## impulse response of filter

Started by in comp.dsp11 years ago 6 replies

Sirs, In many of the textbooks, the impulse response of a filter is given as a SINC function. If we ignore the non-causal nature of the impulse...

Sirs, In many of the textbooks, the impulse response of a filter is given as a SINC function. If we ignore the non-causal nature of the impulse response, still the impulse response extends, in theory at least, for infinite duration. My question is, since the impulse response is infinite in duration, does that mean that this represents IIR type of structure? Thanks, manish

## How can I get Frequency Response from Impulse Freponse In Matlab?

Started by in comp.dsp19 years ago 3 replies

Hi! I want to get FRF of IIR Filter from Impulse Response. So, I got FRF using two method. One is FREQZ, another is FFT of impulse response....

Hi! I want to get FRF of IIR Filter from Impulse Response. So, I got FRF using two method. One is FREQZ, another is FFT of impulse response. But two results are different. Why? My source code are below : clear all close all clc fs=2048; % Sampling Frequency N=65536; % Buffer Size t=[0:N-1]'./fs; % Time f = [0:N/2]'*fs/N; % Frequency x = zeros(N,1); % Impulse Input...

## Complex version of an impulse

Started by in comp.dsp20 years ago 7 replies

Hi all, I've got an analyic signal for which I'm designing an IIR filter with purely real valued coefficients. I'd like to look at the...

Hi all, I've got an analyic signal for which I'm designing an IIR filter with purely real valued coefficients. I'd like to look at the impulse response of this filter, but since the normal impulse is purely real and the coefficients are all real, the impulse response is also purely real. In order to get a complex impulse response, I need a complex impulse. Is this: .... 0 0 0...

## Theory 101 - Impulse response of "perfect" LPF

Started by in comp.dsp17 years ago 41 replies

OK, I'm going to really stick my naive neck out on this one... Why isn't the impulse response of a perfect LPF a flat line (i.e.,...

OK, I'm going to really stick my naive neck out on this one... Why isn't the impulse response of a perfect LPF a flat line (i.e., zero)? For example, an infinitely large mass (the filter) hit by an infinitely small particle (the impulse) would not move at all because of its inertia (acceleration goes to zero as masses go to +/-infinity). So why is the impulse response of an infinitely l...

## Re: Complex version of an impulse

Started by in comp.dsp20 years ago

> Subject: Re: Complex version of an impulse > From: Jerry Avins jya@ieee.org > Date: 4/16/2004 11:46 AM Eastern Daylight Time > Message-id: ...

> Subject: Re: Complex version of an impulse > From: Jerry Avins jya@ieee.org > Date: 4/16/2004 11:46 AM Eastern Daylight Time > Message-id: > > robert bristow-johnson wrote: > > > In article da4d20d8.0404152109.7ed6b813@posting.google.com, Impulse at > > impulse@e.coolworks.com wrote on 04/16/2004 01:09: > > > > > > > Hi all, > > > > > > I've got an analyic

## On symmetric filter impulse responses

Started by in comp.dsp17 years ago 2 replies

Hello all, I was wondering what is the benefit of a SYMMETRIC impulse response for a filter? Lets assume that we have an FIR filter. Does a...

Hello all, I was wondering what is the benefit of a SYMMETRIC impulse response for a filter? Lets assume that we have an FIR filter. Does a symmteric impulse response necessarily produce a linear phase response (and thus a constant group delay) over the frequency band of interest? Are there any other benefits from a filter with a symmetric impulse response? Thanks so much for your replies! ...

## LTI Systems and Impulse Response

Started by in comp.dsp13 years ago 12 replies

In his book, "A Course in Digital Signal Processing", Porat states that it is a common misconception is that every Linear Time-Invariant system...

In his book, "A Course in Digital Signal Processing", Porat states that it is a common misconception is that every Linear Time-Invariant system has an impulse response. He then quotes an example from Kailath's book, "Linear Systems". The crux of the argument is to define the class of inputs such that the impulse does not belong to it and then claim the system has no impulse response. This ...

## design an iir by time-domain impulse response

Started by in comp.dsp17 years ago 2 replies

Hi, I wonder if there are methods to calculate the coefficients of a recursive iir filter, for a given time-domain impulse response. (Of...

Hi, I wonder if there are methods to calculate the coefficients of a recursive iir filter, for a given time-domain impulse response. (Of course I can not give an infinite impulse response, but if I want a filter which follows approximately the given impulse response of maybe 16 samples or so - it can have an additional 'tail' afterwards) I wonder if this might be usefull for the implem...

## impulse response of a nonlinear filter

Started by in comp.dsp13 years ago 6 replies

Hello forum, if a time-invariant (zero memory) nonlinear filter is fed with a delta impulse, it will output a certain output. That output...

Hello forum, if a time-invariant (zero memory) nonlinear filter is fed with a delta impulse, it will output a certain output. That output will be the same no matter when the impulse is applied due to time invariance.... Superposition (convolution) is not valid for nonlinear system. Is there however some generalized impulse response concept for nonlinear systems? After all, nonlinear...

## real valued impulse response

Started by in comp.dsp9 years ago 31 replies

Hello, Books describing LTI systems often make reference to "real valued impulse response". I am little confused here ... what type of...

Hello, Books describing LTI systems often make reference to "real valued impulse response". I am little confused here ... what type of practical systems would have "complex values impulse response" vis-a-vis "real valued impulse response" Thank you _____________________________ Posted through www.DSPRelated.com

## Help to interpret impulse response of an fixed point IIR filter

Started by in comp.dsp18 years ago 11 replies

I have done an impulse response of an IIR filter. The impulse response of the filter does not return to zero but stops at a level close to zero...

I have done an impulse response of an IIR filter. The impulse response of the filter does not return to zero but stops at a level close to zero (I think it?s because limitations in fraction bits). The filter is implemented in fixed point arithmetic?s. And when I make an FFT of the impulse response de 0 Hz gain is not 0 dB as I would like it to be. But when I run a step response I...

## Truncating a measured impulse response

Started by in comp.dsp12 years ago 8 replies

Hi, I have measured the impulse response of a plant using an MLS sequence. I now have a nice 1.3ms (130k points!) long impulse response, for...

Hi, I have measured the impulse response of a plant using an MLS sequence. I now have a nice 1.3ms (130k points!) long impulse response, for which I can take the FFT and see the frequency response. The impulse response vanishes to almost zero after about 1024 samples. In fact, if I simply truncate it to 1024 samples, I get an identical frequency response. However, if I start truncating to les...

## Impulse response of the hilbert transform

Started by in comp.dsp15 years ago 1 reply

hi there, i was going through a paper on using hilbert transform for edge detection in image processing.It said over there that the hilbert...

hi there, i was going through a paper on using hilbert transform for edge detection in image processing.It said over there that the hilbert transform works better than differentiation for edge detection as it has longer impulse response which helps reduce the effect of noise.I am new to the subject and dont understand what exactly does a longer impulse response mean.??.and how does the impulse res...

Started by in comp.dsp15 years ago 12 replies

Here's my problem. I have an image to be processed (well, deconvolved pretty much), and a star-shaped impulse response I want to deconvolve it...

Here's my problem. I have an image to be processed (well, deconvolved pretty much), and a star-shaped impulse response I want to deconvolve it with. The impulse response is symmetric in both the vertical and horizontal axis and pretty much centred, but not very precisely. Of course both the image and the impulse response are appropriately zero- padded as to avoid any circular convolution. ...

Started by in comp.dsp13 years ago 6 replies

Hi all, Please share your views regarding the implementation of impulse radio digitally. Let me be more specific, Since UWB is impulse...

Hi all, Please share your views regarding the implementation of impulse radio digitally. Let me be more specific, Since UWB is impulse radio and therefore transmission has to occur over a wide band of frequencies. However, the frequency spectrum has to be bandpass, rather than baseband. My question is that can we use a pure digital system to transmit impulses? So, we transmit baseb...

## Impulse invariance method

Started by in comp.dsp4 years ago 1 reply

I have a laplace transfer-function G(s)=k(1+sT)/s*2 which I need the discrete-time version G(z) using impulse invariance method. Using...

I have a laplace transfer-function G(s)=k(1+sT)/s*2 which I need the discrete-time version G(z) using impulse invariance method. Using partial fractions I get G(s) = c1/s + c2/s^2 c1=kT and c2=k However when I use Matlab c2d and select "impulse" it gives me a different version though the first term c1 is right. Matlabs second term c2 is negative. I assume for multiple pole...

## Filter Analysis with DFT ?

Started by in comp.dsp18 years ago 7 replies

Hi guys, I'm new at this and still learning. I want to examine (graph) the amplitude vs. frequency response of standard IIR filters...

Hi guys, I'm new at this and still learning. I want to examine (graph) the amplitude vs. frequency response of standard IIR filters (one-pole, two-pole, etc.) Is it correct to pass a delta impulse through the filter, do a DFT, then look at the results ? I've done it like this and the graphs look right but I'm not really sure: (pseudo code) // create delta impulse impulse={1,0,...

## Question about IIR filter design using Impulse Invariance method

Started by in comp.dsp19 years ago 8 replies

I am designing low pass IIR filter using Impulse Invariance method. I've got transfer function H(z) which depends on impulse sample period...

I am designing low pass IIR filter using Impulse Invariance method. I've got transfer function H(z) which depends on impulse sample period T. I was asked to choose an appropriate impulse sample period T for H(z) such that the input signal x(t) = 5 cos(2pi(8000)t ? pi/3) ? 4 cos(2pi(40000)t + pi/2) sampled at a rate of Fs = 100 kHz has only the 8000 Hz sinusoid in the passband. I do...

## What channel impulse response is for this matched response?

Started by in comp.dsp18 years ago

Hi, In one paper, it says: "we give results on a chnnel with sampled impulse response [x-7,...,x7]=[-0.1,-0.1,-0.15,-0.3,-0.33,0.16, 0.33, 1,...

Hi, In one paper, it says: "we give results on a chnnel with sampled impulse response [x-7,...,x7]=[-0.1,-0.1,-0.15,-0.3,-0.33,0.16, 0.33, 1, 0.33, 0.16, -0.33, -0.3,-0.15,-0.1,-0.1] I think this is the response after matched filter from the data symmetry. In the pole/zero plot, there are two pairs of zeros on the unit circle. I don't know what the channel impulse response is, because I ...

## Impulse response of multirate system?

Started by in comp.dsp15 years ago 7 replies

Hi, I was wondering if impulse response of multirate system is defined and can be evaluated? I built a CIC decimator in Matlab, the...

Hi, I was wondering if impulse response of multirate system is defined and can be evaluated? I built a CIC decimator in Matlab, the differential delay is 1, downsample factor is 8. # of stage is 2, transfer function is [(1-Z^-8)/(1-Z^-1)]^2. I realize it is a LTV system. Anyone has idea on how to simulate impulse response of it, not deriving it on paper? cfy30