Help regarding digital filter..its very very urgent

[satish.ghariya]

HI ...Every body.. I need help regarding digital filter. I am attaching (in Doc file) is the digital filter for Analog to digital conversion it is Block diagram of filter routine for solving.
My questions is
1. What is cutoff freq for this filter.
2. and how cutoff frequency is calulated in above. some more questions in mind but later will ask you.but please solve my question....
Satish

 

[zorro]

I suggest you the folowing steps:

Recongize that this a linear time-invariant system.
Plot the signal flow graph from the description in the document.
Get the impulse response just cosidering an impulse entering the filter.
Transform to frequency domain.

Regards

Z

 

[albbg]

Sorry, but I didn't understand clearly your algorithm. Could you, please, put it in a more mathematical form. To do this, call the samples s(1), s(2), s(3) and so on, instead of A, B, C ... then explain better what you mean with "shift A to B and New to A"; it is not clear to me.
I mean, an explanation like (is a simple IIR filter):

if s(i) is the i-th sample, m(i) is the i-th averaged value and k is a constant value in the range (0,1) then:

m(i) = (1-K)*m(i-1) + K*s(i)

the same filter can also be explained as:

m(0) = 0
m(1) = (1-K)*m(0) + K*s(1)
m(2) = (1-K)*m(1) + K*s(2)
.
.
.