Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [envelope]

36 questions
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5 answers

Equal power crossfade

I am working on an audio system where I need to implement an equal power crossfade between two signals over a specified number of samples. Initially I implemented a linear fade but this creates a dip in the middle of the crossfade which I don't…
Philip Bennefall
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envelope rms implementation by Matlab

I am trying to implement the moving RMS by Matlab. x = randn(50, 1); xRMS = sqrt(movmean(x.^2, 21)); xRMSref = envelope(x, 21, 'rms'); plot(xRMSref,'DisplayName','xRMSref');hold on;plot(xRMS,'DisplayName','xRMS');hold off; legend() Why my…
Gideon Genadi Kogan
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True Envelope algorithm: how to speed it up?

Premise (since somebody may ask about the background): I am the author of the spectral modules for SynthEdit, a modular framework for realtime STFT audio processing, currently struggling since months to write a stable and robust spectral envelope…
elena
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3
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2 answers

Bandpass filter that automatically adapts its bandwidth when a transient is detected (to avoid to smoothen the transient)

Let's say we want to isolate a band 1000 hz +/- 50 hz. Obviously, limiting the bandwidth by applying a passband filter will always destroy a bit the sharp transients (a Dirac or a rectangular envelope / Heavyside step function requires all…
g6kxjv1ozn
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3 answers

Beat envelope detection

I am trying to write a python function that checks whether two lets say sine signals would generate a distinct beat envelope or not. I know that the beat frequency = f1-f2 where f1 and f2 are the frequencies of my input signal. Is there a…
bjornhartmann
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1 answer

Why use complex envelope to model raw measurements?

The usual answers when asking "why use complex numbers to model measurements?" is usually: (a) Because you are measuring a phenomenon like electricity and magnetism. (b) Because it is super useful for analysis- Fourier, convolutions,…
JohnRos
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1 answer

Absolute value based AM envelope detection viewed in the frequency domain

In my understanding when a passband AM signal is demodulated with an envelope detector taking the absolute value restores the original baseband version of the signal and the low-pass filter removes all the (passband) high frequency content. It is…
axk
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how to robustly estimate low and up envelope of signal with trend, few level constant steps and noise

I am looking for robust estimation method of low and up envelope of the signal consisting from smooth trend component, constant steps between few fixed levels and additive noise (+ outliers of course). This question raised during my current research…
michal
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What is a constant envelope modulation?

The Book "Digital Modulation Techniques" by Fuqin Xiong groups digital modulation schemes into two classes: "constant envelope" and "nonconstant envelope." However, I was surprised by the inclusion of PSK in the "constant envelope" category. This…
nispio
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How can I plot the spectrum of a signal in MATLAB?

Consider an input signal x_total and the complex envelope of an output signal y_total in MATLAB: T = 10e-9; f_s = 1e12; t = [0 : 1/f_s : T]'; …
user25356
1
vote
1 answer

Calculation of Attack Decay Release durations of a signal

I want to write a program that can calculate the attack, decay, release times and sustain level of the audio signal coming from let's say an analog synthesizer. (the envelope which modulates the amplitude of the signal created by oscillator) The…
someoneunimportant
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can $e^{j\phi_0}$ be incorporated into the sine and cosine terms?

This is from "communication system" by Carlson fifth edition page 109: If transfer function of a channel be like this: $H(f)= Ae^{j\phi_0}e^{-j2\pi ft_g} $ and input to this system be: $x(t)=x_1(t)\cos(\omega_c t) - x_2(t)\sin(\omega_c t) $ will…
m-sh-shokouhi
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Obtain Envelope and Pitch curves of my Singing Voice

I wish, in real time, to hum into a mic and produce via dsp the envelope and pitch of what I am humming, before outputting these two signals to my analog synth. This synth takes a gate and a cv signal. Control Voltage/Gate is an analog method of…
Baz
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Envelope analyis basic question

I have a vibration signal sampled at 25.6 kHz, and I want to perform Envelope Analysis on it. "Vibration-Based Condition Monitoring of Wind Turbines" by T. Barszcz has the following figure: I understand why the frequency is changing in the FFT…
meerkat
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Is it possible to get the envelope of a signal via FIR filter?

I was reading an article about ultrasonic signals, and I read in it that it is possible to get the envelope of a signal by using a band pass FIR filter. My question: Is it possible to get the envelope of a signal by passing it through a band pass…
singrium
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