Multiplexing
Mostrando 1-12 de 124 artigos, teses e dissertações.
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1. Efficient Low-Complexity Optimized Channel Estimating Methods for OFDM-Based Low-Voltage Broadband Power Line Communication Systems
Abstract Broadband Power Line Communication (BB-PLC) technology enables data transmission for smart grid applications. Nevertheless, channel equalizers are required in the receiver to estimate and compensate for the nonlinear time-variant impulse response and noise interference effects introduced by the BB-PLC channel. In this paper, we append the Particle S
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. ANALYSIS OF THE BASELINE DRIFT ARTIFACT IN HADAMARD TRANSFORM SEPARATION TECHNIQUES
The baseline drift artifact (BDA), namely, the baseline bias between the Hadamard transform (HT) spectrum and the signal averaging (SA) spectrum was unfortunately found in the HT pulsed separation techniques, which makes the HT analytical chemistry face the challenge of non-stability and unreliability. In order to find out the origin and eliminate the BDA ph
Quím. Nova. Publicado em: 2020-01
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3. Frequency Domain Interleaving for Dense WDM Passive Optical Network
Abstract In this work, we introduce a new concept of frequency interleaving applied to passive optical networks based in Dense Wavelength Division Multiplexing (DWDM). In order to explore colorless ONUs approach, a single and centralized optical source is used to create the interleaved wavelengths for the downstream and upstream path. In this case, frequency
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 19/06/2019
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4. A Low Complexity Iterative SLM-OFDM for SHF band applications
Abstract The transmitted Orthogonal Frequency Division Multiplexing signal in systems such as Wireless LAN, Mobile WiMAX, Digital Video Broadcasting (DVB) operating in the Super High Frequency (SHF) band suffers from high Peak to Average Power Ratio. This is reduced in Selective Level Mapping (SLM)approach but at the expense of increased complexity. In this
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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5. Heuristics for the optimized deployment of small cells in next-generation networks
Abstract Heterogeneous Networks (HetNets) have been introduced as an alternative means of improving the overall network capacity. However, HetNets increase the complexity and cost of transport due to the large number of smallcells (SCs) that have to be connected, and hence, it is essential to investigate the best way to plan the joint deployment of radio and
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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6. EDFA Design and Analysis for WDM Optical Systems Based on Modal Multiplexing
Abstract Modal multiplexing (MDM) is a core technology to allow a capacity increase in modern optical systems. However, in MDM links, the amplified WDM signal suffers not only from lack of spectral gain equalization but also from unequal modal gain. The proper design of the MDM-EDFA is crucial to provide modal gain equalization and to overcome those impairme
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-03
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7. A Multilayer Approach for Optical Network Planning
With the increase in demand to Backbone networks, one became fundamental the application of new telecommunication technologies for efficient use of devices and optical links, such as xPSK modulations with dual polarization, dispersion compensating fibers, coherent detection and digital processing signals. Thus, network planning using analytical models have b
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-03
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8. Estimation Uncertainties in the Optical Signal-to-Noise Ratio Network Optimization
In this work, we investigate the effects of estimation uncertainties in the optimization of the optical signal-to-noise ratio (OSNR) at the wavelength division multiplexing (WDM) optical networks. The OSNR optimization increases the network throughput and energy efficiency and it enables to minimize the number of retransmissions by higher layers. The OSNR op
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-03
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9. A Compact Dual-Band Octagonal Slotted Printed Monopole Antenna for WLAN/ WiMAX and UWB Applications
AbstractA compact (20 x 20 mm2 size), coplanar waveguide (CPW) fed, octagonal slotted, dual-band antenna is presented in this paper. The proposed antenna has a simple structure consisting of an octagonal slot, L-shape stub, and a two stepped rectangular patch. The introduction of the L-shaped metallic stubs in the ground plane generates a lower resonance fre
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-06
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10. Particle swarm optimization in WDM/OCDM networks with physical impairments
In this paper, optimization procedures based on particle swarm optimization (PSO) are investigated, aiming to efficiently solve the optimal resource allocation for signal-to-noise plus interference ratio (SNIR) optimization of optical code paths (OCPs) from wavelength division multiplexing/optical code division multiplexing (WDM/OCDM) considering imperfectio
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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11. Estudos de sistemas OFDM para comunicações ópticas / Studies OFDM systems for optical communications
The development of digital modulation formats in optical communications systems is considered to be a promising way to increase the spectral efficiency and to combat the effects of signal degradation in optical fiber without changing the infrastructure already deployed. In this context, the technique called OFDM (orthogonal frequency division multiplexing) e
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/10/2012
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12. VHDL SIMPLE SYSTEM FOR DEVELOPING A SETUP OFMULTIPLE ANTENNAS / SISTEMA SIMPLES EM VHDL PARA O DESENVOLVIMENTO DE UM SETUP DE MÚLTIPLAS ANTENAS
MIMO systems (Multiple In - Multiple Out) are the rise of new tele- communication systems. They have the characteristic of generating greater channel capacity with low power transmitters, creating a more efficient use of energy. As the purpose is to provide higher data rate, conventional methods are too limited to improve this, and MIMO systems generate an i
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/09/2012