digital signal question

[helio1972]

if we have a system who its ouptut can be given by y=δ[n+1]-δ[n]
So what is the function of this ystem?

 

[artsil23]

y contains 2 impulses: one positive impulse located an n=-1 and one negative impulse located at n=0.

 

[helio1972]

i don't understand

 

[A.Anand Srinivasan]

δ has an value of 1 only if n=0 i.e δ(0)=1 and δ=0 for n≠0.... so your function has y(0)=-1 and y(-1)=1 and for all others values y is zero.....

 

[artsil23]

most of the time in DSP δ represents an impulse function. your original function contains two impulse functions, one is δ(n+1), it means that is a shifted one (n+1=0), and you can find that is placed at n=-1, the negative impulse is located at n=0.

 

[helio1972]

so do why we need to generate two impulse one + and other one -?































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[artsil23]

you say that y is the system's output. That output depends of transfer function of your system and the system's input. Then, if you want to have a more clear understanding of the output, then you need to know the input applied to the system and the transfer function of your system.

 

[calm]

what is the input signal? if any signal can generate this ouput, this system is a singal generator of y=δ[n+1]-δ[n]

 

[A.Anand Srinivasan]

this system does not have a dependency on x and hence it is a signal generator only......

 

[jahmad]

The y in this case is the impulse response of the discrete time system when input is an impulse function.