Joint Transmission and Computation Power Allocations for Satellite Communication Security

Due to introduction of the non-terrestrial network (NTN) and satellite-air-terrestrial integrated network (SATIN), many applications using satellites are being expected and this will result in a severe security issue. In this paper, we propose a satellite communication security method that jointly considers signal transmission and security computation power based on the orthogonal multiple access (OMA). Before transmission, satellite estimates a security threat based on the number of eavesdroppers (Eves) in the large satellite beam coverage as wide as 50 km for LEO satellites at the L-band. With the security threat, the satellite splits onboard power for signals and security, and controls a beam size. Through the sum capacity optimization problem, we derive the optimal onboard power allocation and security algorithm selection with respect to security threats and channel conditions.