Effect of plasma sheath on high hypersonic vehicle communication systems

The plasma sheath surrounding high hypersonic vehicles traveling through the atmosphere can cause communication interruption, known as blackout. In this study, a multiphysics numerical solution model coupling the electromagnetic field and the plasma fluid field is proposed. The time-domain distortion of broadband digitally modulated signals in plasma sheaths is analyzed for the first time. The effect of plasma sheaths on communication systems is analyzed by studying the typical communication scheme for high hypersonic vehicles. Moreover, the modulation effect of a typical communication signal in plasma is studied. The results show that, although signals can reach the receiver, delay spread and frequency-selective fading occur, resulting in inter-symbol interference. Time-domain distortions such as sampling time offset and waveform envelope broadening are found to be important mechanisms leading to errors. It can cause synchronization problems and significantly increase the bit error rate of communication systems. Finally, a new design method for high hypersonic vehicle communication systems is proposed. Using the numerical solution model proposed earlier, frequency-domain compensation and time synchronization mechanisms are established to improve the receiver performance of the communication system.