• Title/Summary/Keyword: Frequency Shift Keying(FSK)

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Multipath combining method for frequency shift keying underwater communications mimicking dolphin whistle (돌고래 휘슬음을 모방한 frequency shift keying 수중통신기법의 다중경로결합 수신 방법)

  • Ahn, JongMin;Lee, HoJun;Kim, YongChul;Kim, WanJin;Chung, JaeHak
    • 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.

A new Robust Wavelet Shift Keying System Using Scaling and Wavelet Functions (스케일링 함수와 웨이브릿을 이용한 잡음에 강인한 새로운 웨이브릿 편이 변조 시스템)

  • Jeong, Tae-Il
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.2
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    • pp.98-103
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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 paper, We proposed a new robust wavelet shift keying system using scaling and wavelet function in the digital communication. Wavelet Transform consist of a low frequency and high frequency coefficient. When the input signal is one, if it finds the impulse response, the signal is separated from the scaling and wavelet function. The binary data is encoded by modulator which assigned the scaling function to 1(one), and wavelet to zero(0). It was demonstrated by experiment that the proposed algorithm can be a robust noise.

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Space-Time M-ary Orthogonal Walsh Sequence Keying (시공간 M-ary 직교 Walsh 수열 변조)

  • Kim, Jeong-Chang;Cheun, Kyung-Whoon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.3
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    • pp.15-18
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    • 2009
  • In this paper, we propose ST-MWSK (space-time M-ary orthogonal Walsh sequence keying) employing MWSK which does not require channel estimation at the receiver. The computational complexity for the noncoherent ML (maximum-likelihood) detector of ST-MWSK is significantly reduced compared to that of ST-FSK (ST frequency-shift keying). Also, the performance of ST-MWSK is virtually identical to that of ST-FSK.

A Study of the Digital Modulation using DSP (DSP를 이용한 디지털 변조에 관한 연구)

  • 최상권;최진웅;김정국
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.89-92
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    • 2001
  • In this paper, as a study of programmable software radio digital communication, we implemented ASK(Amplitude Shift Keying), FSK(Frequency Shift Keying), and PSK(Phase Shift Keying) modulation using programmable software(algorithm) of DSP(Digital Signal Processor). Moreover, it is possible to select one of those three modulation methods by realizing on single DSP. We adopted Motorola DSP56002 and Crystal CS4215(A/D and D/A converter) for our purpose. The DSP56002 is 24-bit and operates 20 MIPS at 40 MHz, and the CS4215 is 16-bit and supports the maximum 50 kHz sampling frequency.

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Wavelet Shift Keying System Using a Binary Matching Filter (2진 정합필터를 이용한 웨이브릿 편이변조 시스템)

  • Oh, Hyoung-Jin;Jeong, Tae-Il;Lee, Tae-Oh
    • 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.

Study of Optical Transmission Performance in IP-over-WDM Networks Based on FSK/ASK Combined Modulation Format

  • Xiangjun, Xin;Andre, Paulo Sergio de Brito;Teixeira, Antonio Luis Jesus;Monteiro, Paulo P.;Rocha, Jose R. F. da
    • ETRI Journal
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    • v.27 no.3
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    • pp.267-272
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    • 2005
  • The transmission performance of optical labeling based on a combined frequency shift keying/amplitude shift keying (FSK/ASK) format is studied by numerical simulation. The simulation demonstrates that the bit-error ratio (BER) characteristic of an ASK signal is limited by the extinction ratio, received optical power, and dispersion, simultaneously. However, an FSK signal is mainly limited by the extinction ratio (ER) and received optical power when the peak spectrum, which is used to detect the FSK signal, is relatively narrow.

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A Study on Performance Analysis for Error Probability in SWSK Systems

  • Jeong, Tae-Il;Moon, Kwang-Seok;Kim, Jong-Nam
    • Journal of information and communication convergence engineering
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    • v.9 no.5
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    • pp.556-561
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    • 2011
  • This paper presents a new method for shift keying using the combination of scaling function and wavelet named scaling wavelet shift keying (SWSK). An algorithm for SWSK modulation is carried out where the scaling function and the wavelet are encoded to 1 and 0 in accordance with the binary input, respectively. Signal energy, correlation coefficient and error probability of SWSK are derived from error probability of frequency shift keying(FSK). The performance is analyzed in terms of error probability and it is simulated in accordance with the kind of the wavelet. Based on the results, we can conclude that the proposed scheme is superior to the performance of the conventional schemes.

A Study on Signal Processing of Rear Radars for Intelligent Automobile (지능형 차량을 위한 후방 감시용 레이더 신호 처리 기법에 관한 연구)

  • Choi, Gak-Gyu;Han, Seung-Ku;Kim, Hyo-Tae;Kim, Kyung-Tae
    • 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.

OFDM based mimicking dolphin whistle for covert underwater communications (OFDM 기반 돌고래 휘슬음 모방 수중 은밀 통신 기법)

  • Lee, Hojun;Ahn, Jongmin;Kim, Yongcheol;Seol, Seunghwan;Kim, Wanjin;Chung, Jaehak
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.3
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    • pp.219-227
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    • 2021
  • This paper proposed an Orthogonal Frequency Division Multiplexing (OFDM) based biomimetic communication method using a dolphin whistle which covertly transmits communication signals to allies. The proposed method divides the dolphin whistle into several time slots corresponding to a number of OFDM symbols, and modulates the communication signal by mapping differential phase shift keying (DPSK) symbols into subcarriers that have the frequency bands of the dolphin whistle in each slot. The advantages of the proposed method are as follows: In the conventional Chirp Spread Spectrum (CSS) and Frequency Shift Keying (FSK) based biomimetic communication methods, the discontinuity of the frequency contour is large, but the proposed method can reduce the discontinuity. Even if the modulation order is increased, the degradation of the mimicking performance is small. The computer simulations demonstrate that the Bit Error Rate (BER) and mimicking performance of the proposed method are better performance than those of the conventional CSS and FSK.

An Efficient Peak Detection Algorithm in Magnitude Spectrum for M-FSK Signal Classification (M-FSK 변조 신호 분류를 위한 효율적인 진폭 스펙트럼의 첨두 검출 방법)

  • Ahn, Woo-Hyun;Seo, Bo-Seok
    • Journal of Broadcast Engineering
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    • v.19 no.6
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    • pp.967-970
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    • 2014
  • An efficient peak detection algorithm in magnitude spectrum is proposed to distinguish the M-frequency shift keying(FSK) signals from other digitally modulated signal. In addition, recognition of the modulation order estimation of FSK signals is also studied based on the fact that the magnitude spectrum of FSK signals reveals the number of peaks equal to the modulation order. When no a priori information about the signals, we utilize the histogram of the magnitude spectrum to determine the threshold which is important factor in peak detection algorithm. The simulation results show high probability of classification under 500 symbols and signal-to-noise ratio(SNR) higher than 4dB.