Search results for "RaptorQ codes"

showing 7 items of 7 documents

Optical wireless GEO satellite-to-ground downlinks: rateless codes as solution for scintillation fading

2013

Scintillation fading can corrupt a satellite-to-ground optical wireless links with burst errors. Rateless codes, suitable for erasure channel, are able to eliminate or to reduce these communication errors. We analyzed the performances of three different rateless codes in a simulated Geo satellite-to-ground downlink.

Settore ING-INF/03 - TelecomunicazioniSettore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - ElettronicaFree Space Optics Rateless codes LT codes Raptor codes RaptorQ codes channel modeling
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Performance Investigation of Fountaine Codes on a Simulated Terrestrial Free Space Optical Channel

2012

Settore ING-INF/03 - TelecomunicazioniSettore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - ElettronicaFree Space Optics Channel Modeling Fountain Codes Raptor Codes RaptorQ Codes Luby Transform Codes Rateless Codes
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Rateless codes implementation, optimization and application to Free Space Optics links affected by optical turbulence

In this work, I have implemented, optimized and tested the most advanced rateless codes available up to now, i.e., RaptorQ codes. In detail, a multiplatform data transmission software has been appositely developed in order to verify the effectiveness of the above-mentioned codes to decrease packet loss and hence to improve the link quality, under different network and channel conditions. Several simulative and experimental investigations have been carried out to evaluate the performance of the encoding and decoding schemes and the relative recovery capabilities under different test scenarios. In particular, I have applied the software embedding RaptorQ codes to Free Space Optics communicati…

RaptorQ codesoptical turbulenceFree Space Opticrateless codeGamma-Gamma modelSettore ING-INF/01 - Elettronica
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Correlated channel model for terrestrial Free Space Optics: performance analysis of rateless codes

2012

We describe a novel correlated channel model able to predict random temporal fluctuations of optical signal irradiance caused by scintillation. With regards to the same channel, we also report simulation results on the error mitigation performance of Luby-Transform and Raptor codes.

Settore ING-INF/03 - TelecomunicazioniFree Space Optics channel modeling Raptor codes RaptorQ codes LT codes rateless codesSettore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - Elettronica
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Error mitigation using RaptorQ codes in an experimental indoor free space optical link under the influence of turbulence

2015

In free space optical (FSO) communications, several factors can strongly affect the link quality. Among them, one of the most important impairments that can degrade the FSO link quality and its reliability even under the clear sky conditions consists of optical turbulence. In this work, the authors investigate the generation of both weak and moderate turbulence regimes in an indoor environment to assess the FSO link quality. In particular, they show that, due to the presence of the turbulence, the link experiences both erasure errors and packet losses during transmission, and also compare the experimental statistical distribution of samples with the predicted Gamma Gamma model. Furthermore,…

Computer scienceOptical linkReliability (computer networking)Optical linksTelecommunication network reliabilityRytov variance valueSettore ING-INF/01 - ElettronicaTelecomunicacióRaptorQ codesRedundancy (information theory)Indoor free space optical linkFSO communicationsStatisticsTEORIA DE LA SEÑAL Y COMUNICACIONESRedundancy (engineering)Gamma Gamma modelrateless codeElectrical and Electronic Engineeringpacket error rate (PER)Error-free transmissionNetwork packetbusiness.industrySettore ING-INF/03 - TelecomunicazioniSettore ING-INF/02 - Campi ElettromagneticiÒpticaComputer Science ApplicationsTransmission (telecommunications)Bit error rateErasureProbability distributionFree Space Optical (FSO) communicationTelecommunicationsbusinessOptical turbulenceFSO link reliabilityindoor linkError mitigation
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Moderate-to-Strong Turbulence Generation in a Laboratory Indoor Free Space Optics Link and Error Mitigation via RaptorQ Codes

2016

Free Space Optics (FSO) is rapidly gaining interest as a line-of sight communication technology that offers capabilities similar - in terms of bandwidth and transfer rates - to optical fibre, also possessing several advantages compared with traditional radio frequency links. However, FSO link quality can be strongly affected by unfavourable weather conditions and also by the phenomenon of optical turbulence, even in clear sky. In this work, we have implemented an indoor FSO link and generated moderate-to-strong turbulence conditions along the optical path by using heaters and a mechanical ventilation system. In this way, we have been able to investigate the effects of the generated turbulen…

Physicsbusiness.industryNetwork packetFree Space Optics (FSO) indoor link turbulence generation packet loss rateless codes RaptorQ codesSettore ING-INF/03 - Telecomunicazioni05 social sciencesBandwidth (signal processing)050801 communication & media studies020206 networking & telecommunicationsSettore ING-INF/02 - Campi Elettromagnetici02 engineering and technologySettore ING-INF/01 - ElettronicaData recovery0508 media and communicationsOptical path0202 electrical engineering electronic engineering information engineeringBit error rateElectronic engineeringRadio frequencybusinessAdaptive opticsFree-space optical communication
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FREE SPACE OPTICS LINKS AFFECTED BY OPTICAL TURBULENCE: CHANNEL MODELING, MEASUREMENTS AND CODING TECHNIQUES FOR ERROR MITIGATION

2014

FSO is an optical wireless line-of-sight communication system able to offer good broadband performance, electromagnetic interference immunity, high security, license-free operation, low power consumption, ease of relocation, and straightforward installation. It represents a modern technology, significantly functional when it is impossible, expensive or complex to use physical connections or radio links. Unfortunately, since the transmission medium in a terrestrial FSO link is the air, these communications are strongly dependent on various atmospheric phenomena (e.g., rain, snow, optical turbulence and, especially, fog) that can cause losses and fading. Therefore, in worst-case conditions, i…

optical turbulencescintillationrateless codes LT codes Raptor codes RaptorQ codes error mitigation fading mitigation.Free Space Optictime-serieSettore ING-INF/01 - Elettronica
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