• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.439-442
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• 2002

전력선을 이용하여 신뢰성 높은 데이터 통신을 하기 위해서는 다양한 변복조 방법 및 채널코딩의 적용이 필요하다. 본 논문에서는 이러한 변복조 및 채널코딩중에서 FSK 변복조와 HDLC코딩 방식을 적용하여 데이터 통신 시 발생하는 신호감쇠와 잡음을 제거하고, 신뢰성 있는 데이터 전송환경을 구축하기 위해 전력선 통신용 모뎀을 CPLD를 바탕으로 한 ASIC으로 구현하고 실제환경에 적용하였다.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.666-668
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• 2001

전력선통신 변조방식 중 FSK(Frequency Shift Keying) 변조방식을 이용하여 컴퓨터와 RS232 케이블로 전력선모뎀과 연결하여 컴퓨터의 데이터신호를 전력라인으로 직접 송신할 수 있게 하였으며, 수신부에서 데이터신호를 검출하여 가전기기의 전원을 ON/OFF하였다.

• Journal of the Speleological Society of Korea
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• no.81
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• pp.43-46
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• 2007

In this paper, we implement a wireless robot in which the RF communication the dangerous place where human cannot approach. In the proposed network image control system, the noise occurred in wireless communication is reduced by implementing the noise eliminating circuit and the driving time of a wireless robot is increased by adopting the recharge battery. By constructing the wireless communication, controled in the remote site with a wireless robot.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.685-688
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• 2002

This paper deals with new scheme of remote load control management system with communication from RCU to controller using power line Power line communication is useful for economical data link but various problems and limitations are caused in using power lines for communications channel. A power line is not so good in the commercial electrical power, and its load noise and high frequency noise are so much. To decrease these noise, we used the FSK(Frequency Shift Keying) modulation method. The experimental results show that the proposed system in this paper is compatible with the conventional system with low cost and the feasibility is very high for new or remodeling plant.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.5
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• pp.899-906
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• 1997

It is known that the Differential Phase Shift Keying (DPSK) modulation scheme in the coherent optical communication system is suitable for design of long-distance transmission system because its receiver performance is 3-5dB better than ASK and FSK. In this paper, we descrive a fundamental understanding of the effects of laser phase noise on the performance of coherent lighwave communication systems. Formulas are derived for the bit error rate in homodyne and heterodyne DPSK. Based on detailed mathematical analysis and estimates, we explain the following finding. DPSK can operates at rates only 300 times greater than the laser linewidth.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.1805-1810
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• 2014

The phase noise spectrum distribution for remote controller using the BPSK mode and low data rate of 50 kbps was designed and proposed in this paper. In case of applying the BPSK that transmission performance is superior to FSK method, the performance degradations due to phase noise are generated. To minimize the phase noise effect, it is important to dispatch the digital signal in channel environment with required phase noise characteristics. To provide the terminal design technique and the proper channel environment with required phase noise characteristics, the phase noise spectrum distribution was designed for required phase noise characteristics. By analyzing the phase noise effects for damping factor and noise bandwidth of the carrier recovery circuit, the phase noise spectrum design that consider the damping factor and noise bandwidth was performed. Based on the IESS-308 standards, also, the phase noise effects was analyzed. The phase noise spectrum design techniques and phase noise spectrum that is suitable to remote controller were proposed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1933-1938
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• 2008

There are the frequency shift keying(FSK), phase shift keying(PSK) and amplitude shift keying(ASK) in the conventional digital communications method. In this parer, We proposed the algorithm for wavelet shift keying system using a binary matching filter in the digital communication. Wavelet shift keying system are used to a scaling function(low frequency) and wavelet(high frequency) coefficients. The binary data is encoded by modulator which assigned the scaling function to 1(one), and wavelet to zero(0). Wavelet shift keying of the conventional method needs to a post-processing for the decoding. In this paper, wavelet shift keying signal is reconstructed by the decoder using a binary matching filter. So, it was able to the decoding without the post-processing. It was demonstrated by the experiment that the proposed algorithm is a validity.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.476-478
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• 1993

Instead of installing new communication wiring to each house in the apartment house building. the power distribution network. which is already installed in the building. can be use as communication medium. In a safty management, by adoption of power line communication system, at remote we can monitor safty related sensors such as fire, gas leakage, burglar intrusion and emergency call which are located at each house. From this viewpoint, we developed security monitoring system for apartment house building using power lines. Security monitoring system consists of Power Line Communication-Sub Controller (PLC-SC). Power Line Communication-Main Controller (PLC-MC) and Management System (MS). Between a PLC-MC and a PLC-SC, the transmission rate is 1200 bps in power lines and modulation technique is frequency shirt keying (FSK). In between a PLC-MC and a MS, the transmission rate is 1200 bps in communication line (RS-485). As a result of this research. transmission loss is 0.1dB per meter of intrabuilding distribution network. Transmission can be reach in 250 meters. So it is enough to communicate for security monitoring system in apartment house building.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1211-1213
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• 2002

We have frequently felt it inconvenient to collect fare drawing the card in transportation system. Especially, for subway the fares of mass transportation at rush hours of the days, it's important to find a way to collect fares without unnecessarily delaying passengers. In this paper, we proposed a system for the gateless fare collection passing through the booth in only carrying the card. In this system that RF-ID system and Bluetooth are applied. We designed two wireless communication channels. One is the 125kHz communication channel by FSK and PSK for power supplying on the card and identification and the other is 2.4GHz channel for the collection.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.223-229
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• 1987

The error rate eqations of digital modulated signals transmitted through the fading cdannel have been derived in the Gaussian/Impulsive noise environments Whing the derived equations for the error drobadillties of ASK, QAM, FSK, MSK, PSK, and DPSK signais, the error tate performance of digital modulation systems have been evaluated and represented in the graghes as parameters of carrier to \ulcornernoise power ratio (CNR) and fading figures The results show that in the fading environenet the error is occurred more frequently by gaussian noise in the deep fading Howerer in the shallow fading lmpulsive noise is more domiant than gaussian nosie in occurring the error