- #1
btb4198
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can someone do a design of a FIR filter using the Window design method by hand as an example and post it? Please do not use mat lab. I would like to learn how to do it myself by hand. I have been have use Google but no luck .
all the pages I have seen use mat lab in their example.
So I have been reading up on FIR filters and I have learned they can be in the Time domain or the frequency domain. in the Time domain you take the input signal of discrete samples x[n] and its impulse response b and you use convolving to get the output y[n]. this will Zero out any unwanted frequencies. so you can do a band pass or a low pass or a high pass filter.
N
y[n] = Ʃ bi x[N-i]
i = 0
Now I do not really know how to solve the impulse response h[n].
now Wiki says, " h[n] can be calculated if we set x[n] = δ[n] in the above relation, where δ[n] is the Kronecker delta impulse. The impulse response for an FIR filter then becomes the set of coefficients bn, as follows :
N
h[n] = Ʃ bi δ[n-i] = bn
i = 0
for n =0 to N
"
so I am not sure where h[n] come in at in that 1 formula ... I think h[n] is an array of bns.. i guess
or a set of bn .
like h[n] = { b1, b2, b3, b4,bi, ..}
that might be wrong...
"To design a filter means to select the coefficients such that the system has specific characteristics." wiki
"In signal processing, a window function (also known as an apodization function or tapering function[1]) is a mathematical function that is zero-valued outside of some chosen interval." wiki
but from this I still do not know how to get the right coefficients bn.
I know that
ω = 2π F/fs
Δω = 2π TW/Fs
Tw = transition width with "is a range of frequencies, that allows a transition between a passband and a stopband of a signal processing filter. The transition band is defined by a passband and a stopband cutoff frequency or corner frequency." wiki
stopband ripple = -20log10 δ
after this I get really lost...
I do get how convolve works,
http://www.eas.uccs.edu/wickert/ece2610/lecture_notes/ece2610_chap5.pdf
page 12 has a good example...
you would use convolving on h[n] and x[n] right?
but I am not sure how to get h[n]
so can someone workout an example by hand to help feel in the blanks
thanks
also if I have said something wrong in his post please tell me
thanks
all the pages I have seen use mat lab in their example.
So I have been reading up on FIR filters and I have learned they can be in the Time domain or the frequency domain. in the Time domain you take the input signal of discrete samples x[n] and its impulse response b and you use convolving to get the output y[n]. this will Zero out any unwanted frequencies. so you can do a band pass or a low pass or a high pass filter.
N
y[n] = Ʃ bi x[N-i]
i = 0
Now I do not really know how to solve the impulse response h[n].
now Wiki says, " h[n] can be calculated if we set x[n] = δ[n] in the above relation, where δ[n] is the Kronecker delta impulse. The impulse response for an FIR filter then becomes the set of coefficients bn, as follows :
N
h[n] = Ʃ bi δ[n-i] = bn
i = 0
for n =0 to N
"
so I am not sure where h[n] come in at in that 1 formula ... I think h[n] is an array of bns.. i guess
or a set of bn .
like h[n] = { b1, b2, b3, b4,bi, ..}
that might be wrong...
"To design a filter means to select the coefficients such that the system has specific characteristics." wiki
"In signal processing, a window function (also known as an apodization function or tapering function[1]) is a mathematical function that is zero-valued outside of some chosen interval." wiki
but from this I still do not know how to get the right coefficients bn.
I know that
ω = 2π F/fs
Δω = 2π TW/Fs
Tw = transition width with "is a range of frequencies, that allows a transition between a passband and a stopband of a signal processing filter. The transition band is defined by a passband and a stopband cutoff frequency or corner frequency." wiki
stopband ripple = -20log10 δ
after this I get really lost...
I do get how convolve works,
http://www.eas.uccs.edu/wickert/ece2610/lecture_notes/ece2610_chap5.pdf
page 12 has a good example...
you would use convolving on h[n] and x[n] right?
but I am not sure how to get h[n]
so can someone workout an example by hand to help feel in the blanks
thanks
also if I have said something wrong in his post please tell me
thanks