Yk=HkXk
Y
k
H
k
X
k
(1)
where
0≤k≤N-1
0
k
N
1
,
Hk=|Hk|ⅇⅈ∡Hk
H
k
H
k
∡
H
k
,
and
Xk=|Xk|ⅇⅈ∡Xk
X
k
X
k
∡
X
k
.
ie:
|Yk|ⅇⅈ∡Yk=|Hk|ⅇⅈ∡Hk|Xk|ⅇⅈ∡Xk
Y
k
∡
Y
k
H
k
∡
H
k
X
k
∡
X
k
(2)
|Yk|=|Hk||Xk|
Y
k
H
k
X
k
(3)
ie:
magnitude multiply
∡Yk=∡Hk+∡Xk
∡
Y
k
∡
H
k
∡
X
k
(4)
ie: phases
add so
convolution of
x
x by
h
h changes magnitude and phase of
x
x's DFT coeffients.