Pulse Modulation

We demonstrate the potential for 1.85 Mbit/s secure key rates over 101 km of fiber, >100 times faster than previously demonstrated, using the differential phase shift quantum key distribution protocol and superconducting nanowire single-photon detectors.

An alternative code-division multiple-access (CDMA) scheme to spread spectrum (SS), called spread time (ST) is proposed for badlimited multiple-access channels. ST-CDMA can be considered the be-frequency dual of SS-CDMA. In ST-GDMA pslendsraodan (PN) sequences are assigned to each user, and the Fourier tcrursf@rm of the transmitted pulse for a given user is d&mined by modulating the phase of the desired transmitted spectnnn by the user's PN-skquence. The t"Btasd data for a parthdnr mer can be recoverad by sampling t8c output of a Plter matchd tcE tbe w " s pulse. ImplemenEwtloqs rare dascrilred in which wrface acoustic wave devices are used to perform the matched fislteL.ing or Fourier transformation. Averaged signal-to-intdremoe plus noise ratio (SIR) and spectral afldeacy are campuW fbr bo& asynchronous ST a d dCrect-seqnwe SS-CDMA systuns, assuming an arbitrary c h n d t r M e r fbnetion H(f), whicb is the same between all ppirS sf users. Tlhe resnlts are tlnt same for SS and ST providsd W t the magmnipude of the Fourier transform of the chip h p e in the SS system is the 88me 86 the nragnitwde of the Fader transform OP t4e ST pulse shape. The main advantag@ af tbe ST teehnlqus is the fled whick the transmitted spectrum can be sdwtwl. We dcrjlve the transmitted spectrum tbat maximizes the SIR subject to an average power constraint. ' Throughout this paper "transmitted spectrum" refers to the squared magnitude of the Fourier transform of the transmitted pulse.

40Gb/s coherent communication link's components are reviewed, including the electronic elements and supporting algorithms' stack. The migration to a 100Gb/s link is discussed in terms of respective component specification and different coherent communication formats.

All-optical gate control signal generation is demonstrated from flag pulses, using a Fabry-Pérot filter followed by a semiconductor optical amplifier. Ten control pulses are generated from a single flag pulse having less than 0.45-dB amplitude modulation. By doubling or tripling the number of flag pulses, the number of control pulses increases approximately by a factor of two or three. The circuit can control the switching state of all-optical switches, on a packet-by-packet basis, and can be used for nontrivial network functionalities such us self-routing.

1 Abstract— In this paper we propose a Petri net within a diagnosis system for construction design. We assimilate the construction process with an assembly process that composes parts and/or subassemblies into a unique product. We assume that the assembly supervisor (AS) system is distributed, and it solves several local AS attached to the nodes of the Petri net model of the assembly process. The research issues that we address in this work include the modeling of assembly process, determination of cost-effective assembly planes for efficient building, and real time adoption of a plan to a given product to be assembled. This work extends the known assembly Petri nets to a powerful framework enabling to derive the diagnosis of assembly process whose path may vary, and the objective function is maximized. The presented approach can be used to evaluate transient and steady-state performances of alternative design based on a construction example. Possible extensions of the work are also...

We implemented a photon-counting optical receiver using a periodically-poled lithium niobate waveguide and an emulated array of silicon Geiger-mode avalanche photodiodes. We achieved a sensitivity of < 0.5 detected photons/bit at 187.5 Mb/s.

We propose a circuit for generation of modified Hermite polynomial functions for use in impulse radio communications. Simultaneous generation of pulses of differing order is developed, reducing circuit complexity. Pulses are produced by applying modifications to Hermite polynomials. Pulses have the properties of orthogonality and not changing their pulse width and pulse bandwidth significantly dependent on pulse order, or under the differentiation effect of the transmitter or receiver antenna. The usefulness of these pulses applied to a multi-user system by orthogonal pulse modulation is shown by comparison with conventional pulse position modulation by computer simulation.

This paper presents a parallelogram based duty cycle computation method for space vector modulation control using standard pulse width modulation circuitry. This technique maps the voltage source inverter's solution space into only three parallelogram shaped zones and reduces the computational load. The proposed modulation methods are especially suited for a description of the voltage space vector in its α, β components and for modern and high dynamic applications, where demand changes may happen at a frequency comparable with the modulator carrier frequency. Several modulation methods used in scalar applications and extensively studied in the literature are easily obtained by combining the use of the modulation methods proposed in this work. The proposed methods have been validated by simulations and experimental test.

of short (few ns) pulse cell electroperturbation require high-voltage nanosecond pulses delivered to low-impedance (10 Ω) electroporation cuvette loads. Here we present two pulse generators for these applications. The generators comprise of three stages of pulse modulation: an LC resonant stage switched by IGBT/MOSFET; a magnetic pulse compression stage; and a diode opening switch output stage. The all-solid-state design results in reproducible pulses and reliable, long-life operation. Pulses produced by the LC resonant stage are compressed using nonlinear properties of the magnetic material. The compressed pulses are fed to the diode opening switch, which is constructed by series and parallel connecting ordinary automotive rectifying diodes. Two versions of the pulse generator are described: The first version is capable of generating 20 ns wide, 4.5 kV amplitude pulses of 20 Hz repetition rate. A second version generates 5 ns, 7.5 kV amplitude pulses into the same 10 Ω cuvette load.

In satellites, nonlinear amplifiers used near saturation severely distort the transmitted signal and cause difficulties in its reception. Nevertheless, the nonlinearities introduced by memoryless bandpass amplifiers preserve the symmetries of the M-ary quadrature amplitude modulation (M-QAM) constellation. In this paper, a cluster-based sequence equalizer (CBSE) that takes advantage of these symmetries is presented. The proposed equalizer exhibits enhanced performance compared to other techniques, including the conventional linear transversal equalizer, Volterra equalizers, and RBF network equalizers. Moreover, this gain in performance is obtained at a substantially lower computational cost.

We consider the effect of symbol rate on the constrained capacity of linear modulation with a fixed spectral density. We show that constrained capacity grows with the symbol rate for some modulation pulses but shrinks with others. Sufficient conditions on the pulse are derived for the constrained capacity to be monotonically increasing with faster symbol rate. Most standard pulses fulfill these.

A new construction of spherepackings using codes is given, which covers the construction of Leech and Sloane . The dense packings of Sloane [10] are also obtained here, but without the use of complex numbers. Several new records on the packing desity in high dimensions are given. In the second part of this paper three new alternatives of a construction, which leads to the Leech lattice . 24 i ~n lR , are g ven.

Absfrucr-A constrained transform coding procedure is developed which is a combination of transform coding with differential pulse code modulation. The algorithm avoids block boundary mismatch errors, yet retains the coding efficiency of transform coding. A general theory of constrained transform coding is developed which includes the discrete cosine transformation and tensor products of splines as special cases. Results using the cosines and splines are given for two images. A complete discussion of the necessary linear algebra background is also given.

Представлена математична модель індукційно-динамічного приводу форсунки двигуна внутрішнього згоряння. Отримані основні характеристики приводу форсунки при збудженні індуктора однопівперіодним імпульсом зі збереженням частини енергії в ємнісному накопичувачі. Встановлено вплив інтенсивності охолодження та частоти слідування імпульсів на температурні показники приводу. Представлена математическая модель индукционно-динамического привода форсунки двигателя внутреннего сгорания. Получены основные характеристики привода форсунки при возбуждении индуктора однополупериодным импульсом с сохранением части энергии в емкостном накопителе. Установлено влияние интенсивности охлаждения и частоты следования импульсов на температурные показатели привода.

Визначено характер розподілення індукції магнітного поля у лінійних імпульсних електромеханічних перетворювачах (ЛІЕП) індукційного та електромагнітного типів при використанні для феромагнітного якоря та екрану реальної сталі, магнітодиелектрика та ідеальної сталі, що мають нульову електропровідність. Встановлено вплив видів феромагнітних матеріалів на їх електромеханічні характеристики. Запропоновані інтегральний показник ефективності, який враховує ККД, швидкісні, силові та електричні показники ЛІЕП, та варіанти стратегії оцінки ефективності. Показано, що за усіма варіантами стратегії найменш ефективним є ЛІЕП електромагнітного типу, якір та феромагнітний екран (ФЕ) якого виконані з магнітодіелектрика. Встановлено, що ФЕ ЛІЕП індукційного типу доцільно виготовляти з реальної сталі, а ФЕ та якір ЛІЕП електромагнітного типу доцільно виготовляти з ідеальної сталі, що має мінімальну електропровідність. Ключові слова: лінійний імпульсний електромеханічний перетворювач, перетворювач індукційного типу, перетворювач електромагнітного типу, феромагнетик, реальна сталь, магнітодиелектрик, ідеальна сталь. Установлен характер распределения индукции магнитного поля в линейных импульсных электромеханических преобразователях (ЛИЭП) индукционного и электромагнитного типов при использовании для ферромагнитного якоря и экрана реальной стали, магнитодиэлектрика и идеальной стали, которые имеют нулевую электропроводность. Установлено влияние видов ферромагнитных материалов на их электромеханические характеристики. Предложены интегральный показатель эффективности, учитывающий КПД, скоростные, силовые и электрические показатели ЛИЭП, и варианты стратегии оценки эффективности. Показано, что по всем вариантам стратегии наименее эффективным является ЛИЭП электромагнитного типа, якорь и ферромагнитный экран (ФЭ) которого выполнены из магнитодиэлектрика. Установлено, что ФЭ ЛИЭП индукционного типа целесообразно изготавливать из реальной стали, а ФЭ и якорь ЛИЭП электромагнитного типа целесообразно изготавливать из идеальной стали, которая имеет минимальную электропроводимость. Ключевые слова: линейный импульсный электромеханический преобразователь, преобразователь индукционного типа, преобразователь электромагнитного типа, ферромагнетик, реальная сталь, магнитодиэлектрик, идеальная сталь. Purpose. The aim of the article is to estimate the influence of the type of ferromagnet -magnetodielectric, ideal and real steel, on the power, speed and electrical parameters of the linear pulsed electromechanical converter (LPEC) of induction and electromagnetic types. Methodology. The mathematical model of LSET using the finite element method, which takes into account spatio-temporal electromagnetic and electromechanical parameters and indices, is developed and implemented in the Comsol Multiphysics software package. The integral efficiency index has been introduced, taking into account the power, speed, energy, and environmental (induction of the magnetic scattering field) indicators. Results. A mathematical model of the LPEC has been developed, which describes fast and interconnected electromagnetic and electromechanical processes, manifested when the armature moves relative to the inductor. The character of the magnetic field induction distribution in LPEC of induction and electromagnetic types is established when using for a ferromagnetic anchor and a screen of real steel, a magnetodielectric and an ideal steel that have zero electrical conductivity. For these LPEC versions, the influence of the types of ferromagnetic materials on their electromechanical characteristics has been established. An integral efficiency index is proposed that takes into account the efficiency, speed, power and electrical parameters of the LPEC, and variants of the efficiency evaluation strategy. It is shown that for all strategy options the least effective is the LPEC of electromagnetic type, the armature and screen of which are made of a magnetodielectric. It is established that the induction-type LPEC screen should be made of real steel, and the screen and the electromagnetic-type LPEC anchor should be made of an ideal steel that has a minimum electrical conductivity. Originality. It was established for the first time that the least effective is a LPEC of electromagnetic type, the armature and screen of which are made of a magnetodielectric. Ferromagnetic screen LPEC induction type is expedient to make of real steel, and the shield and the anchor of LPEC electromagnetic type is expediently made of an ideal steel that has a minimum electrical conductivity. Practical value. The character of the magnetic field induction distribution in LPEC of induction and electromagnetic types is established when using for a ferromagnetic anchor and a screen of real steel, a magnetodielectric and an ideal steel that have zero electrical conductivity. For these LPEC versions, the influence of the types of ferromagnetic materials on their electromechanical characteristics has been established. An integral efficiency index is proposed that takes into account the efficiency, speed, power and electrical parameters of the LPEC, and variants of the efficiency evaluation strategy.

го індукційно-динамічного прискорювача. В масивний об'єкт, що розганяється, введено мідне кільце, яке встановлене на його зовнішній поверхні. Розроблена математична модель та розрахунковий алгоритм, які враховують швидкоплинні електричні, магнітні, механічні та теплові процеси. Визначено вплив параметрів ємнісного накопичувача, початкової швидкості та зміщення якоря відносно індуктора на ефективність електромеханічного перетворення енергії в індукційно-динамічному прискорювачі.

This paper studies the analog implementation of timing synchronization in impulse radio UWB systems. An insight into various UWB modulation schemes is provided, and an overview of the state-of-the art synchronization techniques is discussed. A novel method is presented for high-speed timing synchronization of UWB receivers in analog domain. The required timing resolution is determined and system-level simulations validating the technique, are demonstrated.

This paper proposes a three-phase multilevel converter topology based on the multiplexed concept which is especially intended for medium-voltage power drives applications. The main potential application are fourquadrant 4.16 kV and 6.6 kV power drives. The proposed topology allows pushing efficiency, switching frequency and cost to values that could not be obtained with HV semiconductors which are expensive and have poor switching performances. This paper will describe the topology, its modulation and control strategy, its main waveforms, the overall efficiency and a comparison with a 5LANPC inverter.