Asymmetry of the Plasma Sheath-Multipath Integrated Channel Between a Hypersonic Vehicle and Ground Station

In hypersonic flight, the coupling mechanisms between the plasma sheath channel and multipath channel are different due to opposite signal transmission directions. As a result, the integrated channel is asymmetric, and the statistical characteristics of the vehicle-to-ground-station (V2G) integrated channel and the ground-station-to-vehicle (G2V) integrated channel vary. In this article, the discrepancies between the two coupling mechanisms of the integrated channels are analyzed, the probability density functions (pdfs) and power spectral density (PSD) functions of the integrated channels are thoroughly derived, and a series of simulations are designed to verify the theoretical derivation results. The results show that the channel asymmetry is mainly reflected in the pdfs of the integrated channel envelopes and that there is no discernible difference between the phase pdfs and PSD functions. Thus, the relevant conclusions can deepen the understanding of the integrated channel of hypersonic vehicles and provide guidance for communication system designs.