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In some applications, such
as
voice synthesis, a signal is first analyzed
to study its characteristics, which are then
used
in digital filtering to
generate a synthetic voice.
In the first half of this book we will deal with the signal-analysis
aspect of DSP. In Chapter
2
we will begin with basic descriptions of
discretetime signals and systems. These signals and systems are analyzed
in the frequency domain in Chapter
3.
A
generalization of the frequency-
domain description, called the t-transform, is introduced in Chapter
4.
The practical algorithms for computing the Fourier transform are dis-
cussed in Chapter
5
in the form of the discrete Fourier transform and the
fast Fourier transform.
The second half of this book is devoted to the signal-filtering aspect
of
DSP. In Chapter
6
we describe various implementations and structures of
digital filters. In Chapter
7
we provide design techniques and algorithms
for designing one type of digital filter called finitsduration impulse re-
sponse (or
FIR)
filters, while in Chapter
8
we provide a similar treatment
for another type of filter called infiniteduration impulse response (or IIR)
filters. In both chapters we discuss only the simpler but practically
use-
ful techniques of filter design. More advanced techniques are not covered.
Finally, the last two chapters provide some practical applications in the
form of projects that can be done using material learned in the first eight
chapters. In Chapter
9
concepts in adaptive filtering are introduced, and
simple projects in system identification, interference suppression, adap
tive line enhancement, and
so
forth are discussed. In Chapter
10
a brief
introduction to digital communications is presented with projects in such
topics
as
PCM, DPCM, and LPC being outlined.
In all these chapters the central theme
is
the generous use and ad-
equate demonstration of
MATLAB
tools. Most of the existing
MATLAB
functions for DSP are described in detail, and their correct use is demon-
strated
in
many examples. Furthermore, many new MATLAB functions are
developed to provide insights into the working of many algorithms. We
believe that this “hand-holding” approach will enable students to dispel
fears about DSP and will provide an enriching learning experience.
A
FEW WORDS
ABOUT
MATLAB@
I
MATLAB is an interactive, matrix-based system for scientific and engi-
neering numeric computation and visualization. Its strength lies in the
fact that complex numerical problems can be solved easily and in a frac-
tion of the time required with a programming language such
as
Fortran
or C. It
is
also powerful in the sense that by using its relatively simple
programming capability,
MATLAB
can be easily extended to create new
commands and functions.
A
Few
Words
about
MATLAB
5