1,536 research outputs found

    Design and Implementation of an RF Front-End for Software Defined Radios

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    Software Defined Radios have brought a major reformation in the design standards for radios, in which a large portion of the functionality is implemented through pro­ grammable signal processing devices, giving the radio the ability to change its op­ erating parameters to accommodate new features and capabilities. A software radio approach reduces the content of radio frequency and other analog components of the traditional radios and emphasizes digital signal processing to enhance overall receiver flexibility. Field Programmable Gate Arrays (FPGA) are a suitable technology for the hardware platform as they offer the potential of hardware-like performance coupled with software-like programmability. Software defined radio is a very broad field, encompassing the design of various technologies all the way from the antenna to RF, IF, and baseband digital design. The RF section primarily consists of analog hardware modules. The IF and baseband sections are primarily digital. It is the general process of the radio to convert the incoming signal from RF to IF and then IF to baseband for better signal processing system. In this thesis, some of major building blocks of a Software defined radio are de­ signed and implemented using FPGAs. The design of a Digital front end, which provides the bridge between the baseband and analog RF portions of a wireless receiver, is synthesized. The Digital front end receiver consists of a digital down converter(DDC) which in turn comprises of a direct digital frequency synthesizer (DDFS), a phase accumulator and a low pass filter. The signal processing block of the DDFS is executed using Co-ordinate Rotation Digital Computer (CORDIC) iii Abstract algorithm. Cascaded-Integrator-Comb filters (CIC) are implemented for changing the sample rate of the incoming data. Application of a DDC includes software ra­ dios, multicarrier, multimode digital receivers, micro and pico cell systems,broadband data applications, instrumentation and test equipment and in-building wireless tele­ phony. Also, in this thesis, interfaces for connecting Texas Instruments high speed and high resolution Analog-to-Digital converters (ADC) and Digital-to-Analog converters (DAC) with Xilinx Virtex-5 FPGAs are also implemented and demonstrated

    Novel Front-end Electronics for Time Projection Chamber Detectors

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    Este trabajo ha sido realizado en la Organización Europea para la Investigación Nuclear (CERN) y forma parte del proyecto de investigación Europeo para futuros aceleradores lineales (EUDET). En física de partículas existen diferentes categorías de detectores de partículas. El diseño presentado esta centrado en un tipo particular de detector de trayectoria de partículas denominado TPC (Time Projection Chamber) que proporciona una imagen en tres dimensiones de las partículas eléctricamente cargadas que atraviesan su volumen gaseoso. La tesis incluye un estudio de los objetivos para futuros detectores, resumiendo los parámetros que un sistema de adquisición de datos debe cumplir en esos casos. Además, estos requisitos son comparados con los actuales sistemas de lectura utilizados en diferentes detectores TPC. Se concluye que ninguno de los sistemas cumple las restrictivas condiciones. Algunos de los principales objetivos para futuros detectores TPC son un altísimo nivel de integración, incremento del número de canales, electrónica más rápida y muy baja potencia. El principal inconveniente del estado del arte de los sistemas anteriores es la utilización de varios circuitos integrados en la cadena de adquisición. Este hecho hace imposible alcanzar el altísimo nivel de integración requerido para futuros detectores. Además, un aumento del número de canales y frecuencia de muestreo haría incrementar hasta valores no permitidos la potencia utilizada. Y en consecuencia, incrementar la refrigeración necesaria (en caso de ser posible). Una de las novedades presentadas es la integración de toda la cadena de adquisición (filtros analógicos de entrada, conversor analógico-digital (ADC) y procesado de señal digital) en un único circuito integrado en tecnología de 130nm. Este chip es el primero que realiza esta altísima integración para detectores TPC. Por otro lado, se presenta un análisis detallado de los filtros de procesado de señal. Los objetivos más importantes es la reduccióGarcía García, EJ. (2012). Novel Front-end Electronics for Time Projection Chamber Detectors [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16980Palanci

    Measurement and control of a superconducting quantum processor with a fully integrated radio-frequency system on a chip

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    We describe a digital microwave platform called Presto, designed for measurement and control of multiple quantum bits (qubits) and based on the third-generation radio-frequency system on a chip. Presto uses direct digital synthesis to create signals up to 9\ua0GHz on 16 synchronous output ports, while synchronously analyzing responses on 16 input ports. Presto has 16 DC-bias outputs, four inputs and four outputs for digital triggers or markers, and two continuous-wave outputs for synthesizing frequencies up to 15\ua0GHz. Scaling to a large number of qubits is enabled through deterministic synchronization of multiple Presto units. A Python application programming interface configures a firmware for synthesis and analysis of pulses, coordinated by an event sequencer. The analysis integrates template matching (matched filtering) and low-latency (184-254\ua0ns) feedback to enable a wide range of multi-qubit experiments. We demonstrate Presto\u27s capabilities with experiments on a sample consisting of two superconducting qubits connected via a flux-tunable coupler. We show single-shot readout and active reset of a single qubit; randomized benchmarking of single-qubit gates showing 99.972% fidelity, limited by the coherence time of the qubit; and calibration of a two-qubit iSWAP gate

    A Hardware-in-the-Loop Platform for DC Protection

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    With the proliferation of power electronics, dc-based power distribution systems can be realized; however, dc electrical protection remains a significant barrier to mass implementation dc power distribution. Controller Hardware-in-the-loop (CHiL) simulation enables moving up technology readiness levels (TRL) quickly. This work presents an end-to-end solution for dc protection CHiL for early design exploration and verification for dc protection, allowing for the rapid development of dc protection schemes for both Line-to-Line (LL) and Line-to-Ground (LG) faults. The approach combines using Latency Based Linear Multistep Compound (LB-LMC), a real-time simulation method for power electronic, and National Instruments (NI) FPGA hardware to enable dc protection design with CHiL. A case study is performed for a 1.5 MW Voltage Source Rectifier (VSR) under LL and LG faults in an ungrounded system. The deficiency in real-time simulation resolution of Commercial-off-the-Shelf (COTS) for dc fault transients is shown, and addressed by using LB-LMC RT solver inside NI FPGA hardware to achieve 50 ns resolution of dc fault transients

    Signal Processing for an Autonomous Underwater Vehicle: an FPGA approach

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    The idea of this thesis comes out from the participation of the University of Central Florida to the Annual International Autonomous Underwater Vehicle Competition of 2007. The objective of this competition is to make the AUV to accomplish to a specific route. A part of this route expects the AUV to detect a ping and following it as a source. The objective of this thesis is to improve the performance of this trajectory tracking. A Field Programmable Logic Array will be used to perform an effective Digital Signal Processing

    Techniques for low-cost spectrum analysis on quadrature demodulation architectures

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    The Decimator, an SED Systems Ltd. product, is a PCI slot card that performs both time and frequency domain measurements of given input signals. It is essentially a more economical version of a bench spectrum analyzer or oscilloscope, with a PC interface. Several issues limit the speed and accuracy of the results of the Decimator, and the study of these issues is the focus of this thesis. These issues, including but not limited to, are as follows: 1) Imbalances between the received In-phase and Quadrature-phase channels; 2) The FFT and Windowing functions are performed by a microcontroller, but it is desired that they be migrated to an FPGA. While solutions to improve the first issue is being implemented and verified, the second issue is not one of simply reducing a source of error. The second issue requires a cost-benefit analysis on the migration of these signal processing algorithms from an ARM microcontroller to a Xilinx FPGA

    Technical aspects of a demonstration tape for three-dimensional sound displays

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    This document was developed to accompany an audio cassette that demonstrates work in three-dimensional auditory displays, developed at the Ames Research Center Aerospace Human Factors Division. It provides a text version of the audio material, and covers the theoretical and technical issues of spatial auditory displays in greater depth than on the cassette. The technical procedures used in the production of the audio demonstration are documented, including the methods for simulating rotorcraft radio communication, synthesizing auditory icons, and using the Convolvotron, a real-time spatialization device
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