Preface
The Global system for mobile communications (GSM) is the dominant wireless cellular
standard with over 3.5 billion subscribers worldwide covering more than 85% of the global
mobile market. Furthermore, the number of worldwide subscribers using high-speed packet
access (HSPA) networks topped 70million in 2008.HSPAis a 3Gevolution ofGSMsupporting
high-speed data transmissions usingWCDMAtechnology.Global uptake ofHSPAtechnology
among consumers and businesses is accelerating, indicating continued traffic growth for high-
speed mobile networks worldwide. In order to meet the continued traffic growth demands,
an extensive effort has been underway in the 3G Partnership Project (3GPP) to develop a
new standard for the evolution of GSM/HSPAtechnology towards a packet-optimized system
referred to as Long-Term Evolution (LTE).
The goal of the LTE standard is to create specifications for a new radio-access technology
geared to higher data rates, low latency and greater spectral efficiency. The spectral efficiency
target for the LTE system is three to four times higher than the current HSPA system. These
aggressive spectral efficiency targets require pushing the technology envelope by employing
advanced air-interface techniques such as low-PAPR orthogonal uplink multiple access
based on SC-FDMA(single-carrier frequency divisionmultiple access)MIMOmultiple-input
multiple-outputmulti-antenna technologies, inter-cell interferencemitigation techniques, low-
latency channel structure and single-frequency network (SFN) broadcast. The researchers
and engineers working on the standard come up with new innovative technology proposals
and ideas for system performance improvement. Due to the highly aggressive standard
development schedule, these researchers and engineers are generally unable to publish
their proposals in conferences or journals, etc. In the standards development phase, the
proposals go through extensive scrutiny with multiple sources evaluating and simulating
the proposed technologies from system performance improvement and implementation
complexity perspectives. Therefore, only the highest-quality proposals and ideas finally make
into the standard.
The book provides detailed coverage of the air-interface technologies and protocols that
withstood the scrutiny of the highly sophisticated technology evaluation process typically
used in the 3GPP physical layer working group.We describe why certain technology choices
were made in the standard development process and how each of the technology components
selected contributes to the overall systemperformance improvement.As such, the book serves
as a valuable reference for system designers and researchers not directly involved in the
standard development phase.
I am indebted to many colleagues at Samsung, in particular to Zhouyue (Jerry) Pi,
Jianzhong (Charlie) Zhang, Jiann-An Tsai, Juho Lee, Jin-Kyu Han and Joonyoung Cho. These
colleagues and other valued friends, too numerous to bementioned, have deeply influencedmyxiv Preface
understanding of wireless communications and standards.Without the unprecedented support
of PhilMeyler, SarahMatthews, Dawn Preston and their colleagues at Cambridge University
Press, this monograph would never have reached the readers. Finally my sincere gratitude
goes to the numerous researchers and engineers who contributed to the development of the
LTE standard in 3GPP, without whom this book would not have materialized.
