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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Využití IPTV v univerzitní síti / IPTV use in academic network

Jireš, Kamil January 2009 (has links)
The purpose of this diploma thesis is to provide readers the deployment of IPTV solutions using free software. In this thesis the reader will familiarize with the theory of IPTV, which implies a necessary part of the system, IPTV related protocols and possible errors that can be when running the IPTV service. The work is divided into four parts. The first part discusses the theory. In theory, the reader familiarize with the definition of basic concepts, which are essential elements of the system, the protocols used in conjunction with IPTV and will also be discussed errors that may occur during operation of IPTV services. The second section outlines the architecture of which the reader can find a solution that was implemented in an experimental operation. The third section focuses on the choice of components (hardware and software) that were used in the test sytem. The variants are mentioned, from which the components were selected. The fourth section contains the actual implementation, which describes each components. At the end of the fourth part is inserted configuration files that can be used in case of repeated implementation of the solution.
22

Interoperabilitet mellan DVB-HTML och DVB-J

Djerf, Lars January 2007 (has links)
Vid sändning av digital television är det möjligt att utöver ljud och bild även sända och erbjuda olika typer av tjänster och applikationer till mottagare. Vid utveckling av applikationer för digital television kan man välja att utveckla i antingen DVB-J (som är en bantad variant av Java för exekvering i Set-Top-Boxar) eller i DVB-HTML (som till stor del överensstämmer med XHTML). Syftet med detta arbete är att utreda hur DVB-J och DVB-HTML kan kombineras i en och samma applikation och hur interoperabilitet kan uppnås mellan DVB-J och DVB-HTML.
23

Cooperation between LTE and emergent DVB technologies for an efficient delivery of mobile TV / Coopération entre LTE et DVB pour une solution de TV mobile optimisée

Abdel-Razzac, Amal 14 January 2015 (has links)
La coopération entre les réseaux de diffusion classiques et les réseaux mobiles cellulaires pour une distribution commune de la télévision mobile est actuellement l'un des éléments clé discutés dans le cadre des nouvelles technologies de diffusion mobile; surtout l'extension mobile de la deuxième génération de diffusion de la télévision numérique terrestre (DVB-T2 Lite) et son suiveur le DVB-Next Generation Handheld (DVB-NGH).En fait, ces technologies de diffusion visent à coopérer avec la récente technologie de téléphonie mobile, connue sous le nom de Long Term Evolution (LTE) qui permet la diffusion de la TV Mobile grâce au protocole de diffusion des services multimédia dans les réseaux de téléphonie mobile (de nature unicast à priori) et connu sous le nom de enhanced-Multimedia Broadcast and Multicast Service feature (e-MBMS).Bien que la coopération entre les réseaux de diffusion DVB et ceux de téléphonie mobile n'est pas un nouveau sujet et a été étudiée avec l'introduction de la technologie de diffusion mobile précédente, connue sous le nom DVB-Handheld (DVB-H), la plupart des travaux traitants ce sujet ont considéré un scénario avec une zone de couverture commune entre le réseau de diffusion et celui cellulaire et ont évalué cette coopération en terme des gains de capacité apportés par DVB au réseau cellulaire et en terme d'amélioration de la fiabilité de transmission apportée par les réseaux cellulaire au DVB grâce à la possibilité des retransmissions unicast. / The broadcast/cellular cooperation for a common delivery of Mobile TV is at the heart of the emerging mobile broadcast technologies, namely the mobile extension of the second generation digital video broadcasting for terrestrial reception (DVB-T2 Lite) and its follower DVB-Next Generation Handheld (DVB-NGH). These broadcast technologies aim to cooperate with the Long Term Evolution (LTE), as the latter is intended to be the bearer of Mobile TV thanks to its enhanced-Multimedia Broadcast and Multicast Service feature (e-MBMS). Even though the 3GPP/DVB cooperation is not a new topic and was investigated with the introduction of the previous DVB technology, known as DVB-Handheld (DVB-H), most of the works addressing this issue considered a common service area covered by both DVB and cellular systems and focused solely on the impact of such cooperation in terms of capacity gains brought by 3GPP and error repair gains brought by DVB. This strategy was judged to be expensive since a new and very dense DVB network was needed. In order to overcome this problem and decrease as much as possible the need for a new broadcast network, we propose in this thesis a hybrid DVB/LTE network with a coverage extension strategy, where the LTE system, planned for almost a universal coverage, is used to deliver Mobile TV in areas not covered by recent DVB-T2 Lite (or eventually DVB-NGH) network. In this context, we explore two main issues:1. Mobile TV services have to share LTE resources with other higher priority services such as voice traffic. The dynamicity of the latter will impact the Quality of Service (QoS) of Mobile TV. We propose a new QoS-based planning for the hybrid DVB/LTE so as to guarantee an acceptable watching experience without over-dimensioning the LTE system. We derive using Markov chain analysis and hitting time theory, several QoS metrics pertaining to mobile TV performance, such as interruption frequency and duration.2. A new business model which clarifies the relationships between the different actors of the ecosystem namely DVB and LTE operators as well as the TV channel providers and constructs the service area from an economic point of view is needed. In fact, the absence of a clear and viable economic model that resolves the monetary conflicts between cellular and broadcast operators was one of the main drawbacks behind the failure of the first attempt of mobile TV delivery by cooperating UMTS/DVB-H. We develop in this thesis a profit sharing strategy for the cooperative network, using coalition game concept Shapley value and Nash equilibrium for a self-enforcing strategy. We further develop a new framework using real option theory coupled with coalition games for investment decision in mobile TV networks (whether an operator should enter the mobile TV market and, if yes, when to do so) and show how operators can incorporate the uncertainties related to demand and network operation costs. We propose a bi-level dynamic programming algorithm to solve numerically the developed real option game.
24

IP Multicasting over DVB-T/H and eMBMS : Efficient System Spectral Efficiency Schemes for Wireless TV Distributions

Rahman, S.M. Hasibur January 2012 (has links)
In today’s DVB-T/H (Digital Video Broadcasting-Terrestrial/Handheld) systems, broadcasting is employed, meaning that TV programs are sent over all transmitters, also where there are no viewers. This is inefficient utilization of spectrum and transmitter equipment. IP multicasting is increasingly used for IP-TV over fixed broadband access. In this thesis, IP multicasting is proposed to also be used for terrestrial and mobile TV, meaning that TV programs are only transmitted where viewers have sent join messages over an interaction channel. This would substantially improve the system spectral efficiency (SSE) in (bit/s)/Hz/site, allowing reduced spectrum for the same amount of TV programs. It would even further improve the multiuser system spectral efficiency (MSSE – a measure defined in this study), allowing increased number of TV programs to be transmitted over a given spectrum. Further efficiency or coverage improvement, may be achieved by forming single-frequency networks (SFN), i.e. groups of adjacent transmitters sending the same signal simultaneously, on the same carrier frequency. The combination of multicasting and SFNs is also the principle of eMBMS (evolved Multicast Broadcast Multimedia Service) for cellular mobile TV over 4G LTE. PARPS (packet and resource plan scheduling) is an optimized approach to dynamically forming SFNs that is employed in this study. The target applications are DVB-T/H and eMBMS. Combining SFNs with non-continuous transmission (switching transmitters on and off dynamically) may give even further gain, and is used in LTE, but is difficult to achieve in DVB-T/H. Seven schemes are suggested and analyzed, in view to compare unicasting, multicasting and broadcasting, with or without SFN, with or without PARPS, and with or without continuous transmission. The schemes are evaluated in terms of coverage probability, SSE and MSSE. The schemes are simulated in MATLAB for a system of 4 transmitters, with random viewer positions. Zipf-law TV program selection is employed, using both a homogeneous and heterogeneous user behavior model. The SFN schemes provide substantially better system spectral efficiency compared to the multi-frequency networks (MFN) schemes. IP multicasting over non-continuous transmission dynamic SFN achieves as much as 905% and 1054% gain respectively in system spectral efficiency and multiuser system  spectral efficiency, from broadcasting over MFN, and 425% and 442% gain respectively from  IP multicasting over MFN, for heterogeneous fading case. Additionally, the SFN schemes gives a diversity gain of 3 dB over MFN, that may be utilized to increase the coverage probability by 4.35% for the same data rate, or to increase the data rate by 27 % for the same coverage as MFN.   Keywords: IP multicasting, broadcasting, coverage probability, system spectral efficiency, multiuser system spectral efficiency, DVB-T/H, eMBMS, mobile TV, IP-TV, SFN, MFN, Dynamic SFN, PARPS, homogeneous, heterogeneous, zipf-law
25

Utveckling av tjänsteportal för MHP-plattformen

Bergling, Olle January 2007 (has links)
<p>Det finns flera olika standarder inom digital-TV för att skapa interaktiva applikationer. Det här arbetet använder den öppna standarden MHP, Multimedia Home Platform, som utgångspunkt för att skapa programkod i programmeringsspråket Java. Arbetet handlar om att skapa ett program för MHPkompatibel utrustning som bekräftar en användares identitet via Smart cards, och levererar interaktiv, personlig information. Denna information levereras via tjänster som beskrivs i XML, och kommunicerar via HTTP med en server som skickar innehåll utifrån de preferenser som finns för denna användare.</p>
26

Utveckling av tjänsteportal för MHP-plattformen

Bergling, Olle January 2007 (has links)
Det finns flera olika standarder inom digital-TV för att skapa interaktiva applikationer. Det här arbetet använder den öppna standarden MHP, Multimedia Home Platform, som utgångspunkt för att skapa programkod i programmeringsspråket Java. Arbetet handlar om att skapa ett program för MHPkompatibel utrustning som bekräftar en användares identitet via Smart cards, och levererar interaktiv, personlig information. Denna information levereras via tjänster som beskrivs i XML, och kommunicerar via HTTP med en server som skickar innehåll utifrån de preferenser som finns för denna användare.
27

Design and Implementation of Low-Cost Dual Mode Channel Decoder

Ding, Yu-Chung 14 September 2006 (has links)
This thesis addresses the design and implementation of a dual-mode channel decoder for two advanced wireless communication systems. One of the targetsystems is the digital video broadcasting for hand-held terminals (DVB-H) , and the other one is Worldwide Interoperability for Microwave Access (WiMAX) system based on the recently approved IEEE 802.16e. Both standards promise to deliver high data bandwidth within very broad regions. The error control coding schemes of both standards are all built on the similar concatenated code, with the exception of the way of data interleaving. Therefore, the decoders for both standards can be highly integrated. To achieve the low-cost and low-power decoder, this thesis proposes several novel design ideas. First, a fast dynamic multiple path convergence mechanism is proposed for the design of Viterbi decoder module, which can determine the survivor path at earlier stage. Furthermore, a new modified forward path prediction method is also presented which can efficiently predict the possiblesurvivor path such that the number of memory operations during the trace-back canbe significantly reduced. The proposed methodology can reduce up to 50% to 80%of memory operations compared with the best prediction scheme in the literature at high signal-to-noise ration. Secondly, for the block deinterleaver adopted by IEEE 802.16. a new multi-bank architecture is proposed by properly splitting and allocating the input data to suitable bank. The proposed block deinterleaver can be highly integrated with the byte-level convolutional deinterleaver adopted by the DVB-H standard by realizing the multiply First-In-First-Out (FIFO) data branches as the circular buffer. The other salient feature of the proposed dual-mode decoder is that all the major data storage units can all be realized by single-port memory such that the overall cost can be highly reduced.
28

A ZigBee Transceiver Used in 2.45 GHz Band and a 2K/4K/8K Multimode Fast Fourier Transformation for DVB-H Receivers

Lee, Lung-hsuan 11 July 2007 (has links)
This thesis includes two topics. The first topic is a ZigBee transceiver used in 2.45 GHz band design. The second topic is a 2K/4K/8K multimode fast Fourier transformation ( FFT ) for DVB-H demodulators. The first topic includes simulations and hardware design. The chip is a physical layer design compliant with IEEE Std 802.15.4 standard, including a transmitter and a receiver for 2.45 GHz band. The measurement of the maximum power on silicon is about 731 £gW at 8 MHz. It is proved to be compliant with the low power consumption requirement specified by the standard. The second topic includes simulations and hardware design of an FFT for DVB-H demodulators. This processor is based on a pipeline architecture with radix-2, radix-22 and radix-23 computation element. We propose one sharing butterfly architecture to be used in the variable length FFT processor.
29

Study and Implementation of DVB-T Receiver RF Module with Frequency Control Circuit Function

Chung, Nan-Hsiang 22 January 2008 (has links)
This thesis consists of two parts. The first part includes design and implementation of an RF tuner module for DVB-T receiver applications. The RF tuner module adopts single-conversion architecture and has a variable gain range of more than 60 dB. After improving the tracking filter characteristics, the module can achieve an image rejection of 60 dB. The second part is focused on DVB-T RF specification test for the implemented RF tuner module. This test uses the instruments accepted by DVB association to perform the standard measurement procedure. The measured sensitivity of the module is about -86 dBm, which has good ability to receive DVB-T signal in practical environment.
30

Design and Implementation of the OFDM Demodulator for DVB-T and the Random Number Generator

Huang, Jian-ming 15 October 2008 (has links)
Digital video broadcasting for Terrestrial (DVB-T) is one of the major standards for the fixed reception of digital television services, and the orthogonal frequency division multiplexing (OFDM) demodulator is a critical module of DVB-T receivers. As the remarkable advace of the VLSI (very large scale integration) circuits, the SOC (system-on-a-chip) of the DVB-T receiver is an inevitabel evolution. Considering the integration of the mixed-signal circuits, the issues ot beat could be the frequency synthesis and the calibration of the mixed-signal circuits. Hence, this thesis proposes an OFDM demodulator and discusses the design issues emerged from the SOC integration. The proposed OFDM demodulator is composed of four blocks: time synchronization, frequency synchronization, 2K/8K mode FFT (fast Fourier transform), and channel estimation. The demodulator utilizes the pilot signals embeded in OFDM symbols to estimate the frequency offset and the channel response. Besides, the demodulator use the cyclic prefix of an OFDM symbol to find the correct starting position of an OFDM symbol, and consequently the payload data of an OFDM symbol can be transmitted to the 2K/8K FFT for further processing. As the demand for a low noise frequency signal, we propose a direct digital frequency synthesizer (DDFS) based on the quadruple angle approximation. According to the proposed trigonometric 2nd-order quadruple angle approximation, the DDFS can produce a high-resolution and low-phase noise digital sinusoid without any ROM (read only memory). The digital calibration is an effective scheme to prevent ADCs (analog-to-digital converter) from the interference of noise. A random number generator (RNG) is an essential component for the calibration circuitry. However, the realization of the RNG is an important but long ignored issue. This thesis proposes a RNG based on a chaotic system wherein the coefficients of the system is dynamically changed to attain an ideal random bit stream with flat power spectrum density.

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