3,447 research outputs found
Design and Validation of a Software Defined Radio Testbed for DVB-T Transmission
This paper describes the design and validation of a Software Defined Radio (SDR) testbed, which can be used for Digital Television transmission using the Digital Video Broadcasting - Terrestrial (DVB-T) standard. In order to generate a DVB-T-compliant signal with low computational complexity, we design an SDR architecture that uses the C/C++ language and exploits multithreading and vectorized instructions. Then, we transmit the generated DVB-T signal in real time, using a common PC equipped with multicore central processing units (CPUs) and a commercially available SDR modem board. The proposed SDR architecture has been validated using fixed TV sets, and portable receivers. Our results show that the proposed SDR architecture for DVB-T transmission is a low-cost low-complexity solution that, in the worst case, only requires less than 22% of CPU load and less than 170 MB of memory usage, on a 3.0 GHz Core i7 processor. In addition, using the same SDR modem board, we design an off-line software receiver that also performs time synchronization and carrier frequency offset estimation and compensation
Analysis of DVB-H network coverage with the application of transmit diversity
This paper investigates the effects of the Cyclic Delay Diversity (CDD) transmit diversity scheme on DVB-H networks. Transmit diversity improves reception and Quality of Service (QoS) in areas of poor coverage such as sparsely populated or obscured locations. The technique not only povides robust reception in mobile environments thus improving QoS, but it also reduces network costs in terms of the transmit power, number of
infrastructure elements, antenna height and the frequency reuse factor over indoor and outdoor environments. In this paper, the benefit and effectiveness of CDD transmit diversity is tackled
through simulation results for comparison in several scenarios of coverage in DVB-H networks. The channel model used in the simulations is based on COST207 and a basic radio planning
technique is used to illustrate the main principles developed in this paper. The work reported in this paper was supported by
the European Commission IST projectâPLUTO (Physical Layer DVB Transmission Optimization)
Recommended from our members
Incorporating Digital Repeaters into the Soft Handover Standard in Digital Video Broadcasting Handheld
Digital Video Broadcasting for Handhelds (DVB-H) is a standard for broadcasting IP data services to portable devices. Handover in unidirectional broadcast networks is a novel issue introduced by this technology. This paper proposes and analyses the Repeater Aided Soft Handover (RA_handover) algorithm for a DVB-H receiver with MIMO antennas and presents the benefits of implementing RA_handover compared with a handover process without repeaters. For network planning and optimisation purposes simulation models are developed to analyse the RA_handover approach. It is shown that RA_handover could greatly improve the quality of service and consume much less front-end battery power than a handover method without repeaters. In addition, the cost introduced by the algorithm is briefly estimated. In conclusion, curves are given that show the relationship between quality of service and consumed battery power, which provide further support for including RA_handover in the DVB-H soft handover standard. The paper provides valuable outcomes for service providers and standard policy makers
Analysis and Simulation of the Signals Transmission in the DVB-H/SH Standards
Tato disertaÄnĂ prĂĄce se zabĂœvĂĄ analĂœzou, simulacĂ a mÄĆenĂm zpracovĂĄnĂ a pĆenosu signĂĄlĆŻ digitĂĄlnĂ televize pro pĆĂjem mobilnĂho TV vysĂlĂĄnĂ ve standardech DVB-H a DVB-SH. Tyto standardy vychĂĄzejĂ z pĆedpokladu, ĆŸe pĆĂjem signĂĄlu je charakterizovĂĄn modely pĆenosovĂœch kanĂĄlĆŻ s vĂcecestnĂœm ĆĄĂĆenĂm. Tyto, tzv. ĂșnikovĂ© kanĂĄly, jsou charakterizovĂĄny hlavnÄ zpoĆŸdÄnĂm a ziskem jednotlivĂœch cest. V zĂĄvislosti na dalĆĄĂch parametrech (rychlost pĆijĂmaÄe, DopplerovskĂ© spektrum), je moĆŸnĂ© rozdÄlit ĂșnikovĂ© kanĂĄly do tĆech hlavnĂch skupin: mobilnĂ, pĆenosnĂ© a fixnĂ. DĂĄ se pĆedpoklĂĄdat, ĆŸe v rĆŻznĂœch modelech kanĂĄlĆŻ bude pĆenĂĄĆĄenĂœ signĂĄl rĆŻznÄ ovlivnÄn. Proto je potĆebnĂ© najĂt optimĂĄlnĂ parametry systĂ©mĆŻ (DVB-H/SH) pro kvalitnĂ pĆĂjem vysĂlanĂœch sluĆŸeb mobilnĂ televize, coĆŸ je hlavnĂm cĂlem tĂ©to disertaÄnĂ prĂĄci. Pro tento ĂșÄel byly vytvoĆeny dvÄ vhodnĂ© aplikace (jedna pro DVB-H a jedna pro DVB-SH) s GUI v prostĆedĂ MATLAB, kterĂ© umoĆŸĆujĂ simulovat a analyzovat mĂru zkreslenĂ signĂĄlu v pĆĂpadÄ mobilnĂch, pĆenosnĂœch a fixnĂch scĂ©nĂĄĆĆŻ pĆenosu. NavĂc, tyto aplikace obsahujĂ i druhĂœ samostatnĂœ simulĂĄtor pro nastavenĂ a modifikaci parametrĆŻ jednotlivĂœch pĆenosovĂœch cest. DĂky tomu je moĆŸnĂ© zhodnotit vliv parametrĆŻ celĂ©ho systĂ©mu a kanĂĄlovĂœch modelĆŻ na dosaĆŸenou chybovost (BER a MER) a kvalitu pĆenosu. Ve vĆĄech pĆenosovĂœch scĂ©nĂĄĆĂch (v zĂĄvislosti na pomÄru C/N) byly zĂskanĂ©, vyhodnocenĂ© a diskutovanĂ© zkreslenĂ signĂĄlĆŻ. NavĂc, u standardu DVB-H, vĆĄechny zĂskanĂ© vĂœsledky ze simulacĂ byly ovÄĆeny mÄĆenĂm. RozdĂly mezi dosaĆŸenĂœmi vĂœsledky (simulace a mÄĆenĂ) byly rovnÄĆŸ podrobeny diskuzi. Tuto disertaÄnĂ prĂĄci je moĆŸnĂ© rozdÄlit do ÄtyĆ hlavnĂch ÄĂĄstĂ. PrvnĂ ÄĂĄst disertaÄnĂ prĂĄce se zabĂœvĂĄ reĆĄerĆĄĂ souÄasnĂ©ho vĂœvoje v oblasti digitĂĄlnĂho televiznĂho vysĂlĂĄnĂ na mobilnĂ terminĂĄly ve standardech DVB-H/SH. Na konci tĂ©to ÄĂĄsti jsou jasnÄ popsĂĄny cĂle tĂ©to disertaÄnĂ prĂĄce. DruhĂĄ ÄĂĄst prĂĄce je zamÄĆenĂĄ na struÄnĂœ popis blokovĂ©ho diagramu vysĂlaÄĆŻ v obou standardech DVB-H/SH. DĂĄle jsou struÄnÄ popsĂĄny modely pĆenosovĂœch kanĂĄlĆŻ, kterĂ© se pouĆŸĂvajĂ pro modelovĂĄnĂ pĆenosu signĂĄlu. StruÄnĂœ popis vytvoĆenĂœch aplikacĂ, i s vĂœvojovĂœm diagramem, kterĂ© jsou vhodnĂ© pro simulaci a analĂœzu pĆenosu v DVB-H/SH, jsou popsĂĄny v tĆetĂ ÄĂĄsti prĂĄce. ÄtvrtĂĄ a nejdelĆĄĂ ÄĂĄst tĂ©to disertaÄnĂ prĂĄce se zabĂœvĂĄ vyhodnocenĂm zĂskanĂœch vĂœsledkĆŻ ze simulacĂ a mÄĆenĂ.This dissertation thesis deals with the analysis, simulation and measurement of the signal processing and transmission in DVB-H and DVB-SH standards. These standards are based on the assumption that signal reception is characterized by the transmission channels with echoes. These, so called fading channels, are mainly characterized by the path delays and path losses. Depending on the other, additional features (speed of the receiver, Doppler spectrum, etc.), it can be possible divided these channels onto three main groups: mobile, portable and fixed. Of course, signal transmission in different transmission channel models are affected differently. Therefore, it is needed found the optimal system parameters in both, DVB-H and DVB-SH standards, for the quality reception of the broadcasted mobile TV services, which is the main goal of this thesis. For this purpose, two appropriate applications (one for DVB-H and one for DVB-SH) with GUI were created in MATLAB, which enable simulated and analyzed the signal distortions in mobile, portable and fixed transmission scenarios. Moreover, these applications also contain a second application with GUI for the easy set and modification of the parameters of the used channel models. Therefore, it is possible to evaluate the effect of parameters of whole system and channel models on the achieved error rate (BER and MER) and quality of the transmission. In all mentioned transmission scenarios, the signal distortions (depending on the Carrier-to-Noise ratio) were obtained, evaluated and discussed in this dissertation thesis. Furthermore, in case of DVB-H, all obtained results from the simulations, were verified by the measuring. Differences between the obtained results (simulation and measuring) are also discussed. This dissertation thesis can be divided into four main parts. The first part of this dissertation thesis, after the short introduction, deals with present state-of-the-art and literature survey in mobile broadcast DVB-H/SH standards. At the end of this part are clearly outlined the main aims of this dissertation thesis. Second part is focused on the brief description of the functional block diagram of transmitters in both, DVB-H/SH standards. Furthermore, there are briefly described the transmission fading channel models, which are commonly used for the modeling of the signal transmission. The brief description of program applications with flowcharts, appropriate for the simulation of the transmission in the DVB-H/SH standards, are presented and described in the third part of this thesis. Finally, the fourth and longest part of this thesis is focused on the evaluation and comparison of obtained results from the simulations and measurements.
Can the Digital Surpass the Analog: DAB+ Possibilities, Limitations and User Expectations
Radio is by far the most accessible medium. With its mobility and availability, it attracts listeners by its simplicity and friendliness. The present information situation is characterized by the convergence of computers, mobile devices, telecommunication and broadcasting technologies and the divergence of different ways of delivering and storing media. Consumers are overwhelmed by new electronic gadgets appearing every year. They are astonished by new technical innovations that are being designed to ease their life and change their habits. Even the broadcasting sector itself is facing significant changes, especially a growing competition between the private and public sector. This article reviews the current status of analog and digital broadcasting technologies. It analyzes a case study of user expectations related with todayâs digital media, particularly radio transmission. We discuss the principal possibilities, limitations and user expectations related with digital audio broadcasting, as well as the economic, technological, regulatory and frequency management factors
Distributed storage manager system for synchronized and scalable AV services across networks
This article has been made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Hindawi Publishing CorporationThis paper provides an innovative solution, namely, the distributed storage manager that opens a new path for highly interactive and personalized services. The distributed storage manager provides an enhancement to the MHP storage management functionality acting as a value added middleware distributed across the network. The distributed storage manager system provides multiple protocol support for initializing and downloading both streamed and file-based content and provides optimum control mechanisms to organize the storing and retrieval of content that are remained accessible to other multiple heterogeneous devices
Recommended from our members
A survey of handover algorithms in DVB-H
Digital Video Broadcasting for Handhelds (DVB-H) is a standard for
broadcasting IP Datacast (IPDC) services to mobile handheld terminals.
Based on the DVB-T standard, DVB-H adds new features such as time
slicing, MPE-FEC, in-depth interleavers, mandatory cell id identifier,
optional 4K-modulation mode and the use of 5 MHz bandwidth in addition
to the usually used 6, 7, or 8 MHz raster. IPDC over DVB-H is proposed
for ETSI to complement the DVB-H standard by combining IPDC and
DVB-H in an end-to-end system. Handover in such unidirectional broadcasting
networks is a novel issue. In the last few years since the birth of
DVB-H technology, great attention has been given to the performance
analysis of DVB-H mobile terminals. Handover is one of the main research
topics for DVB-H in mobile scenarios. Better reception quality and greater
power efficiency are considered to be the main targets of handover
research for DVB-H. New algorithms for different handover stages in
DVB-H have been the subject of recent research and are currently being
studied. Further novel algorithms need to be designed to improve the
mobile reception quality. This article provides a comprehensive survey of
the handover algorithms in DVB-H. A systematic evaluation and categorization
approach is proposed based on the problems the algorithms solve
and the handover stages being focused on. Criteria are proposed and analyzed
to facilitate designing better handover algorithms for DVB-H that
have been identified from the research conducted by the author
Digital Radio Strategies in the United States: A Tale of Two Systems
This essay analyzes how, despite early interest in the Digital Audio Broadcasting standard (DAB) in the United States, an alternative in-band system (HD Radio) was developed as the approved digital radio standard
- âŠ