Secrecy performance of a dual hop cognitive relay network with an energy harvesting relay

In this work, the physical (PHY) layer security is investigated in terms of secrecy outage probability (SOP) for a dual hop decode and forward relaying system in a cognitive relay network (CRN) in presence of an eavesdropper. The relay node harvests energy using a power splitting-based relaying (PSR) scheme from the RF signal of primary user as well as a secondary user. The transmit power of the secondary user (SU) as well as relay is limited by the maximum tolerable interference at primary user (PU) receiver due to the cognitive environment as imposed by quality of service (QOS) of PU. The SOP for the network under study has been analyzed. The impact of several parameters such as PU's peak power, SU's peak power, interference threshold for underlay CRN, channel mean power of legitimate and illegitimate communication channels and energy harvesting conversion efficiency on SOP has been indicated.