Biblio

This paper investigates the secrecy outage performance of Multiple Input Multiple Output (MIMO) secondary nodes for underlay Cognitive Radio Network (CRN) over α–μ fading channel. Here, the proposed system consists of one active eavesdropper and two primary nodes each with a single antenna. The power of the secondary transmitter depends on the harvested energy from the primary transmitter to save more energy and spectrum. Moreover, a Transmit Antenna Selection (TAS) scheme is adopted at the secondary source, while the Maximal Ratio Combining (MRC) technique is employed at the secondary receiver to optimize the quality of the signal. A lower bound closed-form phrase for the secrecy outage performance is derived to demonstrate the effects of the channel parameters. In addition, numerical results illustrate that the number of source transmit antennas, destination received antenna, and the eavesdropper received antenna have significant effects on improving the secrecy performance.

In this article, we study the transmission secrecy performance of primary user in overlay cognitive wireless networks, in which an untrusted energy-limited secondary cooperative user assists the primary transmission to exchange for the spectrum resource. In the network, the information can be simultaneously transmitted through the direct and relay links. For the enhancement of primary transmission security, a maximum ratio combining (MRC) scheme is utilized by the receiver to exploit the two copies of source information. For the security analysis, we firstly derive the tight lower bound expression for secrecy outage probability (SOP). Then, three asymptotic expressions for SOP are also expressed to further analyze the impacts of the transmit power and the location of secondary cooperative node on the primary user information security. The findings show that the primary user information secrecy performance enhances with the improvement of transmit power. Moreover, the smaller the distance between the secondary node and the destination, the better the primary secrecy performance.