from neighboring base stations. Due to the interference signals, the forward link capacity of the cellular system is reduced. Pilot signal received from a neighboring base station is one of the interference signals. Since the pilot signal is a known signal for all the mobile stations, the pilot interference signal can be cancelled by interference cancellation techniques. In this paper, we propose a demodulator with interference canceller to cancel pilot interference signals received from neighboring base stations. The simulation results show that Eb/No value to obtain BER = 10-2 is lowered by 3㏈ in the propose demodulator.

• Broadcasting and Media Magazine
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• v.8 no.1
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• pp.86-97
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• 2003

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1993.10a
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• pp.513-517
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• 1993

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1985.10a
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• pp.123-128
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• 1985

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.31-35
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• 2010

The Ring Laser Gyroscope makes use of the Sagnac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. The space launch vehicle use require the high accuracy Gyro to control and determine the altitude to deliver the satellite in the space. In this paper, The theory of the Path Length Control is explained. The electrical design of Path Length Controller is described. The Design for Path Length Controller is composed of the demodulator, integrator, phase shifter, high voltage amplifier. We apply the circuit to 28cm square ring laser gyro and get the test results.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1121-1128
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• 2019

In this paper, we introduce the combination of OFDM(Orthogonal Frequency Division Multiplexing) and MIMO(Multiple-Input Multiple-Output) technology, and explain that this combination seems to be very preferable when designing very high-rate wireless mobile systems. The application of OFDM, with the block diagrams of an OFDM modulator and demodulator and a MIMO-OFDM system, are described. The several diversities are studied at the receiver, analyzed the performances of diversity in OFDM-MIMO system and simulated results.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.1
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• pp.120-128
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• 2017

This paper describes a neural stimulation system that employs an inductive coupling link to transfer power and data wirelessly. For the reliable data and power delivery, a self-referenced amplitude-shift keying (ASK) demodulator and a wide-range voltage regulator are suggested and implemented in the proposed stimulator system. The prototype fabricated in 0.35 um BCD process successfully transferred 1.2 Kbps data bi-directionally while supplying 4.5 mW power to internal MCU and stimulation block.