Results 21 to 30 of about 118,033 (340)
IEEE Access, 2023 The performance of underwater acoustic communication is significantly affected by multipath propagation and Doppler spread. In this paper, we propose a new communication technique called overlapped chirp spread carrier (OCSC) by modifying the existing ...
Chang-Hyun Youn +3 more
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A Novel Waveform Design Method for Shift-Frequency Jamming Confirmation
International Journal of Antennas and Propagation, 2018 Shift-frequency jamming is generally used to form range false targets for ground-based early-warning radar systems; the frequency shift value of such interference is larger than the Doppler shift value of the moving target, and the key element to ...
Chang Zhou, Zhen-Bo Zhu, Zi-Yue Tang
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Sensors, 2020 In an underwater acoustic cellular (UAC) system, underwater equipment or sensor nodes need to detect the identity of an underwater base station (UBS) and synchronise it with a serving UBS. It is known that, in an underwater acoustic channel, the temporal
Muhammad Asim +3 more
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The Doppler effect induced by earthquakes: A case study of the Wenchuan MS8.0 earthquake
Geodesy and Geodynamics, 2022 Seismologists have found that the first arrival frequencies of P waves at different seismic stations have different widths, that is, different periods or frequencies, and they think that this phenomenon can be used to identify whether a Doppler effect is
Qicheng Li +3 more
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Doppler-Induced Dynamics of Fields in Fabry-Perot Cavities with Suspended Mirrors [PDF]
, 2001 The Doppler effect in Fabry-Perot cavities with suspended mirrors is analyzed. Intrinsically small, the Doppler shift accumulates in the cavity and becomes comparable to or greater than the line-width of the cavity if its finesse is high or its length is
Abramovici +6 more
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Evaluating the effectiveness of Doppler frequency shift determination using pilots in broadband transmission [PDF]
International Journal of Electronics and TelecommunicationsIn underwater communications, reciprocal motion between transmitter and receiver has a significant impact on reception quality. In orthogonal broadband systems that provide high bit rates, this problem becomes more important, especially in the higher ...
Agnieszka Czapiewska +4 more
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Research of Mobile Underwater Acoustic Communication of M-Ary Combining FDM and Piecewise-LFM
Xibei Gongye Daxue Xuebao, 2019 Aiming at the countering doppler shift, a mobile underwater acoustic communication scheme of M-ary via FDM-PLFM is proposed. The cross-correlation between piecewise linear frequency modulation(PLFM) and traditional LFM signal is analyzed based on the ...
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Electromagnetic Doppler effect in non-reciprocal medium
AIP Advances, 2023 Reflected light from a moving object, such as a mirror, is frequency-shifted via the Doppler effect. This well-known phenomenon is used to determine the speed and direction of an object due to the red or blue shifting of the received electromagnetic ...
Douglas M. Baney
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A Note on the Role of Mean Flows in Doppler-Shifted Frequencies [PDF]
Journal of Physical Oceanography, 2013 Abstract The purpose of this paper is to resolve a confusion that may arise from two quite distinct definitions of “Doppler shifts”: both are used in the oceanographic literature but they are sometimes conflated. One refers to the difference in frequencies measured by two observers, one at a fixed position and one moving with the mean ...
Gerkema, T., Maas, L.R.M., van Haren, H.
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Известия высших учебных заведений России: Радиоэлектроника, 2018 Narrowband approximation of Doppler effect by a frequency shift is inappropriate for some problems of radiolocation, hydro acoustics or passive location.
I. V. Gogolev
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