Relevant bibliographies by topics / Modulation discrète

Academic literature on the topic 'Modulation discrète'

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Published: 25 May 2024

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Journal articles on the topic "Modulation discrète"

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Nofal, Abdul-Nasser, Abdel-Nasser Assimi, and Yasser M. Jaamour. "Joint Power Allocation and Bit-Loading for Multicarrier Systems with Discrete Modulation." Mathematical Modelling of Engineering Problems 8, no. 4 (August 31, 2021): 626–34. http://dx.doi.org/10.18280/mmep.080416.

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In this paper, we propose two algorithms for joint power allocation and bit-loading in multicarrier systems using discrete modulations. The objective is to maximize the data rate under the constraint of a suitable Bit Error Rate per subcarrier. The first algorithm is based on the Lagrangian Relaxation of the discrete optimization problem in order to find an initial solution. A discrete solution is found by bit truncation followed by an iterative modulation adjustment. The second algorithm is based on Discrete Coordinate Ascent framework with iterative modulation increment of one selected subcarrier at each iteration. A simple cost function related to the power increment per bit is used for subcarrier selection. A sub-optimal low complexity Discrete Coordinate Ascent algorithm is proposed that overcome the limitations of the Hughes-Hartogs algorithm. The Lagrangian Relaxation algorithm provides a suboptimal solution for non-coded system using M-QAM modulations, whereas the low complexity Discrete Coordinate Ascent algorithm provides a near optimal solution for coded as well as for non-coded system using an arbitrary modulation set. Numerical results show the efficiency of the proposed algorithms in comparison with traditional methods.
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JAMES, GUILLAUME. "NONLINEAR WAVES IN NEWTON'S CRADLE AND THE DISCRETE p-SCHRÖDINGER EQUATION." Mathematical Models and Methods in Applied Sciences 21, no. 11 (November 2011): 2335–77. http://dx.doi.org/10.1142/s0218202511005763.

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We study nonlinear waves in Newton's cradle, a classical mechanical system consisting of a chain of beads attached to linear pendula and interacting nonlinearly via Hertz's contact forces. We formally derive a spatially discrete modulation equation, for small amplitude nonlinear waves consisting of slow modulations of time-periodic linear oscillations. The fully nonlinear and unilateral interactions between beads yield a nonstandard modulation equation that we call the discrete p-Schrödinger (DpS) equation. It consists of a spatial discretization of a generalized Schrödinger equation with p-Laplacian, with fractional p > 2 depending on the exponent of Hertz's contact force. We show that the DpS equation admits explicit periodic traveling wave solutions, and numerically find a plethora of standing wave solutions given by the orbits of a discrete map, in particular spatially localized breather solutions. Using a modified Lyapunov–Schmidt technique, we prove the existence of exact periodic traveling waves in the chain of beads, close to the small amplitude modulated waves given by the DpS equation. Using numerical simulations, we show that the DpS equation captures several other important features of the dynamics in the weakly nonlinear regime, namely modulational instabilities, the existence of static and traveling breathers, and repulsive or attractive interactions of these localized structures.
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Zhang, Hao Chi, Tie Jun Cui, Yu Luo, Jingjing Zhang, Jie Xu, Pei Hang He, and Le Peng Zhang. "Active digital spoof plasmonics." National Science Review 7, no. 2 (October 4, 2019): 261–69. http://dx.doi.org/10.1093/nsr/nwz148.

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Abstract Digital coding and digital modulation are the foundation of modern information science. The combination of digital technology with metamaterials provides a powerful scheme for spatial and temporal controls of electromagnetic waves. Such a technique, however, has thus far been limited to the control of free-space light. Its application to plasmonics to shape subwavelength fields still remains elusive. Here, we report the design and experimental realization of a tunable conformal plasmonic metasurface, which is capable of digitally coding and modulating designer surface plasmons at the deep-subwavelength scale. Based on dynamical switching between two discrete dispersion states in a controlled manner, we achieve digital modulations of both amplitude and phase of surface waves with nearly 100% modulation depth on a single device. Our study not only introduces a new approach for active dispersion engineering, but also constitutes an important step towards the realization of subwavelength integrated plasmonic circuits.
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Ali, Weaam Talaat. "Performance of Discrete Wavelet Transform Based on OFDM with Adaptive Modulation." International Journal of Engineering Research 4, no. 8 (August 1, 2015): 419–25. http://dx.doi.org/10.17950/ijer/v4s8/804.

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Zheleznjak, V. K., S. V. Lavrov, M. M. Baranouski, and A. G. Filipovich. "Mathematical model of speech signal leakage channels during discrete-quantified conversion." Doklady BGUIR 18, no. 4 (June 25, 2020): 89–95. http://dx.doi.org/10.35596/1729-7648-2020-18-4-89-95.

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The purpose of the article is to estimate the leakage channel of a discrete-quantized speech signal with amplitude-pulse modulation. Discrete-quantized analog-to-digital conversion of signals in the article is considered by the example of pulse-amplitude modulation. Development of mathematical model of speech signal leakage channels during discrete-quantified conversion is based on the spectral representation of periodic signals by Fourier series. A periodic pulse train of triangular shape as a measuring signal is proposed. Measuring signal of triangular shape has an advantage over a harmonic signal in the process of quantization noise extraction because it allows one to achieve higher accuracy during signal processing. To evaluate the channel security caused by amplitude-pulse modulation, a harmonic signal is used, which is generated from a periodic pulse sequence of a triangular shape by the Fourier transform method. As a result of constructing the spectrum of the amplitude-pulse modulated signal, it was found that for each harmonic component of the spectrum corresponding to the spectrum of the periodic sequence of pulses, side components corresponding to the spectrum of the modulating signal appear. This side components, together with the low-frequency component in the band of the speech signal, form an information leakage channel. The presence of source modulating signal in the amplitude-pulse modulated signal spectrum allows one to digest the security of the leakage channel of the speech signal with amplitude-pulse modulation by the low-frequency component of the modulating signal. The materials presented in the article are original and can be used in assessing the security of leakage channels of speech signals converted into digital form. In addition, the results obtained allow further studies of the security of speech signals during their inverse transformation from digital to the original signal.
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Zhou, Shiyi, Zhijun Zhang, Chuliang Zhou, Zhongpeng Li, Ye Tian, and Jiansheng Liu. "A high-energy electron density modulator driven by an intense laser standing wave." Laser and Particle Beams 37, no. 2 (April 30, 2019): 197–202. http://dx.doi.org/10.1017/s0263034619000338.

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AbstractA high energy electron density modulator from a high-intensity laser standing wave field is studied herein by investigating the ultrafast motion of electrons in the field. Electrons converge at the electric field antinodes, and the discrete electron density peaks modulated by the field located at the corresponding laser phases of kx = nπ, (n = 0, 1, 2, …), that is, the modulation period is 1/2 the wavelength of the individual laser. We also discussed the influence of the laser parameters such as laser intensity and waist size on the beam modulator. It is shown that a long interaction length (waist) or sufficiently high field intensity is essential for relativistic electron density modulation.
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Xuhong Chu, Xuhong Chu, Liquan Dong Liquan Dong, Yuejin Zhao Yuejin Zhao, Xiaomei Yu Xiaomei Yu, and and Yun Feng and Yun Feng. "Optical readout method based on time-discrete modulation for micro-cantilever array sensing." Chinese Optics Letters 14, no. 10 (2016): 101102–6. http://dx.doi.org/10.3788/col201614.101102.

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Воловач, В. И. "Mathematical modeling of the correlation function and the energy spectra of the noise modulation function." Informacionno-technologicheskij vestnik, no. 1(27) (March 15, 2021): 77–92. http://dx.doi.org/10.21499/2409-1650-2021-27-1-77-92.

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Рассмотрены и проанализированы вопросы, связанные с математическим моделированием корреляционных функций и энергетических спектров функции помеховой модуляции. Показано, что при воздействии на сигнал узкополосной мультипликативной помехи в энергетическом спектре функции помеховой модуляции присутствует дискретная составляющая, мощность которой зависит от глубины фазовых искажений. При импульсно-флуктуационной модулирующей помехе с детерминированным тактовым интервалом энергетический спектр функции помеховой модуляции представляет собой сумму непрерывной и дискретной частей. The issues related to mathematical modeling of correlation functions and energy spectra of the noise modulation function are considered and analyzed. It is shown that when a signal is affected by a narrow-band multiplicative interference, a discrete component is present in the energy spectrum of the interference modulation function, the power of which depends on the depth of the phase distortion. In the case of pulse-fluctuating modulating interference with a deterministic clock interval, the energy spectrum of the interference modulation function is the sum of the continuous and discrete parts.
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Seetha, S., D. P. Sharma, V. N. Padmini, T. M. K. Marar, K. Kasturirangan, U. R. Rao, and J. C. Bhattacharyya. "Periodic Modulations in the Optical Light Curves of EX Hydrae." International Astronomical Union Colloquium 93 (1987): 193–96. http://dx.doi.org/10.1017/s0252921100104853.

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AbstractWe present here new results on the periodic modulations in the optical light curves of EX Hydrae observed during 1982–84. The period analysis has been done using synchronous summation and discrete Fourier transform methods. We report new periodicities at 34.7 min and 26.7 min apart from confirming the detection of 46.3 min modulation recently reported. We also include our data to derive the rate of decrease of the 67 min period.
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Zeng, Zhiyong, Xiaoliang Jin, and Rongxiang Zhao. "Small-signal discrete-time modeling of digitally controlled three-phase PWM boost rectifier under balanced voltage." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 36, no. 1 (January 3, 2017): 18–47. http://dx.doi.org/10.1108/compel-03-2016-0113.

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Purpose The model for digitally controlled three-phase pulse width modulation (PWM) boost rectifiers is a sampled data model, which is different from the continuous time domain models presented in previous studies. The controller, which is tuned according to the model in continuous time domain and discretized by approximation methods, may exhibit some unpredictable performances and even result in unstable systems under some extreme situations. Consequently, a small-signal discrete-time model of digitally controlled three-phase PWM boost rectifier is required. The purpose of this paper is to provide a simple but accurate small-signal discrete-time model of digital controlled three-phase PWM boost rectifier, which explains the effect of the sampling period, modulator and time delays on system dynamic and improves the control performance. Design/methodology/approach Based on the Laplace domain analysis and the waveforms of up-down-count modulator, the small signal model of digital pulse width modulation (DPWM) in the Laplace domain is presented. With a combination of state-space average and a discrete-time modeling technique, a simplified large signal discrete time model is developed. With rotation transformation and feed-forward decoupling, the large-signal model is decoupled into a single input single output system with rotation transformation. Then, an integrated small signal model in the Laplace domain is constructed that included the time delay and modulation effect. Implementing the modified z-transform, a small-signal discrete-time model is derived from the integrated small signal model. Findings In a digital control system, besides the circuit parameters, the location of pole of open-loop transfer function is also related to system sampling time, affecting the system stability, and the time delay determines the location of the zero of open-loop transfer function, affecting the system dynamic. In addition to the circuit parameters discussed in previous literature, the right half plane (RHP) zero is also determined by the sampling period and the time delay. Furthermore, the corner frequency of the RHP zero is mainly determined by the sampling period. Originality/value The model developed in this paper, accounting for the effect of the sampling period, modulator and time delays on the system dynamic, give a sufficient insight into the behavior of the digitally controlled three-phase PWM rectifier. It can also explain the effect of sampling period and control delay time on system dynamic, accurately predict the system stability boundary and determine the oscillation frequency of the current loop in critical stable. The experimental results verify that the model is a simple and accurate control-oriented small-signal discrete-time model for the digitally controlled three-phase PWM boost rectifier.
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Dissertations / Theses on the topic "Modulation discrète"

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Tabaa, Mohamed. "Conception d'un système de transmission ultra-large bande par impulsions orthogonales." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0375/document.

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Dans cette thèse, nous proposons une méthodologie de conception d’architectures de communication dédiées aux réseaux de capteurs basées sur la technique de radio impulsionnelle pour les transmissions ultralarge bande (ULB). La technique impulsionnelle proposée ici repose sur la modulation de forme d’impulsion. L’approche de conception architecturale présentée dans cette thèse se focalise plus particulièrement sur la forme des impulsions et leur génération, qui revêt un intérêt majeur puisqu’elle constitue le support de l’information échangée. L’étude sur le choix de la forme d’impulsion nous a conduit à proposer deux architectures différentes. Une première architecture repose sur les polynômes orthogonaux, et plus particulièrement sur les polynômes d’Hermite, pour la génération des impulsions, et sur une architecture de corrélation pour la détection et la reconnaissance des trains d’impulsions transmis. La deuxième architecture est basée sur la transformée en paquets d’ondelettes discrète et peut être exploitée selon deux modes d’utilisation différents, mono et multiutilisateurs. L’utilisation d’une architecture de synthèse à l’émission et d’analyse à la réception ouvre une nouvelle orientation pour les communications numériques, permettant à la transformée en ondelettes d’assurer à la fois la génération des impulsions à l’émission et leur reconnaissance à la réception. Un intérêt immédiat de la technique proposée permet notamment de faciliter l’accès multiutilisateurs au canal ultralarge bande, et d’autoriser des communications simultanées (Many-to-one, des nœuds vers le puits) ou du broadcast (One-to-many, du puits vers les nœuds) sans surcharger la couche MAC. L’architecture proposée s’inscrit donc à l’interface des couches PHY et MAC et permet de relâcher les contraintes de conception spécifiques à ces couches
In this thesis, we propose a design methodology for communication architectures dedicated to wireless sensor network based on impulse radio techniques for UWB communications. The impulse technique proposed in this work relies on pulse shape modulation. The architecture design approach proposed in this thesis focuses on pulses shape and their generation, which is of major interest as it constitutes the carrier of the information exchanged. The study on the choice of pulse shape led us to propose two different architectures. The first one is based on orthogonal polynomials, more especially on the Hermite polynomials, for impulse generation, and on a correlation architecture for detection and recognition of transmitted impulses. The second architecture is based on discrete wavelet packet transform and can be used according two different modes, mono and multi-users. The use of both synthesis and analysis architectures for emitter and receiver, respectively, offers a new way for digital communications and allows the wavelet transform to ensure the impulses generation on the transmitter and their recognition on the receiver. A major interest point of the proposed technique is to facilitate the multi-users access to the ultra-wideband channel and to allow simultaneous communications (many-to-one, from the sensors to the sink) or broadcast (one-to-many, from the coordinator to the nodes) but without overloading the MAC layer. Hence, the proposed architecture is part of the interface between both PHY and MAC layers, and allows to release their specific design constraints
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Fang, Yi-chin. "Performance evaluation of discrete IR optical system." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270211.

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Bengtsson, Daniel, and Daniel Landström. "Coding in a discrete multitone modulation system." Thesis, Luleå, 1996. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-62422.

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Discrete Multitone (DMT) modulation is a multicarrier technique which makes efficient use of the channel, maximizing the htroughput by sending different numbers of bits on different subchannels. The number of bits on each subchannel depends in the Signal-to-Noise Ratio of the subchannel. The performance of a DMT system can be further increased by using powerful coding techniques. This thesis investigates an implementation of coding for a DMT system. The coding techniques considered are Ree-Solomon coding combined with interleaving, and Trellis Coded Modulation. Wei's 4-dimensional 16-state coder combined with trellis shaping is the suggested trellis code. A single encoder is used which codes across the tones of each DMT-symbol. At a bit error probability of 10 -7 the suggested codes gain 3-6 dB over uncoded transmission. Hardware complexity and algorithmic aspects of coding are covered, as well as simulations to verify it.
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Jenkin, Robin Brian. "On the application of the modulation transfer function to discrete imaging systems." Thesis, University of Westminster, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251647.

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Forbes, Jason. "Discrete signal processing techniques for power converters : multi-carrier modulation and efficient filtering techniques." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45446.

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Digital control has become ubiquitous in the field of power electronics due to the ease of implementation, reusability, and flexibility. Practical engineers have been hesitant to use digital control rather than the more traditional analog control methods due to the unfamiliar theory, relatively complicated implementation and various challenges associated with digital quantization. This thesis presents discrete signal processing theory to solve issues in digitally controlled power converters including reference generation and filtering. First, this thesis presents advancements made in the field of digital control of dc-ac and ac-dc power converters. First, a multi-carrier PWM strategy is proposed for the accurate and computationally inexpensive generation of sinusoidal signals. This method aims to reduce the cost of implementing a sine-wave generator by reducing both memory and computational requirements. The technique, backed by theoretical and experimental evidence, is simple to implement, and does not rely on any specialized hardware. The method was simulated and experimentally implemented in a voltage-controlled PWM inverter and can be extended to any application involving the digital generation of periodic signals. The second advancement described in this thesis is the use of simple digital filters to improve the response time of single-phase active rectifiers. Under traditional analog control strategies, the bandwidth of an active rectifier is unduly restricted in order to reduce any unwanted harmonic distortion. This work investigates digital filters as a proposed means to improve the bandwidth, and thereby create a faster, more efficient ac-dc power converter. Finally, a moving average filter is proposed, due to its simple implementation and minor computational burden, as an efficient means to expand the bandwidth. Since moving average filters are well known and widely understood in industry, this proposed filter is an attractive solution for practicing engineers. The theory developed in this thesis is verified through simulations and experiments.
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Kuznetsov, Nikita A. "Modulation and Coordination of Respiratory Rhythm with Discrete Finger Movements in Manual Precision Aiming." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1291407910.

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Smecher, Graeme. "Discrete-time crossing-point estimation for switching power converters." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115995.

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In a number of electrical engineering problems, so-called "crossing points" -- the instants at which two continuous-time signals cross each other -- are of interest. Often, particularly in applications using a Digital Signal Processor (DSP), only periodic samples along with a partial statistical characterization of the signals are available. In this situation, we are faced with the following problem: Given limited information about these signals, how can we efficiently and accurately estimate their crossing points?
For example, an audio amplifier typically receives its input from a digital source decoded into regular samples (e.g. from MP3, DVD, or CD audio), or obtained from a continuous-time signal using an analog-to-digital converter (ADC). In a switching amplifier based on Pulse-Width Modulation (PWM) or Click Modulation (CM), a signal derived from the sampled audio is compared against a deterministic reference waveform; the crossing points of these signals control a switching power stage. Crossing-point estimates must be accurate in order to preserve audio quality. They must also be simple to calculate, in order to minimize processing requirements and delays.
We consider estimating the crossing points of a known function and a Gaussian random process, given uniformly-spaced, noisy samples of the random process for which the second-order statistics are assumed to be known. We derive the Maximum A-Posteriori (MAP) estimator, along with a Minimum Mean-Squared Error (MMSE) estimator which we show to be a computationally efficient approximation to the MAP estimator.
We also derive the Cramer-Rao bound (CRB) on estimator variance for the problem, which allows practical estimators to be evaluated against a best-case performance limit. We investigate several comparison estimators chosen from the literature. The structure of the MMSE estimator and comparison estimators is shown to be very similar, making the difference in computational expense between each technique largely dependent on the cost of evaluating various (generally non-linear) functions.
Simulations for both Pulse-Width and Click Modulation scenarios show the MMSE estimator performs very near to the Cramer-Rao bound and outperforms the alternative estimators selected from the literature.
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Pham, Dang Kien Germain. "Conversion analogique-numérique Sigma-Delta large bande appliquée à la mesure des non-linéarités des amplificateurs de puissance." Thesis, Paris, ENST, 2013. http://www.theses.fr/2013ENST0003/document.

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Les amplificateurs de puissance, éléments constitutifs essentiels de tout système de télécommunication, vont jouer un rôle capital dans le développement des futurs systèmes de communication. Aujourd'hui l'amélioration des amplificateurs de puissance nécessite un progrès technologique au niveau du composant lui même mais doit aussi tenir compte d'une approche plus globale. En particulier, le progrès dans les traitements numériques permet aujourd'hui de corriger en amont certaines distorsions qui seront générées en aval de la chaîne de communication. La pré-distorsion numérique est une technique de correction des amplificateurs de puissance qui connaît un intérêt grandissant de par son intégration complètement numérique et par les gains en linéarité et en consommation. Cette technique nécessite une voie de retour dont un élément critique est le convertisseur analogique-numérique. Ce composant doit répondre à des contraintes de résolution, de bande passante et de linéarité élevées. Dans cette thèse, nous proposons une nouvelle architecture de convertisseur analogique-numérique à base de modulateurs Sigma-Delta passe-bande. Cette architecture tire partie du fonctionnement passe bande des modulateurs que nous faisons travailler en parallèle, chacun centré sur différentes fréquences, mais aussi d'un agencement en cascade particulier pour éliminer le signal utile, qui est de forte puissance, dans le but de diminuer les contraintes de dynamique.La conception haut niveau et les simulations ont été menées pour des systèmes à temps discret et aussi à temps continu et a nécessité le développement d'outils adaptés de simulation se basant sur la boîte à outils Delta Sigma Toolbox de Richard Schreier
Power amplifiers, which are essential elements of any communication system, will play a crucial role in the development of future communication systems. Today improving power amplifiers requires technological advances at the circuit device level, but one also must consider a more global approach. In particular, advances in digital processing can now correct in the early stage of the communication chain some distortions that are generated downstream in the chain. Digital pre-distortion is a correction technique for power amplifiers that has a growing interest because of its completely digital implementation and of its gains in linearity and energy consumption. This technique requires a feedback path where the analog-to-digital converter is a critical element. This component must satisfy the constraints of high resolution , wide bandwidth, and high linearity. In this thesis, we propose a new architecture of analog-to-digital converter based on bandpass Delta-Sigma modulators. This architecture takes advantage of operating bandpass modulators that are designed to work in parallel, each focusing on different frequencies, but also of a particular cascading arrangement to eliminate the useful signal, which has a high power, in order to reduce dynamics constraints. High-level design and simulations were carried out for discrete time and continuous time systems and also required the development of appropriate simulation tools
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Nathany, Sumit Kumar. "Design of a 14-bit fully differential discrete time delta-sigma modulator /." Online version of the thesis, 2006. https://ritdml.rit.edu/dspace/handle/1850/2799.

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Qu, Zhen, and Ivan B. Djordjevic. "Four-Dimensionally Multiplexed Eight-State Continuous-Variable Quantum Key Distribution Over Turbulent Channels." IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2017. http://hdl.handle.net/10150/626439.

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We experimentally demonstrate an eight-state continuous-variable quantum key distribution (CV-QKD) over atmospheric turbulence channels. The high secret key rate (SKR) is enabled by 4-D multiplexing of 96 channels, i.e., six-channel wavelength-division multiplexing, four-channel orbital angular momentum multiplexing, two-channel polarization multiplexing, and two-channel spatial-position multiplexing. The atmospheric turbulence channel is emulated by a spatial light modulator on which a series of azimuthal phase patterns yielding Andrews' spectrum are recorded. A commercial coherent receiver is implemented at Bob's side, followed by a phase noise cancellation stage, where channel transmittance can be monitored accurately and phase noise can be effectively eliminated. Compared to four-state CV-QKD, eight-state CV-QKD protocol potentially provides a better performance by offering higher SKR, better excess noise tolerance, and longer secure transmission distance. In our proposed CV-QKD system, the minimum transmittances of 0.24 and 0.26 are required for OAM states of 2 (or -2) and 6 (or -6), respectively, to guarantee the secure transmission. A maximum SKR of 3.744 Gb/s is experimentally achievable, while a total SKR of 960 Mb/s can be obtained in case of mean channel transmittances.
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Books on the topic "Modulation discrète"

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Berber, Stevan. Discrete Communication Systems. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198860792.001.0001.

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The book present essential theory and practice of the discrete communication systems design, based on the theory of discrete time stochastic processes, and their relation to the existing theory of digital communication systems. Using the notion of stochastic linear time invariant systems, in addition to the orhogonality principles, a general structure of the discrete communication system is constructed in terms of mathematical operators. Based on this structure, the MPSK, MFSK, QAM, OFDM and CDMA systems, using discrete modulation methods, are deduced as special cases. The signals are processed in the time and frequency domain, which requires precise derivatives of their amplitude spectral density functions, correlation functions and related energy and pover spectral densities. The book is self-sufficient, because it uses the unified notation both in the main ten chapters explaining communications systems theory and nine supplementary chapters dealing with the continuous and discrete time signal processing for both the deterministic and stochastic signals. In this context, the indexing of vital signals and finctions makes obvious distinction beteween them. Having in mind the controversial nature of the continuous time white Gaussian noise process, a separate chapter is dedicated to the noise discretisation by introducing notions of noise entropy and trauncated Gaussian density function to avoid limitations in applying the Nyquist criterion. The text of the book is acompained by the solutions of problems for all chapters and a set of deign projects with the defined projects’ topics and tasks and offered solutions.
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Edwards, Michael, John Kitchen, Nikki Moran, Zack Moir, and Richard Worth. Fundamentals of Music Theory. The University of Edinburgh, 2021. http://dx.doi.org/10.2218/ed.9781912669226.

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This open e-book is the result of a project funded by a University of Edinburgh Student Experience Grant, Open e-Textbooks for access to music education. The project was a collaboration between Open Educational Resources Service, and staff and student interns from the Reid School of Music. As a proof-of-concept endeavour, the project aimed to explore how effectively we could convert existing course content into convenient and reusable open formats suitable for use by staff and students both within and beyond the University. The resulting e-book presents open licensed educational materials that deal with the building blocks of musical stave (sometimes known as staff) notation, a language designed to communicate about musical ideas which is in use around the world. The resources in this e-book include video lectures and their transcripts, as well as supporting text explanations, examples and illustrations. The materials introduce topics such as the organisation of discrete pitches into scales and intervals, and temporal organisation of musical sounds as duration, in rhythm and metre. These rudiments are presented through an introduction to the elements of five-line stave notation, and through critical discussion of the advantages and limitations served by notational systems in the representation and analysis of musical sounds. This serves as the basis of further explanations, to illustrate musical concepts including key, time signature, harmonisation, cadence and modulation. We anticipate that subsequent versions of this e-book will update and develop the contents and presentation of the materials, following the success of this student-led collaboration.
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Book chapters on the topic "Modulation discrète"

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Pelgrom, Marcel J. M. "Time-Discrete Σ Δ Modulation." In Analog-to-Digital Conversion, 861–908. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-90808-9_19.

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Coene, Wim, and Andre Immink. "Modulation coding for a two-dimensional optical storage channel." In DIMACS Series in Discrete Mathematics and Theoretical Computer Science, 1–21. Providence, Rhode Island: American Mathematical Society, 2008. http://dx.doi.org/10.1090/dimacs/073/01.

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Arad, Nur, Eytan Ruppin, and Yehezkel Yeshurun. "Dopaminergic Modulation and Neural Fatigue in Discrete Time Sigmoidal Networks." In Computation and Neural Systems, 369–74. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-3254-5_56.

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Cheng, Jung-Fu. "Performance of MIMO Space-Time Coding with Discrete Modulations." In Information, Coding and Mathematics, 165–81. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4757-3585-7_11.

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Shen, Qi, Weiyin Wang, and Xiaofeng Gu. "Design of Hybrid Continuous-Time/Discrete-Time ΣΔ Modulator." In Lecture Notes in Electrical Engineering, 1725–32. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-4981-2_189.

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Sandnas, Matt, and David B. Spencer. "A NEW GUIDANCE TECHNIQUE FOR DISCRETE-EVENT DRAG MODULATION FOR AEROCAPTURE MISSIONS." In Advances in the Astronautical Sciences, 877–91. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-51928-4_50.

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Wang, Xi, Xiangbin Yu, Tao Teng, and Guangying Wang. "Energy-Efficient Power Allocation Scheme Based on Discrete-Rate Adaptive Modulation in Distributed Antenna System." In Machine Learning and Intelligent Communications, 284–92. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-00557-3_29.

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Vamsidhar, A., P. Rajesh Kumar, and K. Raja Rajeswari. "A New Approach to Investigation of Discrete Wavelet-Based Multiuser MIMO-OFDM for BPSK Modulation Scheme." In Proceedings of 2nd International Conference on Micro-Electronics, Electromagnetics and Telecommunications, 323–32. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-4280-5_34.

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Li, Xiujian, Xiaoguang Hou, Yongming Nie, Wenhua Hu, Jiankun Yang, and Junbo Yang. "Analyze the Discrete Photo-Induced Current Pulses of the Photorefractive Spatial Light Modulator." In Lecture Notes in Computer Science, 102–9. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-10442-8_14.

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Zisapel, Nava, Yossi Anis, and Michal Gavish. "Melatonin Receptors in Discrete Areas of Rat and Hamster Brain: Modulation by Melatonin, Testosterone and the Photoperiod." In Role of Melatonin and Pineal Peptides in Neuroimmunomodulation, 97–106. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3756-4_10.

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Conference papers on the topic "Modulation discrète"

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Warde, Cardinal. "SLM-specific imperfections and their influence on optical processor performance." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oam.1992.tue1.

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Imperfections in today's spatial light modulators (SLMs) include one or more of the following: inactive zones in modulators with spatially discrete pixels, mixed (phase/amplitude) modulation rather than pure phase or pure amplitude modulation, nonlinear transfer characteristics in both optically and electrically addressed SLMs, bandpass spatial frequency characteristics in some devices, and strong readout light absorption losses in certain devices. When SLMs are used in optical processors, these imperfections lead to a variety of problems, including loss of correlation peak sharpness in optical processors, image distortion and blurring, fixed pattern noise in reconstructed images, and low signal throughput in complex systems. Continuous-pixel SLMs with spatially continuous drivers offer sufficient spatial resolution to solve the inactive zone problem. While phase-only and almost-amplitude-only modulators exist, there seems to be no device that offers a linear relationship between modulator output (modulated readout light amplitude or phase) and driver characteristic (e.g., write light intensity or electrode voltage) over the full modulation range of the device. Application-specific modulator choice is therefore an important consideration.
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Dong, Po, Jeffrey Lee, Kwangwoong Kim, Young-Kai Chen, and Chengcheng Gui. "Ten-Channel Discrete Multi-Tone Modulation Using Silicon Microring Modulator Array." In Optical Fiber Communication Conference. Washington, D.C.: OSA, 2016. http://dx.doi.org/10.1364/ofc.2016.w4j.4.

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Wu, Jiuda, and Behrooz Yousefzadeh. "Numerical Analysis of Phase Nonreciprocity in a Linear Spatiotemporally Modulated System." In ASME 2023 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2023. http://dx.doi.org/10.1115/detc2023-110347.

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Abstract Vibration transmissibility in a material with spatiotemporal modulation can be changed by just inverting the direction of transmission. This asymmetric feature of transmission can occur due to nonreciprocity. Various studies have demonstrated nonreciprocity in modulated materials by calculating or measuring the differences in amplitudes of response in opposite transmission directions. However, equal amplitudes do not indicate reciprocity because amplitude difference is blind to phase shift. In this work, we investigate nonreciprocal phase shifts (with equal transmitted amplitudes) in vibration transmission through a discrete one-dimensional periodic material subject to spatiotemporal modulation of grounding stiffness coefficients; the transmitted vibrations along the opposite directions have the same amplitude but undergo different phase shifts. We focus on the effects of the number of degrees of freedom (DoF) and modulation amplitude on vibration transmission nonreciprocity. We use the averaging method to calculate the steady-state response of the modulated system. Reciprocity bias and output norms are calculated to evaluate the degree of nonreciprocity in opposite transmission directions. Phase nonreciprocity is identified in cases where output norms are equal but reciprocity bias is not zero. While the response of the system is quasiperiodic, its envelope is periodic in time. We therefore use the response envelopes to help us identify response regimes that are characterized by nonreciprocal phase shifts. The analysis method based on the envelope of the steady-state response facilitates future parametric studies on phase nonreciprocity in discrete materials with spatiotemporal modulations.
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Khodr, M. F., J. J. Sluss, and T. E. Batchman. "An integrated optical phase modulator using a PbSe-clad BaF2 waveguide." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oam.1992.tuz27.

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We present the design of an optical phase modulator using a PbSe-clad BaF2 waveguide on a CaF2 substrate. This materials combination is useful for integrated optical devices operating in the 3-5 µm wavelength range. The key property that controls the modulator is an induced change in the imaginary part of the PbSe permittivity ε i . We have investigated the behavior of the TE modes over a wide range of ε i for a free space wavelength of 3.4 µm. Our analysis shows that the TE0 mode propagates discretely in the PbSe if ε i <6.501. The discrete TE0 mode converts continuously to a TE1 mode propagating in the BaF2 for an incremental change Δε i . as small as 0.001. A phase modulator was designed for a PbSe cladding thickness of 0.026 µm, which coincides with the critical point where the discrete TE0 mode converts to a continuous TE1 mode for Δε = 0.001. Phase modulation is indicated by a large change in mode index value for a small induced change in the ε i of the PbSe. The attenuation at this critical point remains relatively constant, even though a large phase change is produced.
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Tong, Yeyu, Xinru Wu, Jie Liu, Chester Shu, and Hon Ki Tsang. "Assessment of Integrated Ge Franz-Keldysh Modulator for Discrete Multi-Tone Modulation." In Optical Fiber Communication Conference. Washington, D.C.: OSA, 2018. http://dx.doi.org/10.1364/ofc.2018.w4d.5.

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Manevitch, Leonid I., and Andrey I. Musienko. "Transversal Nonlinear Dynamics of Stretched Chain on Elastic Foundation." In ASME 2005 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/detc2005-84920.

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We present analytical and numerical study of short wavelength breathers in the system of asymmetric nonlinear oscillators coupled by stretched weightless beam. The study is focused on modulations of the nonlinear normal mode with shortest wavelength. A small parameter is introduced as ratio of distance between the particles in the chain and characteristic wavelength of modulation. It is shown that in main asymptotic approach the problem can be reduced to Nonlinear Schro¨dinger Equation (NSE). Breathers (envelope solitons) are localized oscillating solutions of this equation. We reveal the stability and high mobility of such solutions in their numerical study based on integrating of exact discrete equations of motion. We study breathers, localized on chain ends, and radiation of breathers from chain ends, induced by variable external force.
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Baig, Mirza Uzair, Anders Host-Madsen, and Aria Nosratinia. "Discrete modulation for interference mitigation." In 2017 IEEE International Symposium on Information Theory (ISIT). IEEE, 2017. http://dx.doi.org/10.1109/isit.2017.8006766.

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Chatterjee, M. R., P. P. Banerjee, and O. Ziv. "Numerical investigation of the modulation properties of an AM soliton pulse upon reflection from a nonlinear/dispersive interface." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oam.1992.thss4.

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Recently, in an analytical approach based on incommensurate spectral decomposition, Banerjee et al.1 showed that an AM pulse, upon transmission across a linear, nondispersive/ nonlinear, dispersive interface, appeared to indicate the formation of collinear AM and narrowband FM "channels," each with distinctive phase velocities. This indicated that these modulations would spatially separate after some characteristic distance. The above work was based on a nonlinear Klein-Gordon (NKG) system in which the interface was linear/ nondispersive on one side and nonlinear/ dispersive on the other. In this paper, we assume a nonlinear Schrödinger (NLS) system in which the core is assumed to have a Sellmeier-type material dispersion and an n2-type quadratic refractive index nonlinearity. The cladding is made similarly nonlinear but nondispersive for simplicity. By numerical simulations that accommodate exact soliton pulses, the nature of the reflected soliton pulses is examined for variable angles of incidence and for dispersion and nonlinearity parameters. We report here the formation of self-phase modulations on the low-amplitude regions of the propagating pulse, as well as possible phase modulation (resembling the narrowband FM channel analytically derived in Ref. 1) in portions of the reflected pulse. The propagation velocities and amplitudes of the modulations and the carrier are also numerically estimated and are compared with available theory. The case of discrete, incommensurate sidebands is also tested.
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Naito, Takeru, Masahiro Yabuno, Fumihiro China, Shigehito Miki, Hirotaka Terai, and Ryosuke Shimizu. "Spectral modulation of biphotons via Fourier optical synthesis." In Conference on Lasers and Electro-Optics/Pacific Rim. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleopr.2022.cthp7f_04.

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We propose and demonstrate the modulation of the joint spectral intensity of a biphoton wave packet. Manipulating the two discrete joint temporal intensity distributions results in spectral modulation in 2D time-frequency space.
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Adzhemov, A. S., and A. Y. Kudryashova. "Distortion with Multiple Discrete Modulation Techniques." In 2021 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF). IEEE, 2021. http://dx.doi.org/10.1109/weconf51603.2021.9470537.

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Reports on the topic "Modulation discrète"

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Gabella, W., J. Rosenzweig, R. Kick, and S. Peggs. RF voltage modulation at discrete frequencies with applications to crystal channeling extraction. Office of Scientific and Technical Information (OSTI), May 1992. http://dx.doi.org/10.2172/10153150.

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Gabella, W., J. Rosenzweig, R. Kick, and S. Peggs. RF voltage modulation at discrete frequencies with applications to crystal channeling extraction. Office of Scientific and Technical Information (OSTI), May 1992. http://dx.doi.org/10.2172/5153023.

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Weinberg, Zwi G., Adegbola Adesogan, Itzhak Mizrahi, Shlomo Sela, Kwnag Jeong, and Diwakar Vyas. effect of selected lactic acid bacteria on the microbial composition and on the survival of pathogens in the rumen in context with their probiotic effects on ruminants. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7598162.bard.

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This research project was performed in context of the apparent probiotic effect of selected lactic acid bacteria (LAB) silage inoculants on the performance of ruminants (improved feed intake, faster live-weight gain, higher milk yields and improved feed efficiency). The overall objective was to find out how LAB affect ruminant performance. The project included several “chapters” as follows: 1. The effect of LAB silage inoculants on the survival of detrimental bacteria in rumen fluid, in vitro study (Weinberg et al., The Volcani Center). An in vitro model was developed to study the interaction between selected LAB and an E. coli strain tagged with green fluorescence protein (GFP) in buffered RF. Results indicated that both LAB inoculants and E. coli survived in the RF for several days; both LAB inoculants and LAB-treated silages did not affect survival of E. coli in rumen fluid in vitro. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the performance of high-lactating cows (Weinberg et al., The Volcani Center). Treatments included control (no additive), Lacobacillusbuchneri40788 (LB), Lactobacillus plantarumMTD1 40027 (LP) and Pediococcuspentosaceus30168 (PP), each applied at 10⁶ cfu/g FM. The silages were included in the TMR of 32 high milking Holstein cows in a controlled feeding experiment. All baled silages were of good quality. The LB silage had the numerically highest acetic acid and were the most stable upon aerobic exposure. The cows fed the LB silages had the highest daily milk yields, percent milk fat and protein. The microbiome of baled wheat silages and changes during ensiling of wheat and corn (Sela et al., The Volcani Center). Bacterial community of the baled silages was dominated mainly of two genera in total, dominated by Lactobacillus and Clostridium_sensu_stricto_12 with 300 other genera at very low abundance. Fungal community was composed mainly of two genera in total, dominated by Candida and Monascuswith 20 other genera at very low abundance. In addition, changes in the microbiome during ensiling of wheat and corn with and without addition of L. plantarumMTD1 was studied in mini-silos. Overall 236 bacterial genera were identified in the fresh corn but after 3 months Lactobacillus outnumbered all other species by acquiring 95% of relative abundance. The wheat silage samples are still under analysis. The effect of applying LAB inoculants at ensiling on survival of E. coli O157:H7 in alfalfa and corn silages(Adesogan et al., University of Florida). E. coli (10⁵ cfu/g) was applied to fresh alfalfa and corn at ensiling with or without L. plantarumor L. buchneri. The pathogen was added again after about 3 moths at the beginning of an aerobic exposure period. The inoculants resulted in faster decrease in pH as compared with the control (no additives) or E. coli alone and therefore, the pathogen was eliminated faster from these silages. After aerobic exposure the pathogen was not detected in the LAB treated silages, whereas it was still present in the E. coli alone samples. 5. The effect of feeding corn silage treated with or without L. buchnerion shedding of E. coli O157:H7 by dairy cows (Adesogan et al., UFL). BARD Report - Project 4704 Page 2 of 12 Five hundred cows from the dairy herd of the University of Florida were screened for E. coli shedding, out of which 14 low and 13 high shedders were selected. These cows were fed a total mixed ration (TMR) which was inoculated with E. coli O157:H7 for 21 days. The TMR included corn silage treated with or without L. buchneri. The inoculated silages were more stable upon aerobic exposure than the control silages; the silage inoculant had no significant effect on any milk or cow blood parameters. However, the silage inoculant tended to reduce shedding of E. coli regardless of high or low shedders (p = 0.06). 6. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the rumen microbiome (Mizrahi et al., BGU). Rumen fluid was sampled throughout the feeding experiment in which inoculated wheat silages were included in the rations. Microbial DNA was subsequently purified from each sample and the 16S rRNA was sequenced, thus obtaining an overview of the microbiome and its dynamic changes for each experimental treatment. We observed an increase in OTU richness in the group which received the baled silage inoculated with Lactobacillus Plantarum(LP). In contrast the group fed Lactobacillus buchneri(LB) inoculated silage resulted in a significant decrease in richness. Lower OTU richness was recently associated in lactating cows with higher performance (Ben Shabatet al., 2016). No significant clustering could be observed between the different inoculation treatments and the control in non metric multi-dimentional scaling, suggesting that the effect of the treatments is not the result of an overall modulation of the microbiome composition but possibly the result of more discrete interactions. Significant phylum level changes in composition also indicates that no broad changes in taxa identity and composition occurred under any treatment A more discrete modulation could be observed in the fold change of several taxonomic groups (genus level analysis), unique to each treatment, before and after the treatment. Of particular interest is the LB treated group, in which several taxa significantly decreased in abundance. BARD Report - Project 4704 Page 3 of 12
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Dahl, Geoffrey E., Sameer Mabjeesh, Thomas B. McFadden, and Avi Shamay. Environmental manipulation during the dry period of ruminants: strategies to enhance subsequent lactation. United States Department of Agriculture, February 2006. http://dx.doi.org/10.32747/2006.7586544.bard.

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The project resulted from earlier observations that environmental factors, especially photoperiod and temperature, had profound effects on milk yield in dairy cattle during lactation. More recently we had determined that photoperiod manipulation during the dry period altered milk yield in the next lactation, and this was associated with shifts in circulating concentrations of prolactin; specifically exposure to short days during the dry period decreases prolactin but increases milk yield. Because prolactin is also affected by temperature, with heat stress causing an increase in prolactin similar to that of long day exposure, we focused our efforts on determining prolactin signaling provides a common pathway for generation of environmental effects on mammary growth, development and subsequent function during the dry period of dairy ruminants. Over the project period we made significant progress toward testing our hypotheses that (I): In cows, there is a discrete duration of time during the dry period in which exposure to short days will result in optimal enhancement of mammary development and milk yield in the following lactation, and that this effect is mediated through demonstrable changes in mammary gland development, prolactin signaling, and mammary gene expression; and (II): Modulation of photoperiod and temperature during the dry period will affect milk yield in goats in the subsequent lactation via shifts in nutrient and endocrine partitioning, and mammary gene expression, during the dry period and into lactation. Cows exposed to short days for only the final 21 days of the dry period did not produce more milk that those on long day or natural photoperiod when dry. However, cows on short days for the entire 60 days dry did produce more milk than the other 3 groups. This indicates that there is a duration effect of short day exposure on subsequent milk yield. Results of the second study in cows indicate that mammary growth increases differentially during the dry period under long vs. short days, and that short days drive more extensive growth which is associated with altered prolactin signaling via decreases in an suppressors of cytokine signaling that represent an inhibitory pathway to mammary growth. Evidence from the studies in Israel confirms that goats respond to short days during the dry period in a similar manner to cows. In addition, heat stress effects on during the dry period can be limited by exposure to short days. Here again, shifts in prolactin signaling, along with changes in IGF-I secretion, are associated with the observed changes in mammary function in goats. These results have a number of biological and practical implications. For dairy producers, it is clear that we can recommend that cows and goats should be on reduced light exposure during the dry period, and further, cows and goats should be cooled to avoid heat stress during that time. Environmental influences on mammary growth are apparent during the dry period, and those effects have persistent impact in the subsequent lactation. Prolactin signaling is a consistent mechanism whereby extended light exposure and heat stress may depress mammary growth and development during the dry period. Thus, the prolactin signaling system offers an opportunity for further manipulation to improve production efficiency in dairy ruminants.
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