One traditional view of how wireless networks evolve is of a continuous, inevitable progres-
sion to higher link speeds, combined with greater mobility over wider areas. This standpoint
certainly captures the development from first and second generation cellular systems focused
on voice support, and the early short-range wireless data networks, through to today’s 3G
cellular and mobile broadband systems; there is every confidence that the trend will continue
some way into the future.
The rapid growth in mobile communications has led to an increasing demand for wide-
band high data rate communications services. In recent years, Distributed Antenna
Systems (DAS) has emerged as a promising candidate for future (beyond 3G or 4G)
mobile communications, as illustrated by projects such as FRAMES and FuTURE. The
architecture of DAS inherits and develops the concepts of pico- or micro-cell systems,
where multiple distributed antennas or access points (AP) are connected to and con-
trolled by a central unit.
The next-generation wireless broadband technology is changing the way
we work, live, learn, and communicate through effective use of state-
of-the-art mobile broadband technology. The packet-data-based revolu-
tion started around 2000 with the introduction of 1x Evolved Data Only
(1xEV-DO) and 1x Evolved Data Voice (1xEV-DV) in 3GPP2 and High
Speed Downlink Packet Access (HSDPA) in 3GPP. The wireless broad-
band fourth-generation technology (4G) is an evolution of the packet-
based 3G system and provides a comprehensive evolution of the
Universal Mobile Telecommunications System specifications so as to
remain competitive with other broadband systems such as 802.16e
(WiMAX)
With the rapid growth in the number of wireless applications, services and devices,
using a single wireless technology such as a second generation (2G) and third gener-
ation (3G) wireless system would not be efficient to deliver high speed data rate and
quality-of-service (QoS) support to mobile users in a seamless way. The next genera-
tion wireless systems (also sometimes referred to as Fourth generation (4G) systems)
are being devised with the vision of heterogeneity in which a mobile user/device will
be able to connect to multiple wireless networks (e.g., WLAN, cellular, WMAN)
simultaneously.
The first Third Generation Partnership Project (3GPP) Wideband Code Division
Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005
there were 100 open WCDMA networks and a total of over 150 operators having
frequency licenses for WCDMA operation. Currently, the WCDMA networks are
deployedinUniversalMobileTelecommunicationsSystem(UMTS)bandaround2GHz
in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the
existing 850 and 1900 spectrum allocations while the new 3G band at 1700/2100 is
expected to be available in the near future. 3GPP has defined the WCDMA operation
also for several additional bands, which are expected to be taken into use during the
coming years.
With the rapid growth of the wireless mobile applications, wireless voice has
begun to challenge wireline voice, whereas the desire to access e-mail, surf the
Web or download music (e.g., MP3) wirelessly is increasing for wireless data.
While second generation (2G) cellular wireless systems, such as cdmaOne1,
GSM2 and TDMA3, introduced digital technology to wireless cellular systems
to deal with the increasing demand for wireless applications, there is still the
need for more spectrally efficient technologies for two reasons. First, wireless
voice capacity is expected to continue to grow. Second, the introduction of
high-speed wireless data will require more bandwidth.
At recent major international conferences on wireless communications,
there have been several sessions on beyond third generation (3G) or fourth
generation(4G)mobilecommunicationssystems,wheremodulation/demod-
ulation and multiplexing/multiple access schemes related to multicarrier
techniques have drawn a lot of attention. We often met at the conference
venuesandrealizedthatnobookcoveredthebasicsofmulticarriertechniques
to recent applications aiming at the 4G systems. Therefore, we decided to
write a book on multicarrier techniques for 4G mobile communications
systems.
It is more than a decade since GSM was first commercially available. After some unexpected delay, it
seems that finally UMTS is here to stay as a 3G system standardised by 3GPP, at least for another ten
years. UMTS will enable multi-service, multi-rate and flexible IP native-based mobile technologies to be
used in wide area scenarios and also pave the way for a smooth transition from circuit switched voice
networks to mobile packet services.
Convergence between the two largest networks (Telecom and IP) is taking place
very rapidly and at diff erent levels: (1) network level: unifi cation of IP networks
with traditional Telecom networks through evolving standards (Session Initiation
Protocol (SIP), Realtime Transfer Protocol (RTP), SS7, 3G) to support interopera-
bility; (2) service level: traditional Telecom services like voice calls are being provi-
sioned on the IP backbone (VoIP), while traditional IP services (most data-driven
services such as multimedia, browsing, chatting, gaming, etc.) are accessible over
the Telecom network.
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
