The Experts below are selected from a list of 40833 Experts worldwide ranked by ideXlab platform
Zhi Sun - One of the best experts on this subject based on the ideXlab platform.
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increasing the capacity of Magnetic Induction communication using mimo coil array
Global Communications Conference, 2016Co-Authors: Hongzhi Guo, Zhi SunAbstract:Magnetic Induction (MI) is a promising solution for wireless communications in complex environments, such as oil reservoir, underground, indoor, and underwater. Due to the inherent electrically small size and simple structure of the Magnetic coil antenna, it suffers from low radiation efficiency, extremely narrow bandwidth, and dramatic polarization loss. Recently, significant efforts have been made to increase MI communication's performance, for instance, the metamaterial- enhanced Magnetic Induction has been developed to increase the signal strength, the tri-directional coil antenna is used to overcome the polarization loss, among others. However, increasing the bandwidth of MI communication is still a great challenge. In this paper, we propose a MIMO antenna array with each antenna element having its own resonant frequency. Due to the strong coupling in the deep near field, the antenna elements mutually affect each other. Instead of eliminating this coupling, we rigorously derive a model to capture it and use metamaterial-inspired method to find the optimal configuration of the antenna array to achieve multiple bands. As a result, the overall bandwidth can be significantly increased. Meanwhile, the enhanced wireless channel can provide much better signal strength. Finally, we theoretically analyze the channel gain in comparison with the original MI to demonstrate the benefits of MI MIMO.
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Distributed Cross-Layer Protocol Design for Magnetic Induction Communication in Wireless Underground Sensor Networks
IEEE Transactions on Wireless Communications, 2015Co-Authors: Shih-chun Lin, Pu Wang, Zhi SunAbstract:Wireless underground sensor networks (WUSNs) enable many applications such as underground pipeline monitoring, power grid maintenance, mine disaster prevention, and oil upstream monitoring among many others. While the classical electroMagnetic waves do not work well in WUSNs, the Magnetic Induction (MI) propagation technique provides constant channel conditions via small size of antenna coils in the underground environments. In this paper, instead of adopting currently layered protocols approach, a distributed cross-layer protocol design is proposed for MI-based WUSNs. First, a detailed overview is given for different communication functionalities from physical to network layers as well as the QoS requirements of applications. Utilizing the interactions of different layer functionalities, a distributed environment-aware protocol, called DEAP, is then developed to satisfy statistical QoS guarantees and achieve both optimal energy savings and throughput gain concurrently. Simulations confirm that the proposed cross-layer protocol achieves significant energy savings, high throughput efficiency and dependable MI communication for WUSNs.
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On capacity of Magnetic Induction-based wireless underground sensor networks
Proceedings - IEEE INFOCOM, 2012Co-Authors: Zhi SunAbstract:The Magnetic Induction (MI)-based wireless underground sensor networks (WUSNs) use the novel MI waveguide technique to establish long range and low cost wireless communications in harsh underground environments, which enable a large variety of novel and important applications. One of the main research challenges is the theoretical study of the channel and network capacities in these networks. Compared to the traditional wireless networks, both the channel and network capacities of MI-based WUSNs have significant different characteristics due to the completely different signal propagation techniques and network geometric structure. Moreover, the usage of multiple resonant MI relay coils in MI-based WUSNs brings more reliability concerns. In this paper, mathematical models are developed to evaluate the channel capacity, network capacity, and the reliability of MI-based WUSNs. Specifically, the closed-form expression for the channel capacity in MI-based WUSNs is first derived to capture the effects of multiple system parameters. Then the network capacity scaling laws of MI-based WUSNs are investigated under different deployment strategies. Finally, the system reliability of MI-based WUSNs in terms of the channel capacity and network capacity is discussed. The results of this paper provide principles and guidelines for the design and deployment of MI-based WUSNs.
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Magnetic Induction communications for wireless underground sensor networks
IEEE Transactions on Antennas and Propagation, 2010Co-Authors: Zhi SunAbstract:The main difference between the wireless underground sensor networks (WUSNs) and the terrestrial wireless sensor networks is the signal propagation medium. The underground is a challenging environment for wireless communications since the propagation medium is no longer air but soil, rock and water. The well established wireless signal propagation techniques using electroMagnetic (EM) waves do not work well in this environment due to three problems: high path loss, dynamic channel condition and large antenna size. New techniques using Magnetic Induction (MI) create constant channel condition and can accomplish the communication with small size coils. In this paper, detailed analysis on the path loss and the bandwidth of the MI system in underground soil medium is provided. Based on the channel analysis, the MI waveguide technique for communication is developed in order to reduce the high path loss of the traditional EM wave system and the ordinary MI system. The performance of the EM wave system, the ordinary MI system and our improved MI waveguide system are quantitatively compared. The results reveal that the transmission range of the MI waveguide system is dramatically increased.
Bin He - One of the best experts on this subject based on the ideXlab platform.
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magnetoacoustic tomography with Magnetic Induction mat mi for imaging electrical conductivity of biological tissue a tutorial review
Physics in Medicine and Biology, 2016Co-Authors: Kai Yu, Xu Li, Bin HeAbstract:: Magnetoacoustic tomography with Magnetic Induction (MAT-MI) is a noninvasive imaging method developed to map electrical conductivity of biological tissue with millimeter level spatial resolution. In MAT-MI, a time-varying Magnetic stimulation is applied to induce eddy current inside the conductive tissue sample. In the presence of a static Magnetic field, the Lorentz force acting on the induced eddy current drives mechanical vibrations producing detectable ultrasound signals. These ultrasound signals can then be acquired to reconstruct a map related to the sample's electrical conductivity contrast. This work reviews fundamental ideas of MAT-MI and major techniques developed in recent years. First, the physical mechanisms underlying MAT-MI imaging are described, including the Magnetic Induction and Lorentz force induced acoustic wave propagation. Second, experimental setups and various imaging strategies for MAT-MI are reviewed and compared, together with the corresponding experimental results. In addition, as a recently developed reverse mode of MAT-MI, magneto-acousto-electrical tomography with Magnetic Induction is briefly reviewed in terms of its theory and experimental studies. Finally, we give our opinions on existing challenges and future directions for MAT-MI research. With all the reported and future technical advancement, MAT-MI has the potential to become an important noninvasive modality for electrical conductivity imaging of biological tissue.
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Magnetoacoustic tomography with Magnetic Induction: Bioimepedance reconstruction through vector source imaging
IEEE Transactions on Medical Imaging, 2013Co-Authors: Lavanya Mariappan, Bin HeAbstract:Magnetoacoustic tomography with Magnetic Induction (MAT-MI) is a technique proposed to reconstruct the conductivity distribution in biological tissue at ultrasound imaging resolution. A Magnetic pulse is used to generate eddy currents in the object, which in the presence of a static Magnetic field induces Lorentz force based acoustic waves in the medium. This time resolved acoustic waves are collected with ultrasound transducers and, in the present work, these are used to reconstruct the current source which gives rise to the MAT-MI acoustic signal using vector imaging point spread functions. The reconstructed source is then used to estimate the conductivity distribution of the object. Computer simulations and phantom experiments are performed to demonstrate conductivity reconstruction through vector source imaging in a circular scanning geometry with a limited bandwidth finite size piston transducer. The results demonstrate that the MAT-MI approach is capable of conductivity reconstruction in a physical setting.
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magnetoacoustic tomography with Magnetic Induction for imaging electrical impedance of biological tissue
Journal of Applied Physics, 2006Co-Authors: Xu Li, Yuan Xu, Bin HeAbstract:An experimental feasibility study was conducted on magnetoacoustic tomography with Magnetic Induction (MAT-MI). It is demonstrated that the two-dimensional MAT-MI system can detect and image the boundaries between regions of different electrical conductivities with high spatial resolution. Utilizing a Magnetic stimulation coil, MAT-MI evokes Magnetically induced eddy current in an object which is placed in a static Magnetic field. Because of the existence of Lorenz forces, the eddy current in turn causes acoustic vibrations, which are measured around the object in order to reconstruct the electrical impedance distribution of the object. The present experimental results from the saline and gel phantoms are promising and suggest the merits of MAT-MI in imaging electrical impedance of biological tissue with high spatial resolution.
W H Gerstacker - One of the best experts on this subject based on the ideXlab platform.
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survey on advances in Magnetic Induction based wireless underground sensor networks
IEEE Internet of Things Journal, 2018Co-Authors: Steven Kisseleff, Ian F Akyildiz, W H GerstackerAbstract:Underground communication systems present a variety of new research challenges. Here, the goal is to establish an efficient wireless connection between the transceivers in the challenging underground medium. Typical applications for this type of communication systems include soil condition monitoring, earthquake prediction, communication in mines/tunnels, etc. These applications require a gathering of relevant information from multiple locations, which suggests the use of multiple sensor nodes that would be organized in wireless underground sensor networks (WUSNs). Due to the harsh propagation conditions in the soil medium (including rock, sand, and water sheds), traditional wireless signal propagation techniques using electroMagnetic waves can only be applied for very short transmission ranges. In recent years, Magnetic Induction (MI)-based transmission has been proposed to overcome these issues. In this approach, Induction coils are utilized as antennas in the transceivers in order to reduce the vulnerability of signal propagation to the soil properties, in particular the soil conductivity. Correspondingly, the design rules for optimum MI-WUSNs have been shown to substantially differ from the design rules for the traditional wireless communication systems due to unique properties of the transmission channel. In this survey paper, the recent advances in the area of MI-WUSNs are discussed, which range from signal transmission techniques and network design to wireless power transfer and localization. Also, new research challenges in this area are provided.
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localization of a silent target node in Magnetic Induction based wireless underground sensor networks
International Conference on Communications, 2017Co-Authors: Steven Kisseleff, X Chen, Ian F Akyildiz, W H GerstackerAbstract:Wireless underground sensor networks (WUSNs) based on Magnetic Induction (MI) have been recently proposed as a promising candidate for underground networking. The benefit of the MI-WUSNs compared to other solutions (e.g. so-called Through-The-Earth communication) is related to the substantially lower path loss and lower vulnerability to the changes of the soil properties. In the past, some efforts have been made to characterize the signal transmission in MI-WUSNs. Those investigations, however, refer mostly to the information transmission. One of the target applications of the WUSNs is the object localization in the underground medium, which remains an open issue due to the complicated characteristics of the MI channels corrupted by the influence of soil. In this work, we propose a machine learning based solution for localization. In addition, a novel passive localization technique is introduced, which requires no signal from the target node and thus proves useful for rescue operations, where the battery of the node to be localized is either empty or damaged.
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transmitter side channel estimation in Magnetic Induction based communication systems
IEEE International Black Sea Conference on Communications and Networking, 2014Co-Authors: Steven Kisseleff, Ian F Akyildiz, W H GerstackerAbstract:The use of Magnetic Induction (MI) based transmissions in challenging environments has been investigated in various works. Recently, a system model has been proposed, which explains how the pathloss of the Magnetic Induction based transmissions depends on the system parameters. It is frequently assumed, that perfect channel state information (CSI) is available at the transmitter and at the receiver, such that the optimal set of system parameters can be determined in order to maximize the overall data rate. However, in practical systems this knowledge may not always be easily acquired. In addition, a permanent feedback signaling is needed, in order to update the CSI at the transmitter. This feedback signaling usually occupies several time slots and therefore reduces the bandwidth efficiency. An interesting aspect, which has been overlooked in the past, is the channel estimation and prediction of the received signal within the MI transmitter circuit without explicit feedback signaling of CSI. In this paper, we investigate the potential of this technique for the wireless underground sensor networks.
Xu Li - One of the best experts on this subject based on the ideXlab platform.
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magnetoacoustic tomography with Magnetic Induction mat mi for imaging electrical conductivity of biological tissue a tutorial review
Physics in Medicine and Biology, 2016Co-Authors: Kai Yu, Xu Li, Bin HeAbstract:: Magnetoacoustic tomography with Magnetic Induction (MAT-MI) is a noninvasive imaging method developed to map electrical conductivity of biological tissue with millimeter level spatial resolution. In MAT-MI, a time-varying Magnetic stimulation is applied to induce eddy current inside the conductive tissue sample. In the presence of a static Magnetic field, the Lorentz force acting on the induced eddy current drives mechanical vibrations producing detectable ultrasound signals. These ultrasound signals can then be acquired to reconstruct a map related to the sample's electrical conductivity contrast. This work reviews fundamental ideas of MAT-MI and major techniques developed in recent years. First, the physical mechanisms underlying MAT-MI imaging are described, including the Magnetic Induction and Lorentz force induced acoustic wave propagation. Second, experimental setups and various imaging strategies for MAT-MI are reviewed and compared, together with the corresponding experimental results. In addition, as a recently developed reverse mode of MAT-MI, magneto-acousto-electrical tomography with Magnetic Induction is briefly reviewed in terms of its theory and experimental studies. Finally, we give our opinions on existing challenges and future directions for MAT-MI research. With all the reported and future technical advancement, MAT-MI has the potential to become an important noninvasive modality for electrical conductivity imaging of biological tissue.
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magnetoacoustic tomography with Magnetic Induction for imaging electrical impedance of biological tissue
Journal of Applied Physics, 2006Co-Authors: Xu Li, Yuan Xu, Bin HeAbstract:An experimental feasibility study was conducted on magnetoacoustic tomography with Magnetic Induction (MAT-MI). It is demonstrated that the two-dimensional MAT-MI system can detect and image the boundaries between regions of different electrical conductivities with high spatial resolution. Utilizing a Magnetic stimulation coil, MAT-MI evokes Magnetically induced eddy current in an object which is placed in a static Magnetic field. Because of the existence of Lorenz forces, the eddy current in turn causes acoustic vibrations, which are measured around the object in order to reconstruct the electrical impedance distribution of the object. The present experimental results from the saline and gel phantoms are promising and suggest the merits of MAT-MI in imaging electrical impedance of biological tissue with high spatial resolution.
Steven Kisseleff - One of the best experts on this subject based on the ideXlab platform.
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survey on advances in Magnetic Induction based wireless underground sensor networks
IEEE Internet of Things Journal, 2018Co-Authors: Steven Kisseleff, Ian F Akyildiz, W H GerstackerAbstract:Underground communication systems present a variety of new research challenges. Here, the goal is to establish an efficient wireless connection between the transceivers in the challenging underground medium. Typical applications for this type of communication systems include soil condition monitoring, earthquake prediction, communication in mines/tunnels, etc. These applications require a gathering of relevant information from multiple locations, which suggests the use of multiple sensor nodes that would be organized in wireless underground sensor networks (WUSNs). Due to the harsh propagation conditions in the soil medium (including rock, sand, and water sheds), traditional wireless signal propagation techniques using electroMagnetic waves can only be applied for very short transmission ranges. In recent years, Magnetic Induction (MI)-based transmission has been proposed to overcome these issues. In this approach, Induction coils are utilized as antennas in the transceivers in order to reduce the vulnerability of signal propagation to the soil properties, in particular the soil conductivity. Correspondingly, the design rules for optimum MI-WUSNs have been shown to substantially differ from the design rules for the traditional wireless communication systems due to unique properties of the transmission channel. In this survey paper, the recent advances in the area of MI-WUSNs are discussed, which range from signal transmission techniques and network design to wireless power transfer and localization. Also, new research challenges in this area are provided.
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localization of a silent target node in Magnetic Induction based wireless underground sensor networks
International Conference on Communications, 2017Co-Authors: Steven Kisseleff, X Chen, Ian F Akyildiz, W H GerstackerAbstract:Wireless underground sensor networks (WUSNs) based on Magnetic Induction (MI) have been recently proposed as a promising candidate for underground networking. The benefit of the MI-WUSNs compared to other solutions (e.g. so-called Through-The-Earth communication) is related to the substantially lower path loss and lower vulnerability to the changes of the soil properties. In the past, some efforts have been made to characterize the signal transmission in MI-WUSNs. Those investigations, however, refer mostly to the information transmission. One of the target applications of the WUSNs is the object localization in the underground medium, which remains an open issue due to the complicated characteristics of the MI channels corrupted by the influence of soil. In this work, we propose a machine learning based solution for localization. In addition, a novel passive localization technique is introduced, which requires no signal from the target node and thus proves useful for rescue operations, where the battery of the node to be localized is either empty or damaged.
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transmitter side channel estimation in Magnetic Induction based communication systems
IEEE International Black Sea Conference on Communications and Networking, 2014Co-Authors: Steven Kisseleff, Ian F Akyildiz, W H GerstackerAbstract:The use of Magnetic Induction (MI) based transmissions in challenging environments has been investigated in various works. Recently, a system model has been proposed, which explains how the pathloss of the Magnetic Induction based transmissions depends on the system parameters. It is frequently assumed, that perfect channel state information (CSI) is available at the transmitter and at the receiver, such that the optimal set of system parameters can be determined in order to maximize the overall data rate. However, in practical systems this knowledge may not always be easily acquired. In addition, a permanent feedback signaling is needed, in order to update the CSI at the transmitter. This feedback signaling usually occupies several time slots and therefore reduces the bandwidth efficiency. An interesting aspect, which has been overlooked in the past, is the channel estimation and prediction of the received signal within the MI transmitter circuit without explicit feedback signaling of CSI. In this paper, we investigate the potential of this technique for the wireless underground sensor networks.
