On Security Performance of SWIPT Multi-User Jamming Based on Mixed RF/FSO Systems with Untrusted Relay

Area of Science:

• Wireless Communication Security
• Optical Wireless Communication
• Information Theory

Background:

• Untrusted relays pose significant security risks in multi-user wireless networks.
• Simultaneous Wireless Information and Power Transfer (SWIPT) is crucial for powering user nodes.
• Mixed Radio Frequency (RF) and Free Space Optics (FSO) systems offer enhanced communication capabilities.

Purpose of the Study:

• To analyze the security performance of a mixed RF/FSO system employing SWIPT with untrusted relays.
• To derive closed-form expressions for secrecy outage probability (SOP) and average secrecy capacity (ASC).
• To investigate the impact of artificial noise and system parameters on security.

Main Methods:

• Modeling RF channels with Nakagami-m fading and FSO channels with Málaga (M) turbulence.
• Implementing an interference-based security strategy using artificial noise.
• Deriving closed-form expressions for SOP and ASC.
• Validating results through Monte Carlo simulations.

Main Results:

• Closed-form expressions for SOP and ASC were successfully derived and verified.
• Security performance significantly improves with increased signal-interference noise ratio and interfering users.
• Enhanced security is observed with higher time distribution factors and energy conversion efficiency.
• Low RF signal-to-noise ratio (SNR) conditions benefit most from these security enhancements.

Conclusions:

• The proposed artificial noise strategy effectively mitigates security threats from untrusted relays in mixed RF/FSO systems.
• System parameters like SNR, number of users, and energy efficiency critically influence security outcomes.
• The research provides valuable insights for designing secure and efficient wireless communication systems.