Secrecy Analysis on Network Coding in Bidirectional Multibeam Satellite Communications

TL;DR

This paper investigates the confidentiality of network coding in bidirectional multibeam satellite communications, proposing an optimal beamforming and time allocation scheme to maximize secrecy rates and demonstrating its superiority over conventional methods.

Contribution

It introduces an optimal beamforming and time allocation approach for maximizing secrecy in network-coded satellite communications, addressing a gap in understanding its resilience to eavesdropping.

Findings

Network coding significantly improves secrecy rates.

The proposed scheme outperforms conventional methods.

Simulation confirms higher secrecy rates with network coding.

Abstract

Network coding is an efficient means to improve the spectrum efficiency of satellite communications. However, its resilience to eavesdropping attacks is not well understood. This paper studies the confidentiality issue in a bidirectional satellite network consisting of two mobile users who want to exchange message via a multibeam satellite using the XOR network coding protocol. We aim to maximize the sum secrecy rate by designing the optimal beamforming vector along with optimizing the return and forward link time allocation. The problem is non-convex, and we find its optimal solution using semidefinite programming together with a 1-D search. For comparison, we also solve the sum secrecy rate maximization problem for a conventional reference scheme without using network coding. Simulation results using realistic system parameters demonstrate that the bidirectional scheme using network coding provides considerably higher secrecy rate compared to that of the conventional scheme.