Optimizing DF Cognitive Radio Networks with Full-Duplex-Enabled Energy Access Points

TL;DR

This paper proposes a novel full-duplex-enabled energy access point system for cognitive radio networks, enhancing spectrum efficiency and wireless power transfer through joint information and energy cooperation, optimized via convex approximation techniques.

Contribution

It introduces a full-duplex-enabled energy access point architecture for wireless powered cognitive radio networks, with optimized beamforming and relay strategies for improved performance.

Findings

The proposed scheme outperforms benchmark methods in sum-rate performance.

Full-duplex operation significantly enhances energy transfer and data relaying efficiency.

Tradeoffs between sum-rate and system parameters are characterized through numerical analysis.

Abstract

With the recent advances in radio frequency (RF) energy harvesting (EH) technologies, wireless powered cooperative cognitive radio network (CCRN) has drawn an upsurge of interest for improving the spectrum utilization with incentive to motivate joint information and energy cooperation between the primary and secondary systems. Dedicated energy beamforming (EB) is aimed for remedying the low efficiency of wireless power transfer (WPT), which nevertheless arouses out-of-band EH phases and thus low cooperation efficiency. To address this issue, in this paper, we consider a novel RF EH CCRN aided by full-duplex (FD)-enabled energy access points (EAPs) that can cooperate to wireless charge the secondary transmitter (ST) while concurrently receiving primary transmitter (PT)'s signal in the first transmission phase, and to perform decode-and-forward (DF) relaying in the second transmission phase. We investigate a weighted sum-rate maximization problem subject to the transmitting power constraints as well as a total cost constraint using successive convex approximation (SCA) techniques. A zero-forcing (ZF) based suboptimal scheme that requires only local CSIs for the EAPs to obtain their optimum receive beamforming is also derived. Various tradeoffs between the weighted sum-rate and other system parameters are provided in numerical results to corroborate the effectiveness of the proposed solutions against the benchmark ones.