Enhancing covert communication in NOMA systems with joint security and covert design

Area of Science:

• Wireless Communication
• Information Security
• Network Engineering

Background:

• Internet of Things (IoT) devices increase vulnerabilities to data breaches via wireless systems.
• Covert communication offers enhanced data privacy, complementing physical layer security.
• Non-Orthogonal Multiple Access (NOMA) systems face challenges with eavesdropping on sensitive information.

Purpose of the Study:

• To enhance secure data transmission for nearby users in NOMA systems under eavesdropping scenarios.
• To analyze system performance metrics including outage probability (OP), secrecy outage probability (SOP), and detection error probability (DEP).
• To optimize resource power allocation for minimizing OP and maximizing covert rates.

Main Methods:

• Comprehensive mathematical analysis of NOMA systems including exact and asymptotic closed-form expressions for OP, SOP, and DEP.
• Derivation of closed-form formulas for users' covert and public rates.
• Formulation of resource power allocation optimization problems to meet security and performance requirements.

Main Results:

• Exact and asymptotic closed-form expressions for key performance metrics were derived.
• Closed-form solutions for sub-optimal power allocation coefficients were obtained.
• Proposed power allocation strategies demonstrated significant performance improvements over fixed allocations.

Conclusions:

• The analytical framework effectively models and analyzes covert communication in NOMA systems.
• Optimized power allocation is crucial for enhancing security and data rates in covert NOMA transmissions.
• The proposed methods offer a robust approach to secure wireless communications in the presence of eavesdroppers.