15 questions linked to/from Amplitude modulation vs sampling rate?
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### ADC sampling of incoming signal and aliasing effect [duplicate]

I know from the sampling theorem, that the signal frequency $f_{sig}$ shouldn't exceed 0.5 of sampling frequency $f_{samp}$. I decided to have a look at it and tried for example $f_{samp} = 50$ $kHz$ ...
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### Sampling and reconstruction of signal in Matlab

I'm trying to write a program in Matlab that samples (using Nyquist theorem) and recovers signal. I got stucked on recovery part...recovery signal doesn't match with the original one (see photo). And ...
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### FFT of a AM modulated signal

I am generating an AM modulated sinusoidal wave. The carrier frequency is set at $1000 \ \rm Hz$; the modulation frequency is set to $40 \ \rm Hz$ and $100 \%$ of the amplitude is modulated. I ...
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### Why does twice the sampling rate (Nyquist Theorem) seem inadequate?

I was told in my electronics course that "to reproduce a wave, we need to sample it at least twice every period." If I take this to be literally true, then a sine wave with only 2-3 samples ...
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1 vote
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### How do audio readers interpolate?

$124$ Hz sampled at $256$ Hz has "beats", but $128$ doesn't - a phenomenon of this question: Whether these are "legitimate" beats is up to interpretation, but suppose the goal is ...
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### What is the minimum sampling frequency to reconstruct a 1 Hz sine signal by using only FOH?

Consider a signal $s(t) = \sin(2\pi ft)$ where $f = 1$. Let's now discretise it by replacing $t$ with a vector of $n$ sampling instants equi-spaced by a sampling interval $T_s = \frac{1}{201}$ s, thus ...
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### Why does the amplitude of a reconstructed sine wave change based on its phase?

Let's say we have some 5 different sine waves, each having a frequency of 10 Hz but differing in phase i.e. 0, Pi/6, Pi/4, Pi/3, and Pi/2. Each of these signals is sampled at twice the signal ...
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### Why complex signal doesn't remove "beatings" while sampling?

My motivation to this post has arisen from the accepted answer to Amplitude modulation vs sampling rate? Sampling the signal with the frequency close to $f_s/2$ can lead to some kind of "beatings&...
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1 vote
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### How to detect and distinguish oscillations in a signal?

I would like to detect oscillations in a signal $s$ and determine the nature of the oscillations, i.e. whether they are high-frequency oscillations or not. Edit : An example of $s$ is given below : ...
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### What can be meant by "bandlimited"?

This question was a source of disagreement on whether "amplitude aliasing" can occur for a signal bandlimited to below half the sampling frequency. The question was closed before the ...
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### Relationship between amplitude and sampling rate

I'm loading a signal with librosa in python. With the original sample rate of 22050 Hz, i get the following waveplot: When i choose to resample my signal with the sample rate of 512 Hz, i get the ...
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### How is sampling affecting this sine wave?

I am trying to create a sine wave in python, but when I graph it, it looks like this: here is the code I used to make the signal: ...
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### How is a discretized 1D signal be considered a 'vector'?

This question is perhaps related to the semantics or jargon of signal processing. I have checked plenty of advanced books/monographs on multivariable calculus and signal processing but could find an ...
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A closed form solution to $$X[k] = \texttt{DFT}\{\cos(2\pi f t + \phi)\}$$ confirmed many known properties of a finite sine's spectrum, also revealed new ones. Can the same be done for $|X|$, or \$|X|...