Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [impulse-response]

The impulse response of a dynamic system is its output when presented with a brief input signal, called an impulse.

0
votes
0answers
19 views

Time gating of FFT for audio Measurements or Multi Time Windowing

I am learning more about DSP specifically for audio measurement purposes. I can an app, where I can create a log sine sweep from start frequency to end frequency over a certain length. I can perform ...
0
votes
0answers
18 views

Determining position and g-forces from accelerometer and gyroscope data

I'm analyzing gyroscope + accelerometer data acquired from an IMU for a run of a water skiing slalom course, sampled at 100Hz. The double spikes represent spurious ~15G jitter from crossing both ...
0
votes
2answers
61 views

My impulse response does not tend to zero

I am doing an IFFT of frequency response data achieved with Simulation tools. When I plot my impulse response it looks wrong as the response does not tend to zero as it should. Instead there seems ...
0
votes
0answers
10 views

What is difference between natural response and zero-input response of a system and how to find natural response? [duplicate]

In most books it is said that natural response is another name to zero-input response while in some resources is is mentioned that the classification is based on poles of transfer function and input....
0
votes
0answers
11 views

Methodology for log some sweep audio measurement impulse response

I am trying to implement a method for measuring the response of a loudspeaker in a room using a log sine sweep stimulus. To check my method: 1. I create the stimulus using: Make recording length ...
0
votes
0answers
24 views

Solving impulse response using summation of singularity functions

I'm stuck at Problem 2.56 of Alan Oppenheim's Signals and Systems book. Here is the solution given. I did learn basic differential equations before from Boyce's book but I have never encountered ...
1
vote
0answers
18 views

Simple Impulse Response DSP Hardware

I developed some complex chains of filters and crossovers. After that I have created IRs from the entire chains. Applying these IRs in software works perfectly. Now I wonder what is the easiest (and ...
2
votes
0answers
32 views

What is the difference between an impulse response and a kernel?

It seems to me they are two terms used to refer to the same concept, but, according to the Wikipedia page on Guassian filter a Gaussian filter is a filter whose impulse response is a Gaussian ...
0
votes
0answers
34 views

Find output from a system with x(n) = u(n)

I've started learning signal processing and I'm trying to understand this exercise: Assume an LTI system, described by the difference equation: $$y(n) - y(n-1) - 6y(n-2) = x(n-1)$$ Q: Find ...
1
vote
1answer
52 views

Discrete Time Fourier Analysis

Suppose we're given the following: $ x[n] = 2 + (-1)^n $, and are given the impulse response $ h[n] = u[n] a^n $, of an LTI system where $ |a| < 1$. We're asked to find the output $y[n]$, if $x[n]$...
0
votes
0answers
21 views

Impulse response of discrete time system

I am learning about discrete systems and in this derivation something struck me as quite odd. Solving for $A_0$ in this equation seems dubious as it ignored all other values of $n$. For example, at $n=...
0
votes
1answer
75 views

How to determine the filter type based on the impulse response?

When given a discrete impulse response, let us say it is from an FIR filter so it is finite, how can I assume the filter type? The task is to recognize or to preclude one or more of the following ...
0
votes
0answers
89 views

How do I play and record audio at the same time?

So this question is more related to Matlab itself. Some background info: I'm trying out the Exponential Sine Sweep method to obtain the Room Impulse Response with my laptop speakers and microphone ...
0
votes
1answer
159 views

What will the impulse response of a matched filter look like if the input is complex?

If $h(t)$ is the impulse response of a filter matched to a signal $s(t)$, I read that $h(t) = ks(t_o - t)$. But what if the signal is complex? I went through the derivation of the matched filter and ...
0
votes
1answer
47 views

Self study question about Padé Approximation and transfer functions

Given a signal $x[n] = [1, 2, 3, 4, 5]$. How many transfer functions can be found with Padé approximation which have a causal impulse response and start with those five samples. How many of them are ...
1
vote
1answer
87 views

Numerical Calculation of impulse response out of frequency response

Currently I work on my Masterthesis which deals with structural dynamic simulation. As a part of it I have to filter a Signal with a FIR-Filter. From that Filter I know the Frequency Response (picture)...
0
votes
1answer
59 views

How to find the impulse response of filter that outputs the autocorrelation of the input?

I am trying to solve question 9.61 in the attached image. I guess, by evaluating the autocorrelation for a specific instance, say $ t = 0 $ , that the impulse response, $h(t)$, should be : $$ h (t)...
-1
votes
2answers
63 views

How does an LTI system produce multiple values from a unit impulse

I understand that in a discreet system, an impulse is 1 at the origin point and 0 everywhere else. I've seen many examples showing the impulse response of an LTI system to be many points, have many ...
0
votes
1answer
35 views

channel estimation for cdma

I am looking for a method to make a multi-user channel estimation with CDMA. Here is my question: Is there a way to estimate multi-user channels with their spreading codes? If yes, what is the ...
1
vote
1answer
52 views

Calculating an output of a system (Z- transform question)

I have a following question to answer: An LTI system is described by its impulse response h[n]. For input x[n] it gives output y[n]. $$h[n] = u(n) - u(n-N) $$ $$x[n] = u(n) - u(n-M)$$ I want to ...
-1
votes
1answer
56 views

Impulse response resampling : IIR aproximation vs windowing

I have a long measured impulse response and I wand to shorten it. I imagined two options. The first is a simple windowing. The second is to model it as an IIR (prony, yulewalker, stmcb method) before ...
2
votes
1answer
69 views

Are there DC removal techniques that do not introduce a filtering transient?

I have an application in which I need to remove DC components from a sampled signal in real time (basically the same constraints of ECG, but it has nothing to do with the brain). My measured signal in ...
6
votes
7answers
471 views

Intuition behind commutativity of convolution in LTI systems

Why is convolution commutative, as it seems to treat two signals in a different way in an LTI system? If you imagine $y[n] = x[n] \star h[n]$ with $x[n]$ being an input signal and $h[n]$ being the ...
1
vote
1answer
131 views

How to represent impulse function in 2D?

To be more specific I want to show that impulse function in 2D can be represented as $β(r)=δ(r)/πr$. Also I want to show that each projection of a two dimensional impulse function at the origin is a ...
1
vote
1answer
104 views

Simple Impulse Response

I am trying to find the impulse response to this system: At first it looks easy enough, $y(n)=x(n)(-1)^n$, set $x(n)=\delta(n)$, which makes $h(n)=(-1)^n$. But something seems wrong. What am I ...
0
votes
2answers
107 views

Block diagram for a complex impulse response

I have this question regarding digital systems which might not handle sinusoidal signals in general. So let us say that I have a system with impulse response $h(n) = \{1+j, -1, 2j \}$ with first ...
0
votes
1answer
147 views

How to find the impulse response of this system with complex roots?

I've been working trying to analyze a causal stable system. Hopefully a numeric example such as the one I am working on, and the problems I face during it could be useful to others. I have this ...
1
vote
1answer
1k views

How to calculate impulse response of a RC circuit

I have an $RC$ circuit and I calculate the differential equation as $$RC \frac{dV_c}{ dt} + V_c = V_g$$ that is the same of $$RCy'(t) + y(t) = x'(t).$$ If I assume $x(t) = u(t)$ I have that the ...
1
vote
1answer
166 views

Impulse response of a second order LTI

I have a set of measurement which I want to model with 2nd-order difference equations (first order eqs don't model well enough). The equation is $$y[n] = \alpha_1 y[n-1] + \alpha_2 y[n-2] + \beta_0 ...
1
vote
1answer
61 views

Steady state value of a complex convolution

I am trying few problems on the introductory part of DSP. One of the problem asks to calculate the steady state response of a system with impulse response $h[n] = (\frac{j}{2})^{n} u[n] $ to an input ...
0
votes
1answer
36 views

Why is the impulse response function of this system 0?

Suppose I have an system $ y(t) = t^{2}x(t)$. The impulse response of this system would be: $h(t) = t^{2} \delta(t)$. Since $\delta(t) = 0$ for $t \neq 0 , h(t) = 0$ for $t \neq 0$. And at $t=0, h(...
-2
votes
2answers
107 views

Impulse response when input to a system is differentiated, and its applicability to find response to general inputs

I will first give a short explanation of what I am asking, and then give a more comprehensive context. If we have a LTI dynamic system acted upon by inputs $y(t)$ and producing outputs $x(t)$, , we ...
2
votes
1answer
132 views

Convolution of Input signal and Impulse response

I can solve the output if the input is $$ x[n] = \delta[n+1] + \delta[n] + 2\delta[n-1] + \delta[n-2]$$ and the impulse response is $$ h[n]= 3\delta[n] − 2 \delta[n−1] − \delta[n−2] + \delta[n−3]$...
6
votes
4answers
1k views

Why is the first value in digital first-order IIR filter impulse response not the largest?

When I create a digital first-order IIR low-pass filter with scipy (code below), I get the following coefficients: B: [ 0.1367 0.1367] A: [ 1. -0.7265] The ...
0
votes
1answer
106 views

Impulse response from Frequency response: why using $e^{j\omega}$ as an input?

Every resource that I can find uses this identity when deriving impulse response: $h[n] = IDTFT \Big\{H(e^{j\omega}) \Big\}$ Suggesting that the input signal was $e^{j\omega}$. But by definition ...
0
votes
1answer
87 views

Phase wrap when computing impulse response from frequency response [closed]

Short: I have the frequency response of a system as a set of complex numbers. I want the impulse response for that system. Problem: The phase of my frequency response wraps around 2pi multiple times....
0
votes
2answers
55 views

How can I calculate what a recording would sound like if it was played through my speakers and mic?

I am trying to isolate the sound of someone speaking while music plays back in a noisy environment. I have multiple speakers and a microphone in my system. I am able to play back just music and ...
0
votes
1answer
59 views

Simple question about Sinc()

Suppose I use the ideal lowpass filter eq to attempt creating a IIR filter using it : $$ h[n] = \frac{\sin(\omega_c \, n)}{\pi \, n}, \qquad -\infty < n < \infty $$ Obviously, I can't really (...
5
votes
6answers
280 views

Optimal $ n $ -th Order IIR /AR Approximation of a Moving Average Filter

I would like to approximate a moving average filter with an IIR filter of much lower order than the tap-length of the moving average filter. Optimality shall refer to the $L_2$ norm of the impulse ...
1
vote
2answers
122 views

How to compute the impulse response from incomplete frequency response data?

I need to compute the impulse response of a system, but I only have access to the frequency response data. This data contains the output magnitude of the system (for a fixed input amplitude) at ...
1
vote
1answer
79 views

Poles of the transfer function in Z Transform

Given that: $H(z)$ has 4 poles maximum. $H(z)$ has a pole at $z_1=a+bi$ Given that the impulse response $h[n]$ is: Symmetric: $h[n] = h[-n]$ Real: $\forall$$n$ , $h[n]$$\in$$\mathbb{R}$ How we can ...
0
votes
1answer
188 views

FIR Impulse response & transfer function

I am working though a dsp past paper and I have come across the questions "find the impulse response in the time domain" & "find the transfer function in the time domain" I know its really simple ...
0
votes
0answers
78 views

Estimation of the frequency response data using Matlab command invfreqz?

I would like to determine frequency response and then impulse response of the displacement equation (eq. 1 please see screen shot of the task below). In this example we study a response of the finite ...
0
votes
1answer
89 views

I want to get impulse response of causal system

I want to get impulse response of this causal system on first photo. So I got frequency response on second photo from this system. and now I am trying to transform this frequency response to impulse ...
2
votes
2answers
129 views

Frequency response of marginally stable LTI systems

The frequency response of a system is defined as: $$\int_0^\infty{h(t)e^{-j\omega t}dt}$$ where $h(t)$ is the impulse response. But in marginally stable systems, $h(t)$ does not decay so the integral ...
0
votes
2answers
56 views

Equalize Speaker using impulse response

So I have this school project where my aim is to improve a loudspeaker in general, my idea is to mesure the impulse response of the room using a mic, then use this mesure to conceive a loudspeaker ...
3
votes
0answers
104 views

Multilateration of Sound in 3D Space

TL:DR - How can you find the 3D coordinates of a emitter than transmits an impulse signal? STORY: I'm working on something to improve my bird-watching. I've got a camera that can take pictures of ...
1
vote
1answer
262 views

Impulse response of a causal system from transfer function in z-domain

The transfer function is $$H(z)=(z+1)/(z^2+z+0.5)$$ I need to find the impulse response h[n] of a causal system with x[n] as unit impulse. I have tried to find the impulse response by the following ...
1
vote
3answers
237 views

Why use transfer functions than differential equations?

I have some simple questions regarding DSP and Control Systems, but found no simple answers. I just need simple and easy to understand answers, not complex answers with huge maths. Why we use ...
0
votes
1answer
69 views

Homework Help: What does $h[0] = 1$ represent? What is $\ln \big| H(e^{j \omega})\big|$?

I have been staring at this problem for a week now... Suppose $H(e^{j \omega})$ is the frequency response of a stable and causal minimum-phase discrete-time system with $h[0]=1$ ($h[n]$ is the ...