Questions tagged [continuous-signals]
A continuous signal or a continuous-time signal is a varying quantity (a signal) whose domain, which is often time, is a continuum.
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Find LF component of AM signal
I'm trying to figure out how to find the low frequency component of an AM-signal when I have regained the carrier.
So the signal is:
$$U_{AM} = 2[3+0.4cos(2\pi\cdot2\cdot 10^3\cdot t)]\cdot sin(2\pi\...
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Signal Header:Physical Min is not less than Physical Max- after opening EDF file on the viewer
Whenever I open an EDF file on the Case Western Research University's EDF Viewer Application, I get a Scaling Warning-"Signal Header:Physical Min is not less than the Physical Max ". I am reading ...
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1answer
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What is the effect on Hilbert transform of signal after multiplication by sinusoid?
Question :
Find Hilbert transform of $[u(t-a)-u(t-b)]\cos2\pi f_{0}t\\\\$ such that $\\0<a<b$
my attempt:
we know Hilbert transform of
$[u(t-a)-u(t-b)]\xrightarrow{\mathcal H} \dfrac{1}{\pi}\...
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1answer
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Continuous time double exponential filtering in state space form?
I'm trying to determine the continuous time formulation of the double exponential filter so that I can adapt it more flexibly for my particular problem.
Typically, this model is expressed as a pair ...
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0answers
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Bandwidth of Time Division Multiplexing
Why is it said that bandwidth of output of a TDM transmitter is half of Sum of individual sampling frequencies.Is their a mathematical proof.
I know that sampling frequency should be greater then ...
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2answers
43 views
How is frequency defined for a periodic signal?
For sinsusoids, frequency is $2\pi/T$, but for general periodic signals, how is frequency defined? Is it $1/T$ or $2\pi/T$?
($T$ is the fundamental period of the signal)
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2answers
51 views
PSD of modulated signal
I know this question has been previously asked just saw it and tried to do myself but reaching an expression which is different from expression of PSD which I remember for modulated signal
Actual ...
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0answers
24 views
Low pass representation of Bandpass Random process
Can A WSS random process with non-zero mean be also represented in such form.
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34 views
How to Derive Rayleigh distribution using transformation formula
Consider a complex random variable $Z=X+\jmath Y$, where the probability density function of $X$ and $Y$ are given by $$p(x) = \frac{1}{\sqrt{2\pi\sigma^2}} {\rm
e}^{-\frac{x^2}{2\sigma^2}}\quad\mbox{...
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3answers
89 views
Confusion in AC and DC signals
I have certain doubts in the fundamentals of AC and DC signals.
Most of the time, we deal with DC signals in the form of batteries, whose waveform is a constant signal with peak as 1.5v
However, i ...
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2answers
44 views
Independence of Functions of random Variable
Consider I am given two functions of one random variable each for example x=cos(at),y=rect(bt) where a and b are random variables.And I am given Probability density function for a and b then if I am ...
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Notch filtering minimizing artifacts in signal
I have to notch filter the following signal
As you can see it is a signal with really high amplitude.And this causes me a lot of problems. I've designed a bandstop filter (46-55 Hz).The MATLAB code ...
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1answer
25 views
Diode demodulation for AM
What is the capacitor and resistance at output of LPF meant for in the document it was mentioned that it is DC blocker I don't get it can't message contain DC value.
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1answer
70 views
Is convolution distributive over multiplication?
Is there any formula or expansion for
$$a(t)*[b(t) \cdot c(t)]$$
$$a(t) \cdot[b(t)*c(t)]$$
where $*$ denotes the convolution?
By expansion I mean something like $a(t)\cdot[b(t)+c(t)]=a(t)b(t)+a(t)...
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Envelope detector for AM signals
How or what are the constraints for deciding factors of envelope detector for AM As far as I know that charging time of capacitor should be below 20T where T is periodic time of carrier and ...
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2answers
60 views
Digital Equations problem - The fundamental ones that everyone should know
I think I am looking at conflicting equations from a few sources, or maybe I just dont understand it. But please can someone help me with these fundamental equations that everyone should know
$ \...
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0answers
41 views
How to find fundamental frequency of two signals?
I am facing difficulty with finding fundamental frequency of signals
I mean by fundamental frequency=(1/Time period)
Correct me if I am wrong
consider two continuous time signals with
Time period ...
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3answers
272 views
How to Prove a System Is Invertible?
what i know is that for a system to be invertibel it should be one-one ,
but I am confused that if i am given a transfer function of a LTI system how can I prove or verify if it is invertible.
...
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0answers
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What is definition of cross correlation function?
I mean there are three different formulas for cross correlation that I have studied f and g are two functions whose correlation has to be found
1.For Energy signals
2.For Power signals
3.For ...
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1answer
32 views
Peak Detection on ECG signal
I've been working on a ECG signal collected during exercise through my chest mount heart rate monitor. My goal is to accurately detect the location of the R-wave; R-wave is the narrow peak similar to ...
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1answer
54 views
Discrete Kalman filter for a continuous system
The question is related to the implementation of a discrete kalman filter given a description of the system model in continuous time.
I will give an example. Suppose we have a mass, spring and damper ...
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1answer
53 views
Computing response of LTI system in terms of its step response
I have solved a problem, Kindly help me in determing if I solved it correctly.
I will post the question and my own working below.
Problem
My working
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1answer
1k views
Why doesn't sampling a periodic continuous-time signal yield a periodic discrete-time signal?
I have been studying signals and systems lately and I have came across the following claim:
The uniform sampling of a periodic continuous-time signal may not be periodic!
Can someone please ...
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1answer
45 views
Conversion from continuous to sampled signal?
I am bit confused regarding sampling as i read different types of statements in different texts
Forexample i have a continous time signal $x=sin(t)$ defined for $t=0:10$
and i want to sample it with ...
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0answers
21 views
why we use time step only in continuous convolution in MATLAB? But not in discrete convolution?
I am studying convolution from book of alex palamides but i am confused because he uses time step(in this case 0.01) in his code for continuous convolution as shown highlighted in attached photo but ...
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1answer
36 views
Usefulness of Matched $z$ transform Method
I'm aware that the matched $z$ transform method maps between the continuous $s$ plane and the discrete/digital $z$ plane but my question is - when would this be necessary? Why would we need to convert ...
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1answer
32 views
explanation of Hybrid systems?
I want to study Detailed explanation of hybrid systems?Which incorporate both continuous and discrete time signals & systems?
for example
In which a continuous-time input signal is transformed ...
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2answers
68 views
negative value of signals
can we say there is no sound produced when the amplitude is 0?
if yes what can we say when the amplitude is negative?
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0answers
17 views
Continuous-time RNN and Shannon sampling theorem
The most-used discrete-time RNN equations used in Deep Learning these days are those of Elman:
I have seen two very different continuous-time version of these, with different justifications. The most ...
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1answer
32 views
Are the error probability of orthogonal signal and on/off signal the same?
I have to write the error probability of orthogonal signal and on/off signal,and now i have finished the error probability of on/off signal,but i don't know how to write the code about error ...
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1answer
25 views
Time Setting of $z$ and Laplace Transforms
I'm aware that the z-transform and the Laplace Transform have an analogous relationship but I want to be doubly-sure that the z-transform only works in discrete-time and that the Laplace transform ...
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2answers
37 views
Confused in difference between sequence versus signal?
I am learning basics of signals and systems with MATLAB
If i create a vector in matlab such that
x=[ 2 5 10 20], will it be considered a sequence or a signal?
As ...
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43 views
Detect the Beginning and Ending of a Signal
I have a signal that looks more or less like square wave signal with different phases (Like in the picture below).
However, the signal fluctuates a lot, we can see in the image below:
At first, I ...
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1answer
36 views
Consider the integrator and check for time invariance
I'm trying to check the following system for for time-invariance.
$$ y(t) = \int_0^t x(\lambda) d\lambda$$
Please explain me why it is time-invariant.
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2answers
74 views
Confusion in linearity?
I am studying linear systems from the book "Signals and Systems Laboratory with MATLAB". I have performed an example on MATLAB myself in this regard.
Code is as follow:
...
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0answers
24 views
Using MATLAB to plot the input and the magnitude spectrum of the signal
I have an aperiodic signal $v_{out} = e^{-t} u(t)$ (real exponential signal) from discharging capacitor.
I was trying to plot using MATLAB 15 seconds of this signal in time domain? I am thinking how ...
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31 views
how can I know this system is Time invarient?
y(t) = 0 (t<0);
x(t) + x(t-2) (t>=0);
y(t) = 0 (x(t) < 0);
x(t) - x(t-2) (x(t) >= 0);
y[n] = x[n] (n>=1)...
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Can anyone please describe the relation between linear convolution and circular convolution? [duplicate]
It would be great if anyone could help. I am not able to find any relation amongst them, to me they are different things altogether.
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Is there any python code for applying a-law/mu-law on 3D numpy array?
I have 3D numpy array of probabilities between [0,1], I need to emphasize on some area with lower probabilities. I was suggested to apply a-law and mu-law.
I am wondering if there is python library/...
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0answers
26 views
How to remove varying noise from strain data in MATLAB
I'm very new to signal processing. I have some data measured over time at 800 Hz. I'm interested in the high frequency signals. You can easily identify them in the image below (in this case, 3 signals)...
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0answers
22 views
Extracting signal from data using Otsu thresholding in MATLAB?
I am very new to signal processing. I am trying to extract a signal from my data using otsu threholding but it's not fully accurate. In this case I know that there is going to be a single signal in ...
2
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2answers
51 views
How to identify the beginning and the end of a signal using MATLAB
I have multiple signals as shown in this image. I'd like automatically detect time for the earliest detection of the signal (approx 0.7e4 in S1-B3-B (orange)) and last detected occurrence of the ...
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1answer
43 views
Area under waveform in t-domain including 2 delta functions
question:
my attempt:
$(a)$ $\displaystyle\int_{-\infty}^{\infty} f(t) dt=2 u (t)+r(t)-r(t-T)+Ku(t-T)$
then we draw it's diagram and found it was unbounded so,we doubt how area can be zero for any ...
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1answer
31 views
How would I find the function given the magnitude plot and the phase response?
I'm wondering how I'd find the Fourier Transform X(jw) given the following information:
My understanding is that the expression for the continuous time fourier transform (CTFT) is magnitude(CTFT)exp(...
0
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1answer
29 views
Processing using Matlab
I'm new to Matlab.As a beginner, I want to work on few signals which are used in day today life and extract useful information through it. Can someone please help me from where I could start or share ...
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1answer
42 views
Confusion in the derivation of convolution formula [closed]
$$x(t)=\int_{-\infty}^{\infty}x(\tau)\delta(\tau-t)d\tau=\int_{-\infty}^{\infty}x(\tau)\delta(t-\tau)d\tau$$
Due to linearity,
$$y(t)=T\{x(t)\}=\int_{-\infty}^{\infty}x(\tau)T\{\delta(\tau-t)\}d\tau=\...
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1answer
48 views
Are there any signals with brickwall autocorrelation?
Are there any signals whose autocorrelation $R(\tau)$ has the following form? Assuming $\tau_c > 0$ and $R_0 > 0$ a constant,
$$R(\tau) = \begin{cases}R_0, \text{ for $|\tau| < \tau_c$} \\ 0,...
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1answer
39 views
Reason of effect of continuity and discreteness on periodicity of signal?
We know that a sine signal in continuous time is a periodic signal with a period $2\pi$ whereas the same sine signal in discrete time is aperiodic.
My question is how changing just a type of signal (...
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1answer
34 views
response of LTI system to a Random Input Signal
what is LTI filter? what is the output when x(t) is input?
let x(t) be the input signal to the system and y(t) denote the output signal. The output of the system may be expressed in terms of ...
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2answers
165 views
A question on Fourier Series and the frequency of the sinusoids
On studying about Fourier series, I encountered 2 doubts:
How is it that a non-periodic function has a Fourier series?
When expressing a periodic function as summation of sinusoids, why is the ...
