## FIR Filter

Started by in comp.dsp15 years ago 22 replies

Hi, As i've got problems using FFT or Goertzel algorithm (for those who are interested by the reason see my previous post called...

Hi, As i've got problems using FFT or Goertzel algorithm (for those who are interested by the reason see my previous post called "some goertzel questions"), i'll try to use a narrow bandpass filter. I already made one some months ago. It was a FIR filter with a bandpass 300-1000 Hz and a sample frequency of 8000 Hz. Now i'd like to design a narrower filter centered on 9 kHz with a highe...

## Analog to FIR filter design method

Started by in comp.dsp15 years ago 4 replies

Anyone, What is the best method to convert a analog filter design to a FIR filter design? Lets say I have the tranfer function in the S...

Anyone, What is the best method to convert a analog filter design to a FIR filter design? Lets say I have the tranfer function in the S domain of a analog filter and I want to design a FIR filter with the same freq response. I know there are many ways to do this for IIR filters but I would like a more predictable phase response. Phil Black

## FIR filter design

Started by in comp.dsp15 years ago 3 replies

Are there any iterative design techniques,for FIR filters, other than park's-mclellan and least squares.

Are there any iterative design techniques,for FIR filters, other than park's-mclellan and least squares.

## frequency sampling method implementation

Started by in comp.dsp15 years ago 1 reply

Dear group, I have implemented an algorithm that calculates the coefficients of an FIR filter using the frequency sampling method. The result...

Dear group, I have implemented an algorithm that calculates the coefficients of an FIR filter using the frequency sampling method. The result I obtain using my algorithm and that obtained using the fir2 function in MATLAB differ in the following way. My ideal frequency response consists of peak in the gain that is aproximated with a high degreee of accuracy by the frequency response of t...

## Compile Warnings and Errors

Started by in comp.dsp15 years ago 6 replies

Hello, Just trying my first program. It's a FIR filter below. For some reason, if it is put in "void main()" without the "return y" line, it...

Hello, Just trying my first program. It's a FIR filter below. For some reason, if it is put in "void main()" without the "return y" line, it spits out a compile warning on the line "float y[20]" saying the variable y was never referenced. If I put it into its own function, "float fir()", and then call it from "void main()", it produces a compile error on the line "return y" saying "retu...

## Statistics of linearly filtered signal

Started by in comp.dsp15 years ago 4 replies

Hi all, I would like to know "the" right method to analytically calculate the Probability Density Function (PDF) of the output of a FIR filter...

Hi all, I would like to know "the" right method to analytically calculate the Probability Density Function (PDF) of the output of a FIR filter whose input PDF is not gaussian (the indicator function for instance)... I learnt that when i was a student (long time ago) and i can't remember the way to make such calculation... :( Can anyone help ? Thanx in advance. A.Herbert

## A stupid question about FIR filter

Started by in comp.dsp15 years ago 30 replies

Hi guys, Excuse me for this stupid question but i want to understand. I send a sine at 9 kHz in the ADC input. I sample it. Then i apply...

Hi guys, Excuse me for this stupid question but i want to understand. I send a sine at 9 kHz in the ADC input. I sample it. Then i apply a FIR filter which features are a bandpass of 8000-10000 Hz with a unity gain (and 401 coefficients). Logically, if i've understood well (thing that i'm doubting now) by recovering the y(n) of the FIR output, i should recover the input sine, shouldn't...

## A stupid question about FIR filter

Started by in comp.dsp15 years ago 3 replies

Hi everyone, Jim wrote: > No I probably, haven't read all your posts. Have you somewhere explained what > results you are getting?...

Hi everyone, Jim wrote: > No I probably, haven't read all your posts. Have you somewhere explained what > results you are getting? Disregarding the first 400 samples of your output - > Is the output a scaled version of your input sinusoid? Or what? I don't remember if i explained the results i get. Anyway my output is a "kind of sine". It has the same number of "samples" per period as t

## statistics of a linearly filtered (digital) signal

Started by in comp.dsp15 years ago 1 reply

Hi all, I would like to know "the" right method to analytically calculate the Probability Density Function (PDF) of the output of a FIR filter...

Hi all, I would like to know "the" right method to analytically calculate the Probability Density Function (PDF) of the output of a FIR filter whose input PDF is not gaussian (the indicator function for instance)... I learnt that when i was a student (long time ago) and i can't remember the way to make such calculation... :( Can anyone help ? Thanx in advance. A.Herbert

## All-Pass FIR

Started by in comp.dsp15 years ago 13 replies

Just a simple question on how to create an all-pass FIR filter. I think that know how to do an odd tap all-pass: Coefficients for a three tap...

Just a simple question on how to create an all-pass FIR filter. I think that know how to do an odd tap all-pass: Coefficients for a three tap all-pass filter: 0 1 0 What are the coefficients for a four tap, all-pass filter? Thanks for any help for such a novice question. John

## Inverse of a simple non-linear-phase FIR filter

Started by in comp.dsp15 years ago 7 replies

Hello everyone, Can anyone tell me if there is a known way to find the inverse of a given FIR filter? The idea is that given some signal...

Hello everyone, Can anyone tell me if there is a known way to find the inverse of a given FIR filter? The idea is that given some signal y(x), and an FIR filter f(x), I want to find a way to compute g(x) which is the inverse of f(x) such that: y(x) * f(x) * g(x) = y(x). (* = convolution) Meaning if I have some signal, I can apply an FIR filter to shape it then apply ...

## The Parks-McClellan algorithm

Started by in comp.dsp15 years ago 18 replies

Hi All. To make a short story long, my little FIR filter project is happily trodding along. I am starting to get the various window...

Hi All. To make a short story long, my little FIR filter project is happily trodding along. I am starting to get the various window functions in place for LP prototypes, and with some luck, it's not a big deal to generate HP or BP versions from the LP prototypes. Band-stop filters are a bit more cumbersome, I have to thing about how to implement them. All the FIR window design stuf...

## TI 54x FIRS Not Compatible with Circular Buffering?

Started by in comp.dsp15 years ago 17 replies

The FIRS instruction, FIRS xmem, ymem, pmad doesn't seem to be compatible with circular buffering! The problem is the limited addressing...

The FIRS instruction, FIRS xmem, ymem, pmad doesn't seem to be compatible with circular buffering! The problem is the limited addressing modes available with by dual-memory operands, namely, just *ARx *ARx- ; post decrement *ARx+ ; post increment *ARx+0% ; post increment circularly by AR0 amount The problem is that, for a symmetric FIR filter operating on dat...

## FIR Filter Question

Started by in comp.dsp15 years ago 11 replies

I have read some papers about how to calculate filter coefficients. That is fine. Then there are some other papers, which just give...

I have read some papers about how to calculate filter coefficients. That is fine. Then there are some other papers, which just give expressions for the frequency response of the filter, and say this is the design. Could any one please tell me how are these designs useful? My understanding is that to use these filters, one has to take Fourier Transform of the signal, then multiply it with f...

## timing recovery & equalizer latency

Started by in comp.dsp15 years ago 3 replies

Hi, I have a fully digital receiver where timing recovery and equalizer are adding significant latency and I would like to try and reduce it as...

Hi, I have a fully digital receiver where timing recovery and equalizer are adding significant latency and I would like to try and reduce it as much as possible. The timing recovery is done with a fractional delay filter (a farrow type FIR filter) where only one fractional value which gets multiplied by the outputs of the multi-branch fixed FIR filters is adapted. The equalizer is a fully ...

## cutoff frequency of a FIR Filter

Started by in comp.dsp15 years ago 30 replies

Hi, I have learnt some amount of DSP recently by reading a few artickes (and using this newsgroup). I had a question regarding...

Hi, I have learnt some amount of DSP recently by reading a few artickes (and using this newsgroup). I had a question regarding cut-off frequency. Given an FIR Filter with Transfer function: H(z,N) = J . sigma_k={0...N-1} (z^{k-N}[k -1 ]) where J is a constant, is it possible to get a relation for the cutoff frequency in terms of N (in closed form)? In general, how does one determi...

## FIR facts: True or False.

Started by in comp.dsp15 years ago 12 replies

Hey guys, I was wondering if anyone could validate my current understanding of FIR dsp filters. Consider an input sequence "x" of size M...

Hey guys, I was wondering if anyone could validate my current understanding of FIR dsp filters. Consider an input sequence "x" of size M and a FIR filter sequence "f" of size "N", then: 1. The filtered output "y" is: y[k] = SUM:n-N (x[k-n] * f[n]) 2. The size of the "y" is the same as "x" 3. M must be greater than N 4. The runtime of filtering is O(M*N) Thanks, --Shafik ...

## How to load datum produced by Matlab to ccs6000?

Started by in comp.dsp15 years ago 1 reply

I have designed a fir filter in Matlab,and produced an coefficient array of the filter. I wanted to utilize these coefficients on a 6711DSK...

I have designed a fir filter in Matlab,and produced an coefficient array of the filter. I wanted to utilize these coefficients on a 6711DSK board to do some calculation.But when I loaded these datum,ccs showed the data file made by Matlab couldn't be opened. I don't know why and I am always expecting your answer. 3x

## How to load datum produced by Matlab to CCS?

Started by in comp.dsp15 years ago 1 reply

I have designed a FIR filter by Matlab, and saved the filer coefficients as a data file. I want to utilize these coefficients on 6711DSK...

I have designed a FIR filter by Matlab, and saved the filer coefficients as a data file. I want to utilize these coefficients on 6711DSK board to do some calculation. But when I load the coefficient data file to CCS,CCS showed the data file can not be open. I don't know why I am always expecting your answer. 3x

## Conceptual model for pointer arithmetic in FIR filter implementation?

Started by in comp.dsp15 years ago 105 replies

In preparing a class on DSP, with programming, I want to explain the following piece of code that implements the inner loop of an FIR: ...

In preparing a class on DSP, with programming, I want to explain the following piece of code that implements the inner loop of an FIR: *(y+n) = 0; for (k = 0; k