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Questions tagged [signal-processing]

Digital signal processing of sound, video or other single or multidimensional data

Digital signal processing (DSP) is the mathematical manipulation of an information signal to modify or improve it in some way. It is characterized by the representation of discrete time, discrete frequency, or other discrete domain signals by a sequence of numbers or symbols and the processing of these signals. --Wikipedia

See also

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How to demodulate an FM signal in continuous-time?

I'm not sure if this is a math or Mathematica question, but I'm posting it here because I'm interested in possible Mathematica tools/functions to solve the problem. I'm stuck. I want to simulate the effect of a EMP (ElectroMagnetic Pulse)…
stevenvh
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Hilbert-Huang transform package

I am trying to learn Hilbert-Huang transform (HHT) and its applications (especially in ECG signal processing). There are several HHT packages (scripts) HHT for R and Matlab. Is there any known solution for Mathematica or I should write my own…
Methdotnet
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How to generate a chirped signal?

As there is no ChirpSignal function in Mathematica, can anyone tell me how to write a custom function to generate a sinusoid with a frequency that changes continuously from frequency f1 to f2 over a certain time of t? This is what I done to…
kvnF2
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Estimating Power Spectral Density from Autocorrelation

I have been tasked with computing the power spectrum of a noisy signal. Specifically, I am asked to do so through first attaining the autocorrelation function. From what I have read, the PSD is simply the Fourier transform of the biased…
Alex
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What does OutputResponse[sys, { {u1,u2,u3}, {v1,v2,v3} } ] do?

I am puzzled by the result of OutputResponse[sys, {{u1,u2,u3},{v1,v2,v3}}]. OutputResponse is used this way in the first "Application" in the documentation for KalmanEstimator. I don't see much in the documentation for OutputResponse that helps…
Ted Ersek
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How do I bandpass a signal in Mathematica 8

I would like to use the bandpassing function that is available in newer versions of Mathematica but not Mathematica 8: BANDPASSALPHA[x_] := BandpassFilter[x, {8 Pi, 13 Pi}, SampleRate -> 500] Is there a pice of custom code that would allow me to…
user13675
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Bandpassing EEG's using Mathematica's Bandpass Function

Let's say we have an EEG signal approximated using a fractional Brownian motion: EEG[hurst_,t_low,thigh_,tinc_]=RandomFunction[ FractionalBrownianMotionProcess[hurst], {tlow, thigh, tinc}, 1] for some parameters hurst_, tlow_, thigh_, tinc_. The…
user13675
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Sampling and filtering data

I'm trying to teach myself about sampling and filtering — and I'm not sure if I'm misunderstanding the concepts or misapplying Wolfram Language. I started by creating a simple test signal with contributions at 2 and 3 Hz, f[t_] := Sin[6 Pi t] +…
GeekyCool
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What do we get from OutputResponse[sys {u1,u2}]?

I understand what OutputResponse is doing in the first two examples below. sys=TransferFunctionModel[{{{1+z}},0.1-0.667*z+z^2},z,SamplingPeriod->1]; u1=Join[{-1},ConstantArray[0,17]]; ListPlot[OutputResponse[sys, u1]] (* result is not displayed…
Ted Ersek
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How to predict the delay of a digital filter?

I define a simple digital filter. transferFunction = TransferFunctionModel[{{{0.13793103448275862*z}}, {{-0.9 + z}}}, z,SamplingPeriod -> 1] Then I put samples of a sine wave in the filter. input = Table[Sin[0.1 t], {t, 0, 250}]; filtered =…
Ted Ersek
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Obsolete Signal Processing functions

I need some tools to detect the fundamental frequency and pitch of a sound. I Googled for "pitch detect" and found some .nb files that do these tasks, but all the files are in Mathematica 3.0 format. I downloaded and installed the Signal Processing…
user5326
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LowpassFilter Mathematica

I have this example signal: w1 = 3; (* rad/s *) w2 = 50; (* rad/s *) w3 = 4; (* rad/s *) signal[t_] = Sin[w1*t] + Sin[w2*t] - Sin[w3*t] I would filtrer this signal with ideal Low Pass filter (w3=50 rad/s) using command LowpassFiltersuch that the…
plus91
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Whitening the data from the LIGO project

I'm following the official LIGO tutorial and I want to do a whitening process now. I computed FFT using hf=Fourier[data] then PSD using psd=PeriodogramArray[data, Round[1/dt], 1, HannWindow]. In next step I interpolated PSD…
astrotom94
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Digital filter. Why do these two methods produce such different results?

I am trying to produce a transfer function with a peak=3000 and gain=1 first order on the high pass side and second order on the low pass side. I believe the below two methods should produce approximately the same function, but they do not. Why are…
Indiana
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How can i use Butterworth filter written in matlab to Mathematica

i need help to convert this code written in matlab about Butterworth filter: %remove high-frequency components by 0.5-h butterworth filter; n =2; Wn =[1/30/0.5]; %30-min low-pass filter (LPF)% [z11, p11, k11] = butter(n,Wn,'low'); …
Iman Khaki
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