Abstract
Physical layer security has become popular in recent years. In satellite communication systems, wire-tap users are easy to obtain information from satellite side for the range of the beam is broad. In this work, we consider the multi user scenario, by adopting the dynamic beam forming in satellite networks, the beam could be restricted into the small range, where wire-tap users could not obtain information from the side band and the information security has been obtained by using the scheme. From the simulation result, we can conclude that, by using the proposed physical layer security method, the wiretap user could not retreat enough information.