Convolution: 1D and 2D signal processing provides about consider the delta function; time-shift delta; sample the input; Fourier Coefficients; Euler’s identity; Sine-cos Rep; Harmonic Analysis; Convolution Thm; Spectrum reproduced.
Trang 11D and 2D signal processing
Trang 2Consider the delta function
else
0
0
) 0
( )
( )
x
(t)dt 1
Trang 3Time-shift delta
)
(n k
k
k
x ( )
Trang 4Sample the input (it’s a
convolution!)
] [ ]
[ ] [
] )[
*
k
s(t) (t n / f s)
n
v s (t) v(t)s(t) v(t ) (t n / f s )
n
Trang 5What does sampling do to
spectrum?
Trang 6What is the spectrum?
v(t) a0 (a1 cost b1sin t) (a2 cos2t b2sin 2t) K
Trang 7Fourier Coefficients
v(t) a0 (a1 cost b1sin t) (a2 cos2t b2sin 2t) K
Trang 8CTFT
Trang 9Euler’s identity
Trang 10Sine-cos Rep
n 1
n 0
v(t) a0 (a1 cost b1sin t) (a2 cos2t b2sin 2t) K
Trang 11Harmonic Analysis
T
T
T
Trang 12V * W( f ) V ( )W( f )d
Trang 13Convolution Thm
V * W( f ) F(v(t)w(t))
multiplication in the time domain =
convolution in the frequency domain
Trang 14n
n
n
Trang 15Spectrum reproduced
n
spectrum to be reproduced at intervals
f s