Experimental study on correlation between amplitude and phase of electromagnetic wave affected by time-varying plasma by amplitude-modulated radio frequency plasma generator

Abstract

The time-varying plasma channel can increase the bit error rate of the phase modulation signal. The essential reason is that there is a correlation between the amplitude variation and phase variation caused by time-varying plasma. It can cause constellation rotation, and traditional communication methods cannot deal with this special interference. In this paper, the relationship between the amplitude and phase of electromagnetic wave affected by time-varying plasma is investigated. The correlation coefficient is derived. The result shows that the close correlation exists and the signs of correlation coefficients are different under different parameters. A verification experiment is also designed, and the time-varying transmission coefficients, constellations of QPSK signals, and correlation coefficients are measured under different conditions. The experimental results and the theoretical results are in good agreement. The conclusions can provide prior knowledge for communication methods and contribute to improving communication efficiency.