L'avènement de terminaux avancés permet l'accès à des services toujours plus gourmands en bande passante, avec notamment le déploiement de services de vidéo mobile sans couture offert par le mode diffusion mobile intégré standardisé par le 3GPP. Dans le même temps, la communauté << broadcast » s'est adaptée aux nouveaux usages de télévision mobile avec la norme DVB-NGH (Digital Video Broadcasting - Next Generation Handheld). Dans ce contexte, l'objectif de cette thèse est d'étudier la convergence spectrale entre les deux réseaux DVB et LTE en déployant une petite cellule LTE au sein d'une grande cellule DVB. Les deux technologies utilisent une forme d'onde OFDM (Orthogonal Frequency Division Multiplexing), en liaison descendante pour le LTE, ct possèdent donc quelques similarités tout en étant assez différentes par leurs caractéristiques. Dans ces travaux, nous nous intéressons aux performances atteignables lorsque les deux systèmes se recouvrent spectralement sans coopération. Le problème considéré étant analogue à un problème d’utilisateur secondaire opérant en mode recouvrement avec un utilisateur primaire, on commence par étudier le problème de la capacité ergodique du système secondaire, i.e. utilisateur LTE, sous contraintes de puissance moyenne générée par le secondaire sur le primaire, i.e LTE sur DVB, et de puissance crête au secondaire lorsque l'utilisateur primaire interfère sur le secondaire. Le problème est résolu analytiquement dans le cas général du canal croisé avec évanouissements de Rayleigh. Dans un deuxième temps nous étendons cette étude préliminaire au cas où la forme d'onde des deux systèmes primaire et secondaire est effectivement de type OFDM. En considérant d'abord un modèle simple de recouvrement total des sous-porteuses, nous délivrons la capacité ergodique globale ce qui nous permet d'évaluer l'influence des paramètres des systèmes, comme le nombre de sous-porteuses de chaque système ou les puissances interférentes, sur les capacités globales et individuelles. Nous nous intéressons ensuite à l'optimisation de la capacité globale où deux stratégies sont étudiées. D'une part, la capacité globale étant la somme de deux fonctions convexe et concave respectivement, la solution obtenue conduit au minimum de capacité globale mais mène à une situation d'équilibre entre les systèmes DVB et LTE. D'autre part, la maximisation de la capacité globale sous contrainte conduit à favoriser largement un système sur l'autre. Enfin, une étude fine de l'interférence causée par un système sur l'autre par recouvrement partiel est menée. L'effet de la variation du taux de recouvrement spectral entre les bandes du DVB et du LTE sur l'efficacité spectrale globale est étudié. On suppose ensuite que le récepteur possède une capacité de réjection de l'interférence permettant de déterminer le recouvrement optimal maximisant la capacité globale. Les différentes contributions de ces travaux ont permis d'avoir une approche théorique sur la modalité d'allocation de puissance des deux systèmes DVB et LTE co-existants et sur le taux de recouvrement approprié entre leurs spectres respectifs. Cette étude pourrait être ut le pour les opérateurs intéressés par un scénario de déploiement dense afin de choisir les configurations optimales des ressources dans une perspective de réutilisation agressive des fréquences. / Since the launch of the first numerical mobile telecommunications networks in the nineties, the quantity of the transmitted data over the networks is increasing year by year. Advanced user equipments enable to implement more and more bandwidth consuming services such as mobile T and multimedia internet, available in the integreted mobile broadcast mode recently standardized by the 3GPP group. In the meanwhile, the digital vide broadcasting - next generation handled (DVB-NGH) has been released in order to satisfy the increasing demand for mobile TV. These technologies compete for a more and more constrained spectral resource leading to question the possibility to deploy DVB and Long Term Evolution (LTE) service in a spectral overlay mode as it has been investigated by the Ml project funded by the National Research Agency. In this context, this thesis aims at studying the spectral convergence between DVB and LTE networks by deploying a small LTE cell in a large DVB cell. Both technologies present some similarities, i.e. both use orthogonal frequency division multiplexing (OFDM) waveform (in downlink for LTE), but technical characteristics remain rather different between those. In this work, we deal with achievable performance when DVB and LTE spectrally overlap without cooperation. The considered problem being analog to the Seconda1y User (SU) - Primary User (PU) coexistence in overlay scenario, the SU ergodic capacity under average power generated on PU and peak power at SU constaints is investigated. An analytic solution is proposed in X-Channel with Rayleigh fading. In a second time, SU and PU are considered to be LTE and DVB respectively with their particular OFDM signal characteristics. With a first model of overlapping subcarriers, LTE and DVB ergodic capacities and global capacity as well are derived in closed form allowing to study the influence of several system parameters on ergodic capacities. The global capacity is then optimized using a convex-concave procedure leading to the minimum on the global capacity but to balanced capacity on individual links. On a second hand, global capacity maximization leads to favor one system over the other. Last but not least, a careful study of the interference caused by one system over the other by partial overlay is led. The effect of spectral overlap ratio between DVB and LTE systems over the global spectral efficiency is investigated. Advanced interference rejection ability is then assumed at receivers and the optimal spectral overlap, i.e. maximizing the global capacity, is then derived in that case. The different contributions in this work give a theoretical approach on the power allocation modality of two coexisting DVB and LTE systems and on the appropriate spectral overlap ratio between their respective spectrums. This study can be useful for operators interested in dense network deployment scenarios to decide the operating point of allocated resources in a very aggressive frequency reuse pattern.

La croissance rapide du trafic aérien et les besoins en nouveaux services notamment pour les passagers imposent l'introduction de nouveaux moyens de communication pour les avions avec une bande passante globale fortement accrue. Les satellites sont appelés à jouer un rôle important dans ce contexte, non seulement en complément des systèmes terrestres pour les services « cockpit » (services ATM, Air Traffic Management) mais aussi pour les services « cabine » (In-Flight Entertainment). L'objectif de la thèse est d'étudier l'architecture d'un système satellite supportant l'ensemble de ces services, en se focalisant sur l'architecture du terminal embarqué à bord des aéronefs. L'architecture retenue repose sur des liaisons DVB-S2/DVB-RCS normalisées par l'ETSI. Cette option permet d'utiliser efficacement l'importante bande passante disponible en bande Ka pour les services mobiles aéronautiques (allocation primaire) ou en bande Ku (allocation secondaire). Ces normes ont été conçues pour les applications multimédia (Broadband Satellite Multimedia). Le défi est alors d'utiliser de telles liaisons satellite pour des services aux caractéristiques et besoins fortement hétérogènes. Par ailleurs, l'utilisation de la bande Ka n'est pas concevable sans l'activation de techniques de lutte contre les affaiblissements (FMT – Fade Mitigation Techniques). L'utilisation d'une marge statique conduit à une perte importante de capacité. Les techniques FMT reposent sur une évaluation dynamique du bilan de liaison et permettent une modification de la forme d'onde. Le système utilise ainsi la forme d'onde la plus efficace spectralement pour chaque terminal et maximise la capacité globale du système. Par contre, chaque terminal observe une modification de la ressource allouée au fil du temps. L'objectif de la thèse est de concevoir une architecture au niveau terminal qui permette d'exploiter les liaisons DVB-S2/RCS afin de fournir les services passagers (Internet et téléphonie mobile de type GSM/UMTS) et un canal haute fiabilité pour les services aéronautiques. Deux approches ont été retenues. La première repose sur une application du modèle ETSI BSM (Broadband Satellite Multimedia) en couches séparant strictement les couches dépendantes satellite et les couches indépendantes satellite. Les simulations de cette architecture montrent que les liaisons ne peuvent être utilisées de façon efficace sans une interaction entre couches afin de tenir compte de l'évolution de la capacité disponible. La seconde approche consiste en la concentration de la gestion de la ressource et la gestion de la qualité de service dans la même couche protocolaire. L'idée de départ est d'utiliser la méthode d'encapsulation générique Generic Stream Encapsulation (GSE). GSE a été conçu pour la projection des paquets de couches supérieures à l'intérieur des trames DVB-S2. GSE tient compte de la taille variable des trames DVB-S2 et introduit une capacité de multiplexage entre différents flux (identification de fragments). Sur cette base, une gestion de l'accès est introduite pour gérer la liaison DVB-RCS au format MF-TDMA. Nous introduisons ainsi une utilisation conjointe de GSE, d'une politique de service différentiée et de flux de signalisation inter-couches (« cross-layer »). Les performances des deux approches sont étudiées à l'aide d'un modèle de simulation développé à l'aide du logiciel OPNET Modeler (simulations à événements discrets). Les résultats obtenus démontrent le meilleur comportement de la seconde architecture avec une meilleure utilisation de la ressource et des performances de transmission satisfaisant les objectifs. / The rapid growth of air traffic needs a new communication infrastructure with increased bandwidth, high speed services and applications to satisfy expected air-ground communication requirements. Satellite communication systems play a significant role in this context, not only as a complement to terrestrial systems for Air Traffic Management (ATM) by offering global coverage but also as a promising solution to enrich In-Flight Entertainment (IFE) for passengers. DVB-S2/RCS technology is an attractive proposition to provide the cost-effective broadband services for both ATM and IFE, mainly because a large radio bandwidth is primarily allocated to aeronautical mobile communications in Ka-band, where the open standards DVB are implemented. However, such system design with convergence of heterogeneous traffics involves two main challenges. Firstly, using Ka-band means the implementation of Fade Mitigation Techniques (FMT) in order to cope with deep fades caused by atmospheric attenuation. Otherwise, the waste of capacity would be excessively high in a constant link margin design. FMT adapt in real time the link budget to the propagation conditions, this adaptivity has an impact not only on physical layer but also on upper layers. An efficient ressource management strategy with dynamic bandwidth allocation is required in this case, especially in DVB-RCS return link where FMT are not natives. Secondly, the proposed system must be able to multiplex the trafic flows with highly different characteristics and Quality of Service (QoS) expectations into a single link, the corresponding capacity management and QoS support seem with higher complexity. In this paper, we present an adaptive system design using a single DVB-S2/RCS based satellite link to provide Internet access and mobile telephony (GSM/UMTS) for passengers and a high-reliability channel for ATM. Concerning the airborne terminal architecture, two approaches are investigated. The first one is in compliance with ETSI Broadband Satellite Multimedia (BSM) architecture and based on a layering paradigm. The conducted simulation experiments highlight the need of dynamic interactions and adaptations among the layers to achieve an overall performance optimization. We propose then an enhanced approach with the concentration of both resource allocation and QoS management at the same interface – adaptation layer. The idea comes from the success of the recent Generic Stream Encapsulation (GSE) protocol, which carries the network protocol packets over DVB-S2 forward link in a simple, flexible and efficient way, especially when used with Adaptive Coding and Modulation (ACM). Furthermore, GSE can be easily extended to use in our design for DVB-RCS return link thanks to a proper design of MF-TDMA structure in which the suitable FMT (ACM and Dynamic Rate Adaptation) are context-aware configured. With the combined use of GSE, service policy and the interactions between adaptation and access layers, incoming heterogeneous traffics can be dynamically scheduled, segmented and encapsulated at the same adaptation layer. Performance evaluation of two proposed approaches is derived by a network-level simulation model developed using OPNET. Results prove the enhanced approach outperforms the first one leading to better resource utilization and satisfactory performance.

Project is focused on description DVB broadcasting for hand-held’s. It describes standard DVB-H that is founded on DVB-T and uses its transmission infrastructure. Standard DVB-SH is a hybrid system that adds to terrestrial broadcasting satellite connection. Signal can extend by various environments, therefore it are defined models transmission channel with defined parameters. Simulation of the transmission in both channel are realized in user application created in MATLAB. Finally, obtained results are evaluated and discussed.

This thesis is focusing on the second satellite digital TV standard, DVB-S2. It deals with the principle of the digital TV and the first standard DVB-S. It also describes the very beginning and characteristics of the DVB-S2, new technologies in use, architecture and the individual topics are then explained more in detail. The thesis also contains the program of transmission simulation of DVB-S2 in MATLAB. In the laboratory of television technology UREL, two standards were measured and compared with the values obtained from the program. The functionality of the program and the benefits of DVB-S2 were verified afterwards.

This Master thesis deals with description, analysis and simulation of standards of digital video broadcasting DVB-C and DVB-C2. There is described mainly the transmission system, channel coding, type of modulation and OFDM symbols generation. Furthermore, channel models, used for the exploring of their performances are described too. There was created an application with a graphical interface in MATLAB, which simulates transmission in DVB-C2. Based on simulations there are compared influences of each settings on bit error rate of data transmission for both standards. Finally, obtained simulation results are compared with theoretical values.

Master’s thesis is focused on SFN (Single Frequency Network) and MFN (Multi Frequency Network) networks design in digital television broadcasting based on DVB-T standard and digital radio broadcasting based on T-DAB standard. First part of the thesis is focused on the theoretical description of the MPEG-2 TS transmission, its propagation from transmitter across free space, to be decoded in the DVB-T receiver. In the second, practical part of the thesis, basic parameters of a software package for broadcast network design in RadioLab, RadioBase and Sítě SFN are introduced and the results are displayed on the digital terrain map and morphologic map. Within solution of this thesis was created signal coverage model of DVB-T digital transmitters in entire area of the Czech Republic, so called networks no. 1-4, according to its status in spring 2010, and its future expansion, which is known from TPP (Technical Plan of Conversion) document. At the conclusion of thesis there were made experiments with the modeling of transmitters’ radiated power, guard interval selection and location of DVB-T transmitters in the SFN network.

This work aims at the creation of a~system of massive recording of multimedia data, especially speech data in various languages. The first issue is to find out high quality data source, the second is to build the system for managing and storing received data in the digital form. A digital satellite transmission is chosen as a signal source (DVB-S system). Main system features include recording of multiple streams in parallel, support of multiple cards, retrieving and storing of additional information (from Internet) and scheduling of recordings. The system will provide massive amounts of data for training of a language identification system.

由於數位電視產業的發展，將來每個家庭都會利用電視使用數據化的資訊服務，並且使得資訊管理的議題從企業轉向家庭。目前現行的國際標準有歐規的DVB-MHP以及美規的OCAP，均係試圖整合目前所有平台的標準，並且讓整體產業的各環節有最佳的技術解決方案。本研究採取訊息方式(Message-oriented Middleware, MOM)和WebSevices來設計社區機頂盒(set-top box, STB)的管理平台，並且藉由本研究所定義的商業模式(Business Model)，來導入相關的理論設計，建置以服務為導向的STB管理平台，讓STB得以加強其內容服務與分享網際網路的資源。

<p>DVB (Digital video broadcasting) is the television digital system. It's however much more than a simple replacement for existing analogue television transmission, this system has many advantages such as picture quality and allows you a range of new features and services including subtitling, multiple audio tracks, interactive content, multimedia content... </p><p>The system is based in the OFDM technology, which allows DVB system to exploit the spectrum frequencies in a better way, saving spectrum, but OFDM has an important drawback that is the peak to average power ratio problem. OFDM is based on the FFT algorithms generating several orthogonal subcarriers. This thesis talks about the improvement of the PAPR problem using the clipping method. </p><p>The simulation has been developed in Simulink® and Matlab®. With all the information presented in this thesis, any user can simulate the system. Thus, this thesis can be improved using other using other techniques to solve the PAPR problem.</p>

<p>Digital television is one of the biggest broadcasting media available. All over the world television companies are rearranging their broadcasting from analogue to digital transmission. Former standard disagreements in the analogue era have lead to an agreement of one common European standard for digital television. Countries like USA and Japan have their own similar standards.</p><p>The report consists of two objectives; a survey of the most commonly used standards for digital television today and the construction of a prototype receiver for the second generation satellite DVB-standard.</p><p>A thorough literature study and careful design resulted in a fully functioning system. Measurements performed on the DVB-S sections gave exemplary results. Comparing these results with corresponding measurements performed on the DVB-S2 section showed much better performance for DVB-S2 with the same code rates. This shows some of the advantages of the new standard and proving the coding theory right. New coding algorithms make it possible to transmit more information on noisier channels of inferior quality. In laymen’s words; DVB-S2 gives a better picture and more television channels on the same satellite compared to DVB-S.</p>