Physical Layer Security Enhancement for Satellite Communication among Similar Channels: Relay Selection and Power Allocation

TL;DR

This paper proposes a physical layer security scheme for satellite communication channels with similar characteristics, using relay selection and power allocation to improve security against eavesdroppers, supported by theoretical analysis and simulations.

Contribution

It introduces a relay selection and power allocation framework tailored for satellite channels with similar legitimate and eavesdropper channels, addressing limitations of terrestrial security methods.

Findings

Relay selection based on CSI reduces secrecy relay probability.

Optimized power allocation minimizes secrecy outage probability.

Simulation results confirm improved security performance.

Abstract

Channels of satellite communication are usually modeled as Rician fading channels with very large Rician factor or Gaussian channels. Therefore, when a legitimate user is close to an eavesdropping user, the legitimate channel is approximately the same as the eavesdropping channel. The physical layer security technology of traditional terrestrial wireless communication mainly takes advantage of the difference be-tween the legitimate channel and the eaves-dropping channel; thus, it is not suitable for satellite communication. To implement secure communication in similar channels for satellite communications, a secure communication mod-el based on collaboration of the interference relay of the satellite physical layer is proposed. Relay selection and power allocation are further studied to enhance the security performance of the satellite communication system based on the model. The relay selection standard under known instantaneous channel state information (CSI) and statistical CSI conditions is theoreti-cally derived, thereby accomplishing minimiza-tion of the probability of secrecy relay. In addi-tion, the power allocation factor is optimized based on minimization of the secrecy outage probability. Moreover, a power allocation method based on the statistical CSI is present-ed. The secrecy outage probability performance of each relay selection criterion and power al-location scheme are analyzed via a simulation.