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Questions tagged [signal-analysis]

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0
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1answer
64 views

Counter design for audio signals

I am designing a schematic in which a Counter is to be increased whenever a particular band of frequencies is received at the Audio input. We are receiving the audio input as electrical Signal and I ...
-1
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2answers
2k views

What the terms Basis functions and Orthogonal denote in case of signals?

I am a beginer. I have read that any given signal whether it is simple or complex one,can be represented as summation of orthogonal basis functions. Here, what the terms Orthogonal and Basis ...
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2answers
144 views

As DCT Does Compaction of Energy, Can We Say IDCT Does Energy Spreading?

Like energy compaction transforms, the inverse transforms like IDCT are energy spreading transforms?
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1answer
2k views

Convolution of a signal by itself properties [closed]

I'm studying for a test and I can't really explain this question very well. If we convolve a signal by itself, will it have the same properties (time-invariant, linear, stable, casual)? I know how ...
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3answers
57 views

How does real-time signal processing work when the signal we deal with is assumed to be known for all times?

One thing that never sat right with me after my signal processing course is that in order to do signal processing, we must know the entire signal $x(t)$. For instance, I cannot take the Fourier or Z ...
-1
votes
1answer
292 views

FMCW Radar Signal Processing Flowchart / Ambiguity Function

I Read many papers on signal processing for pulsed and FMCW radars, taking the FMCW type, the signal processing start after mixing the received and transmitted signal, the result of this operation is ...
-1
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1answer
613 views

What is the product of Dirac Delta function and $t$? [closed]

$t\cdot \delta (t)$ Does it equal to zero? If so, how can we prove it?
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2answers
151 views

How to look at Rubidium frequency standard using the oscilloscope?

This question is about the checking hardware, please help if someone who has done it before. I have the Rubidium frequency standard: http://www.thinksrs.com/products/PRS10.htm and the Oscilloscope: ...
-1
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1answer
255 views

Conversion from RMS to pk-pk units

I have this problem. I am trying to convert my measurement resuls that I got from my analyzer from RMS units to pk-pk units.The signal is modulated with square signal. I already have a factor to ...
-1
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1answer
129 views

What is the best approach for studying the information within frequencies of an unknown signal

If we have a signal and we do not know anything about this signal. We do not know which frequencies contain specific information, and which frequencies does not contain information. Which is the ...
-1
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1answer
2k views

Compare two audio tracks

I need to compare two audio tracks and compute the difference. The difference is how close they are in terms of pronunciation, rhythm etc. ignoring speaker voice characteristics. The first track is ...
-1
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1answer
495 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: ...
-1
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1answer
19 views

When does a color channel such as RGB carry more info than a grayscale channel or image?

Typically a gray-scale image gives us more information about an image in terms of a signal processing problem. But when does a color channel carry more info than a gray-scale channel? I understand ...
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1answer
24 views
-1
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1answer
234 views

Power or Energy Signal of $x(t) = t \cdot u(t)$ [closed]

Is $x(t)=t \cdot u(t)$ a power signal or an energy signal? Please "show" me why - preferably using equations.
-1
votes
1answer
407 views

How to detect and remove ringback-tone and ivrs voice etc from the beginning of an audio call recording

In an audio recording (say a telephone conv. b/w two people), how would I programatically detect and remove the dial-tone at the beginning of a call using python. Ex : As you can see the first 15 ...
-1
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3answers
234 views

What is the physical meaning of Fourier Transform having only $\delta(\omega)$ functions?

While calculating the Fourier Transform of the signal $$x(t) = 1 + \cos(6 \pi t + \pi/8)$$ I found that its Fourier Transform is purely in terms of Dirac Delta $\delta(\omega)$, that is its transform ...
-1
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1answer
332 views

Accuracy of sampling rate

I have data corresponding to 300 seconds. Sampling rate is 500Hz. I should have 500*300 = 150000 samples. But due to hardware error, I am receiving a few extra samples. What is the optimal way of ...
-1
votes
1answer
169 views

Accumulator with decay?

I am using an accumulator in the form of X + [Y-1], X plus the unit delay of the output. Is there an accumulator that follows this form, but will fall to 0 over time, similar to a differentiator?
-1
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1answer
192 views

Q and I part in QAM

I have one confusion in QAM about in-phase I and quadrature Q part, i.e. do they transmit identical data or not? For e.g. if i have 11001001 as a byte to be transferred, so will 4-QAM separate it like?...
-1
votes
1answer
515 views

how to read full input signal with STFT in matlab

Please help! I am trying to figure out why in the code i have below my input signal is being cropped but in the code I have a full signal created. The white noise created is 5000 samples for the right ...
-1
votes
2answers
377 views

Need to learn wavelet, suggest steps and resources [closed]

I am looking for a good introduction to wavelets and wavelet transforms. that covers the following: Vector Spaces – Properties– Dot Product – Basis – Dimension, Orthogonality and Orthonormality – ...
-1
votes
1answer
565 views

Shifting / Permutation of an array taking a long time [closed]

I'm using matlab/octave and would like some help trying to improve the speed of my code. I've tried to vectorize the code but I run out of memory so I went back to for loops. What I'm trying to do ...
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0answers
26 views
-1
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1answer
43 views

What does this spectrogram mean?This is spectrogram of a multitone FM signal

! The spectrogram of FM signal has been generated by using Matlab.Now I want to what does these scratch like lined represent, though I have only two frequency components in my message signal(https://i....
-1
votes
1answer
74 views

Signal Denoising Uniformly in Frequency Domain

I have a noisy sparse signal containing number of frequency components. Is there any method to uniformly denoise this signal. in other words, a method that estimated and eliminates the noise power ...
-1
votes
1answer
113 views

Why do we need the power spectral density?

Since the power spectral density is just the squared of the fourier transform, why is it useful ? Can't I just replace every solution that requires the psd with the fourier transform ?
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1answer
24 views

Is it possible to classify biosignal data based on feature extraction through multiple linear regression model? [closed]

i have 16 channel 2 class motor imaginary right hand ,right leg data.IS it possible to classify this through multiple linear regression model based on feature extraction?can i classify 3 class data ...
-1
votes
1answer
146 views

Spectral Subtraction python implementation error

I am trying to implement Spectral subtraction in python. I am new to DSP. I used this article as reference and below code is what I can come up with. Of course I did not get the expected output. I ...
-1
votes
1answer
62 views

Finding number of independent samples using autocorrelation

I have a pressure signal (y) with 512000 samples and with a sampling frequency ...
-1
votes
1answer
105 views

Weird noise floor slope when capturing with USRP E310

I'm experiencing a weird effect on my captures. It may just be due to my bad dsp understanding. I'm using an E310 SDR platform to capture a multitone (4 carriers) signal: Fc = 150 MHz Bw = 286 KHz ...
-1
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1answer
27 views

Order of MR Imaging Encoding Steps

Why is it so important to have the phase gradient encoding step come before the frequency gradient encoding step when collecting MR Images? Currently, the phase encoding step is turned on briefly, ...
-1
votes
1answer
120 views

Quadtree decomposition of Discrete Wavelet Transform using bio4.4/CDF wavelet

My problem is pretty basic but fundamental. It relates to the way discrete wavelet transform behaves for biorothognal 4.4 or CDF wavelets. When using most wavelets (e.g., CDF 9/7 or bio4.4 or ...
-1
votes
1answer
85 views

signal saturation [duplicate]

My signal is an actuator displacement signal. It is a sinusoidal signal with the max amplitude of 10cm. I want to clip amplitude at 7 cm in Simulink. But with saturation block, I will get flat ...
-1
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0answers
62 views

need help about DFT? [closed]

I am trying to get the answer from some of my questions: ...
-1
votes
1answer
230 views

Finding frequency of data given in time domain

Think there is an analog signal source and we are recording it with a data logger. Sampling rate isn't important in here. We know the analog signal is 0 mV when time 0 and goes to 1000mV in 1000 ...
-1
votes
1answer
43 views

How can dilation of a wavelet function lead to its sign reversal? [closed]

I am studying wavelets and it has been given that $$ \psi_{a,b} = \frac{1}{\sqrt{|a|}} \psi \left(\frac{t-b}{a}\right) $$ now the function $$ \psi(t)= \begin{cases} 1,& \text{if } 0\leq ...
-1
votes
1answer
101 views

Analyzing fluctuations within the Signal

I am trying to figure out how to analyze the signal shown below. It shows the fluctuation of number of review in for a product in Amazon, where positive means addition number of review while negative ...
-1
votes
1answer
262 views

Alignment of signals for ensemble averaging? Something else?

I have been applying ensemble averaging (adding signals of different trials to obtain one signal) to improve Signal to noise ratio in my data. I have achieved good results in terms of classification ...
-1
votes
1answer
97 views

Exact formula for alias of Discrete Fourier transform for periodic sigals

Suppose that $f(t): \mathbb{R} \to \mathbb{C}$ is a $T$-periodic signal, with highest frequency $f_h$. Now suppose that our sampling rate frequency is lower than $f_h$, and is not any multiples of $1/...
-1
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2answers
2k views

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

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
votes
1answer
353 views

Confusion when applying Hamming window to signal

I am writing some code which takes a signal of length $n$, and processes it in 20 ms chunks with 5 ms of overlap... So basically I have a buffer of 20 ms worth of sampled data, and I am trying to ...
-1
votes
1answer
235 views

BCI project using EEG signals

I want to make a BCI project, based on EEG signals, to control a robot using the brain's P300 wave. I have read a lot of papers, which give me a wide knowledge on how to deal with those signals, but ...
-1
votes
1answer
263 views

Describing Function for non-symmetric Saturation Model

Let's talk about a standard saturation model: with bounds $bound_{lower}$ and $bound_{upper}$. So in this example the output $y$ will be: \begin{equation} y(u) = \begin{cases} bound_{lower} ...
-1
votes
1answer
231 views

STFT Time Variance - Threshold

This is a follow up question to: Segment/Idenfication of signal from a spectrogram My main goal is to identify (segment) all of the calls from a given signal. The signal looks like the following (...
-1
votes
3answers
467 views

How we decide sample rate and number of samples while doing discrete Fourier transform

I solved a differential equation numerically and I want to find the frequencies present in the solution but I am not able to figure out sample rate/frequency and no. of samples that I should take.can ...
-1
votes
1answer
82 views

simulating noise with Yuler and burg

I want to simulate short term white noise with Yuler and Burg. It's said that it can give better results than Gauss-Markov. The problem is that each time the series diverge. Do you think that I made ...
-1
votes
1answer
95 views

Parameters for signal analysis

I am extremely new to signal analysis. And before posting I did a lot of reading on signal analysis, FFT and windowing. I am working on my thesis which involves comparison of speech signals lets say ...
-2
votes
2answers
564 views

Is the system $h(t)=\frac{u(t)}{t+1}$ time-variant or time-invariant?

Following this answer , I tried like this $$h(t)=\frac{u(t)}{t+1}$$ where $u(t)$ is unit step function. I can write the input-output relation like this: \begin{align} y(t)&=\int_{-\infty}^{+\...
-2
votes
1answer
305 views

Comparison using cross correlation [closed]

I have 2 stereo audio files to compare. Comparison of files include change in frequency, amplitude, phase shift Code: ...