Secure Satellite Communication Systems Design with Individual Secrecy Rate Constraints

TL;DR

This paper proposes a novel secure satellite communication design using physical layer security techniques, optimizing power and beamforming to meet individual secrecy rate constraints, and evaluates its performance under various practical conditions.

Contribution

It introduces an iterative algorithm for joint power and beamforming optimization in secure satellite systems, considering CSI uncertainties and demonstrating improved performance over fixed beamforming.

Findings

Joint beamforming outperforms fixed beamforming, especially with more antennas and higher secrecy rates.

The iterative algorithm converges under reasonable assumptions.

Performance is validated considering antenna count, beam number, and CSI accuracy.

Abstract

In this paper, we study multibeam satellite secure communication through physical (PHY) layer security techniques, i.e., joint power control and beamforming. By first assuming that the Channel State Information (CSI) is available and the beamforming weights are fixed, a novel secure satellite system design is investigated to minimize the transmit power with individual secrecy rate constraints. An iterative algorithm is proposed to obtain an optimized power allocation strategy. Moreover, sub-optimal beamforming weights are obtained by completely eliminating the co-channel interference and nulling the eavesdroppers' signal simultaneously. In order to obtain jointly optimized power allocation and beamforming strategy in some practical cases, e.g., with certain estimation errors of the CSI, we further evaluate the impact of the eavesdropper's CSI on the secure multibeam satellite system design. The convergence of the iterative algorithm is proven under justifiable assumptions. The performance is evaluated by taking into account the impact of the number of antenna elements, number of beams, individual secrecy rate requirement, and CSI. The proposed novel secure multibeam satellite system design can achieve optimized power allocation to ensure the minimum individual secrecy rate requirement. The results show that the joint beamforming scheme is more favorable than fixed beamforming scheme, especially in the cases of a larger number of satellite antenna elements and higher secrecy rate requirement. Finally, we compare the results under the current satellite air-interface in DVB-S2 and the results under Gaussian inputs.