24,994 research outputs found
Design and control of a bidirectional wireless charging system using GaN devices
Most of the existing wireless power transfer system works in unidirectional with one-direction control signals. This paper presents a bidirectional wireless charging system with duplex communication method, which is not only able to achieve the two-way wireless power transmission, but also transfer control signals bi-directionally. The power circuit operation mode is actively controlled by using the wireless transceiver module which can duplex communication to deliver measured signals remotely. The operational principle is analytically studied in details and is verified by simulation. Finally, a prototype of the bidirectional charging system using GaN devices has been successfully designed and tested. In addition, the measured feedback signals are effectively transmitted to validate the control algorithm
RCFD: A Novel Channel Access Scheme for Full-Duplex Wireless Networks Based on Contention in Time and Frequency Domains
In the last years, the advancements in signal processing and integrated
circuits technology allowed several research groups to develop working
prototypes of in-band full-duplex wireless systems. The introduction of such a
revolutionary concept is promising in terms of increasing network performance,
but at the same time poses several new challenges, especially at the MAC layer.
Consequently, innovative channel access strategies are needed to exploit the
opportunities provided by full-duplex while dealing with the increased
complexity derived from its adoption. In this direction, this paper proposes
RTS/CTS in the Frequency Domain (RCFD), a MAC layer scheme for full-duplex ad
hoc wireless networks, based on the idea of time-frequency channel contention.
According to this approach, different OFDM subcarriers are used to coordinate
how nodes access the shared medium. The proposed scheme leads to efficient
transmission scheduling with the result of avoiding collisions and exploiting
full-duplex opportunities. The considerable performance improvements with
respect to standard and state-of-the-art MAC protocols for wireless networks
are highlighted through both theoretical analysis and network simulations.Comment: Submitted at IEEE Transactions on Mobile Computing. arXiv admin note:
text overlap with arXiv:1605.0971
Control of Multilayer Networks
The controllability of a network is a theoretical problem of relevance in a
variety of contexts ranging from financial markets to the brain. Until now,
network controllability has been characterized only on isolated networks, while
the vast majority of complex systems are formed by multilayer networks. Here we
build a theoretical framework for the linear controllability of multilayer
networks by mapping the problem into a combinatorial matching problem. We found
that correlating the external signals in the different layers can significantly
reduce the multiplex network robustness to node removal, as it can be seen in
conjunction with a hybrid phase transition occurring in interacting Poisson
networks. Moreover we observe that multilayer networks can stabilize the fully
controllable multiplex network configuration that can be stable also when the
full controllability of the single network is not stable
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