Preface
Knowledge, the object of knowledge, and the knower are the
three factors that motivate the action; the senses, the work, and the doer are
the three constituents of action.
- The Bhagvad Gita (I 8. 18)
From September 1996 to August 1997, we worked together at the
Delft Univetsity of Technology, The Netherlands, in order to realize future
wireless personal multimedia communications (WPMC). During our joint research period,
research and development were done on higher layers such as the media access
control (MAC) layer and the physical layer, and many researchers came from
Europe, Asia, the United States, and The Netherlands to work with us. We also
starred new projects and established a joint cooperation with several research
institutes, companies, and universities. Once a project is defined, many new
researchers are allocated. Among the researchers, some newcomers arc
occasionally involved. Moreover, most projects are time-limited. In this
situation, the answer to the question of how newcomers prepare to evaluate the
target is one of key issues to success in the time-limited project. We
considered the answer carefully.
When we instructed the newcomers on how to evaluate a
communication system, we used the following procedure. First, the newcomers
read some
books about a basic communication theory for the target topic to obtain basic knowledge
for the target topic on the project. Then they read many writings about the
target topic to understand the state-of-the-art technology, defined the
remaining problems, and found new solutions suitable for the target topic. Then,
once the newcomers set their research direction, by using references on how to
use computer languages, they began their own programs to design and
evaluate the target communication system. This procedure may seem quite
logical. However, during the procedure, newcomers have many questions, which take too long to
discuss. Moreover, when we viewed our research field, we found many excellent
books on the basic communication theory. However, there are few books on how
to design a telecommunications system using computer simulation. There is
currently no single book on how to design and evaluate a telecommunications
system from the physical to the upper layer. It is too
time-consuming to prepare the newcomers to design and evaluate their own
communication system. We therefore decided to write a new book to describe how to
design telecommunications systems and evaluate them from the physical
layer to the upper layer. In writing this book, we have attempted to set our concept
as follows. In each chapter, we have described a simple explanation for a
target telecommunications system, before showing programs. The explanation is
quite simple. If you need more concrete explanation, you can find many
excellent books on the subject. We chose MATLAB, one of the most popular
computer simulation languages in the world, as the computer language to design the telecommunications
systems. Moreover, we showed source programs in this book
and included them on the accompanying CD-ROM. The users can
customize our programs to their favorite systems. We believe that this book and
accompanying CD-ROM are a must-have for all engineers, researchers, academics,
and students of telecommunications technology.
Chapter
1 presents a general introduction to the history of the wireless communication
system and the latest information on WPMC. This chapter also describes
why we need to evaluate the performance of telecommunications system by computer
simulation and why we can realize the simulation.
Chapter
2 describes several key parameters to perform computer simulations smoothly.
MATLAB, a good software simulation tool, is mainly used in this book.
Therefore, we first describe how to use the MA TLAB language.
We summarize frequently used commands
and functions and the methods of creating a hierarchical program, in addition
to the methods of programming nmctlon blocks, whIch are commonly used
to evaluate all communication systems.
Chapter
3 explains the basic configurations of the phase shift keying (PSK)-based
digital radio transmission scheme and describes the method of evaluating
transmission performance by computer simulation. The PSKbased digital radio
transmission schemes-binary phase shift keying (BPSK), quadrature phase shift
keying (QPSK), offset QPSK (OQPSK), minimum shift keying (MSK), and Gaussian-filtered
minimum shift keying (GMSK)-and quadrature amplitude modulation (QAM) are
inttoduced and their performances are evaluated by creating computer simulation programs.
Parts of the
programs are based on contributions from Takako Yamamura of
the National Police Agency in Tokyo, Japan, and Ryo Sawai and Ryuhei Funada of
Chuo University, also in Tokyo, Japan.
Chapter
4 presents the configuration of the orthogonal frequency division multiplexing
(OFOM) transmission scheme, which can reduce the influence of multipath fading
and realize broadband communication while retaining high-frequency utilization
efficiency. This chapter also describes the method of simulating transmission
performance using computer simulation programs. Takako Yamamura has also
contributed to parts of the programs in this chapter.
Chapter
5 presents the configuration of code division multiplexing (COM), which can
retain robustness against multipath fading and is used in third-generation
mobile communication systems. fu did Chapter 4, this chapter also describes the method of
simulating transmission performance using computer simulation programs. Makoto
Okita from the National Police Agency in Tokyo also contributed to parts of the
programs in this chapter.
Chapter
6 evaluates the transmission performance of a point-tomultipoint communication
system with multiple-access protocols by computer simulation.
Pure ALOHA, slotted ALOHA, nonpersistent carrier-sense multiple access (CSMA),
and slotted nonpersistent inhibit sense multiple access (ISMA) are
explained as examples of multiple-access protocols. In this chapter, the methods of
simulating throughput and average delay time are described using computer
simulation programs. This chapter and its programs contain contributions
and suggestions from Makoto Okita.
Chapter
7 describes the basic simulation method for a multipoint-tomultipoint corp.munication
system based on a cellular telecommunications system. The dynamic
channel assignment (DCA), fixed channel assignment (FCA), and
adaptive cellular zone configuration (AZC) algorithms using an adaptive
antenna are introduced. In this chapter, the method used to simulate call-blocking
probability is described by using computer simulation programs. This
chapter and all of its programs contain contributions from Fumihide Kojima
and Ami Harada from the Communication Research Laboratory, Independent
Administrative Institution, in Japan.
Chapter
8 describes a software radio communication system as a future application of
the software programming method presented in this book. Computer simulation
languages have a good relationship with software languages that configure
digital signal processing hardware (OS PH) such as a digital signal processor (DSP)
andlor field programmable gate array (FPGA) andlor application-specific
integrated circuit (ASIC). The concept of software radio bridges the
software programming examined in this book and real hardware implementation.
To
make the learning process fast and easy, MA TLAB code is provided at the end of
each chapter and on the accompanying CD-ROM. This CD-ROM will allow users
to exercise the simulations for real without having to write their own programs,
which is always a barrier and prone to error. One of the main strengths of
this book is that the learning process can be hands-on, allowing the readers to see
the effects of varying parameters on the output of the simulation, a great aid to learning.
Providing the MATLAB code at the end of each chapter is very helpful for
readers. This book has a great deal to offer to researchers, practicing
engineers, and to everyone in the field of wireless information and multimedia
communication. Finally, we would like to state that this book is a work in
ptogress. We wish
to develop new discussions about evaluating the communication system through worldwide
computer simulations. If you have any comments or questions, please let us
know. Through your comments, this book will evolve with the future. Please
enjoy this book.
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