Robust Resource Allocation for Integrated Satellite–Terrestrial Communication Systems With Eavesdroppers

To solve the problems of low system security and poor transmission quality in integrated satellite-terrestrial communication systems due to eavesdroppers and channel uncertainties, a robust resource allocation (RA) problem is studied. First, considering the constraints of users’ quality of service, the maximum transmit power of the satellite and the base station (BS), and the bounded channel uncertainties, an RA optimization problem is established by jointly optimizing the beamforming vectors, artificial noise (AN) vectors, and power allocation factors. Then, S-Procedure, successive convex approximation (SCA), and alternating optimization are adopted to convert the nonconvex problem with parameter perturbation into a convex one that can be solved efficiently. Finally, a robust RA algorithm based on the alternating approach is proposed to obtain the solutions. Simulation results show that the proposed algorithm has good security and robustness, and the outage probability is reduced by 9.12% compared to the traditional nonrobust algorithms without AN.