Energy-Efficient Secure Transmission for Cognitive Radio Networks with SWIPT

Ke WANG  Wei HENG  Xiang LI  Jing WU  

Publication
IEICE TRANSACTIONS on Communications   Vol.E103-B   No.9   pp.1002-1010
Publication Date: 2020/09/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2019EBP3180
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
Keyword: 
artificial noise,  cognitive radio network,  simultaneous wireless information and power transfer,  physical-layer security,  energy efficiency,  

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Summary: 
In this paper, the artificial noise (AN)-aided multiple-input single-output (MISO) cognitive radio network with simultaneous wireless information and power transfer (SWIPT) is considered, in which the cognitive user adopts the power-splitting (PS) receiver architecture to simultaneously decode information and harvest energy. To support secure communication and facilitate energy harvesting, AN is transmitted with information signal at cognitive base station (CBS). The secrecy energy efficiency (SEE) maximization problem is formulated with the constraints of secrecy rate and harvested energy requirements as well as primary user's interference requirements. However, this challenging problem is non-convex due to the fractional objective function and the coupling between the optimization variables. For tackling the challenging problem, a double-layer iterative optimization algorithm is developed. Specifically, the outer layer invokes a one-dimension search algorithm for the newly introduced tight relaxation variable, while the inner one leverages the Dinkelbach method to make the fractional optimization problem more tractable. Furthermore, closed-form expressions for the power of information signal and AN are obtained. Numerical simulations are conducted to demonstrate the efficiency of our proposed algorithm and the advantages of AN in enhancing the SEE performance.