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A new method for digital encoder adaptive velocity/acceleration evaluation using a TDC with picosecond accuracy

MICROPROCESSORS AND MICROSYSTEMS 2009年第7-8期33卷 453-460页

作者： Lygouras, J. N. Kodogiannis, V. Pachidis, T. P. Sirakoulis, G. Ch. Democritus Univ Thrace Dept Elect & Comp Engn Elect Lab GR-67100 Xanthi Greece Univ Westminster Sch Elect & Comp Sci Computat Intelligence Grp London HA1 3TP England

In this paper, a new methodology for deriving the velocity and the acceleration information of a digital encoder through processing its pulse train, is presented. The proposed method is based on accurate time measurement (with picosecond accuracy) as well as encoder pulse counting in adaptively changing time intervals, providing thus a wide-range velocity evaluation with very good accuracy. The method offers better response times at low speeds and very high-accuracy at the full range of measured velocities. By using the proposed method, the velocity measurement accuracy is improved compared to currently known methods, since high-resolution time-to-digital converters (TDC) are included in the design. The increased accuracy in velocity measurement allows the application of the simple arithmetic differentiation method on the velocity information in order to derive the acceleration, which in other cases would not be suggested due to accumulated quantization noise. A digital signal processor (DSP) also allows the implementation of numerous other methods to calculate acceleration. The proposed configuration has been implemented in specific hardware (FPGA), reserving thus the computational power of the system controlling DSP for high-level control tasks. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Field programmable gate array (FPGA) digital encoder Adaptive sampling interval Velocity/acceleration evaluation Time-to-digital converter (TDC)

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Simultaneous demonstration on all-optical digital encoder and comparator at 40 Gb/s with semiconductor optical amplifiers

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OPTICS EXPRESS 2007年第23期15卷 15080-15085页

作者： Wang, Yang Zhang, Xinliang Dong, Jianji Huang, Dexiu Huazhong Univ Sci & Technol Sch Optelect Sci & Engn Wuhan Natl Lab Optelect Wuhan 430074 Peoples R China

We proposed and experimental demonstrated all-optical two line-four line encoder and two bit-wise comparator of RZ data streams at 40Gb/s based on cross gain modulation (XGM) and four wave mixing (FWM) in three parallel SOAs. Five logic functions for digital encoder and comparator between two signals A and B: (A) over bar.(B) over bar, (A) over barB, A (B) over bar, AB and A circle dot B, were achieved simultaneously. The first three optical logics are realized based on XGM in SOAs, the fourth is realized with FWM, and the fifth is the mixing result of the first and the fourth. A detuning filter is employed to improve the output performance. The output extinction ratio ( ER) for the XGM operation is above 10dB, and the ER for FWM operation is around 8 dB. Wide and clear eye patterns for the five logic outputs can be observed. (c) 2007 Optical Society of America

关键词： .amplifiers All-optical FWM comparator wavelength conversion semiconductor optical SOAs output performance logic functions digital encoder based on XGM logic outputs

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Two VLSI CMOS ICs for digital X-ray 2-D imaging system: Low noise front-end amplifier and 80 MHz digital encoder interface

Two VLSI CMOS ICs for digital X-ray 2-D imaging system: Low ...

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1996 IEEE-CAS Region-8 Workshop on Analog and Mixed IC Design

作者： Marchesini, R Beccherle, R Bisogni, MG Cisternino, A DelGuerra, A Folli, M Kipnis, I Rosso, V Tripiccione, R Universita di Ferrara Ferrara Italy

ISBN: (纸本)0780336259

We describe a VLSI-based data acquisition to perform X-Y coincidences with a two side microstrip digital detector, optimized for applications in digital mammography. A two components chip set is described in detail: a low noise Front-End analog amplifier and an 80 MHz synchronous digital encoder. These two components can be used to solve the problems arising with the use of a large number of channels and low signal amplitude as in our application.

关键词： digital radiology front end amplifier digital imaging digital encoder

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A 1-Bit/Pel digital encoder for Achromatic Pictures

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IETE journal of research 1982年第4期28卷 132-136页

The paper describes a scheme for producing and digitizing a low-resolution (256 × 256 pels) achromatic picture signals. Using the technique of time expansion at the transmitter, it is possible to send a higher quality picture at a lower bit rate. A DM-encoded picture at 8 MHz is transmitted at 4 Mb/s in the channel achieving a band compression by four. Suitable interpolation at the receiver improves the quality of the picture.

关键词： digital encoder Band Compression Interpolation

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Low-noise front-end amplifier and channel encoder for a 2-D X-ray digital imaging system with single photon counting capability

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NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 2001年第1期460卷 213-220页

作者： Sartori, L Ramusino, AC Del Guerra, A Marchesini, R Tripiccione, R Univ Ferrara Dipartmento Fis I-44100 Ferrara Italy Ist Nazl Fis Nucl Sez Ferrara I-44100 Ferrara Italy Univ Pisa Dipartimento Fis I-56100 Pisa Italy Ist Nazl Fis Nucl Sez Pisa I-56100 Pisa Italy Univ Calif Berkeley Lawrence Berkeley Lab Berkeley CA 94720 USA

We describe two VLSI CMOS ICs for 2-D X-ray digital imaging systems with single photon counting capability: a low noise front-end analog amplifier and an 80 MHz synchronous digital encoder. Our VLSI system will be optimized to perform X-Y coincidences with double-sided microstrip digital detector. The main application we are investigating is stereotaxic mammography, because of low X-ray energy used and the small area involved. (C) 2001 Published by Elsevier Science B.V.

关键词： digital imaging front-end amplifier digital encoder

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Ultrafast all-optical 4-bit digital encoders using differential phase modulation in semiconductor optical amplifier-Mach-Zehnder interferometer configuration

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OPTICAL ENGINEERING 2013年第3期52卷 035202-035202页

作者： Mehra, Rekha Jaiswal, Shikha Dixit, Hemant Kumar Govt Engn Coll Dept Elect & Commun FOSI MIEEELMISTE Ajmer India CCS Univ Dept Phys SDPG Coll Meerut Uttar Pradesh India Univ Allahabad Dept Elect & Commun Allahabad 211002 Uttar Pradesh India

A novel approach for all-optical digital encoder for both binary-to-gray code and gray-to-binary code have been proposed. Design is based on the basic concept of digital encoder using the exclusive OR (XOR) addition. The XOR gate used in these encoders has been implemented using differential phase modulation between two arms of the Mach-Zehnder interferometer (MZI), in which a semiconductor optical amplifier is placed symmetrically in both arms of MZI. For the most severely degraded output bit, i.e., least significant bit for gray-to-binary encoder, the extinction ratio obtained is 2.35 while the minimum bit error rate is zero at 10 GB/s. For the second most significant bit of gray-to-binary encoder and for all the three bits except the most significant bit of binary-to-gray encoder, the extinction ratio obtained is around 27 dB. For the most significant bit, as input and output bits are same, the extinction ratio is very high, approaching infinity. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10.1117/***.52.3.035202]

关键词： semiconductor optical amplifier Mach-Zendher Interferometer gray code binary code digital encoder

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Adaptive high-performance velocity evaluation based on a high-resolution time-to-digital converter

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2008年第9期57卷 2035-2043页

作者： Lygouras, John N. Pachidis, Theodore P. Tarchanidis, Kostas N. Kodogiannis, Vassilis S. Democritus Univ Thrace Dept Elect & Comp Engn GR-67100 Xanthi Greece Kavala Inst Technol Dept Petr & Nat Gas Technol Kavala 65500 Greece Univ Westminster Harrow Sch Comp Sci London W1B 2UW England

In this paper, an improved method is presented to derive the velocity information in a pulse-number measurement/time-duration-type digital tachometer by processing its pulse train. The method incorporates encoder pulse counting and very accurate time measurement. The velocity sampling interval is not constant but is continuously modified. An adaptive algorithm provides a wide-range velocity evaluation with very good accuracy. The adaptation of the next sampling period, according to the instant velocity, results in better response times at low speeds and a very high accuracy at medium and high speeds. Compared to currently known methods, the time measurement resolution and, consequently, the velocity accuracy is improved by using the proposed method due to the inclusion of high-resolution time-to-digital converters in the design. The proposed configuration can be implemented in specific hardware by using field-programmable gate arrays (FPGAs), thus saving the computational power of the digital signal processor that supervises the system for higher level control tasks.

关键词： adaptive sampling interval digital encoder field-programmable gate arrays (FPGAs) time-to-digital converter (TDC) velocity evaluation

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A Hybrid Amplitude/Time Encoding Scheme for Enhancing Coding Efficiency and Dynamic Range in digitally Modulated Power Amplifiers

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IEEE JOURNAL ON EMERGING AND SELECTED TOPICS IN CIRCUITS AND SYSTEMS 2013年第4期3卷 498-507页

作者： Xia, Jingjing Garg, Siddharth Boumaiza, Slim Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

architecture for practical and highly efficient software-defined radio transmitters. Signal encoding schemes for DMPAs have primarily focused either on amplitude or time domain encoding, neither of which can simultaneously provide high coding efficiency, high dynamic range and low design complexity. In this paper, we propose, analyze and evaluate a new hybrid amplitude/ time signal encoding scheme that significantly improves the coding efficiency and dynamic range of DMPAs without significantly increasing design complexity. The proposed hybrid amplitude/time encoding scheme combines both the amplitude domain and the time domain to optimally encode information. Evaluation results show that hybrid amplitude/time encoding yields a 35% increase in the average coding efficiency with respect to conventional time encoding, and is only 6.7% lower than peak efficiency when applied to a Wireless Local Area Network signal with a peak to average power ratio equal to 9.9 dB. A new DMPA architecture, based on the proposed hybrid encoding, is also proposed.

关键词： digital encoder digitally modulated power amplifier pulse-width modulation software-defined ratio

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digital excess loop delay compensation technique with embedded truncator for continuous-time delta-sigma modulators

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ELECTRONICS LETTERS 2016年第1期52卷 20-21页

作者： He, Tao Zhang, Yi Temes, Gabor C. Oregon State Univ Sch EECS Corvallis OR 97331 USA

A novel implementation is proposed to relax the specifications of the internal feedback path for a continuous-time delta-sigma modulator. A truncator is embedded into the digital excess loop delay (ELD) compensation path. Thermometer-coded truncation is achieved by reordering the reference voltages of the internal quantiser. This requires only a small amount of extra digital circuitry compared to the conventional digital ELD compensation. The digital encoder controlling the digital-to-analogue converter is simple, and it only introduces a small ELD.

关键词： delta-sigma modulation digital circuits reference circuits thermometers continuous-time delta-sigma modulators digital encoder digital excess loop delay compensation digital-to-analogue converter embedded truncator extra digital circuitry internal feedback path internal quantiser reference voltages thermometer-coded truncation

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System for Generation and Analysis of Line Codes 28

System for Generation and Analysis of Line Codes

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28th International Symposium for Design and Technology in Electronic Packaging (SIITME)

作者： Visan, Daniel Alexandru Lita, Adrian Ioan Univ Pitesti Elect Comp & Elect Engn Dept Pitesti Romania Axiplus Engn SRL Bucharest Romania

ISBN: (纸本)9781665461016

This paper presents a microcontroller based digital encoder capable to generate baseband signals using different types of line codes. The baseband coding is an essential processing found in a very wide range of industrial data transmission systems, wireless and optical communications and also in computer networks. The proposed system has the capability to operate with an extended range of unipolar, bipolar and multilevel codes. In addition to data transmission, the presented design can also be used in analysis and experimental study of nonstandard encoding schemes as well as for didactical purposes. The hardware structure of the system is based mainly on PIC18F4580 microcontroller. Codes requiring bipolar and multilevel operation are implemented using dedicated converters connected to the output ports of the microcontroller. The data source for the encoding system can be internal or external, being selectable by the user. The relevant parameters regarding the system operation are continuously presented on a local LCD. Compared to other similar structures, the system provides a compact and reliable implementation, based on a high-performance microcontroller, and offers an extended versatility in the selection of the coding schemes.

关键词： digital encoder line codes microcontroller

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