In this paper we revisit hybrid analog-digital precoding systems with emphasis on their modelling
and radio-frequency (RF) losses, to realistically evaluate their benefits in 5G system implementations.
For this, we decompose the analog beamforming networks (ABFN) as a bank of commonly used RF
components and formulate realistic model constraints based on their S-parameters. Specifically, we
concentrate on fully-connected ABFN (FC-ABFN) and Butler networks for implementing the discrete
Fourier TRANSFORM (DFT) in the RF domain. The results presented in this paper reveal that the performance
and energy efficiency of hybrid precoding systems are severely affected, once practical factors are
considered in the overall design. In this context, we also show that Butler RF networks are capable of
providing better performances than FC-ABFN for systems with a large number of RF chains.
Before delving into the details of orthogonal frequency division multiplexing (OFDM), relevant
background material must be presented first. The purpose of this chapter is to provide the necessary
building blocks for the development of OFDM principles. Included in this chapter are reviews of stochastic
and random process, discrete-time signals and systems, and the Discrete Fourier TRANSFORM (DFT). Tooled
with the necessary mathematical foundation, we proceed with an overview of digital communication
systems and OFDM communication systems. We conclude the chapter with summaries of the OFDM
wireless LAN standards currently in existence and a high-level comparison of single carrier systems versus
OFDM.
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.
I love telecommunications. It is powerful and it empowers, with
far-reaching consequences. It has demonstrated the potential to TRANSFORM
society and business, and the revolution has only just begun. With the invention
of the telephone, human communications and commerce were forever changed: Time
and distance began to melt away as a barrier to doing business, keeping in touch
with loved ones, and being able to immediately respond to major world events.
Through the use of computers and telecommunications networks, humans have been
able to extend their powers of thinking, influence, and productivity, just as
those in the Industrial Age were able to extend the power of their muscles, or
physical self, through use of heavy machinery.
With all the recent hype over radio frequency identification (RFID) and
the requirements to implement it, you might think that RFID can turn
water into wine, TRANSFORM lead into gold, and cure the world’s diseases. You
might also be worried that RFID will enable Big Brother to track your move-
ments to within a foot of your location from a satellite five hundred miles up
in space. The truth is, RFID can do none of these things.
In this chapter, you find out the basics of what RFID is, what forces are dri-
ving RFID as a replacement for the bar code in the marketplace, and what
benefits RFID can offer
Signals convey information. Systems TRANSFORM signals. This book introduces the mathe-
matical models used to design and understand both. It is intended for students interested
in developing a deep understanding of how to digitally create and manipulate signals to
measure and control the physical world and to enhance human experience and communi-
cation.
Artificial Intelligence (AI) has undoubtedly been one of the most important buz-
zwords over the past years. The goal in AI is to design algorithms that TRANSFORM com-
puters into “intelligent” agents. By intelligence here we do not necessarily mean an
extraordinary level of smartness shown by superhuman; it rather often involves very
basic problems that humans solve very frequently in their day-to-day life. This can
be as simple as recognizing faces in an image, driving a car, playing a board game, or
reading (and understanding) an article in a newspaper. The intelligent behaviour ex-
hibited by humans when “reading” is one of the main goals for a subfield of AI called
Natural Language Processing (NLP). Natural language 1 is one of the most complex
tools used by humans for a wide range of reasons, for instance to communicate with
others, to express thoughts, feelings and ideas, to ask questions, or to give instruc-
tions. Therefore, it is crucial for computers to possess the ability to use the same tool
in order to effectively interact with humans.
