Joint Resource Allocation in Secure OFDM Two-Way Untrusted Relay System.

Area of Science:

• Wireless Communication Security
• Cooperative Relay Systems
• Orthogonal Frequency Division Multiplexing (OFDM)

Background:

• Untrusted relays in wireless communication pose significant security risks, particularly in broadcast-based systems.
• Existing resource allocation schemes for single-carrier systems are not directly applicable to multi-carrier OFDM systems.
• Two-way relay systems offer improved data transmission efficiency over one-way systems.

Purpose of the Study:

• To develop a joint secure resource allocation scheme for two-way cooperative OFDM systems with untrusted relays.
• To maximize the sum secrecy rate under individual power constraints.
• To address the unique challenges of resource allocation in multi-carrier systems with untrusted relays.

Main Methods:

• Formulation of a joint power allocation and subcarrier pairing problem.
• Development of an algorithm based on the alternative optimization method to solve the non-convex problem.
• Evaluation of the proposed algorithm through simulations and comparison with existing benchmarks.

Main Results:

• The proposed algorithm effectively solves the joint secure resource allocation problem.
• Numerical results demonstrate significant improvements in achievable sum secrecy rate.
• In high signal-to-noise ratio (SNR) scenarios, the algorithm improves the sum secrecy rate by over 15% compared to conventional methods.

Conclusions:

• The proposed joint secure resource allocation algorithm is efficient and effective for two-way cooperative OFDM systems with untrusted relays.
• The algorithm provides a substantial performance gain in terms of sum secrecy rate, particularly under high SNR conditions.
• This work offers a valuable solution for enhancing wireless communication security in challenging relay environments.