Artificial noise aided physical layer security for LEO satellite communications

Abstract

Low Earth Orbit (LEO) satellite communications are vulnerable to eavesdropping over open wireless links. This paper proposes a simplified artificial noise (AN)-aided physical layer security scheme. A system model with a multi-antenna LEO satellite, a single-antenna ground user, and multiple eavesdroppers is built under shadowed-Rician fading and imperfect channel state information. AN is projected into the null space of the legitimate channel to avoid interference, and fixed power allocation is adopted for low complexity. Simulations show the scheme achieves better secrecy rate and secrecy outage probability than traditional methods, suitable for resource-constrained LEO satellite systems.