Achievable Rate Region of Energy-Harvesting Based Secure Two-Way Buffer-Aided Relay Networks

• Published in: IEEE transactions on information forensics and security Vol. 16; pp. 1610 - 1625
• Main Authors: Nie, Yulong, Lan, Xiaolong, Liu, Yong, Chen, Qingchun, Chen, Gaojie, Fan, Lisheng, Tang, Dong
• Format: Journal Article
• Language: English
• Published: New York IEEE 2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: achievable secrecy rate region; Buffer storage; buffer-aided relaying; Buffers; Communication system security; Constraints; Energy; Energy harvesting; Energy storage; Exchanging; Jamming; Modal choice; Optimization; Power consumption; Relay networks; Relaying; Relays; Resource management; Security; Time division; two-way secure relaying; Wireless networks
• ISSN: 1556-6013; 1556-6021
• DOI: 10.1109/TIFS.2020.3039047

This paper considered an energy-harvesting based secure two-way relay (EH-STWR) network, where two users exchanged information with the assistance of one buffer-aided relay that harvested energy from two users. To realize the confidential message exchange between two users in the presence of a potential eavesdropper, a secure bidirectional relaying scheme based on time division broadcast (TDBC) was proposed, where one user sent artificial noise to suppress the eavesdropper and another user transmitted data to the relay. A secure sum-rate maximization problem was formulated subject to average and peak transmit power constraints, data buffer and energy storage causality, and transmission mode constraints. By employing the Lyapunov optimization framework, a security-aware adaptive transmission scheme was proposed to jointly adapt transmission mode selection, power allocation, and security rate allocation according to channel/buffer/energy state information (CSI/BSI/ESI). Analysis results showed that the average achievable secrecy rate region can be significantly improved and there exists an inherent trade-off among transmission delay, requirement of transmit power consumption, and achievable secure sum-rate. Moreover, the channel condition between the energy-constrained relay and the potential eavesdropper is a critical factor on the achievable long-term average secrecy rate performance.