The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
H. Muralidhara - One of the best experts on this subject based on the ideXlab platform.
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ICNC - Use of Radio Propagation maps in a single moving beacon assisted localization in MANETs
2014 International Conference on Computing Networking and Communications (ICNC), 2014Co-Authors: J. Miles, Suresh Muknahallipatna, Robert F. Kubichek, J. Mcinroy, H. MuralidharaAbstract:A mobile ad-hoc network (MANET) of small robots (sensor nodes) adjusting their positions to establish network connectivity would be able to provide a communication infrastructure in an urban battlefield environment. A sensor node would be capable of moving to a particular position to establish network connectivity, provided it knows its current position, positions of other sensor nodes and the Radio Propagation characteristics of the sensor area. Typically, the nodes in the MANET determine their positions using a localization algorithm. Most localization algorithms use either the free space or the “two ray” Radio Propagation models, which are only accurate in communication environments where there are no hills or buildings. In an urban environment, direct transmission through buildings is limited and most communications rely on reflections and refractions around buildings. The presence of the buildings, therefore, greatly influences Radio Propagation. Consequently, free space or two-ray Propagation models are inaccurate in outdoor urban areas. This paper, presents a single moving beacon assisted localization algorithm that incorporates an urban Radio Propagation map to localize sensor nodes in a MANET. First, the paper describes using a convex hull to represent irregular Radio Propagation shapes in terms of regular geometric shapes. Next, an algorithm to determine intersection (localized area) of multiple convex hulls is discussed. Simulation results, comparing the performance of localization using an urban Radio Propagation map against the free space model are presented. The simulation results show the effect of the Radio Propagation map on localization accuracy and demonstrate the free space model inaccuracy.
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Use of Radio Propagation maps in a single moving beacon assisted localization in MANETs
2014 International Conference on Computing Networking and Communications (ICNC), 2014Co-Authors: J. Miles, S. Muknahallipatna, R. F. Kubichek, J. Mcinroy, H. MuralidharaAbstract:A mobile ad-hoc network (MANET) of small robots (sensor nodes) adjusting their positions to establish network connectivity would be able to provide a communication infrastructure in an urban battlefield environment. A sensor node would be capable of moving to a particular position to establish network connectivity, provided it knows its current position, positions of other sensor nodes and the Radio Propagation characteristics of the sensor area. Typically, the nodes in the MANET determine their positions using a localization algorithm. Most localization algorithms use either the free space or the “two ray” Radio Propagation models, which are only accurate in communication environments where there are no hills or buildings. In an urban environment, direct transmission through buildings is limited and most communications rely on reflections and refractions around buildings. The presence of the buildings, therefore, greatly influences Radio Propagation. Consequently, free space or two-ray Propagation models are inaccurate in outdoor urban areas. This paper, presents a single moving beacon assisted localization algorithm that incorporates an urban Radio Propagation map to localize sensor nodes in a MANET. First, the paper describes using a convex hull to represent irregular Radio Propagation shapes in terms of regular geometric shapes. Next, an algorithm to determine intersection (localized area) of multiple convex hulls is discussed. Simulation results, comparing the performance of localization using an urban Radio Propagation map against the free space model are presented. The simulation results show the effect of the Radio Propagation map on localization accuracy and demonstrate the free space model inaccuracy.
Konstantinos B. Baltzis - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Fading Statistics of mmWave (28 GHz and 38 GHz) Outdoor and Indoor Radio Propagation Channels
Technologies, 2019Co-Authors: Sardar Muhammad Gulfam, Syed Junaid Nawaz, Konstantinos B. Baltzis, Abrar Ahmed, Khan, Munaz Ahmed NoorAbstract:Extension of usable frequency spectrum from microwave to millimeter-wave (mmWave) is one of the key research directions in addressing the capacity demands of emerging 5th-generation communication networks. This paper presents a thorough analysis on the azimuthal multipath shape factors and second-order fading statistics (SOFS) of outdoor and indoor mmWave Radio Propagation channels. The well-established analytical relationship of plain angular statistics of a Radio Propagation channel with the channel’s fading statistics is used to study the channel’s fading characteristics. The plain angle-of-arrival measurement results available in the open literature for four different outdoor Radio Propagation scenarios at 38 GHz, as well as nine different indoor Radio Propagation scenarios at 28 GHz and 38 GHz bands, are extracted by using different graphical data interpretation techniques. The considered quantifiers for energy dispersion in angular domain and SOFS are true standard-deviation, angular spread, angular constriction, and direction of maximum fading; and spatial coherence distance, spatial auto-covariance, average fade duration, and level-crossing-rate; respectively. This study focuses on the angular spread analysis only in the azimuth plane. The conducted analysis on angular spread and SOFS is of high significance in designing modulation schemes, equalization schemes, antenna-beams, channel estimation, error-correction techniques, and interleaving algorithms; for mmWave outdoor and indoor Radio Propagation environments.
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Characterization of second-order fading statistics of 28GHz indoor Radio Propagation channels
2018 7th International Conference on Modern Circuits and Systems Technologies (MOCAST), 2018Co-Authors: Sardar Muhammad Gulfam, Syed Junaid Nawaz, Konstantinos B. BaltzisAbstract:Extension of usable frequency spectrum from microwave to millimeter-wave (mmWave) range is one of the key research direction in addressing the capacity demands of 5th generation (5G) land mobile Radio communication networks. This paper presents a thorough analysis on the second-order fading statistics of indoor mmWave range Radio Propagation channels. The well established analytical relationship of plain angular statistics of a Radio Propagation channel with the channel's fading statistics is utilized to study the fading characteristics of indoor mmWave Radio Propagation channels. The plain angle-of-arrival (AoA) measurement results published in the open literature for three different indoor Radio Propagation scenarios at 28GHz band are extracted by using different graphical interpretation techniques. The extracted plain AoA statistics are extended to study the dispersion of energy in angular domain and second-order fading statistics of the channel. The considered quantifiers for energy dispersion in angular domain and second-order fading statistics are true standard-deviation, angular spread, angular constriction, and direction of maximum fading; and spatial coherence distance, spatial auto-covariance, average fade duration (AFD), and level-crossing-rate (LCR); respectively. The conducted analysis on angular spread and second-order fading statistics is of high significance in designing antenna-beams, error-correction techniques, channel estimation and equalization schemes, modulation schemes, and interleaving algorithms; for 28GHz indoor Radio Propagation environments.
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MOCAST - Characterization of second-order fading statistics of 28GHz indoor Radio Propagation channels
2018 7th International Conference on Modern Circuits and Systems Technologies (MOCAST), 2018Co-Authors: Sardar Muhammad Gulfam, Syed Junaid Nawaz, Konstantinos B. BaltzisAbstract:Extension of usable frequency spectrum from microwave to millimeter-wave (mmWave) range is one of the key research direction in addressing the capacity demands of 5th generation (5G) land mobile Radio communication networks. This paper presents a thorough analysis on the second-order fading statistics of indoor mmWave range Radio Propagation channels. The well established analytical relationship of plain angular statistics of a Radio Propagation channel with the channel's fading statistics is utilized to study the fading characteristics of indoor mmWave Radio Propagation channels. The plain angle-of-arrival (AoA) measurement results published in the open literature for three different indoor Radio Propagation scenarios at 28GHz band are extracted by using different graphical interpretation techniques. The extracted plain AoA statistics are extended to study the dispersion of energy in angular domain and second-order fading statistics of the channel. The considered quantifiers for energy dispersion in angular domain and second-order fading statistics are true standard-deviation, angular spread, angular constriction, and direction of maximum fading; and spatial coherence distance, spatial auto-covariance, average fade duration (AFD), and level-crossing-rate (LCR); respectively. The conducted analysis on angular spread and second-order fading statistics is of high significance in designing antenna-beams, error-correction techniques, channel estimation and equalization schemes, modulation schemes, and interleaving algorithms; for 28GHz indoor Radio Propagation environments.
Y.p. Zhang - One of the best experts on this subject based on the ideXlab platform.
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Ray-optical modeling of simulcast Radio Propagation channels in tunnels
IEEE Transactions on Vehicular Technology, 2004Co-Authors: Y.p. Zhang, H.j. HongAbstract:Simulcast Radio Propagation channel characteristics inside tunnels are considered in this paper. Based on the image theory of ray optics, a simulcast Radio Propagation channel in a rectangular tunnel is exactly formulated. As only the field components of horizontal and vertical polarization are of interest in real implementation, the exact formulation is approximated to facilitate the numerical computation. The calculated simulcast Radio Propagation channels are comparable fairly to measurements at 900 MHz and 2.0 GHz. The validated ray-optical modeling approach is then applied to simulate simulcast Radio Propagation channel characteristics at 900 MHz and 2.0 GHz to gain deeper insight and better understanding of this type of channels in tunnels. Results show that large fluctuations occur in the capture regions of the distributed antennas for both 900 MHz and 2.0 GHz. The fluctuations in the simulcast regions are larger at 2.0 GHz than at 900 MHz. The root-mean-squared (rms) delay spread is greater in the simulcast regions than in the capture regions of the distributed antennas. This larger delay spread is mainly due to the delay introduced by the transmission medium. Large values of the rms delay spread can be avoided by a careful design of the distance between the distributed antennas.
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Bandwidth characteristics of UHF Radio Propagation channels in rectangular tunnels
IEEE Antennas and Propagation Society International Symposium. 1996 Digest, 1996Co-Authors: Y.p. Zhang, Y. HwangAbstract:The paper deals with the bandwidth characteristics of idealized UHF Radio Propagation channels in rectangular tunnels. The analysis reveals that the channels have very broad bandwidths which imply the possible high data rate transmission without equalization. The bandwidths are found to be Propagation distance dependent.
Nathan Blaunstein - One of the best experts on this subject based on the ideXlab platform.
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Radio Propagation in cellular networks
1999Co-Authors: Nathan BlaunsteinAbstract:From the Publisher: Radio Propagation in Cellular Networks delivers the most comprehensive description of Propagation phenomena in urban, suburban, and rural environments to help you improve the efficiency of wireless communications systems. It is also the first book to consider the full algorithm for Radio coverage prediction and cellular characteristic prediction to increase performance of Radio and cellular map design. This thorough book helps wireless local loop, stationary and wireless system designers construct Radio coverage maps, predict cellular characteristics in communications channels, design and split cellular maps, and predict cellular systems performance in complex, urban environments. This book includes analysis of free space Propagation over regular and irregular terrain, reflection and diffraction by various obstacles, including hills, buildings, and trees, and well as the effects of scattering due to such obstacles and terrain. This is an essential sourcebook on Radio Propagation for wireless communication planners, designers and engineers, and it emphasizes behavior of waves in the UHF/L-frequency band throughout.
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Ionospheric Radio Propagation
Radio Propagation and Adaptive Antennas for Wireless Communication Networks, 1Co-Authors: Nathan Blaunstein, Christos G. ChristodoulouAbstract:The effects of the ionosphere on Radio Propagation are very important in Radio communication between the terrestrial antennas and air vehicles (stationary or moving) or satellites. This chapter begins by briefly presenting information about the ionosphere as a continuous medium consisting of plasma, and describes the common effects of ionospheric plasma on Radio Propagation, following the description of ionospheric effects as well as on the authors’ computations. Then, it discusses the effects of large‐scale and small‐scale ionospheric plasma inhomogeneities, and illustrates the main results of signal amplitude and phase variations, that is, the fast fading, resulting from the inhomogeneous structure of the ionosphere, on the basis of numerical computations carried out by the authors according to proposed ionospheric models. Finally, the chapter considers the effects of an inhomogeneous ionosphere on Radio Propagation at long distances.
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Indoor Radio Propagation
Radio Propagation and Adaptive Antennas for Wireless Communication Networks, 1Co-Authors: Nathan Blaunstein, Christos G. ChristodoulouAbstract:The WLAN user needs to understand the relationship between indoor Propagation effects and how WLAN performance is affected. This chapter presents the importance of accounting for the signal distribution not only in path loss‐distance domain, but also in joint time‐of‐arrival (TOA) and angle‐of‐arrival (AOA) domains for positioning and service of each subscriber located in indoor environment of service. The propagated electromagnetic signal can undergo three primary physical mechanisms: reflection, diffraction, and scattering. Multipath phenomena of multiple reflection, diffraction, and scattering give rise to additional Radio Propagation paths beyond the direct line‐of‐sight (LOS) path between the Radio transmitter and receiver. The chapter outlines models for path loss within buildings: numerical ray‐tracing unified theory of diffraction (UTD) model; physical waveguide model of Radio Propagation inside a building corridor; physical model of Radio Propagation between floors and walls; and empirical models. Finally, it discusses the budget link design of indoor communication links.
Yih-shyh Chiou - One of the best experts on this subject based on the ideXlab platform.
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VTC Spring - An Adaptive Positioning Scheme Based on Radio Propagation Modeling for Indoor WLANs
2006 IEEE 63rd Vehicular Technology Conference, 2006Co-Authors: Chin-liang Wang, Yih-shyh ChiouAbstract:This paper presents an adaptive location estimator based on Radio Propagation modeling and Kalman filtering for indoor wireless local area networks. In this positioning scheme, the location of a mobile terminal is extracted from the constant-velocity trajectory by linear equations and the Radio Propagation model by nonlinear equations. Results from simulation exhibit that the positioning error can be reduced with smaller sampling time of the Kalman filter. The simulation results also show that more than 95 percent of the estimated locations have error distances less than 1.55 meters.
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A location algorithm based on Radio Propagation modeling for indoor wireless local area networks
2005 IEEE 61st Vehicular Technology Conference, 2005Co-Authors: Chin-liang Wang, Yih-shyh ChiouAbstract:This paper presents a location algorithm for indoor wireless local area networks (LANs) that is based on the signal-to-noise ratio (SNR) and a Radio Propagation model. The proposed Radio Propagation modeling approach reduces the number of training data points with no significant degradation in the location accuracy, as compared to the conventional empirical method. Experimental results obtained from an indoor wireless LAN are given to demonstrate its effectiveness.
