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Questions tagged [signal-analysis]

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2
votes
2answers
651 views

How do I find the fundamental period of the given signal?

I am having a problem in finding the fundamental period of the signal $x(t)$ given below: \begin{align} x(t) &= 2\cos\left(\frac 45 \pi t\right)\sin^2\left(\frac{16}{3} t\right)\\ &= 2\cos\...
0
votes
3answers
57 views

How do I know if the given signal is discrete?

If I am given an expression of a signal then how do I know if it is a discrete signal or not? If this signal is given how do I know if it's a discrete or continuous? $$x(n) = e^{j (n \pi/2 + \pi/8) ...
1
vote
1answer
86 views

Question about Fourier descriptor and the physical meaning of the coefficients

I would have some questions about the Fourier descriptor and the physical interpretation of the individual coefficients. I'm rather new to this concept, so I would be looking for a simple answer. To ...
3
votes
2answers
123 views

How to calculate the Fourier transform of absolute-valued sinusoid?

The signal $x(t) = |1+a\sin(\omega t)|,(a>0)$ is a continuous waveform. In order to extract the frequency parameter $\omega$, I conduct the FFT of it and obtain its spectrum showed as follows. The ...
1
vote
0answers
32 views

How can we determine the channel impulse response using correlation process from the spectrum of the signal?

I am sending the pulsed signal from the transmitter antenna, and at the receiver side, I captured the received signal in the time domain, and also in the spectrum of the signal. How can I get the ...
0
votes
1answer
203 views

Is there a way to obtain the transfer function from a bode plot on Python? (I know that it is possible on Matlab)

Quite simply, I have a bode plot obtained from a source signal. Now I wish to obtain the transfer function. I know it is possible with Matlab: http://www.mathworks.com/help/ident/examples/frequency-...
-1
votes
1answer
20 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 ...
0
votes
1answer
107 views

signal reconstruction [closed]

I'm new to DSP so the question might seem a little bit stupid: When using a low pass filter (say Butterworth filter) with Python, I came across an algorithm with which I can reconstruct my signal ...
0
votes
1answer
42 views

Analyzing audio by looking at its time-frequency points in real- imaginary plane

I am performing Short-time Fourier transform on an audio signal (I dont know how to attach the audio file here). The sound was recorded in anechoic chamber and the source is supposed to come from left....
1
vote
1answer
52 views

Separating two frequency component

How can we separate two frequency component when they get mixed means when signal get mixed with noise how receiver can judge which part is signal and which is noise ?
0
votes
1answer
51 views

Band limited signals that are sparse

I am looking for examples of signals that are band limited but also sparse. For instance, the spiking of the neurons can be modeled as banded in frequency domain and sparse in time domain. What other ...
2
votes
1answer
40 views

Maximum of cross-correlation not moving

I already asked this question here yesterday, but it was very poorly worded I think. I made a much more detailled post explaining my problem of stackoverflow, as it might also be a code problem. Here ...
0
votes
1answer
235 views

Computing the Power Spectrum Density (PSD) on a CSV File in Python

im quit new with signal processing and im trying to calculate the PSD of a signal im sampling. the signal is an output of a DC buck converter this is the code im using and this is the plot im getting ...
0
votes
2answers
979 views

Spectrogram from scipy.signal with Python

To test the python spectrogram (from scipy.signal) , I've created a signal with 2 harmonics: 2 Hz and 8 Hz. Then I've added 50Hz noise and a trend (https://i.imgur.com/t1SnQck.png). I wanted to ...
0
votes
1answer
78 views

2D CFAR detectors

Constant False Alarm Rate is an adaptive detector used to distinguish between true and false detections. There are many types of CFAR and the number of these detectors reaches 25 like (CA-CFAR, OS-...
2
votes
2answers
120 views

Detect valleys of a signal

I have raw values that are coming directly from a sensor (on the fly). These values are coming from a wearable sensor installed on a cows neck. When the cow ruminates (meaning that it chews food that ...
-2
votes
1answer
26 views

Signal extraction [closed]

I have a receiver which receives several signals. The different signals are summed to the receiver. How can we find a signal in this sum? I know we can use PN (pseudo-random noise) codes but I do not ...
0
votes
0answers
54 views

Facing problem in plotting histogram of DCT coefficient of an image

In digital image forensic, it is assumed that the histogram of DCT coefficients of the un-compressed natural image has the smooth histogram. However, the histogram of DCT coefficients of the ...
0
votes
2answers
119 views

IQ modulation: baseband to bandpass transformation

can someone explain me these doubts? it is a baseband signal representation. A- complex signal, R- real. If I multiply baseband signal with FT( cos) then the signal will look like this ( on the ...
1
vote
1answer
233 views

Seven term Blackman Harris window

I am currently trying to evaluate a high resolution ADC for which I need to window my output data for the FFT. Up until now I have been using the default 4 term Blackman harris window in MATLAB. ...
3
votes
1answer
604 views

Calculating SNR from Frequency Domain

As I am newbie to signals, I have collected an appliance signal in frequency domain as follows: (PSD- Power Spectral Density). So, I need to calculate the SNR (Signal to Noise Ratio) and BER (Bit ...
0
votes
2answers
689 views

what is a pneumatic signal exactly?

I'm starting to learn about automatic process control, and there are types of signals transmitted in a control system. Among that is pneumatic signal that is a pressure signal. But I still don't know ...
2
votes
0answers
60 views

Digital vs Analog music [closed]

What are the different constraints for mastering audio content for either Vinyl or CD? By the way, I'd like to know if there're any papers or documents, with a comparison between different digital ...
1
vote
1answer
143 views

Plotting Hilbert Spectrum from Hilbert Huang Transform

Before anyone calls it a repeat post from past posts. I'd like to point out I've read all of those; however, I have questions on making a hard coded version of the hilbert spectrum. I do indeed have ...
0
votes
1answer
18 views

How do you estimate necessary dynamic range?

Say I have a signal (1D in my case, but could be an image, etc.) that has been captured adequately on nice equipment with sufficient resolution and range to get all the details of the signal that are ...
-1
votes
1answer
203 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 ...
0
votes
3answers
32 views

Is there a problem with using the WAV format for non-audio signals?

I have biological signals sampled at 1 kHz. The signals tend to behave fairly simply, sinusoidally. The software I've used to collect these data uses their proprietary format (*.adicht) and so I have ...
-1
votes
1answer
100 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
vote
1answer
65 views

Sparse Recovery Best Algorithms

In the big data era, in order to control the cost, complexity, and bandwidth of collecting and processing high-dimensional data systems, it is critical to exploit models that ...
0
votes
2answers
157 views

Why does the addition of noise improve coherence between two signals?

Taking a simple example of the coherence between two signals, each composed of two sinusoids of frequency 100 and 200 Hz, I expect the coherence to show two peaks in the spectrum located at precisely ...
0
votes
1answer
92 views

Get I and Q components from a signal (multple frequency signal)?

Is there anyway to get the I and Q components from a signal in the time domain? The signal has multiple frequencies. So far I have been doing this in a SIMPLE situation: Fast fourier transform to ...
0
votes
2answers
91 views

How to convert a sound signal function to wave file? [closed]

I am new to understanding sound signals. A sound signal, as far as I know, is a real function of time $x:[0,\infty)\to \Bbb R$. For example, $x(t)=\sin(t)$ is a sinusoidal signal. What is $x(t)$. For ...
0
votes
1answer
132 views

Radar video signal and matched filtering

In order to make my question more clear and give more details I'm trying to understand the processing signal procedure in radars,i understood till this moment that a transmitter generates a signal ...
1
vote
3answers
90 views

Resample audio signal with a low factors

Currently, we need to handle a piece of an audio signal. We want to resample it with different factor rate (p/q) starting with 1.0002 to 0.9998 with a decrement of 0.000005. But Matlab function cannot ...
0
votes
0answers
20 views

How to find the highest band?

I'm a programmer who has only googled basics of signal processing. Now I have a project where I have been given a wav file and limits where to measure. I have to compute the highest band form the ...
0
votes
0answers
17 views

ways of interference cancellation in WiB signals

I m working in broadcast company so , this company using DTT ( digital TV terrestrial) . The new research studying about technology using a single wide-band signal instead of narrow signal (8 MHz) ,...
0
votes
2answers
141 views

Expectation of deterministic signals

Maybe this a stupid question, but I came along with this point and I would like to confirm that I am not wrong. I found some similar posts in StackExchange, like: Expectation and Auto-correlation of ...
0
votes
0answers
12 views

Is there a criterion that says at what point you can distinguish 2 partially overlapping Lorentzian peaks?

If you have 2 Lorentzian peaks that partially overlap and you have some frequency resolution df (your points in frequency space are separated by df) and both Lorentzian peaks have FWHM $\Gamma$ is ...
0
votes
1answer
38 views

FFT for distance-limited sum of pairwise products

I have a sequence of fixed length $N$ input arrays ($x_0$, $x_1$, ..., $x_{n-1}$), and my goal is to compute output arrays as such: $$d_{00}[l] = \sum_{i = 0}^{N - l} x_0[i]x_0[i + l]$$ $$d_{01}[l] = ...
0
votes
2answers
107 views

matched filter for doppler

To remove the Doppler shift, we can use a bank of matched filter. But, to use this method, we need an interval $[-f_{max};f_{max}]$. How can we approximate this interval?
1
vote
4answers
477 views

Why does the frequency in the DFT have to be an integer?

I don't know why the result of DFT and FFT in MATLAB like below images.. fs=128; t=0:1/fs:1-1/fs; x=cos(2*pi*3.5*t); X=fft(x); N=length(x); n=0:N-1; f=fs*n/N; plot(f,abs(X)/N); If I set the ...
0
votes
1answer
71 views

Why does it mean that the process/signal is not stationary when its variance varied with time? [closed]

Why does it mean that the process/signal is not stationary when its variance varied with time? that is, $VAR[X(t)]= \alpha \times t$,$t$ is time,and $\alpha$ is a constant,then $X(t)$ is not the WSS ...
0
votes
0answers
23 views

Correctly finding Bands(pulses) in a discrete signal

I'm trying to find a way to detect bands in a signal so that I can assign a metric to that band based off of width and amplitude. An example of the signal can be seen below, where the signal is in red,...
0
votes
0answers
40 views

spectral kurtosis binary masking (matlab)

Following this research paper, under section 4, equation 13, we can calculate the binary mask. However, I am a little bit confused on how to do this, considering I have already a complex STFT of a ...
0
votes
3answers
426 views

Power of a Discrete time signal

I was learning on power of signal and i went through different formula in internet . I get different results when i go through internet . But in other site average power is written as I dont know ...
0
votes
0answers
122 views

Why MFCC have varying length dimensions?

I have recently started to use MFCC as a feature for a project. However, I am unable to understand why MFCC have varying 2nd dimension size even when I chose the number of coefficients to be 40.
1
vote
2answers
99 views

Isolate High Variance vs Low Variance Sections of Signals

I have the following one-dimensional signals: The goal is to identify the sections with smaller variances compared to the rest (For Python, that is to get their index value in the array). In the ...
0
votes
1answer
42 views

Measure 3-D length using smart-phone's accelerometer

I'm wondering if we can measure 3-D length only by our smart-phone's accelerometer. And we all know these low cost IMUs are not accurate. You can model accelerometer's error this way: $$ a = f*a' + g ...
0
votes
2answers
46 views

Why the angle of a real signal in frequency is continuous?

This original signal is shown below (time domain): It is a real signal. According to the signal processing theory, the form part of the angle is conjugate to that of the latter part. That is, $\...
1
vote
0answers
17 views

Spectral entropy and moments and non stationary signal processing [duplicate]

What is Spectral entropy and spectral moments? I know what the normal entropy of a signal is! And also what are some good time-frequency features for the analysis of non-stationary signals?