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/

Global: Zendy Plus annual

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

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Radio-frequency wireless energy transfer (WET) is a promising technology torealize wireless-powered underground sensor networks (WPUSNs) and enablesustainable underground monitoring. However, due to the severe attenuation inharsh underground soil and the tight energy budget of the underground sensors,traditional WPUSNs relying on the channel state information (CSI) are highlyinefficient, especially in massive WET scenarios. To address this challenge, wecomparatively assess the feasibility of several state-of-the-art CSI-freemulti-antenna WET schemes for WPUSNs, under a given power budget. Moreover, toovercome the extremely low WET efficiency in underground channels, we propose adistributed CSI-free system, where multiple power beacons (PBs) simultaneouslycharge a large set of underground sensors without any CSI. We consider theposition-aware K-Means and the position-agnostic equally-far-from-center (EFFC)approaches for the optimal deployment of the PBs. Our results evince that theperformance of the proposed distributed CSI-free system can approach or evensurpass that of a traditional full-CSI WET strategy, especially when adoptingan appropriate CSI-free scheme, applying the advisable PBs deployment approach,and equipping the PBs with an appropriate number of antennas. Finally, wediscuss the impact of underground parameters, i.e., the burial depth of devicesand the volumetric water content of soil, on the system's performance, andidentify potential challenges and research opportunities for practicaldistributed CSI-free WPUSNs deployment.

On CSI-Free Multi-Antenna Schemes for Massive Wireless-Powered Underground Sensor Networks