English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

This paper studies a cognitive or secondary multi-antenna wireless powertransfer (WPT) system over a multi-carrier channel, which shares the samespectrum with a primary wireless information transfer (WIT) system that employsadaptive water-filling power allocation. By controlling the transmit energybeamforming over sub-carriers (SCs), the secondary energy transmitter (S-ET)can directly charge the secondary energy receiver (S-ER), even purposelyinterfere with the primary WIT system, such that the primary informationtransmitter (P-IT) can reactively adjust its power allocation (based onwater-filling) to facilitate the S-ER's energy harvesting. We investigate howthe secondary WPT system can exploit the primary WIT system's reactive powerallocation, for improving the wireless energy harvesting performance. Inparticular, our objective is to maximize the total energy received at the S-ERfrom both the S-ET and the P-IT, by optimizing the S-ET's energy beamformingover SCs, subject to its maximum transmit power constraint, and the maximuminterference power constraint imposed at the primary information receiver(P-IR) to protect the primary WIT. Although the formulated problem isnon-convex and difficult to be optimally solved in general, we propose anefficient algorithm to obtain a high-quality solution by employing the Lagrangedual method together with a one-dimensional search. We also present twobenchmark energy beamforming designs based on the zero-forcing (ZF) andmaximum-ratio-transmission (MRT) principles, respectively, as well as theconventional design without considering the primary WIT system's reaction.Numerical results show that our proposed design leads to significantly improvedenergy harvesting performance at the S-ER, as compared to these benchmarkschemes.

Cognitive Wireless Power Transfer in the Presence of Reactive Primary Communication User