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0answers
73 views

Removing unwanted square-wave noise from a signal

I have a signal, s, given at the end of this message. I need to remove the square wave shape from it. The desired signal is actually very small and it has been contaminated by a strong square-shape ...
0
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0answers
15 views

Running 2D array through FFT in matlab

I have an input file that is a 2D array but don't know how to convert code that I have to accept the original file and bandpass filter around 18-20 for frequency and then create the bandpassed output ...
-1
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0answers
43 views

Convolution Between Signals

How can I find the convolution between $$ g_1(t)= \cases{\int A/\sqrt{T}, & 0<t<T/2\\ -A/\sqrt{T}, & T/2<t<T \\ 0, & elsewhere } $$ and $$ g_2(t)= \cases{-\int A/\sqrt{T}, ...
0
votes
0answers
23 views

energy and power type signals [duplicate]

How can I determine if the signal $$\begin{array} \\g_1(t)=A\cos (2\pi f_c t), & \frac{-T}{2}<t<\frac{T}{2} \\ 0, &\text{otherwise} \end{array}$$ and: $$g_2(t)=\cos(t), -\infty < ...
0
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0answers
22 views

Signal Processing using Fourier Transform1 [duplicate]

How can I derive the fourier transform of ...
0
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1answer
69 views

Signal Processing using Fourier Transform

How can I derive the fourier transform of ...
1
vote
2answers
50 views

DFT vs FFT: does odd number works for DFT only?

I am always confused between FFT and DFT. In both algorithm, it has been assumed that the signal is periodic (so my understanding is that, if you have a 20 sample point signal, and you do DFT or FFT, ...
2
votes
0answers
19 views

Determining the point in a temporal signal when a periodic behavior begins to occur

I'm a newcomer to digital signal processing, so I'm looking for some general advice and direction on this problem I have. I have a signal like that shown below. Starting around x=40000, you can see a ...
0
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0answers
39 views

How to check whether a continuous signal is periodic or not?

How to check if a continuous signal is Periodic or not? My notes says $\cos(\frac{3}{2}\pi t)$ is periodic because $T=4/3$. And $\cos(\frac{3}{2}t)$ is not periodic as $T=4\pi/3$.
0
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1answer
15 views

Significance of Lambda in Basis pursuit

In basis Pursuit,l1 minimization is done to perform compressed sensing.In the literature there is a lamba parameter used as a regulizer. What is its significance?
0
votes
1answer
31 views

Teager-Kaiser Operator vs. Hilbert Transform

Since a couple of months I started working on the extraction (estimation) of signal frequency and amplitude components by means of two different time-frequency approaches, namely the Hilbert transform ...
3
votes
2answers
74 views

How to identify useful elements of audio recording and ignore lulls?

I assume this is a relatively simple DSP task, but I'm having trouble finding any information on how to approach my problem. Hopefully someone with more experience and brain power can help me out: I ...
2
votes
3answers
99 views

when is a kalman filter different from a moving average?

this thread asks when a discrete-time Kalman filter is better/different from a simple moving average of the observations: ...
0
votes
1answer
39 views

How to find transfer function looking bode plot

I have some Bode plot (only in amplitude) as these: Now, I must to find their transfer functions, in particular the exact value of their zeros and poles. It is clear that their are a low pass ...
2
votes
2answers
65 views

What is exactly the relationship between poles and system stable?

I see two notions that describe the relationship between poles and system stability. But they are not the same from my understanding The system is BIBO stable if and only if all the poles are in the ...
-3
votes
1answer
40 views

Causal question on a discrete signal

Given a signal with a list of discrete values 1,2,3 (t=0),0,1, Whether the signal is causal when the arrow is in 3 and why? I know the definition of causal is that the output will not depend on ...
1
vote
1answer
24 views

How to concatenate IIR filter (Butterworth) with a Matlab function and evaluate the integral

I have a function of $j\Omega$ and $v$ (velocity), i.e.: $$A(j\Omega,v)=\frac{(j\Omega)^2}{p + \frac{j\Omega}{v}}$$ where $p$ is the pole. I want know how $A(j\Omega,v)$ modify its behavior, when I ...
1
vote
2answers
98 views

What is meant by *sampling* in terms of the *sampling theorem*?

Let $y:\left(-\frac T2,\frac T2\right)\to\mathbb{C}$ be a square integrable function. The Fourier coefficients of $y$ are $$\underline{Y}(k):=\frac ...
1
vote
1answer
47 views

Calculating the power of a signal

I'm trying to calculate the power of a signal and my tutor has given me this formula to do it I've spent the past while building a program and now the foundations are there it's time to implement ...
0
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2answers
57 views

Negative values of the FFT

I try to describe a simple signal in the frequency domain with the use of FFT function: ...
0
votes
1answer
49 views

Periodic Signal Fourier Transform

If I have a signal x(t) as follow x(t)=$\sum\limits_{k=-∞}^∞ R_{T}(t-2kT)$ $R_{T}(t) = \begin{cases}1 ;&[\dfrac{-T}{2},\dfrac{T}{2}] \\ 0; & \text{otherwise} \end{cases}$ ...
0
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0answers
22 views

Stationarity tests of time series in the frequency domain for signal analysis in FFT or multitaper

Strict stationarity is the strongest form of stationarity. It means that the joint statistical distribution of any collection of the time series variates never depends on time. So, the mean, variance ...
0
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0answers
26 views

Common audio signal extraction from multiple similar audio files

Say you have two mono audio tracks recorded from a pair of matching omnidirectional microphones (call them A and B) that were, say, 20cm apart. The audio tracks were recorded at precisely the same ...
0
votes
1answer
36 views

WSS Ergodic Process with Power Spectrum

i was given a WSS ergodic process $x(t)$ with power spectrum 􏰎 $$ \begin{array}{rcl} G_x(f) &=&1−\left|\frac{f}{B}\right| &\mbox{for } |f|<B\\ G_x(f) &=& 0 & ...
2
votes
1answer
44 views

How to remove text region in a document image? or extract image from a document image

Given a document image (i.e. newspaper), how to extract photos in it or remove text region? I think traditional OCR methods may not be suitable here, as I don't need to recognize the text, and OCR is ...
-1
votes
2answers
58 views

How do I identify CUTOFF frequency from my audio signal? [on hold]

I was able to recorded an audio signal through the MIC and i applied FFT and Hanning window function to it. Now I want to know how do I identify CUTOFF frequency from it to apply the High Pass Filter. ...
1
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3answers
112 views

Need critical help: How to detect and distinguish two very similar looking signals?

Hi guys I have a really tough signal processing question here. How do you detect and distinguish two very very similar looking waves? I need to distinguish between these two signals for an online ...
0
votes
2answers
57 views

Use wavelet transform to extract a waveform of certain frequency [closed]

how to apply wavelet transform method to extract alpha waveform( higher and lower band frequency known) from a given known signal ?
0
votes
0answers
25 views

multidimensional signal means more than 2 independent variables and amplitude being dependent variable?

Does multidimensional signal mean more than 2 independent variables and amplitude being dependent variable? Can we conclude mathematically that the number of independent variables increases if ...
0
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0answers
24 views

Signal onset difference between 2 audio signals

I have 2 signals recorded in the same conditions although one was further away from the microphone than the other. I am attempted to find the difference between the time of the signals hitting the ...
0
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0answers
6 views

How do we find the SNRseg if I have a block with 2D in time domain

I always get the answer -.0017 and it suppose to have some negative number around 30. I get the average for the plane voice then the average for the difference between plain and the encrypted voice ...
-1
votes
1answer
61 views

System Properties; Linear, Causal, Time-Invariant, Stable?

I know the answers of the below question but I dont know why, except linear, could you explain the rest? Small tick: correct, small tick with dash incorrect answer.
-1
votes
1answer
29 views

How convert scal to frequency when use cwt in matlab

I am new in DSP.I have the flowing code t = linspace(0,1,1000); x = cos(2*pi*60*t); CWTcoeffs = cwt(x,1:64,'sym8','plot'); colormap jet; and my output is: ...
5
votes
1answer
104 views

Duration of unknown rectangular pulse with additive white Gaussian noise

Problem. There is a discrete signal $f[i]$ (example below). It is known, that $f[i]$ have a form of rectangular pulse with additive white Gaussian noise. $f[i] = s[i] + n[i]$, $s[i] = ...
3
votes
2answers
129 views

OFDM transmitter bandwidth

Theory Suppose an OFDM transmitter with four subcarriers is implemented using the structure shown below. If the serial data input rate is 40 bps, each parallel stream will run at 10 bps. ...
1
vote
1answer
44 views

Sampling orthogonal signals

Suppose I have two signals $f,g$ which are orthogonal in the sense of the usual inner product on $\mathbb R^d$. Then if I'm not mistaken these signals have disjoint spectral support, i.e their fourier ...
0
votes
2answers
48 views

Fundamental frequency

Can someone help me: I have a signal which consist of three frequencies; for example, $f_1=800\,\text{Hz}$, $f_2=1050\,\text{Hz}$, $f_3=1600\,\text{Hz}$. How can i compute the fundamental frequency? ...
0
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1answer
23 views

how do you compute the channel gain from path loss index in wireless communication? [closed]

how do you compute the channel gain from path loss index in wireless communication?
1
vote
1answer
19 views

Is a negative Es/No for an SCPC RF signal possible, and what would such a value signify?

I apologize if this isn't the correct Stack on which to ask this question, but it seemed like the best fit. I've tried to Google an answer, but I haven't been able to find anything that applies ...
1
vote
2answers
69 views

What is a 'time-variant' signal?

I have found in the literature a "time-variant signal" term , but I could not understand what that's mean. I know that there is "time-variant systems", but this is the first time, which I see a ...
0
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0answers
28 views

Using bilinear method while filtering a signal - Matlab

i have to current signal in matlab: Fs = 8000; T = 1/Fs; N=512; t = (0:N-1)*T; ...
0
votes
0answers
23 views

USB-connectable ECG machine

I would like to buy some kind of ECG (electrocardiogram) machine for developing signal processing and machine learning applications. I am looking for something that is not overly expensive, can be ...
2
votes
2answers
64 views

Periodicity of the output of causal time-invariant systems when the input is periodic

For time-invariant systems, if the input is periodic, the we can argue that the output is periodic: If we shift the input signal one period, we come up with the same signal as before, and since the ...
0
votes
0answers
24 views

Applying Bilinear filter to a signal -MATLAB

I have the following code: ...
1
vote
2answers
70 views

Normalization purpose in signal processing

What is the purpose of normalizing the signal? If we have two signals on hand, how is it used when comparing these two signals?
0
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0answers
26 views

To determine dominating frequency from pressure time plot

I have pressure data over time. I need to find the dominating frequency of this data. I tried fft in fluent and also in matlab. Both gives me the same plot which is having too much of peaks. I need to ...
1
vote
1answer
83 views

Beat Detection with Arduino

I'm trying to make a robot dance on several songs using Arduino. I need to understand how to get the rhythm from the songs, something like detecting the beats, calculating the bpm.. I'm not expert but ...
0
votes
0answers
32 views

Feature extraction and Variance

I see there is a relationship between the Variance of a signal (i.e EEG signal) and features extraction of that signal. for example PCA tend to take almost of the variance of the original signal , but ...
2
votes
2answers
72 views

Effects of DC offset on a signal

What are some of the reasons why DC offset is considered undesirable for a timeseries signal other than wastage of power during transmission ? Specifically, How does it cause spectral leakage and out ...