Cognitive radios have become a vital solution that allows sharing of the scarce frequency spectrum available for wireless systems. It has been demonstrated that it can be used for future wireless systems as well as integrated into 4G/5G wireless systems. Although there is a great amount of literature in the design of cognitive radios from a system and networking point of view, there has been very limited available literature detailing the circuit implementation of such systems. Our textbook, Radio Frequency Integrated Circuit Design for Cognitive Radios, is the first book to fill a disconnect in the literature between Cognitive Radio systems and a detailed account of the circuit implementation and architectures required to implement such systems. In addition, this book describes several novel concepts that advance state-of-the-art cognitive radio systems.
标签: Cognitive Systems Design Radio RFIC for
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The single-carrier frequency division multiple access (SC-FDMA) system is a well-known system that has recently become a preferred choice for mobile uplink channels. This is attributed to its advantages such as the low peak-to-average power ratio (PAPR) and the use of frequency domain equalizers. Low PAPR allows the system to relax the specifications of linearity in the power amplifier of the mobile terminal, which reduces cost and power consumption.
标签: Communications SC-FDMA Mobile for
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The first question most readers of an O’Reilly book might ask is about the choice of the cover animal. In this case, “why a duck?” Well, for the record, our first choice was a unicorn decked out in glitter and a rainbow sash. That response always gets a laugh (we are sure you just giggled a little), but it also brings to the surface a common perception of software-defined networks among many expe‐ rienced network professionals. Although we think there is some truth to this perception, there is certainly more meat than myth to this unicorn.
标签: Networks Software Defined SDN
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Short-range communications is one of the most relevant as well as diversified fields of en- deavour in wireless communications. As such, it has been a subject of intense research and development worldwide, particularly in the last decade. There is no reason to believe that this trend will decline. On the contrary, the rapidly crystallizing vision of a hyper-connected world will certainly strengthen the role of short-range communications in the future. Concepts such as wireless social networks, Internet of things, car communications, home and office network- ing, wireless grids and personal communications heavily rely on short-range communications technology.
标签: Communications Short-Range Wireless
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This paper presents a Hidden Markov Model (HMM)-based speech enhancement method, aiming at reducing non-stationary noise from speech signals. The system is based on the assumption that the speech and the noise are additive and uncorrelated. Cepstral features are used to extract statistical information from both the speech and the noise. A-priori statistical information is collected from long training sequences into ergodic hidden Markov models. Given the ergodic models for the speech and the noise, a compensated speech-noise model is created by means of parallel model combination, using a log-normal approximation. During the compensation, the mean of every mixture in the speech and noise model is stored. The stored means are then used in the enhancement process to create the most likely speech and noise power spectral distributions using the forward algorithm combined with mixture probability. The distributions are used to generate a Wiener filter for every observation. The paper includes a performance evaluation of the speech enhancer for stationary as well as non-stationary noise environment.
标签: Telecommunications Processing Signal for
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Software defined radio (SDR) is an exciting new field for the wireless indus- try; it is gaining momentum and beginning to be included in commercial and defense products. The technology offers the potential to revolutionize the way radios are designed, manufactured, deployed, and used. SDR prom- ises to increase flexibility, extend hardware lifetime, lower costs, and reduce time to market
标签: Software Defined Radio for 3G
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Software Radio (SR) is one of the most important emerging technologies for the future of wireless communication services. By moving radio functionality into software, it promises to give flexible radio systems that are multi-service, multi- standard, multi-band, reconfigurable and reprogrammable by software. Today’s radios are matched to a particular class of signals that are well defined bytheircarrierfrequencies,modulationformatsandbandwidths.Aradiotransmitter today can only up convert signals with well-defined bandwidths over defined center frequencies, while, on the other side of the communication chain, a radio receiver can only down convert well-defined signal bandwidths, transmitted over specified carrier frequencies.
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In this thesis several asp ects of space-time pro cessing and equalization for wire- less communications are treated. We discuss several di?erent metho ds of improv- ing estimates of space-time channels, such as temp oral parametrization, spatial parametrization, reduced rank channel estimation, b o otstrap channel estimation, and joint estimation of an FIR channel and an AR noise mo del. In wireless commu- nication the signal is often sub ject to intersymb ol interference as well as interfer- ence from other users.
标签: Communications Space-Time Processing Wireless for
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Spread-spectrum communication is a core area within the field of digital communication. Originally used in military networks as countermeasures against the threats of jamming and interception, spread-spectrum systems are now widely used in commercial applications and are part of several wireless and mobile communication standards. Although spread-spectrum communication is a staple topic in textbooks on digital communication, its treatment is usually cursory. This book is designed to provide a more intensive examination of the subject that is suitable for graduate students and practicing engineers with a solid background in the theory of digital communication. As the title indicates, this book stresses principles rather than specific current or planned systems, which are described in manyotherbooks.My goal in this bookis to providea concisebut lucidexplanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles.
标签: Spread-Spectrum Communication Systems 2nd
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Part I provides a compact survey on classical stochastic geometry models. The basic models defined in this part will be used and extended throughout the whole monograph, and in particular to SINR based models. Note however that these classical stochastic models can be used in a variety of contexts which go far beyond the modeling of wireless networks. Chapter 1 reviews the definition and basic properties of Poisson point processes in Euclidean space. We review key operations on Poisson point processes (thinning, superposition, displacement) as well as key formulas like Campbell’s formula. Chapter 2 is focused on properties of the spatial shot-noise process: its continuity properties, its Laplace transform, its moments etc. Both additive and max shot-noise processes are studied. Chapter 3 bears on coverage processes, and in particular on the Boolean model. Its basic coverage characteristics are reviewed. We also give a brief account of its percolation properties. Chapter 4 studies random tessellations; the main focus is on Poisson–Voronoi tessellations and cells. We also discuss various random objects associated with bivariate point processes such as the set of points of the first point process that fall in a Voronoi cell w.r.t. the second point process.
标签: Stochastic Geometry Networks Wireless Volume and
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