Search results for "FAD"

showing 10 items of 292 documents

Performance Analysis of M-DPSK Modulation over Fast-Hoyt Fading Channels under Non-Isotropic Scattering Conditions

2021

In this paper, we analyze the symbol error probability (SEP) performance of M-ary differential phase shift keying (M-DPSK) modulation schemes over frequency-flat fast-varying Hoyt multipath fading channels. Assuming general non-isotropic scattering conditions, we first derive a finite-range integral expression for the probability density function (PDF) of the phase difference between two non-isotropic Hoyt vectors perturbed by additive white Gaussian noise (AWGN). Based upon the theory of M-DPSK modulation and the obtained PDF formula, the SEP of M-DPSK and its corresponding asymptotic behavior in non-isotropic fast-Hoyt fading channels are derived. Specifically, a double semi-finite range …

ScatteringComputer scienceIsotropyMathematical analysisProbability density functionComputer Science::Performancesymbols.namesakeAdditive white Gaussian noiseModulation (music)Computer Science::Networking and Internet ArchitecturesymbolsFadingMultipath propagationComputer Science::Information TheoryRayleigh fading2021 IEEE 32nd Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)
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An ergodic wideband MIMO channel simulator based on the geometrical T-junction scattering model for vehicle-to-vehicle communications

2010

In this paper, a wideband multiple-input multiple-output (MIMO) simulation model for vehicle-to-vehicle (V2V) channels in T-junction propagation environments is proposed. This simulation model takes the exact relationship between the angle-of-arrival (AOA) and the angle-of-departure (AOD) into account. In order to determine the parameters of the simulation model, the Riemann sum method (RSM) is applied. Furthermore, the statistical and ergodic properties of the simulation model are studied. Closed-form solutions are derived for the space-time-frequency cross-correlation function (STF-CCF), the two-dimensional (2D) spatial cross-correlation function (CCF), the temporal autocorrelation functi…

Scatteringbusiness.industryComputer scienceAutocorrelationMIMOFunction (mathematics)Correlation function (quantum field theory)TopologyAngle of arrivalFadingWidebandTelecommunicationsbusinessCommunication channelInternational Conference on Communications and Electronics 2010
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Fading mitigation coding techniques for space to ground free space optical communications

2014

In this manuscript, a Geostationary satellite-toground Free Space Optics (FSO) downlink channel model has been implemented, which is able to predict temporal irradiance fluctuations caused by scintillation at a wide range of turbulence conditions and for different values of the zenith angle. In order to mitigate fading events that occur in FSO communications, we have also tested the performance of three different families of Rateless Codes (Luby Transform, Raptor and RaptorQ) into our model and found that RaptorQ is the best candidate to mitigate errors in FSO links. Keywords— Optical Wireless Communications; Space-toGround FSO links, time-series, rateless codes; fading mitigation

ScintillationFading distributionGeographyOptical communicationGeostationary orbitElectronic engineeringFadingZenithOptical wireless communicationsFree-space optical communication2014 Euro Med Telco Conference (EMTC)
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On the First- and Second-Order Statistics of Selective Combining over Double Nakagami-m Fading Channels

2014

Second order statisticsElectronic engineeringFadingNakagami distributionAlgorithmMathematics2014 IEEE 80th Vehicular Technology Conference (VTC2014-Fall)
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Effects of sea cage farm on wild fish populations. A case study of bluefin tuna (thunnus thynnus) fattening in Castellammare del Golfo (Western Sicil…

2008

Settore BIO/10 - BiochimicaFAD aquaculture biomarkers fatty acids
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I fenoli come nuovi materiali per la dosimetria EPR in campo misto neutroni-gamma

2014

Settore FIS/01 - Fisica SperimentaleSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Dosimetria EPR NCT Gadolinio neutroni fading
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Non-Hermitian Hamiltonians in Quantum Physics

2016

This volume collects the selected contributions presented at or inspired by the15th International Workshop on Pseuso-Hermitian Hamiltonians in QuantumPhysics(PHHQP15), held in Palermo, Italy, from May 18 to 23, 2015. Thisworkshop was the 15th in the series of international meetings that was started in2003. These meetings were mainly attended by mathematicians and physicistsinterested in the study of non-Hermitian operators and Hamiltonians, and in theirphysical applications. About 80 mathematicians and physicists attended the 2015Workshop in Palermo.

Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciNon-Hermitian physical modelNon-selfadjoint operatorsSettore MAT/05 - Analisi MatematicaSettore MAT/07 - Fisica MatematicaNon Hermitian Hamiltonian
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Analysis of the Behaviour of an Optimized Magnetorheological Brake

2013

This paper presents the optimization process of MR – magnetorheological brake in order to define its configuration, and to reach the requested vehicle braking torque. FEM analysis previously carried out, concerning structural sizing of such a brake, showed that both braking torque and brake mass did not satisfy the requirements. Due to the necessity of limitation on the suspended mass of a motor vehicle, the optimization of the form of MR brake stator has been executed, including determination of its contribution to the total mass of the brake. Thus a percentage reduction of approximately 40% was obtained. In order to estimate the brake temperature which results from the transformation into…

Settore ING-IND/14 - Progettazione Meccanica E Costruzione Di MacchineFade Braking TestMagnetorheological BrakeThermal FEMMagnetic FEMFEM Optimization
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Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniFree Space Optics (FSO) technologies for satellite communications offer several advantages: wide bandwidth high rate capability immunity to electromagnetic interference and small equipment size. Thus they are suitable for inter-satellite links deep space communications and also for high data rate ground-to-satellite/satellite-to-ground communications. Nevertheless FSO links suffer impairments that cause power signal degradation at the receiver. Scattering and absorption cause power signal attenuations predictable by suitable deterministic models. Optical turbulence causes random irradiance fluctuations which can generate signal fading events and can thereby only be predicted by statistical models. Attenuation and fading events can corrupt FSO links and so it would be recommended to add mitigation error codes on the communication link. FSO channel can be described as an erasure channel: fading events can cause erasure errors. We have identified in rateless codes (RCs) a suitable solution to be employed in FSO links. RCs do not need feedback and they add a redundant coding on the source data that allows the receiver to recover the whole payload despite erasure errors. We implemented two different of rateless codes: Luby Transform (LT) and Raptor. We analyzed their performances on a simulated turbulent GEO FSO downlink (1 Gbps - OOK modulation) at a 106 μm wavelength and for different values of zenith angles. Assuming a plane-wave propagation and employing Hufnagel-Valley we modeled the downlink using: 1) a temporal correlated channel model based on Gamma-Gamma probability distribution and 2) an irradiance covariance function that we converted on a time function using Taylor frozen eddies hypothesis. Our new channel model is able to simulate irradiance fluctuations at different turbulence conditions as it will be shown in the full paper. We will also report performance results of LT and Raptor codes at overhead range varying between 0 and 50% and for different values of source packets.Settore ING-INF/01 - Elettronica
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Fading mitigation coding techniques for space to ground free space optical communications

2014

Settore ING-INF/03 - TelecomunicazioniSpace-to-Ground FSO links time-series rateless codefading mitigationSettore ING-INF/02 - Campi ElettromagneticiOptical Wireless CommunicationSettore ING-INF/01 - Elettronica
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