Linked Questions

0 votes
0 answers
44 views

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 $ $kHz$ ...
Curious's user avatar
  • 355
0 votes
2 answers
13k views

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 ...
Ivica Prašina's user avatar
4 votes
3 answers
5k views

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 ...
Mathieu's user avatar
  • 213
1 vote
5 answers
1k views

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 ...
Andrew's user avatar
  • 113
1 vote
2 answers
415 views

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 ...
OverLordGoldDragon's user avatar
2 votes
1 answer
488 views

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 ...
Barzi2001's user avatar
  • 121
0 votes
2 answers
472 views

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 ...
Sâu's user avatar
  • 101
2 votes
2 answers
251 views

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&...
Curious's user avatar
  • 355
1 vote
1 answer
313 views

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 : ...
Mistapopo's user avatar
  • 135
-1 votes
2 answers
1k views

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 ...
OverLordGoldDragon's user avatar
0 votes
1 answer
243 views

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 ...
mojbius's user avatar
1 vote
1 answer
286 views

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: ...
user57935's user avatar
2 votes
2 answers
185 views

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 ...
AChem's user avatar
  • 569
1 vote
2 answers
84 views

Nyquist frequency Plotting Distortions

I'm trying to plot some sinusoidal signals in Matlab. But while frequency is getting higher (closing to fs/2), results are getting distorted. I guess it's lack of my knowledge but distortion is ...
BugraKezan's user avatar
0 votes
2 answers
94 views

DFT modulus of a sine, closed form solution and insights

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|...
OverLordGoldDragon's user avatar