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Channel modeling of a plasma sheath for hypersonic reentry vehicles is important in addressing reentry communication blackout issues. Given that the time-varying property of the transmission medium is caused by physical factors such as large-scale flight conditions variation, especially angle of attack, and small-scale fluid turbulence, a new adaptive multistate Markov channel modeling method is proposed...
In order to investigate the effect of dynamical plasma sheath on communication signals, this paper proposes band finite-state Markov channel model to represent the dynamic plasma effect on signals at Ka band. First, the amplitude attenuation characteristics induced by dynamic plasma are calculated by Transmission Line Analogy method. Then the Ka band finite-state Markov channel model of dynamic plasma...
For the plasma sheath formed around the hypersonic vehicle flying in atmosphere, the effects of plasma fluctuations on electromagnetic wave propagation is studied in this paper. Both the amplitude and phase of EM signal are modulated by the time-varying plasma. The propagation in the time-varying plasma experiment is designed and the modulation phenomenon is observed in the experiment.
Performances of single electric field, single magnetic field and E×B field for reentry blackout mitigation are studied by numerical simulation. All three schemes seem to be more effective at high altitude. The single magnetic field is recommended for GPS system during the reentry phase.
A simple and effective method for evaluating the parameters of specific attenuation model induced by rain is presented. The parameters at the frequencies from 20GHz to 50GHz are given using the specific attenuation calculated by equivalent permittivity model under the measured raindrop size distribution and the method presented in this paper, which are more applicable in Xi'an, China. The parameters...
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