The unguided TRanSMISSION of information using electromagnetic waves
at radio frequency (RF) is often referred to as wireless communications,
the first demonstration of which took place at the end of the 19th cen-
tury and is attributed to Hertz. The technology was, shortly thereafter,
commercialised by, amongst others, Marconi in one of the first wire-
less communication systems, i.e., wireless telegraphy. In the first half of
the 20th century the technology was developed further to enable more
than the mere TRanSMISSION of Morse code. This first resulted in uni-
directional radio broadcasting and several years later also in television
broadcasting.
The market for cellular phones and wireless data TRanSMISSION equipment has changed
dramatically since the late 1970s when cellular phones were first introduced and the
late 1980s when wireless data equipment became available. As would be expected,
duringthistime RF test requirements and RF test equipment has changed dramatically.
Wireless communication has become increasingly important not only for professional appli-
cations but also for many fields in our daily routine and in consumer electronics. In 1990,
a mobile telephone was still quite expensive, whereas today most teenagers have one, and
they use it not only for calls but also for data TRanSMISSION. More and more computers use
wireless local area networks (WLANs), and audio and television broadcasting has become
digital.
Fourth Generation (4G) wireless communication systems aim to allow peak data
rates in the range of 1 Gbps for nomadic access and 100 Mbps for vehicular mobil-
ity. 4G aims to support current and emergent multimedia services, such as mobile
TV, social networks and gaming, high-definition television and video telecon-
ference, multimedia messaging service, using the All-over IP concept and with
improved quality of service.
Public telephone operators and new independent wireless operators through-
out the world are deploying wireless access in an effort to drastically reduce
delivery costs in the most expensive part of the network?the local loop.
Available radio technology enables both existing and new entrants to access
subscribers in a rapid manner and deliver their basic telephony products and
broadband-enhanced services.
An acronym for Multiple-In, Multiple-Out, MIMO communication sends the same data as several signals
simultaneously through multiple antennas, while still utilizing a single radio channel. This is a form of
antenna diversity, which uses multiple antennas to improve signal quality and strength of an RF link. The
data is split into multiple data streams at the TRanSMISSION point and recombined on the receive side by
another MIMO radio configured with the same number of antennas. The receiver is designed to take
into account the slight time difference between receptions of each signal, any additional noise or
interference, and even lost signals.
Wavelength division multiplexing (WDM) refers to a multiplexing and TRanSMISSION
scheme in optical telecommunications fibers where different wavelengths, typically
emitted by several lasers, are modulated independently (i.e., they carry independent
information from the transmitters to the receivers). These wavelengths are then
multiplexed in the transmitter by means of passive WDM filters, and likewise they
are separated or demultiplexed in the receiver by means of the same filters or
coherent detection that usually involves a tunable local oscillator (laser).
Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and
power-hungry electrical and electromechanical devices for low data rate TRanSMISSION of telegraph data
in the Marconi age, they have transformed, thanks to substantial advances in electronic technology,
into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia
communications. This, however, would not have been possible unless significant progress had been
made in recent decades in the field of signal processing algorithms for baseband and passband signals.
In fact, the core of any modern digital radio consists of a set of algorithms running over programmable
electronic hardware. This book stems from the research and teaching activities of its co-authors in
the field of algorithmic techniques for wireless communications. A huge body of technical literature
has accumulated in the last four decades in this area, and an extensive coverage of all its important
aspects in a single textbook is impossible. For this reason, we have selected a few important topics
and, for ease of reading, organized them into two parts.
For more than a century, overhead lines have been the most commonly used
technology for transmitting electrical energy at all voltage levels, especially on the
highest levels. However, in recent years, an increase in both the number and length
of HVAC cables in the TRanSMISSION networks of different countries like Denmark,
Japan or United Kingdom has been observed. At the same time, the construction of
offshore wind farms, which are typically connected to the shore through HVAC
cables, increased exponentially.
The solid high-polymer-film-type fuel cell (PEM-FC) system is used as the power
supply equipment for transportation and replaces an internal combustion engine. A
reduction of the environmental load is expected through the cogeneration system’s
(CGS) use of the PEM-FC system as a distributed power supply to individual
houses, apartments, and so forth [1–3]. The growing use of distributed power
systems, such as fuel cells, the reduction of power-TRanSMISSION losses, and an
increase of waste heat recovery are expected. Therefore, the reduction of carbon-
dioxide emission is also expected as compared to conventional energy supply
methods using commercial electric power.
