Electromagnetic coupling effect in the complex integrated channel of hypersonic vehicles and experimental verification

The communication link of hypersonic vehicles suffers in a complex electromagnetic channel environment with the multipath effect, large Doppler effect caused by the high speed of the hypersonic vehicles, and parasitic modulation caused by vortex turbulence of dynamic plasma sheath. The inherent coupling relationship between these effects exists even though they are with different physical generation mechanisms, which will seriously affect the reception effect of the communication signal from the perspective of the wireless channel. This study investigates the electromagnetic coupling relation between the hypersonic spatial channel and the dynamic plasma sheath channel. The coupling relation is derived in the frequency domain, and the integrated channel simulation model is established as well. Theoretical simulation results demonstrate that the harmonic spectral lines of the plasma sheath power spectrum are moved to the right with the line-of-sight Doppler frequency shift. The spectral spread of the hypersonic spatial channel is coupled to the channel power spectrum of the plasma sheath that forms multiple spectrum extension areas. The new spectral extensions caused by coupling effect will make the traditional narrowband matching receive mode face enormous challenges. The electromagnetic coupling effect in the integrated channel is also verified through channel sounding experiments on ground integrated channel emulation environment composed of plasma simulation device and wireless channel simulator. The deep understanding of this coupling effect is essential to wireless channel modeling and design of adaptive reception methods for hypersonic vehicles.