Results 61 to 70 of about 1,881 (201)

Diffraction‐Free Natural Optical Skyrmions and Their Subwavelength Confinement Around Vortices

Laser &Photonics Reviews, EarlyView.
ABSTRACT Diffraction causes waves to spread out as they propagate freely. The tighter the lateral confinement, the faster the spreading. Past research on how to suppress diffraction has been based on wave engineering and has led so far to idealized waves that, in real settings, eventually diffract.
Nilo Mata‐Cervera, Deepak K. Sharma, Ramon Paniagua‐Dominguez, Yijie Shen, Miguel A. Porras   +4 more
wiley   +1 more source

Analysis of the fractional scattering contribution in the forward peak for multicomponent systems

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Derivation and justification of mixing rules for multicomponent systems. A novel formulation of the delta‐Eddington scaling rule. Analytical guidance for comparing radiative transfer results. Abstract The widely used δ‐Eddington approximation improves the accuracy of radiative transfer calculations by representing the fraction of scattering into the ...
Jiangnan Li, Yue Cai
wiley   +1 more source

Space-Time Trellis Coded 8PSK Schemes for Rapid Rayleigh Fading Channels

EURASIP Journal on Advances in Signal Processing, 2002
This paper presents the design of 8PSK space-time (ST) trellis codes suitable for rapid fading channels. The proposed codes utilize the design criteria of ST codes over rapid fading channels. Two different approaches have been used.
Salam A. Zummo, Saud A. Al-Semari
doaj   +1 more source

Photonic nanovoids for tailored optoelectronic response in silicon solar cells

Responsive Materials, EarlyView.
Optoelectronic workflow followed by experimental validation, demonstrating state‐of‐the‐art efficiency gains. Abstract As crystalline silicon (c‐Si) solar cells become thinner to reduce cost and weight, the optical design principles that govern light trapping (LT) must evolve.
Ivan M. Santos, Miguel Alexandre, Valentin D. Mihailetchi, Kezheng Li, António T. Vicente, Eva Almeida, Mónica Dyreby, Tiago Mateus, Tomás Calmeiro, Elvira Fortunato, Rodrigo Martins, Hugo Águas, Manuel J. Mendes   +12 more
wiley   +1 more source

Bit Error Rate Closed-Form Expressions for LoRa Systems under Nakagami and Rice Fading Channels

Sensors, 2019
We derive exact closed-form expressions for Long Range (LoRa) bit error probability and diversity order for channels subject to Nakagami-m, Rayleigh and Rician fading.
Claudio Ferreira Dias, Eduardo Rodrigues de Lima, Gustavo Fraidenraich   +2 more
doaj   +1 more source

Directive Antenna Clutter Loss in Slant Paths

International Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT This paper investigates the development of a clutter loss model specifically for slant paths involving directive antennas. Conventionally, clutter loss is characterized by using isotropic antennas to facilitate standard link budget calculations via single antenna gain values.
Fernando Pérez Fontán, Vicente Pastoriza‐Santos, Fernando Machado Domı́nguez, Thomas Prechtl, Pavel Pechac   +4 more
wiley   +1 more source

KALMAN FILTERING FOR SPACE-TIME CODED TRANSMISSIONS OVER FREQUENCY-SELECTIVE RAYLEIGH FADING CHANNELS

Electrica, 2005
The problem of multichannel estimation for space-time coded transmissions over frequency-selective Rayleigh fading channels is addressed. Under  fast fading conditions, receivers employing Kalman filtering and moderate complexity equalization schemes are
Ahmet Korhan TANÇ, Reyat YILMAZ
doaj   +2 more sources

Hybrid deep learning for robust spectrum sensing over AWGN and fading channels

EURASIP Journal on Advances in Signal Processing
Accurate and reliable spectrum sensing (SS) is crucial for optimal spectrum usage in cognitive radio (CR) networks under challenging low signal-to-noise ratio (SNR) and fading channel conditions. The Bi-CLNetwork, a hybrid deep learning (DL) architecture,
Sarah Yahya Salih Al-Hajm, Ibrahim Develi, Kenan Kockaya   +2 more
doaj   +1 more source

Dynamic Spatial Diversity Combiner pada Kanal Fading

Jurnal Elkomika, 2019
ABSTRAK Kanal transmisi radio berkontribusi pada terjadinya efek fading yang dapat berpengaruh pada terjadinya penurunan kualitas sinyal pada penerima.
DWI ARYANTA, RIENZY PRATAMA LONDONG ALLO
doaj   +1 more source

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

International 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, Xavier Boulanger, Vegard Arneson   +2 more
wiley   +1 more source