Re: [Discuss-gnuradio] Hello everyone. I am a new here. I have some questions.

[Tom Rondeau]

Alex Miua wrote:
> So I have started reading Discrete Time Signal Processing by Oppenheim 
> / Schafer / Buck.
>  
> Chapter 4/ Page 168 says : -
Which edition are you using? I have the second edition and this is on 
page 142 :)  I'm assuming your copy is a new edition.
>  
> x_s(t)=x_c(t)s(t)
>          =x_c(t) Sigma ( from n = -inf to inf ) [ delta (t-nT) ]
>  
> Through the sifting property of the impulse function , x_s(t) can be 
> expressed as :
>  
> x_s(t) = Sigma (from - inf to inf ) [ x_c(nT) delta ( t-nT) ]
>  
> Now this version of the sifting property is for the DISCRETE impulse 
> function NOT the continuous Dirac delta function, but just before the 
> discussion starts it says that delta(t) is the unit impulse function 
> or the Dirac delta function. Is this a typo ? Shouled this have been 
> the discrete delta function? If it is'nt, how do the above steps hold?
>  
> Thank you,
> Alex.

They are still representing all of this in the time domain. The sampling 
function is a continuous time signal as is x_c(t) as it x_s(t) where the 
discrete time representation is x_s[n] = x_s(nT).

I don't see this as a typo, and I don't see how this changes anything.

Tom