Propagation Modeling and Analysis for Terahertz Inter-satellite Communications Using FDTD Methods

Inter-satellite links (ISL), referring to the communications between satellites, are essential for interconnected low-earth-orbit (LEO) systems in the ionosphere. While microwave bands and optical technologies are being widely adopted in ISL, the Terahertz (THz) band is promising to enhance the wireless data rate and improve the pointing accuracy. As a fundamental challenge, propagation modeling and analysis of the THz wave in the ionosphere medium that consists of magnetized plasma are investigated in this paper, by using finite-difference time-domain (FDTD) methods. Furthermore, the pointing error is modeled as a Rayleigh distributed random variable, and the resulting pointing error loss model is proposed based on a reflectarray antenna radiation pattern. The ISL performance influenced by the propagation in the ionosphere medium and pointing error is numerically evaluated, with the metric of interests including outage probability, average bit error rate, and ergodic capacity.