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Questions tagged [signal-analysis]

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0
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1answer
44 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?
0
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0answers
78 views

How to remove echo/reflected-sound caused by stationary objects when building a ultrasound based radar

I am emitting ultrasound with a speaker and am trying to track moving objects with a microphone array by detecting doppler shifts. I have succeeded to detect movement. However, to detect the direction ...
0
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1answer
165 views

Carrier Recovery, Frequency and Phase offset in (CP)FSK

I wanted to ask what exactly is meant for phase recovery of signal (at least intuitively). I have a working example of an acoustic fsk modulation and demodulation software but i don't know how to ...
0
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0answers
99 views

Filter Bank Common Spatial Pattern (FBCSP) Algorithm

I know that for Common Spatial Pattern (CSP) algorithm i need two covariance matrices, for Filter Bank CSP algorithm i have filtered one trial of EEG signal into 9 frequency bands. My question is ...
0
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0answers
98 views

Graph signal processing

What's the intuition behind a ''Graph fourier transform'' ? I'm not so much interested in mathematical details or technical applications. I'm trying to grasp what a graph fourier transform actually ...
0
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0answers
220 views

How to do cross correlation in real time?

I want to measure the signal similarities between two time domain signals a and b in real time. I do not know where to start. I think cross correlation might help but not sure how. Please guide me :-) ...
2
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1answer
77 views

Gaussian Equivalent of Convolving an Image 50 Times with a Box Filter

I have a image that I'm convolving 50 times with a box filter, and I like to replace this with a single gaussian filter. Because both box filter and gaussian filter are separable I can just study the ...
1
vote
1answer
216 views

How can I transform a time signal into a third octave spectrum?

I try to make a third-octave spectrum from a time signal and I have some troubles with the algorithm. I'm not an expert in signal processing so I don't know what is wrong. Here what my algorithm ...
0
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1answer
23 views

Investigating correlation for unequal signal lengths

I have measurements from two tablet sensors. The first sensor measures the touch pressure applied to the tablet and the second sensor is the acceleration of the tablet (in z direction). The sensor ...
2
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0answers
152 views

What are F0 counters in Speech signals? What is represented by F0?

I can't find any dedicated definition for Frequency F0 counters. Can anyone tell me what does F0 exactly mean, I am confused about that.
0
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1answer
51 views

Improvement of SNR by sampling different number of cycles using FFT of a fixed length singal

My question relates to Fourier transform of signals with different lengths in time but the same fixed length of the digitized signal with different sampling rates. Specifically, how does the number ...
0
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0answers
192 views

Getting the velocity in Radar FMCW

I have managed to get the frequency (the beat) frequency from an FMCW. Here is a screen shot of a wall that's detected by the Radar. I performed an FFT of complex I,Q data. My questions are 1. How ...
0
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0answers
49 views

autocorrelation and ISI histogram of oscillatory neuron

I'm trying to learn about different kinds of neurons and I got to a question that I'm stuck on: Given an oscillatory neuron that shoots poissonically for 50 ms and rests for 100ms:how it's ...
0
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0answers
35 views

Modulation Index in Case of Quadrature Modulation (IQ-modulation)

It says that in case of quadrature modulation, the modulation index can be maintained at exactly 0.5 without any settings or adjustments. I don't get it why. What is it which is making it sure that ...
0
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2answers
93 views

Demodulation in Rayleigh Flat Fading Channels

A core part of demodulation in Flat-Fading channels is (assuming) the channel as a(random) constant complex number multiplied with your signal. This is done in order to de-rotate the symbol for ...
0
votes
1answer
222 views

removing vertical lines in grayscale images by thickness

Suppose we have a grayscale image that contains vertical lines. Now suppose that not all vertical lines are the same, some of them have different thickness. Question is, is there a way, in MATLAB or ...
0
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1answer
49 views

Unexpected peaks in power density following downsampling and filtering

I first applied a 100 Hz lowpass filter to my data, which was recorded at 30000 Hz: ...
1
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1answer
53 views

Parabolic fiting for sub-sample precision

I am performing cross-correlation between two double[1024] arrays. I want to track the correlation's maximum with sub-sample accuracy, so I decided to implement parabolic fitting to my code. I used ...
0
votes
1answer
129 views

Wavelet transform and FFT using to extract feature power bands with EEG signals

I am using 5 channels [ fz , cz , c3 , c4 , pz] to detect drowsiness of driver My First Question is, what is the right input to get feature power band ( Theta , alpha , gamma , beta ) to wavelet ...
0
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0answers
188 views

How to manipulate output of Matlab's 'spectrogram' function for additional spectral analyses

all, I have an audio recording that contains several frequency-modulated elements (think animal calls like birds/bats). I have read this file into Matlab using 'audioread' and plotted the oscillogram ...
1
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1answer
327 views

Create a third octave spectrum from a time signal

I have to create a third-octave spectrum from a time signal on Octave GNU. I found some code on the net to help me but I don't have all the parts of the algorithm. I have a .csv file which contains ...
2
votes
1answer
161 views

Cross-correlation, sharp peak at 0?

First of all, I have to stress that I am not a professional of coding, no more than a professional of signal processing. I am a chemist that happen to be working on a project involving both. So in ...
0
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3answers
54 views

Human ear - freq log scale

I am not sure if it's DSP question or physic. But I wonder is there any math equation (method) that describe that graph? (It could be anything approximately like that). I am working on audio freq ...
3
votes
1answer
135 views

Phase Modulation and Intermodulation Anomaly ? (Spectrum plots inside - **Updated**)

I have a MATLAB script for modelling a two tone signal (a sum of two sinusoids) going through a non linear transfer function (such as an amplifier). The amplitude of a signal is amplified non linearly,...
1
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1answer
37 views

Need help deriving the energy of a signal

I am solving old exam problems in preparation of my exam in signals, and I'm having trouble with a question. For a continuous aperiodic signal with the spectrum $X(\omega)=\exp(-\omega^2)$ I am to ...
0
votes
1answer
42 views

Separate speech signals that are bandlimitted

I have 2 kind of signals (refer figures) in a folder. One is band limited to 4khz and another is band limited to 8khz, both are with sampling frequency 16khz. I need to separate them. Any idea??
1
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2answers
126 views

Adding phase to a signal that has multiple frequencies

An amplifier changes the phase at different amplitudes of asignal. I am using amplifier data in a MATLAB model. I have constructed a signal that is a sum of sinusoids of different frequencies with ...
0
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2answers
208 views

How to recover frequency and damping coefficient from superposition of damped oscillators?

I have a signal which is (more or less) the superposition of multiple damped oscillators. There are relatively few oscillators involved, 2-3 would account for most of the signal. They have periods ...
0
votes
1answer
78 views

Confusion in Peak to Average Power Ratio (PAPR)

(1) What does it mean by 'a system with low peak to average power ratio requirement'? Doesn't every system idealises it to be lower? Or there are some exceptions to it? (2) Higher PAPR can be a ...
0
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0answers
20 views

how to make the amplitude equal zero on the desired frequency?

I know that cut off frequency pass 0.707 from the input amplitude of the signal but I want to remove a noise let say it starts at 1700 kHz and ends at 2000 kHz how can I choose the cutoff frequency?!
1
vote
1answer
103 views

CMV: COLA constraint is not necessary

In the literature on the short-time Fourier transform (STFT) it is often stated or implied that the constant overlap-add (COLA) constraint must be satisfied in order for the STFT to be invertible. ...
0
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0answers
36 views

Model Based CoSAMP

I am currently studying compressive sensing, and am trying to implement algorithms. I successfully implemented CoSAMP, but then came across model-based CoSAMP. The algorithm looks very similar to me, ...
0
votes
1answer
21 views

What would be the proper notation for denoting part of signal that satisfies a condition?

I have a signal $E(t)$ which start at $t=0$ and dies out overtime. What would be a proper notation to specify part of which is above a certain threshold (say for e.g. C)?. Is $E_{interested} = E(t)>...
0
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0answers
18 views

Can the Tonality index in psychoacoustics model be positive?

I have an issue with understanding the attached equation of Calculating the Tonality index. If you trace the equation, it appears that it is always less than 1 because the spectrum unpredictability (...
1
vote
2answers
252 views

How to edit audios so that they have the same length

I have a dataset of audio files, which differ on their lengths by a couple of milliseconds. Some are little shorter than 1s and some are little longer than 1s. They all have the same sampling rate, ...
0
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1answer
47 views

Power Amplifier Characterization

I am trying to characterize a power amplifier fitted to transmitter board. I applied a sinewave at the required carrier frequency and I collected the input samples and the output samples by using a ...
0
votes
1answer
98 views

Summing magnitudes of individual frequency bins

I am working on signal analyser and have problem with understanding relationship between display resolution and frequency resolution (range). My frequency range is $ 1-20000\quad [ H z ] $ so to ...
0
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0answers
22 views

Is it possible to find a signal that reduce the PSLR without expanding 3dB main lobe for autocorrelation?

Considering a signal $s(t) = rect(t/T_p)exp(j\theta(t))$, the autocorrelation is $ACF=IFFT(s^2(f))$. It's possible to construct the $\theta(t)$ to get a signal which has the same 3dB main lobe as the ...
0
votes
1answer
129 views

Accelerometer BMI160 changing bias

Goal: Obtain the 3-axis accelerations from the Bosch BMI160 IMU when measuring the accelerations of the bogie of a commercial train. The accelerometer used is installed in a PCB and used by an mbed ...
0
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1answer
47 views

Does changing the frequency of a wave cause a change of the phase of the same wave? [closed]

I know that the phase is the delay between two different waves . But if we change the frequency of two waves by a different value does it cause a varying in the phase between them let say that two ...
-3
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1answer
247 views

what is angular frequency ! what does it mean?

I know that $$ \omega = 2 \pi f $$ why do we use angular freq to expression about the instantaneous values of the wave?
1
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2answers
111 views

Calculating impulse response of system

Given is the illustrated circuit diagram of a linear, time-invariant, time-discrete system: How do I show that the total system has the impulse response $h[n] = aδ[n] + bδ [n - 1] + cδ [n - 2]$ and ...
0
votes
1answer
115 views

Uncertainty Relation between time and frequency

Typically, humans can hear sound waves in the frequency range 20 Hz to 20 kHz. If one wants to make digital record of sound such that no audible information is lost, what is the longest time interval ...
2
votes
1answer
90 views

Any better way to detect Signal with ADC Overflow problem?

I am trying to create an algorithm to detect signal with "ADC overflow" as shown in picture on lower right. It happened because someone had incorrectly down converted an int16 signal into int8 signal. ...
0
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0answers
36 views

DVB-T RF signal to digital

we would like to implement a simple security encryption to an RF COFDM signal . this is to prevent any dvb-t receiver to view a channel transmited by air from an ambulance to a station the RF signal ...
2
votes
1answer
183 views

MFCC Classification

I'm working on gender estimation from speech signal and I completed MFCC feature extraction. So now I'm trying to estimate gender from these features. But I have frames for an audio file and I ...
0
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0answers
15 views

Implementing Wavelet family matrices

I want to use CS to reconstruct an image from fewer samples, and I would like to use wavelet coefficients but I don't know how to define them when making a Psi matrix. I have written wavelets ...
0
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0answers
39 views

Angular re sampling

I have a vibration signal acquired from a rotary machine. I want to perform angular resampling on the data in Matlab. The link to the data file is here. Description of the signals is as follows: ...
0
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1answer
59 views

Getting a weired behavior when windowing an audio signal

I am processing audio signals using Essentia, an open-source library and tools for audio and music analysis, description and synthesis. Here is a waveform corresponding to a frame extracted from an ...
0
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0answers
34 views

Calculate RMSE and DTW before or after signal normalization

I want to calculate RMSE and DTW of clear speech signal and noisy speech signal. Im normalizing signal using division by max possible value (for 16bit audio its 32756) to have signal in range [-1;1]. ...