231 research outputs found

    Replacing the automatic gain control loop in a mobile, digital TV broadcast receiver by a software based solution

    Get PDF
    The power level (the amplitude) of an electro-magnetic signal wave suffers from attenuation the greater the distance between the transmitter and the receiver is. The receiver of that signal therefore has components which try to amplify the signal so that it can be processed optimally by a processor. In a mobile or portable environment the signal power level can vary strongly, because the position of the receiver to the transmitter is not fixed. In order to compensate that movement a control loop exists, which dynamically is adapting the front-end to the right level. This work describes a new, software-based way to handle the signal level control loop (formerly automatic gain control) in a digital TV receiver. Starting with a very basic introduction into digital communications, including the description of the traditional front-end architecture, followed by a detailed description of the new method. Finally some conclusions of this new method are made which are giving an idea about how in the future it might be possible to reach better receiving performances using this mechanism

    CMOS RF front-end design for terrestrial and mobile digital television systems

    Get PDF
    With the increasing demand for high quality TV service, digital television (DTV) is replacing the conventional analog television. DTV tuner is one of the most critical blocks of the DTV receiver system; it down-converts the desired DTV RF channel to baseband or a low intermediate frequency with enough quality. This research is mainly focused on the analysis and realization of low-cost low-power front-ends for ATSC terrestrial DTV and DVB-H mobile DTV tuner systems. For the design of the ATSC terrestrial tuner, a novel double quadrature tuner architecture, which can not only minimize the tuner power consumption but also achieve the fully integration, has been proposed. A double quadrature down-converter has been designed and fabricated with TSMC 0.35õm CMOS technology; the measurement results verified the proposed concepts. For the mobile DTV tuner, a zero-IF architecture is used and it can achieve the DVB-H specifications with less than 200mW power consumption. In the implementation of the mobile DVB-H tuner, a novel RF variable gain amplifier (RFVGA) and a low flicker noise current-mode passive mixer have been proposed. The proposed RFVGA achieves high dynamic range and robust input impedance matching performance, which is the main design challenge for the traditional implementations. The current-mode passive mixer achieves high-gain, low noise (especially low flicker noise) and high-linearity (over 10dBm IIP3) with low power supplies; it is believed that this is a promising topology for low voltage high dynamic range mixer applications. The RFVGA has been fabricated in TSMC 0.18õm CMOS technology and the measurement results agree well with the theoretical ones

    Digital television applications

    Get PDF
    Studying development of interactive services for digital television is a leading edge area of work as there is minimal research or precedent to guide their design. Published research is limited and therefore this thesis aims at establishing a set of computing methods using Java and XML technology for future set-top box interactive services. The main issues include middleware architecture, a Java user interface for digital television, content representation and return channel communications. The middleware architecture used was made up of an Application Manager, Application Programming Interface (API), a Java Virtual Machine, etc., which were arranged in a layered model to ensure the interoperability. The application manager was designed to control the lifecycle of Xlets; manage set-top box resources and remote control keys and to adapt the graphical device environment. The architecture of both application manager and Xlet forms the basic framework for running multiple interactive services simultaneously in future set-top box designs. User interface development is more complex for this type of platform (when compared to that for a desktop computer) as many constraints are set on the look and feel (e.g., TV-like and limited buttons). Various aspects of Java user interfaces were studied and my research in this area focused on creating a remote control event model and lightweight drawing components using the Java Abstract Window Toolkit (AWT) and Java Media Framework (JMF) together with Extensible Markup Language (XML). Applications were designed aimed at studying the data structure and efficiency of the XML language to define interactive content. Content parsing was designed as a lightweight software module based around two parsers (i.e., SAX parsing and DOM parsing). The still content (i.e., text, images, and graphics) and dynamic content (i.e., hyperlinked text, animations, and forms) can then be modeled and processed efficiently. This thesis also studies interactivity methods using Java APIs via a return channel. Various communication models are also discussed that meet the interactivity requirements for different interactive services. They include URL, Socket, Datagram, and SOAP models which applications can choose to use in order to establish a connection with the service or broadcaster in order to transfer data. This thesis is presented in two parts: The first section gives a general summary of the research and acts as a complement to the second section, which contains a series of related publications.reviewe

    DVB-NGH: the Next Generation of Digital Broadcast Services to Handheld Devices

    Full text link
    This paper reviews the main technical solutions adopted by the next-generation mobile broadcasting standard DVB-NGH, the handheld evolution of the second-generation digital terrestrial TV standard DVB-T2. The main new technical elements introduced with respect to DVB-T2 are: layered video coding with multiple physical layer pipes, time-frequency slicing, full support of an IP transport layer with a dedicated protocol stack, header compression mechanisms for both IP and MPEG-2 TS packets, new low-density parity check coding rates for the data path (down to 1/5), nonuniform constellations for 64 Quadrature Amplitude Modulation (QAM) and 256QAM, 4-D rotated constellations for Quadrature Phase Shift Keying (QPSK), improved time interleaving in terms of zapping time, end-to-end latency and memory consumption, improved physical layer signaling in terms of robustness, capacity and overhead, a novel distributed multiple input single output transmit diversity scheme for single-frequency networks (SFNs), and efficient provisioning of local content in SFNs. All these technological solutions, together with the high performance of DVB-T2, make DVB-NGH a real next-generation mobile multimedia broadcasting technology. In fact, DVB-NGH can be regarded the first third-generation broadcasting system because it allows for the possibility of using multiple input multiple output antenna schemes to overcome the Shannon limit of single antenna wireless communications. Furthermore, DVB-NGH also allows the deployment of an optional satellite component forming a hybrid terrestrial-satellite network topology to improve the coverage in rural areas where the installation of terrestrial networks could be uneconomical.Gómez Barquero, D.; Douillard, C.; Moss, P.; Mignone, V. (2014). DVB-NGH: the Next Generation of Digital Broadcast Services to Handheld Devices. IEEE Transactions on Broadcasting. 60(2):246-257. doi:10.1109/TBC.2014.2313073S24625760

    Architecture and algorithms for the implementation of digital wireless receivers in FPGA and ASIC: ISDB-T and DVB-S2 cases

    Full text link
    [EN] The first generation of Terrestrial Digital Television(DTV) has been in service for over a decade. In 2013, several countries have already completed the transition from Analog to Digital TV Broadcasting, most of which in Europe. In South America, after several studies and trials, Brazil adopted the Japanese standard with some innovations. Japan and Brazil started Digital Terrestrial Television Broadcasting (DTTB) services in December 2003 and December 2007 respectively, using Integrated Services Digital Broadcasting - Terrestrial (ISDB-T), also known as ARIB STD-B31. In June 2005 the Committee for the Information Technology Area (CATI) of Brazilian Ministry of Science and Technology and Innovation MCTI approved the incorporation of the IC-Brazil Program, in the National Program for Microelectronics (PNM) . The main goals of IC-Brazil are the formal qualification of IC designers, support to the creation of semiconductors companies focused on projects of ICs within Brazil, and the attraction of semiconductors companies focused on the design and development of ICs in Brazil. The work presented in this thesis originated from the unique momentum created by the combination of the birth of Digital Television in Brazil and the creation of the IC-Brazil Program by the Brazilian government. Without this combination it would not have been possible to make these kind of projects in Brazil. These projects have been a long and costly journey, albeit scientifically and technologically worthy, towards a Brazilian DTV state-of-the-art low complexity Integrated Circuit, with good economy scale perspectives, due to the fact that at the beginning of this project ISDB-T standard was not adopted by several countries like DVB-T. During the development of the ISDB-T receiver proposed in this thesis, it was realized that due to the continental dimensions of Brazil, the DTTB would not be enough to cover the entire country with open DTV signal, specially for the case of remote localizations far from the high urban density regions. Then, Eldorado Research Institute and Idea! Electronic Systems, foresaw that, in a near future, there would be an open distribution system for high definition DTV over satellite, in Brazil. Based on that, it was decided by Eldorado Research Institute, that would be necessary to create a new ASIC for broadcast satellite reception. At that time DVB-S2 standard was the strongest candidate for that, and this assumption still stands nowadays. Therefore, it was decided to apply to a new round of resources funding from the MCTI - that was granted - in order to start the new project. This thesis discusses in details the Architecture and Algorithms proposed for the implementation of a low complexity Intermediate Frequency(IF) ISDB-T Receiver on Application Specific Integrated Circuit (ASIC) CMOS. The Architecture proposed here is highly based on the COordinate Rotation Digital Computer (CORDIC) Algorithm, that is a simple and efficient algorithm suitable for VLSI implementations. The receiver copes with the impairments inherent to wireless channels transmission and the receiver crystals. The thesis also discusses the Methodology adopted and presents the implementation results. The receiver performance is presented and compared to those obtained by means of simulations. Furthermore, the thesis also presents the Architecture and Algorithms for a DVB-S2 receiver targeting its ASIC implementation. However, unlike the ISDB-T receiver, only preliminary ASIC implementation results are introduced. This was mainly done in order to have an early estimation of die area to prove that the project in ASIC is economically viable, as well as to verify possible bugs in early stage. As in the case of ISDB-T receiver, this receiver is highly based on CORDIC algorithm and it was prototyped in FPGA. The Methodology used for the second receiver is derived from that used for the ISDB-T receiver, with minor additions given the project characteristics.[ES] La primera generación de Televisión Digital Terrestre(DTV) ha estado en servicio por más de una década. En 2013, varios países completaron la transición de transmisión analógica a televisión digital, la mayoría de ellas en Europa. En América del Sur, después de varios estudios y ensayos, Brasil adoptó el estándar japonés con algunas innovaciones. Japón y Brasil comenzaron a prestar el servicio de Difusión de Televisión Digital Terrestre (DTTB) en diciembre de 2003 y diciembre de 2007 respectivamente, utilizando Radiodifusión Digital de Servicios Integrados Terrestres (ISDB-T), también conocida como ARIB STD-B31. En junio de 2005, el Comité del Área de Tecnología de la Información (CATI) del Ministerio de Ciencia, Tecnología e Innovación de Brasil - MCTI aprobó la incorporación del Programa CI-Brasil, en el Programa Nacional de Microelectrónica (PNM). Los principales objetivos de la CI-Brasil son la formación de diseñadores de CIs, apoyar la creación de empresas de semiconductores enfocadas en proyectos de circuitos integrados dentro de Brasil, y la atracción de empresas de semiconductores interesadas en el diseño y desarrollo de circuitos integrados. El trabajo presentado en esta tesis se originó en el impulso único creado por la combinación del nacimiento de la televisión digital en Brasil y la creación del Programa de CI-Brasil por el gobierno brasileño. Sin esta combinación no hubiera sido posible realizar este tipo de proyectos en Brasil. Estos proyectos han sido un trayecto largo y costoso, aunque meritorio desde el punto de vista científico y tecnológico, hacia un Circuito Integrado brasileño de punta y de baja complejidad para DTV, con buenas perspectivas de economía de escala debido al hecho que al inicio de este proyecto, el estándar ISDB-T no fue adoptado por varios países como DVB-T. Durante el desarrollo del receptor ISDB-T propuesto en esta tesis, se observó que debido a las dimensiones continentales de Brasil, la DTTB no sería suficiente para cubrir todo el país con la señal de televisión digital abierta, especialmente para el caso de localizaciones remotas, apartadas de las regiones de alta densidad urbana. En ese momento, el Instituto de Investigación Eldorado e Idea! Sistemas Electrónicos, previeron que en un futuro cercano habría un sistema de distribución abierto para DTV de alta definición por satélite en Brasil. Con base en eso, el Instituto de Investigación Eldorado decidió que sería necesario crear un nuevo ASIC para la recepción de radiodifusión por satélite, basada el estándar DVB-S2. En esta tesis se analiza en detalle la Arquitectura y algoritmos propuestos para la implementación de un receptor ISDB-T de baja complejidad y frecuencia intermedia (IF) en un Circuito Integrado de Aplicación Específica (ASIC) CMOS. La arquitectura aquí propuesta se basa fuertemente en el algoritmo Computadora Digital para Rotación de Coordenadas (CORDIC), el cual es un algoritmo simple, eficiente y adecuado para implementaciones VLSI. El receptor hace frente a las deficiencias inherentes a las transmisiones por canales inalámbricos y los cristales del receptor. La tesis también analiza la metodología adoptada y presenta los resultados de la implementación. Por otro lado, la tesis también presenta la arquitectura y los algoritmos para un receptor DVB-S2 dirigido a la implementación en ASIC. Sin embargo, a diferencia del receptor ISDB-T, se introducen sólo los resultados preliminares de implementación en ASIC. Esto se hizo principalmente con el fin de tener una estimación temprana del área del die para demostrar que el proyecto en ASIC es económicamente viable, así como para verificar posibles errores en etapa temprana. Como en el caso de receptor ISDB-T, este receptor se basa fuertemente en el algoritmo CORDIC y fue un prototipado en FPGA. La metodología utilizada para el segundo receptor se deriva de la utilizada para el re[CA] La primera generació de Televisió Digital Terrestre (TDT) ha estat en servici durant més d'una dècada. En 2013, diversos països ja van completar la transició de la radiodifusió de televisió analògica a la digital, i la majoria van ser a Europa. A Amèrica del Sud, després de diversos estudis i assajos, Brasil va adoptar l'estàndard japonés amb algunes innovacions. Japó i Brasil van començar els servicis de Radiodifusió de Televisió Terrestre Digital (DTTB) al desembre de 2003 i al desembre de 2007, respectivament, utilitzant la Radiodifusió Digital amb Servicis Integrats de (ISDB-T), coneguda com a ARIB STD-B31. Al juny de 2005, el Comité de l'Àrea de Tecnologia de la Informació (CATI) del Ministeri de Ciència i Tecnologia i Innovació del Brasil (MCTI) va aprovar la incorporació del programa CI Brasil al Programa Nacional de Microelectrònica (PNM). Els principals objectius de CI Brasil són la qualificació formal dels dissenyadors de circuits integrats, el suport a la creació d'empreses de semiconductors centrades en projectes de circuits integrats dins del Brasil i l'atracció d'empreses de semiconductors centrades en el disseny i desenvolupament de circuits integrats. El treball presentat en esta tesi es va originar en l'impuls únic creat per la combinació del naixement de la televisió digital al Brasil i la creació del programa Brasil CI pel govern brasiler. Sense esta combinació no hauria estat possible realitzar este tipus de projectes a Brasil. Estos projectes han suposat un viatge llarg i costós, tot i que digne científicament i tecnològica, cap a un circuit integrat punter de baixa complexitat per a la TDT brasilera, amb bones perspectives d'economia d'escala perquè a l'inici d'este projecte l'estàndard ISDB-T no va ser adoptat per diversos països, com el DVB-T. Durant el desenvolupament del receptor de ISDB-T proposat en esta tesi, va resultar que, a causa de les dimensions continentals de Brasil, la DTTB no seria suficient per cobrir tot el país amb el senyal de TDT oberta, especialment pel que fa a les localitzacions remotes allunyades de les regions d'alta densitat urbana.. En este moment, l'Institut de Recerca Eldorado i Idea! Sistemes Electrònics van preveure que, en un futur pròxim, no hi hauria a Brasil un sistema de distribució oberta de TDT d'alta definició a través de satèl¿lit. D'acord amb això, l'Institut de Recerca Eldorado va decidir que seria necessari crear un nou ASIC per a la recepció de radiodifusió per satèl¿lit. basat en l'estàndard DVB-S2. En esta tesi s'analitza en detall l'arquitectura i els algorismes proposats per l'execució d'un receptor ISDB-T de Freqüència Intermèdia (FI) de baixa complexitat sobre CMOS de Circuit Integrat d'Aplicacions Específiques (ASIC). L'arquitectura ací proposada es basa molt en l'algorisme de l'Ordinador Digital de Rotació de Coordenades (CORDIC), que és un algorisme simple i eficient adequat per implementacions VLSI. El receptor fa front a les deficiències inherents a la transmissió de canals sense fil i els cristalls del receptor. Esta tesi també analitza la metodologia adoptada i presenta els resultats de l'execució. Es presenta el rendiment del receptor i es compara amb els obtinguts per mitjà de simulacions. D'altra banda, esta tesi també presenta l'arquitectura i els algorismes d'un receptor de DVB-S2 de cara a la seua implementació en ASIC. No obstant això, a diferència del receptor ISDB-T, només s'introdueixen resultats preliminars d'implementació en ASIC. Això es va fer principalment amb la finalitat de tenir una estimació primerenca de la zona de dau per demostrar que el projecte en ASIC és econòmicament viable, així com per verificar possibles errors en l'etapa primerenca. Com en el cas del receptor ISDB-T, este receptor es basa molt en l'algorisme CORDIC i va ser un prototip de FPGA. La metodologia utilitzada per al segon receptor es deriva de la utilitzada per al receptor IRodrigues De Lima, E. (2016). Architecture and algorithms for the implementation of digital wireless receivers in FPGA and ASIC: ISDB-T and DVB-S2 cases [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61967TESI

    Tunable Balun Low-Noise Amplifier in 65nm CMOS Technology

    Get PDF
    The presented paper includes the design and implementation of a 65 nm CMOS low-noise amplifier (LNA) based on inductive source degeneration. The amplifier is realized with an active balun enabling a single-ended input which is an important requirement for low-cost system on chip implementations. The LNA has a tunable bandpass characteristics from 4.7 GHz up to 5.6 GHz and a continuously tunable gain from 22 dB down to 0 dB, which enables the required flexibility for multi-standard, multi-band receiver architectures. The gain and band tuning is realized with an optimized tunable active resistor in parallel to a tunable L-C tank amplifier load. The amplifier achieves an IIP3 linearity of -8dBm and a noise figure of 2.7 dB at the highest gain and frequency setting with a low power consumption of 10 mW. The high flexibility of the proposed LNA structure together with the overall good performance makes it well suited for future multi-standard low-cost receiver front-ends

    Low cost passive radar through software defined radio

    Get PDF
    Passive radars utilise existing terrestrial radio signals, such as those produced by radio or television stations, to track objects within their range. This project aims to determine the suitability of low cost USB TV tuners as hardware receivers for a Software Defined Radio (SDR) based passive radar receiver. Subsequently determining its effectiveness in producing inverse synthetic aperture radar images using data collected from Digital Television signals. Since the initial identification of passive radar, Militaries the world over have been using it as a part of electronic warfare. The evolution of SDR has enabled greater access to the technologies required to implement passive radar, with the greatest limitation being the cost of the required hardware. The availability of low cost hardware was therefore investigated to determine its suitability and subsequently the availability of passive radar to a wider audience. Research was conducted into the available SDR receivers, and comparison of specifications was made against the low cost receiver used in the project. A functional hardware platform based around the Realtek RTL2832U chipset has been developed to determine its suitability as a low cost receiver verifying its ability to coherently receive radio signals for target identification. A complex ambiguity function was implemented to interpret sampled data windows, with the output of these windows to be compared to the requirements for an inverse synthetic aperture radar input, thus determining the suitability of the device. Interpretation of the received data has identified that although the hardware is capable, a real time implementation of data processing is not yet possible, impeding the ability to determine the suitability of the receiver as an inverse synthetic aperture receiver. The results of testing show that the hardware is capable of receiving and producing radar images, however due to the bandwidth of DVB-T signals , and the bandwidth limitations inherent in RTL-SDR dongles, they have proven not to be suitable for DVB-T based inverse synthetic aperture radar receivers

    TV Ghost Cancellation System Using Switched Capacitor Circuits

    Get PDF
    In the TV reception, picture quality has been one of the primary criterion in its design. The presence of ghost signals, which are due to reflections of TV signal from high rise building, towers, mountains, etc., is one of the major causes of distortion and is Iiot avoided at the receiver end. The ghost signals are in fact time delayed versions of tht:: actual transmitted signals at the receiver and have many adverse effects on picture quality due to partial cancellation of main signal. The perceptibility of the ghost signal is strongly subj ective and is a function of picture content and quality. Thus it is essential to filter the ghost signals for better reception. In this thesis we present the design of a television ghost cancellation system using switched capacitor circuits. Ghost cancellation is a nullifying operation and allows one to reduce its effect on the picture quality as much as possible. In this thesis two-stage switched capacitor (SC) transversal filter has been used for reduction of distortion. The system has been able to suppress ghosts with delays ranging from 0.1 µs to 20 µs with ghost suppression threshold at 1 % amplitude. The algorithm uses a special training signal to determine the ghost's characteristics. For a single ghost once the ghost's parameters have been determined, the transversal filter delays the incoming signal by td (the time delay of ghost) and multiplies it by a factor - G (G being the gain of ghost). The result signal is added to original signal. We obtain an output which gives no output due to original ghost but adds up another ghost. The process is repeated until the ghost's amplitude is within acceptable limits. In this thesis we have simulated the system at the block diagram level using MATLAB and at component level using PSpice. The results of the simulation are in close conformity with the theoretical value. This suggested circuit can be fabricated using the MOS technology allowing the manufacturer to provide a better quality in TV reception

    High definition systems in Japan

    Get PDF
    The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems

    Experimental Verification of a Harmonic-Rejection Mixing Concept using Blind Interference Canceling

    Get PDF
    Abstract—This paper presents the first practical experiments\ud on a harmonic rejection downconverter, which offers up to 75 dB of harmonic rejection, without an RF filter. The downconverter uses a two-stage approach; the first stage is an analog multipath/ multi-phase harmonic rejection mixer followed by a second stage providing additional harmonic rejection based on blind adaptive interference canceling in the discrete-time domain. The aim is to show its functional operation and to find practical performance limitations. Measurement results show that the harmonic rejection of the downconverter is insensitive to frontend nonlinearities and LO phase noise. The canceler cannot cope with DC offsets. The DC offsets are removed by highpass filters. The signal paths used to obtain an estimate of the interference must\ud be designed to provide as much attenuation of the desired signal as possible
    corecore