1,721,327 research outputs found
Reti di telecomunicazioni a larga banda: importanza della simulazione del loro comportamento nella fase di pianificazione
No full textVengono presi in esame gli elementi fondamentali di una rete a commutazione di pacchetto nel contesto, più generale, delle reti dedicate a larga banda. L’obiettivo dell’analisi è quello di sottolineare l’importanza della simulazione ai fini di una efficiente e corretta pianificazione tanto della topologia della rete quanto delle relative regole di instradamento, prevedendo e cercando di eliminare gli effetti di possibili situazioni di congestione
Effetti del rumore di fase sui sistemi di trasmissione coerenti a frequenze ottiche
No full textRapporto interno no 4/90, Dipartimento di Elettronica ed Automatica, Università di Ancon
Single-Mode Optical Fibers and Devices”, in “Single-Mode Optical Fiber Measurement: Characterization and Sensing
No full textError correcting codes in telecommand and telemetry for European Space Agency missions: An overview and new perspectives
No full textError correcting codes have always played a prominent role in the definition of secure and reliable space missions. Both telecommand (TC) and telemetry (TM) have benefited by the introduction of suitable co/decoding schemes, ranging from classic Bose-Chaudhuri-Hocquenghem, Reed-Solomon and convolutional codes to more recent state-of-the art codes based on soft-decision and iterative decoding. As a matter of fact, space TM was one of the first scenarios to propose implementation of the concept of turbo coding that, since twenty years, has traced a new paradigm in the field of error correction. At present the scene is dominated by low-density parity-check codes and these are being progressively included in the design of future missions, in either deep-space or near-Earth scenarios, for the possibility they offer to increase the data rate and/or to reduce the signal-to-noise ratio. The European Space Agency is very active in the field and continuously gives relevant contributions to the standardization activities within the Consultative Committee for Space Data Systems. This paper provides an overview of the error correcting codes included in the current TC and TM recommendations and discusses the new solutions recently proposed in view of most demanding missions, also able to operate in hostile environments like, for example, in the presence of jamming
New non-algebraic decoding method for cyclic block codes with application to satellite communications
No full textRecent progress in fibre optics
No full textIn recent years optical communications and optical signal processing have experienced remarkable progress. This is essentially due to the advent of fibre optics. This paper deals with theoretical and practical aspects regarding fibre optics, with particular attention to some recent applications, and to the most attractive future perspectives. In order to give an exhaustive treatment of this subject, some related technologies are discussed as well, e.g. optical sources and detectors, semiconductor opto-electronic and photonic devices, and crystalline and polymeric materials for non-linear wave interactions
Enlarged shufflenet architecture for optical networks
No full textAlso included in “Applications of Photonic Technology 2”, G. A. Lampropoulos and R. A. Lessard (Eds.), pp. 217-222, Plenum Press, New York, 199
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