Results 41 to 50 of about 1,206,111 (210)

Multi‐Vendor and Multi‐Site Characterization of 13C Coils for Clinical Studies

open access: yesMagnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose Due to the inherently low signal‐to‐noise ratio (SNR) domain for 13C imaging, optimal coil performance is essential to maximize data quality. Quality control (QC) for 13C coils employed in magnetic resonance spectroscopy (MRS) is of paramount importance.
Emil S. Christensen   +7 more
wiley   +1 more source

Relationship Between Mean Kärger Model Water Exchange Rate and Intercellular Water Transition Rate

open access: yesMagnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To derive a quantitative relationship between the mean Kärger model (KM) water exchange rate and the mean intercellular water transition rate applicable to brain and other complex biological tissues. Theory and Methods The mean KM water exchange rate applies to any KM, accommodates an arbitrary number of compartments, and can be ...
Jens H. Jensen   +3 more
wiley   +1 more source

DETERMINATION OF DEPENDENCE OF ENERGY STEALTH COEFFICIENT OF SATELLITE COMMUNICATION SYSTEMS AT SIGNAL DETECTION FROM CHOICE OF OPERATING FREQUENCY ON THE BASIS OF NUMERICAL METHODS FOR SOLVING NONLINEAR EQUATIONS

open access: yesСовременная наука и инновации, 2022
In the article on the basis of results of signal detection in a channel with the Rician fading, analysis of depth of fadings in a transionospheric radio channel and numerical methods of solving nonlinear equations, developed a methodology of estimation ...
Alexey Vladimirovidi Lyakhov
doaj  

Respiratory‐Resolved Isotropic 3D T1 Mapping of the Carotid Vessel Wall With B1+ Correction (CARISMAT1C)

open access: yesMagnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To develop, optimize, and characterize a respiratory motion‐resolved free‐running isotropic 3D carotid vessel wall T1 mapping technique named CARISMAT1C. Methods An inversion‐recovery gradient‐echo free‐running pulse sequence with interleaved double flip‐angle (2FA) was implemented, and an extended‐phase‐graph dictionary was used to ...
Isabel Montón Quesada   +7 more
wiley   +1 more source

Multiuser Decorrelating Based Long-Range Frequency-Domain Channel Transfer Function Prediction in Multicarrier DS-CDMA Systems

open access: yes, 2006
In this contribution, multiuser decorrelating based frequency-domain channel estimation and long range channel prediction techniques are proposed for a generalized Multicarrier DS-CDMA (MC DS-CDMA) system communicating over a fast fading and frequency ...
Yang, L.-L., Liu, W., Hanzo, L., Hu, B.
core   +1 more source

Performance Improvement of LeastSquares Adaptive Filter for High-Speed Train Communication Systems

open access: yesJournal of ICT Research and Applications, 2017
The downlink communication channel from high-altitude platform (HAP) to high-speed train (HST) in the Ka-band is a slowly time-varying Rician distributed flat fading channel with 10-25 dB Rician K factor.
Irma Zakia, Adit Kurniawan
doaj   +1 more source

Low‐Complexity Hybrid Beamforming for LEO Satellites: Beam Update Rate Analysis and Advanced Adaptive Precoding

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT Low Earth Orbit (LEO) satellite constellations offer unprecedented opportunities for global broadband connectivity but pose significant beamforming challenges due to rapid platform motion and stringent onboard hardware constraints. Fully digital architectures, while optimal in theory, remain impractical for satellite payloads, motivating ...
Mohammad Momani   +2 more
wiley   +1 more source

Integrating Image Segmentation and Deep Learning to Improve Radio Frequency Propagation Models

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT This paper proposes a multi‐sensor approach to improve radio frequency (RF) propagation models, which play a key role in the rapidly expanding field of connected vehicle technology. Focusing on the 1‐ to 20‐GHz frequency range, which is critical for both satellite‐to‐vehicle and base station‐to‐vehicle communications, our study introduces a ...
Jonathan Israel   +2 more
wiley   +1 more source

Rate Loss Analysis of Reconfigurable Intelligent Surface-Aided NOMA With Limited Feedback

open access: yesIEEE Open Journal of the Communications Society
The design of feedback channels in frequency division duplex (FDD) systems is a major challenge because of the limited available feedback bits. We consider non-orthogonal multiple access (NOMA) systems that incorporate reconfigurable intelligent surfaces
Mojtaba Ahmadi Almasi, Hamid Jafarkhani
doaj   +1 more source

Combined diversity and improved energy detection in cooperative spectrum sensing with faded reporting channels

open access: yesJournal of King Saud University: Computer and Information Sciences, 2016
In this paper we evaluate the performance of cooperative spectrum sensing (CSS) where each cognitive radio (CR) employs an improved energy detector (IED) with multiple antennas and uses selection combining (SC) for detecting the primary user (PU) in ...
Srinivas Nallagonda   +2 more
doaj   +1 more source

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