1,520 research outputs found
On Capacity of Active Relaying in Magnetic Induction based Wireless Underground Sensor Networks
Wireless underground sensor networks (WUSNs) present a variety of new
research challenges. Magnetic induction (MI) based transmission has been
proposed to overcome the very harsh propagation conditions in underground
communications in recent years. In this approach, induction coils are utilized
as antennas in the sensor nodes. This solution achieves longer transmission
ranges compared to the traditional electromagnetic (EM) waves based approach.
Furthermore, a passive relaying technique has been proposed in the literature
where additional resonant circuits are deployed between the nodes. However,
this solution is shown to provide only a limited performance improvement under
practical system design contraints. In this work, the potential of an active
relay device is investigated which may improve the performance of the system by
combining the benefits of the traditional wireless relaying and the MI based
signal transmission.Comment: This paper has been accepted for presentation at IEEE ICC 2015. It
has 6 pages, 5 figures (4 colored), and 17 reference
Beamforming for Magnetic Induction based Wireless Power Transfer Systems with Multiple Receivers
Magnetic induction (MI) based communication and power transfer systems have
gained an increased attention in the recent years. Typical applications for
these systems lie in the area of wireless charging, near-field communication,
and wireless sensor networks. For an optimal system performance, the power
efficiency needs to be maximized. Typically, this optimization refers to the
impedance matching and tracking of the split-frequencies. However, an important
role of magnitude and phase of the input signal has been mostly overlooked.
Especially for the wireless power transfer systems with multiple transmitter
coils, the optimization of the transmit signals can dramatically improve the
power efficiency. In this work, we propose an iterative algorithm for the
optimization of the transmit signals for a transmitter with three orthogonal
coils and multiple single coil receivers. The proposed scheme significantly
outperforms the traditional baseline algorithms in terms of power efficiency.Comment: This paper has been accepted for presentation at IEEE GLOBECOM 2015.
It has 7 pages and 5 figure
Signals in the Soil: An Introduction to Wireless Underground Communications
In this chapter, wireless underground (UG) communications are introduced. A detailed overview of WUC is given. A comprehensive review of research challenges in WUC is presented. The evolution of underground wireless is also discussed. Moreover, different component of UG communications is wireless. The WUC system architecture is explained with a detailed discussion of the anatomy of an underground mote. The examples of UG wireless communication systems are explored. Furthermore, the differences of UG wireless and over-the-air wireless are debated. Different types of wireless underground channel (e.g., In-Soil, Soil-to-Air, and Air-to-Soil) are reported as well
A Survey on Subsurface Signal Propagation
Wireless Underground Communication (WUC) is an emerging field that is being developed continuously. It provides secure mechanism of deploying nodes underground which shields them from any outside temperament or harsh weather conditions. This paper works towards introducing WUC and give a detail overview of WUC. It discusses system architecture of WUC along with the anatomy of the underground sensor motes deployed in WUC systems. It also compares Over-the-Air and Underground and highlights the major differences between the both type of channels. Since, UG communication is an evolving field, this paper also presents the evolution of the field along with the components and example UG wireless communication systems. Finally, the current research challenges of the system are presented for further improvement of the WUCs
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