Interference-Assisted Wireless Energy Harvesting in Cognitive Relay Network with Multiple Primary Transceivers

TL;DR

This paper explores a spectrum sharing scenario where a secondary relay harvests energy from primary interference to assist secondary communication, deriving outage probability expressions and analyzing the impact of primary transceivers on performance.

Contribution

It introduces a closed-form outage probability expression for an interference-assisted energy harvesting relay in cognitive networks, considering multiple primary transceivers and optimal energy harvesting duration.

Findings

Using primary interference as energy improves secondary outage performance.

Optimal energy harvesting duration depends on the number of primary transceivers.

Closed-form expression for secondary outage probability under constraints.

Abstract

We consider a spectrum sharing scenario, where a secondary network coexists with a primary network of multiple transceivers. The secondary network consists of an energy-constrained decode-and-forward secondary relay which assists the communication between a secondary transmitter and a destination in the presence of the interference from multiple primary transmitters. The secondary relay harvests energy from the received radio-frequency signals, which include the information signal from the secondary transmitter and the primary interference. The harvested energy is then used to decode the secondary information and forward it to the secondary destination. At the relay, we adopt a time switching policy due to its simplicity that switches between the energy harvesting and information decoding over time. Specifically, we derive a closed-form expression for the secondary outage probability under the primary outage constraint and the peak power constraint at both secondary transmitter and relay. In addition, we investigate the effect of the number of primary transceivers on the optimal energy harvesting duration that minimizes the secondary outage probability. By utilizing the primary interference as a useful energy source in the energy harvesting phase, the secondary network achieves a better outage performance.