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0
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2answers
31 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
0answers
16 views

Doppler compensation in a multi-user communication [on hold]

How to estimate and compensate for doppler shift in a multi-user communication for example the cdma?
0
votes
1answer
13 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-...
-1
votes
0answers
14 views

how to plot data from Vector Network Analyzer using Matlab? [on hold]

Please help: I have a VNA HP8735D 30KHz-6GHz. I am working on my project to measure the spectrum of the signal. I succeeded. I am trying to do a report with a plot which I have seen on the VNA using ...
2
votes
2answers
48 views

Detect valleys of a signal

I have raw values that are coming directly from a sensor (on the fly). I do a quick calculation on these values and I end up with a graph like the bellow image. I would like to be able to detect ...
0
votes
0answers
23 views

orthogonal base of chirp [on hold]

Do you know a method to construct an orthogonal base of chirp?
0
votes
0answers
14 views

multi-user communications techniques

I am working on multi-user communications. But I saw several differences in communication with one user. For example, there are several techniques to compensate for Doppler in a communication with ...
-2
votes
1answer
23 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 ...
-1
votes
0answers
40 views

Detect car crash using smartphone sensors

I'm trying to understand if it is possible to detect car accident or crash using the sensors present in a smartphone. There are many sensors including accelerometer, gyroscope, etc in a smartphone. ...
0
votes
0answers
19 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
54 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
31 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. ...
2
votes
1answer
132 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
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0answers
16 views

RADAR clutter modeling and suppression

Clutter in radar systems are the unwanted reflections from the surrounding environment. I have just started reading about clutter modeling in radar and i need some guide . Any books or papers to get ...
0
votes
2answers
32 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 ...
0
votes
0answers
20 views

Blind Signal Separation for Sparse Signals / Sources

Assume we have $N$ measurements $z_1, ..., z_N \in \mathbb{R}^{n_z} $ that generated by $$ z_i = M v_i + e_i $$ where $v_i \in \mathbb{R}^{n_v}$, $n_v < n_z$ and $e_i$ an error sampled from ...
0
votes
0answers
52 views

Music Spectral Analysis

Let's say I have any arbitrary mp3 song that's been decoded to a 16-bit signed pcm (little endian) at 44,100Hz, and I'm analyzing it at 60fps for realtime visualization, giving 735 samples per frame, ...
0
votes
0answers
32 views

Hilbert-Huang transform - Denoising

I have a signal I want to denoise using Hilbert Huang Transform (HHT). I know, I could have used some plain methods instead, but the reason I'm using it is that 1. It's a nonstationary nonlinear ...
0
votes
0answers
26 views

Blind Signal Separation for Sparse Signals

Assume we have $N$ measurements $z_1, z_2, \dots, z_N \in \mathbb{R}^{n_z}$ that are generated by $$ z_i = M v_i + e_i $$ where $v_i \in \mathbb{R}^{n_v}$, $n_v < n_z$ and $e_i \in \mathbb{R}^{...
2
votes
0answers
51 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
55 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
15 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 ...
0
votes
0answers
26 views

scale amplitude to [0 - 1] range

I'm trying to plot a "real time frequency domain graph" obtained by performing STFT on audio files. I can retrieve the amplitude using ...
-1
votes
1answer
29 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
27 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
33 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
52 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
0answers
28 views

How to add overlapping frames after processing a signal

I have to perform spectral subtraction on a signal in python. I have followed the steps specified in this link http://practicalcryptography.com/miscellaneous/machine-learning/tutorial-spectral-...
0
votes
2answers
49 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
0answers
38 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
59 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
26 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
44 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
19 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
9 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
49 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
11 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
34 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
59 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
165 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
62 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
21 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
20 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
46 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
27 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
53 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
34 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
39 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
15 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?
0
votes
1answer
32 views

Detecting whether reverb is present

I have two different audio short samples of an instrument playing. If one of the samples has a reverb effect applied, how easy is it to detect which sample has reverb? Is this possible?