Performance of Wireless Powered Cognitive Radio Sensor Networks With Nonlinear Energy Harvester

This article analyzes the performance of simultaneous wireless information-and-power transfer (SWIPT) in a cognitive radio sensor network (CRSN) under Nakagami-m fading. A pair of sensor nodes (SNs) is considered in which one SN facilitates relay cooperation for communications between two primary users (PUs). In return, SNs make use of PUs' signals for energy harvesting and realize their own communications. In such a network, bidirectional communications between the two PUs and unidirectional information exchange between the SNs can be performed in three phases. A power splitting (PS) based approach is adopted for enabling SWIPT. The relaying SN applies an amplify-and-forward protocol to broadcast primary and secondary signals, whereas the PUs perform selection combining to access the active direct link. Accurate expressions of the outage probability and throughput are derived for the primary system by considering a nonlinear energy harvester at the relaying SN under Nakagami-m fading.