Course Outline
Review of Signals and Systems:
Discrete time complex exponentials and other basic signals—scaling of
the independent axis and differences from its continuous-time
counterpart—system properties (linearity, time-invariance, memory,
causality, BIBO stability)—LTI systems described by linear constant
coefficient difference equations (LCCDE)—autocorrelation.
Discrete-Time Fourier Transform (DTFT):
Complex exponentials as eigensignals of LTI systems—DTFT
definition—inversion formula—properties—relationship to
continuous-time Fourier series (CTFS).
Z-Transform:
Generalized complex exponentials as eigensignals of LTI
systems—z-transform definition—region of convergence
(RoC)—properties of
RoC—properties of the z-transform—inverse z-transform methods
(partial fraction expansion, power series method, contour integral
approach)—pole-zero plots—time-domain responses of simple pole-zero
plots—RoC implications of causality and stability.
Frequency Domain Analysis of LTI Systems:
Frequency response of systems with rational transfer
function—definitions of magnitude and phase response—geometric
method of frequency response evaluation from pole-zero plot—frequency
response of single complex zero/pole—frequency response of simple
configurations (second order resonator, notch filter, averaging filter,
comb filter, allpass systems)—phase response—definition of
principal phase—zero-phase response—group delay—phase response of
single complex zero/pole—extension to higher order systems—effect
of a unit circle zero on the phase response—zero-phase response
representation of systems with rational transfer function—minimum
phase and allpass systems—constant group delay and its
consequences—generalized
linear phase—conditions that have to be met for a filter to have
generalized linear phase—four types of linear phase FIR
filters—on the zero locations of a linear phase FIR
filter—constrained zeros at z = 1 and at z = -1 and their
implications on choice of filters Type I through Type IV when designing
filters—frequency response expressions for Type I through Type IV
filters.
Sampling: Impulse
train sampling—relationship between impulse trained sampled
continuous-time signal spectrum and the DTFT of its discrete-time
counterpart—scaling of the frequency axis—relationship between true
frequency and digital frequency—reconstruction through sinc
interpolation—aliasing—effect of sampling at a discontinuous
point—relationship between analog and digital sinc—effects of
oversampling—discrete-time processing of continuous-time
signals—non-integer delay—up-sampling and
down-sampling—introduction to sample-rate alteration.
Discrete Fourier Transform (DFT):
Definition of the DFT and inverse DFT—relationship to discrete-time
Fourier series—matrix representation—DFT as the samples of the DTFT
and the implied periodicity of the time-domain signal—recovering the
DTFT from the DFT—circular shift of signal and the "index mod N"
concept—properties of the DFT—circular convolution and its
relationship with linear convolution—sectioned convolution methods:
overlap add and overlap save—effect of zero padding—introduction to
the estimation of frequencies of sinusoids—windowing and spectral
leakage—introduction to the Fast Fourier Transform (FFT)
algorithm—decimation-in-time and decimation-in-frequency algorithms.