Cooperative Beamforming for Secure Satellite-Terrestrial Transmission

Jun Du, Chunxiao Jiang, Haijun Zhang +3 more

In this paper, we consider a scenario where the satellite-terrestrial network is overlaid over the legacy cellular network. The established communication system is operated in the millimeter wave (mmWave) frequencies, which enables the massive antennas arrays to be equipped on the satellite and terrestrial base stations (BSs). The secure communication in this coexistence system of the satellite-terrestrial network and cellular network through the physical-layer security techniques is studied in this paper. To maximize the achievable secrecy rate of the eavesdropped fixed satellite service, we design a cooperative secure transmission beamforming scheme, which is realized through the satellite's adaptive beamforming, artificial noise, and BSs' cooperative beamforming implemented by terrestrial BSs. A non-cooperative beamforming scheme is also designed, according to which BSs implement the maximum ratio transmission beamforming strategy. Applying the designed secure beamforming schemes to the coexistence system established, we formulate the secrecy rate maximization problems subjected to the power and transmission quality constraints. To solve the nonconvex optimization problems, we design an approximation and iteration-based genetic algorithm, through which the original problems can be transformed into a series of convex quadratic problems. Simulation results show the impact of multiple antenna arrays at the mmWave on improving the secure communication. Our results also indicate that through the cooperative and adaptive beamforming, the secrecy rate can be greatly increased. In addition, the convergence and efficiency of the proposed iteration-based approximation algorithm are verified by the simulations.

Shiqi Gong, Chengwen Xing, Zesong Fei +1 more

Chen Chen, Lingyang Song

In this paper, we study satellite secure communications with physical layer security techniques in the presence of multiple eavesdroppers. In order to increase the secrecy rate to the legitimate user, a terrestrial base station operates as a two-stage amplify-and-forward (AF) relay to assist the secure transmission. In the first stage, the legitimate user sends artificially generated noise to the satellite using paired carrier multiple access (PCMA) such that the artificial noise only degrades the eavesdroppers' channels. In the second stage, the base station forwards its received satellite signal to the legitimate user via beamforming. In this two-stage transmission, we consider two scenarios with non- colluding eavesdroppers and colluding eavesdroppers. We design beamforming schemes for both the two scenarios and compare the proposed beamforming schemes with the null-space beamforming scheme, which nulls out the signal leakages at all eavesdroppers. Simulation results demonstrate the proposed beamforming scheme performs better than the null-space beamforming scheme. It is also shown that the proposed terrestrial network aided satellite communication has a significant performance improvement of secure performance as compared to direct transmissions.

Xiaoxiao Wang, Zhenlei Dan, Chenwei Gu +2 more

Bin Li, Zesong Fei, Xiaoming Xu +1 more

In this letter, we investigate the secure transmission in a cognitive satellite-terrestrial network with a multi-antennas eavesdropper, where the interference from terrestrial base station is introduced to enhance security of the satellite link. Our objective is to minimize the transmit power by jointly optimizing the cooperative beamforming and artificial noise while guaranteeing the secrecy rate constraint for satellite link, the information rate constraint for terrestrial link and the total transmit power constraint. Both scenarios of the perfect and imperfect channel cases are considered. The resulting optimization problems are non-convex and challenging, which are efficiently solved via certain transformations to be reformulated more tractable versions, respectively. Numerical results are provided to corroborate the proposed schemes.

Zou Jingbo, Shûichi Ohno