Questions tagged [group-delay]

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Group delay (MATLAB $\tt grpdelay$)

I have been trying to figure out how it is I have an IIR filter with large negative group delay. It's my understanding that if a filter is causal and stable, the group delay can't be negative at all ...
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1answer
2k views

How to remove a costant group delay?

I have to subtract, from a signal x[n], its version filtered thorugh an LPF FIR filter, like this: xf=filter(h_lpf,1,x); y=x-xf; How can I remove the group delay introduced by the filter h_lpf into ...
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1answer
245 views

Lag in financial trading vs Group Delay in signal processing

I'm a newbie to Signal Processing - and so I'm providing a "background" and a "question" section separately. Background: Suppose I have a linear filter (w.r.t. given as $\theta_{t+1} = \theta_t + ...
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1answer
158 views

Sketching Phase Spectra Using Group Delay and Magnitude Spectra Informations

I have only magnitude spectra and group delay information and I need to sketch phase spectra from this information. For example, group delay is given like this: $\tau_{g}(\omega) = c$ where c is a ...
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2answers
3k views

How to design a filter with custom group delay -- why is it an IIR?

Say I have an FIR filter with desired magnitude characteristics. I could imagine using an allpass IIR in series with the FIR to alter the group delay characteristic to provide both a 'magnitude ...
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1answer
2k views

once again,confusion between phase and group delay [duplicate]

Despite,reading up on this I'm unable to find crystal clear clarity on the differences b/w phase and grpdelay functions and interpretation of grpdelay's output. I have designed a low pass butterworth ...
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2answers
1k views

Allpass group delay formula and effect on Karplus-Strong

Some introductory questions: What is the unit of the group delay in a digital filter (is it samples?) What is $\Omega$ in the equations below (is it $\Omega=2 \pi\frac{f}{f_{sample}} ?) $ If I got ...
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1answer
550 views

Interpret group delay of a filter

I keep reading that a constant group delay over a frequency band is desirable for a filter. But a constant group delay means a linear decrease in the phase delay, which would distort the signal. Let'...
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2answers
1k views

group delay of an fir filter

suppose we have an fir filter: t=[-50:50]; x=[sinc(.1*t).*cos(2*pi*.15*t),sinc(.1*t),sinc(.1*t).*cos(2*pi*.3*t)]; using matlab command grpdelay(x,1),we observe the groupd dalay of the system. then we ...
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3answers
7k views

Converting from a phase response to a group delay response and vice-versa

I'm trying to figure out how to convert any phase response to the corresponding group delay response. Is there a way to do that, and vice-versa if possible?
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3answers
8k views

How to find the group delay of IIR filters in Python/SciPy

I sent a square wave signal (red) through a IIR filter (butterworth in this case), to make it more "realistic". Then there's a slight group delay in my output signal (blue). Is there a way to find out ...
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4answers
9k views

How can a filter have zero group delay?

If you put a wave packet through the passband of a 1st-order low-pass filter, it will be delayed by the group delay of the filter, and remain the same amplitude, right? If you put the same wave ...
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5answers
68k views

What is the difference between phase delay and group delay?

I'm studying some DSP and I'm having trouble understanding the difference between phase delay and group delay. It seems to me that they both measure the delay time of sinusoids passed through a ...

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