• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.12
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• pp.1792-1799
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• 1990

Two cases of block coded phase/frequncy modulations are investigated. minimum Euclidean distances are calculated as the function of modulation index h and rotation angle \ulcorner in the cases of 2-FSK/4-PSK and 2-FSK/8-PSK. Method of signal set partitioning is described, especially for the case of 2-FSK/8-PSK. The results are compared with S.I. Sayegh's work and shown better performance. For example, with simple parity check and repetition codes, we can get coding gain of 3 dB in the case of 2-FSK/4-PSK with block length n=4. We get 5.33 dB in the case of 2-FSK/8-PSK with n=4. And it is believed that we can get higher coding gain with proper combinations of block code and n-FSK/m-PSK type channel signal constellations.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.412-414
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• 1999

The FSK demodulation module is the circuit which detects the data being transmitted from reader by FSK method. It doesn't use the PLL, and has lower power consumption and easier integration than conventional FSK detector using the PLL. So in a smart card, it is suitable to apply. In this study, the FSK demodulation module of the low power smart card is designed and analyzed.

• The Journal of the Acoustical Society of Korea
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• v.37 no.6
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• pp.404-411
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• 2018

This paper proposes a dolphin whistle mimicking underwater communication method using FSK (Frequency Shift Keying) and method to improve BER (Bit Error Rate) performance by using multipath gain combining. The proposed method divides whistle sound into short time intervals and transmits FSK modulated signal that ensures orthogonality of the symbol. Multipath gain can be obtained by using characteristic of mimicked signal frequency that varies with time. To demonstrate the performance of the proposed method, computer simulations and lake experiments were conducted. Computer simulation results show that an additional multipath gain is obtained by multipath. From lake experiments, when symbol length is 20 msec and modulation band is 900 Hz, the proposed FSK method with multipath combining gain obtains BER of 0.002, which is better than CSS (Chirp Spread Spectrum) with BER of 0.185. he proposed based on FSK method has higher imitation degree than the CSS method by analyzing mean cross-correlation value in the time - frequency domain of the imitated signal and actual whistle signal.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.2
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• pp.194-200
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• 2003

In this paper, FSK(Frequency Shift Keying) demodulator which is widely used for FH-SS system is designed and the experimental results are analyzed. The performance of the ADPLL(All-digital Phase-Locked-Loop), which is the main part of the demodulator circuit, is analyzed by the computer program. Using Maxplus-II tool provided by altera. co., ltd, each part of the ADPLL is designed and all of them is integrated into EPM7064SLC44-10 chip. And the simulation results are compared with the characteristics of the implemented circuits for analysis. There is about 2${\mu}\textrm{s}$ difference in time constant of the PLL. This difference is not critical in the demodulator. And the experimental results show that the transmitted data is well demodulated when the phase difference between the FSK modulated signal and the reference signal is about 180 degree.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1134-1136
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• 2002

This paper proposes a FSK(Frequency Shift Keying) transmitter which has a inverter for power amplification instead of linear amplifier. As it can generate large signal using resonant circuit under the low voltage source even if the impedance of antenna is large as like a loop antenna of TWC(Train to Way-side Communication) system. In this paper, the proposed fully digital controlled transmitter including FSK modulation is presented and its control schemes are discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.7
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• pp.663-679
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• 1991

본 논문에서는 다중 경로 페이딩 채널에서 최대 다중 경로 지연폭이 한 비트 폭보다 큰 경우 발생할 수 있는 심볼간 간섭을 극복하기 위해 M-ary 신호 방식과 절환 신호 방식을 채용한 다중 경로 다이버시티 수신 noncoherent F나 ds / SSMA 통신 시스템의 평균 오율을 평가하였다. 시스템의 평균 오율은 가우스 근사법을 이용해 채널 파라메타와 PN 시퀀스의 길이와 같은 시스템 파라메타에 대한 식으로 표현하였고, 이러한 결과식을 이용해 M-ary FSK 시스템과 두 종류의 절환 수신기에 대한 FSK시스템의 평균 오율을 수치적으로 분석하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.11
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• pp.1070-1077
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• 2011

This paper introduces a radar signal processing technique for intelligent rear view monitoring of an automobile. The linear frequency modulation-frequency shift keying(LFM-FSK) waveform, which is the combination of frequency modulation continuous wave(FMCW) and frequency shift keying(FSK) waveform, is employed to simultaneously estimate the range, relative aspect angle, and velocity of an automobile. Hence, it can be applied to monitor the rear view of an automobile. FMCW waveform has high range resolution capability, but it produces ghost targets under a multiple target environment. In contrast, FSK waveform can provide high velocity resolution and avoids the problem of ghost targets. However, it fails to identify multiple targets along the radar's line of sight. With LFM-FSK waveform, we can estimate the ranges and velocities of multiple targets with very high resolution, which avoids the ghost target problem of an FMCW waveform. Simulation result shows that LFM-FSK wavefrom is suitable for use in the lane change assistance system for an automobile.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1805-1811
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• 2005

We analyzed of the receiver which received OOK and the FSK transmission signal that were a general digital transmission technique in a WDM system. We expressed various error probability with the m which was bandwidth and a bit numerical function and carried out performance evaluation of a receiver in a performance evaluation way. When error probability was $10^{-4}$ which is m=10, as for the receive sensitivity of OOK, the $1.7{\times}10^2$, FSK got $2.2{\times}10^2$ through simulation. And the receive sensitivity of OOK and FSK was able to get each $2.15{\times}10^2$ and $3.07{\times}10^2$ when it was error probability of $10^{-9}$ which is m = 25. Transmission of 23Gb/S showed that it was possible when we does the $10^{-9}$ that was basis error probability of a light communication system with a basis through this, and a coding profit was with for and transmission capacity of 75Gb/s confirmed that it was possible if a code rate was with 0.8.

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.99-103
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• 2000

최근 많은 분야에서 사용피고 있는 소형 전광판을 이용하여 원거리에서도 메시지 전달이 가능한 광고용 전광판을 제작하였다. FSK Modem과 RF-Module을 이용하여 실시간으로 광고의 내용을 바꾸는 것을 원칙으로 구현하였다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.1
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• pp.14-21
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• 1979

This paper deals with tIne interface error in the on-line computer systems by using the FSK radio communications. The wideband frequency shrift keying method is used for briary data transmission between the remote terminals and the main computer. To mintmize the error rate In the decoder systems of the main computer, a synchronizing pulse is added to the frame, so that the phase In both receiver and transmitter are synchronized. When the information signal with a constant error bit is received through FSK, It is designed to use the microprocessor for calculation of error bit. As results, most bit error are caused in FSK radio communications. and a few error bit Is me - asured to enter the mirroprocessor from the input buffer.