# Questions tagged [group-delay]

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### 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 ...
637 views

### Negative group delay and envelope advance

I am having a doubt reading about delays in signal processing. Let there be an input to a LTI system with frequency response $H(f)$, given signal $x(t) = a(t)\cos(2\pi f_ot)$, where $a(t)$ is a ...
3k views

### Physical Meaning of Negative Group Delay for causal LTI systems

I have implemented in Matlab (with minor variations) the example 5.1.2 "Illustration of Effects of Group Delay and Attenuation" I found in Alan Oppenheim's Discrete-Time Signal Processing 3rd edition. ...
725 views

### What is meant by "Group delay"?in simple words?

Although likes of this question have been asked many times on DSP SE But i am unable to understand those and i wish to have a crystal clear explanation in simple words with example The only thing ...
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 ...
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 ...
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?
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 ...
3k views

### Interpolating/Decimating CIC Filter Group Delay

I have an Interpolating Cascaded Integrator Comb (CIC) filter designed as so: Rate Change = 100 Number of Stages = 4 Differential Delay = 1 I'd like to calculate ...
249 views

### Group Delay for Hilbert Transformer and Resulting Dispersion

An ideal Hilbert Transformer shifts the phase for all positive frequencies by $-\pi/2$ and all negative frequencies by $+\pi/2$ while maintaining constant magnitude everywhere. Group Delay is the ...
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 ...
733 views

### Calculate the time delay introduced by group delay for IIR-Filters

First of all, let me show what I mean by a simple example of an FIR-Filter: I designed an FIR-Filter with a constant group delay of 323 samples and my sampling rate is 500 Hz. Now I can calculate the ...
410 views

### How do you calculate the group delay in samples of a Biquad Filter at a given frequency from the coefficients?

If I have a BiQuad all-pass filter with a given set of coefficients such as: g: 0.903228 a1: -1.88142 a2: 0.903228 B1: -2.08299 B2: 1.10714 And my operation per ...