Cooperative Energy Harvesting Cognitive Radio Networks With Spectrum Sharing and Security Constraints

Abstract

Physical layer security is an important and timely topic in the research of future wireless systems and it constitutes a part of the Internet of Things (IoT) notion. IoT oriented systems are largely characterized by a stringent quality of service and enhanced security requirements, which comes at a cost of increased computational complexity that needs to be maintained within sustainable levels. In the present contribution, we investigate the physical-layer security of a dual-hop energy RF-Powered cognitive radio network over realistic multipath fading conditions. Assuming a spectrum sharing scenario, our analysis assumes that a source S communicates with a destination D with the aid of a multi-antenna relay R and in the presence of an eavesdropper E who is attempting to overhear the communication of both S-R and R-D links. The involved relay is powered by the renewable energy harvested from the signal sent by the source based on the power-splitting energy harvesting strategy. Furthermore, the relay uses a maximum ratio combining technique to process effectively the received signals. In addition, owing to the underlying strategy, both S and R adjust their respective transmit powers in order to avoid causing interference to the primary network. By considering both the independent identically distributed and the independent but not necessarily identically distributed flat Rayleigh fading channels, closed-form expressions for the secrecy outage probability are derived, based on which an asymptotic analysis is carried out. Our results quantify the impact of the main key system parameters and point out the optimal values ensuring a high-security performance of such a communication system. The validity of the derived results is verified extensively through comparisons with respective Monte Carlo simulation results and useful theoretical and technical insights are developed which are expected to be useful in the design of future cooperative CRNs.INDEX TERMS Cognitive radio network, energy harvesting, maximum ratio combining, physical layer security, power splitting, interference, secrecy outage probability.

A PHY Layer Security Analysis of Uplink Cooperative Jamming-Based Underlay CRNs with Multi-Eavesdroppers

“…• One can see from (14) and (15), that the PHY layer security at the first hop in the presence of a friendly jammer can be enhanced by increasing separately…”

“…Indeed, the increasing scale of the SNR at the relay exceeds the one of the kth eavesdropper as a jamming signal is added to the one received by E k . However, in the absence of a friendly jammer, one can see from (14) and (16) that only the impact of legitimate and wiretap channels' parameters can make the distinction between the two associated SNRs. Consequently, the smaller λ S i R , the greater the secrecy capacity and then the security gets improved.…”

On the performance of underlay cognitive radio system with random mobility under imperfect channel state information

“…Cognitive radio systems have been recently considered as a distinguished technology to alleviate the spectrum scarcity in wireless communication systems 1,2 . This concept of cognitive radio significantly improves the spectral efficiency of wireless systems by allowing the unlicensed secondary user(s) (SUs) to access the licence resource spectrum of the primary user(s) (PUs) 3 .…”

A PHY Layer Security Analysis of Uplink Cooperative Jamming-Based Underlay CRNs with Multi-Eavesdroppers

“…Under these conditions, closed-form and asymptotic expressions for the SOP and intercept probability (IP) were derived over either Nakagami-m [6] or Rayleigh [7]- [9] fading channels. The IP and SOP analysis of cooperative underlay EH-based CRNs have been investigated in [10] and [10]- [14], respectively. Specifically, the SUs have been assumed to harvest energy from the PU's signals in [10]- [12].…”

“…Specifically, the SUs have been assumed to harvest energy from the PU's signals in [10]- [12]. In contrast, in [13]- [14] the relay is harvesting energy from the SU signals instead.…”