Bøger af Marcelo Sampaio de Alencar

In recent years, a considerable amount of effort has been devoted, both in industry and academia, towards the design, performance analysis and evaluation of modulation schemes to be used in wireless and optical networks, towards the development of the next and future generations of mobile cellular communication systems. Modulation Theory is intended to serve as a complementary textbook for courses dealing with Modulation Theory or Communication Systems, but also as a professional book, for engineers who need to update their knowledge in the communications area. The modulation aspects presented in the book use modern concepts of stochastic processes, such as autocorrelation and power spectrum density, which are novel for undergraduate texts or professional books, and provides a general approach for the theory, with real life results, applied to professional design. This text is suitable for the undergraduate as well as the initial graduate levels of Electrical Engineering courses, and is useful for the professional who wants to review or get acquainted with the a modern exposition of the modulation theory. The books covers signal representations for most known waveforms, Fourier analysis, and presents an introduction to Fourier transform and signal spectrum, including the concepts of convolution, autocorrelation and power spectral density, for deterministic signals. It introduces the concepts of probability, random variables and stochastic processes, including autocorrelation, cross-correlation, power spectral and cross-spectral densities, for random signals, and their applications to the analysis of linear systems. This chapter also includes the response of specific non-linear systems, such as power amplifiers. The book presents amplitude modulation with random signals, including analog and digital signals, and discusses performance evaluation methods, presents quadrature amplitude modulation using random signals. Several modulation schemes are discussed, including SSB, QAM, ISB, C-QUAM, QPSK and MSK. Their autocorrelation and power spectrum densities are computed. A thorough discussion on angle modulation with random modulating signals, along with frequency and phase modulation, and orthogonal frequency division multiplexing is provided. Their power spectrum densities are computed using the Wiener-Khintchin theorem.

Style is a distinctive manner of expression, in writing or speech. The wordevolved from Latin stilus, an instrument for writing, marking, or incising,such as something used by the ancients in writing on clay or waxed tablets.It is the way in which something is said or done, as distinguished fromits substance. Style is also a convention with respect to spelling, punctuation,capitalization, and typographic arrangement and display followed in writingor printing.Scientific Style in English aims to help students with the reading and writing of scientific and technical texts in English, with a particular focus on style, grammar and math. It can be used by students and professionals with basic or intermediate understanding of theEnglish language.Technical topics discussed in the book include: i Scientific Style in Englishi Mathematical Style in Englishi Technical Stylei Stylistic Problems in Englishi How to write Theses and Dissertations

A considerable amount of effort has been devoted, both in industry and academia, towards the design, performance, analysis and evaluation of amplification schemes and filters to be used in control systems, audio/video equipment, instrumentation and communication systems.This book is intended to serve as a complementary textbook for courses dealing with Linear Amplification, but also as a professional book, for engineers who need to update their knowledge in the electronics, control, and communications areas.The book is suitable for the undergraduate as well as the initial graduate levels of Electrical Engineering courses and is useful for the professional who wants to review or get acquainted with amplification theory. The book presents essential concepts in plain language and covers the most important applications of amplifier circuits. The book has four appendices, an appendix to detail the operational amplifier model, an appendix with specification data sheets, an appendix on Fourier transform and signal spectrum, including the concepts of convolution, autocorrelation and power spectral density, for deterministic signals, and a final one that presents and explains the usual electronics acronyms.

Starting with the historical evolution of computer and communications networks and their security, the book then arrives at the main definitions of cryptography and network security. Next, the basics of information theory, how to measure information, the information associated with a certain source are also discussed. Source codes are presented, along with the concepts of information transmission, joint information, conditional entropy, mutual information and channel capacity. Computer networks are discussed, including the main protocols and network architectures, and the important TCP/IP protocol. Network security, a topic intrinsically connected to computer networks and the Internet, is presented, along with information about basic hacker attacks, alternatives to prevent attacks, data protection and secure protocols. The information theoretical aspects of cryptography are described including the hash function. An appendix includes a review of probability theory. Illustrations and graphics will help the reader understand the theory.

The book presents the fundamentals of music science, followed by a discussion on the historical evolution of music. An introduction to the analysis of signals in time and frequency is presented, which includes sound and noise. Features and mathematical aspects of the sound are discussed, including vibration and timbre.The book presents a review of existing voice models and discusses the voice production, sound perception, music characteristics and acoustics, tempo, rhythm and harmony. Musical theory is presented, including staff, notes, alterations, keys and intervals, tones and associated frequencies and wavelengths. The creation of major and minor scales is emphasized, along with a study on consonance and dissonance, measure, metric, tempo markings, dynamics, modulation. The book also explains the chord formation, and discusses melody and composition.The book has four appendices, including an appendix on the basic differentiation and integration theorems, another with useful Fourier tables, and an appendix featuring the notes, their frequencies and wavelengths. The book also has a glossary of music terms.

Offers an introduction to cellular network planning, covering conventional and contemporary wireless systems. Spectral allocation and the frequency plan are discussed, along with the essential characteristics of wireless systems. The book presents a review of existing models, considering both green field dimensioning and network expansion strategies.