- #1
electronic engineer
- 145
- 3
let us asuume this discrete signal:
f(n)=a^n * u(n) ; where u(n) is unit step function
; u(n)=1 where n>=0
u(n)=0 where n<0
;0=<a<1
and the foruier transform for discrete signals is defined as :
F(i)=sum ( f(n)*e^(-j2*pi*n/N) ;n=0 to inifinity
i know that the sum is equal to:
F(i)=sum(1/(1-a*e^-j2*pi*n/N)
but actually i don't know why! could anyone help!
thanks in advance!
f(n)=a^n * u(n) ; where u(n) is unit step function
; u(n)=1 where n>=0
u(n)=0 where n<0
;0=<a<1
and the foruier transform for discrete signals is defined as :
F(i)=sum ( f(n)*e^(-j2*pi*n/N) ;n=0 to inifinity
i know that the sum is equal to:
F(i)=sum(1/(1-a*e^-j2*pi*n/N)
but actually i don't know why! could anyone help!
thanks in advance!