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2 votes

Removing DC bias

I suspect the waveform is already down-converted to be a complex baseband signal, yet the plot has the carrier frequency arbitrarily added. Instead of doing the following: ...
Dan Boschen's user avatar
  • 52.1k
0 votes

Can Autocorrelation be used to Differentiate Signal Quality (High, Medium, Low, Very Low) for Periodic Signals?

An alternative to the comb filters is to determine the period, chop up the signal into individual cycles, determine the average cycle and than simply subtract it out. Whatever is left is the noise. As ...
Hilmar's user avatar
  • 45.4k
0 votes

Can Autocorrelation be used to Differentiate Signal Quality (High, Medium, Low, Very Low) for Periodic Signals?

So "quality" means less noise? And the signal is periodic? Would the period be an integer number of samples? Some form of autocorrelation can be used for pitch detection. And, once you ...
robert bristow-johnson's user avatar
0 votes

Sawtooth wave Fourier coefficients

For anyone else visiting this question trying to solve for coefficients, I just had something complex like: $$ \begin{align} a_k &= \frac{1}{T_0} \int^{T_0}_0 x(t) e^{-j2\pi f_0 k t}\,\, dt\\ &...
Freddy Mcloughlan's user avatar
0 votes

Is it possible to find the FFT of a 1024-point signal by taking 8-input points at a time and calculating the FFT of those 8-points until the end?

There is a divide and conquer approach to computing the FFT detailed in this PDF. Here is an implementation as in section 8.1 ...
rtclark's user avatar
  • 121
1 vote

How to remove known noise from acquired signals

The simplest filtering options I can think of are the following: Comb filter Use a comb filter with a discrete transfer function of $(1+z^{-30})/2$. The reason this works is the gain is $|\cos(15\...
Stephen's user avatar
  • 381
0 votes

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

The sharpness of fft is related to the frequency resolution. Frequency resolution is the ability to distinguish two close frequency. If the frequency resolution is fine, then you will get a sharper ...
Denil's user avatar
  • 1
2 votes

How to remove known noise from acquired signals

I don't know what caused this Yes you do: "In my country The frequency of the national grid supply is 50Hz." You have electromagnetic interference or crosstalk in your sensor signals. By ...
Hilmar's user avatar
  • 45.4k
2 votes

Maximum of the sum of different sinusoids

As Hilmar says, you can get pretty loose bounds. Might be better just to grind it out: ...
Peter K.'s user avatar
  • 25.8k
2 votes

Maximum of the sum of different sinusoids

Not really. If your frequencies are equidistant, i.e. something like $f_n = n\cdot f_0$, you can do an inverse FFT, which would be reasonably efficient. Otherwise you can try to estimate it. The power ...
Hilmar's user avatar
  • 45.4k
0 votes

very basic confusion about the bandwidth of constant signal function

Yes a constant pulse indeed occupies zero bandwidth. This is consistent with the Fourier Transform of a constant in time, which is an impulse in frequency. However that constant in time must extent as ...
Dan Boschen's user avatar
  • 52.1k
1 vote
Accepted

very basic confusion about the bandwidth of constant signal function

Usually, one would assume that the circuit is not in a transient in order to be able to talk about a "frequency analysis". So, assume that you have a DC source of K volts switched on since $...
coal's user avatar
  • 36
0 votes

very basic confusion about the bandwidth of constant signal function

You seem to be regarding two different types of signals as equivalent, yet they are not. Any signal can be decomposed into a sum of sinusoids, and the frequencies of those sinusoids define the ...
Stephen's user avatar
  • 381
2 votes

Frequency components in graph signal processing

It seems that in many cases, the principal harmonics do not offer meaningful insights. Recent work on combinatorial Hodge theory has given us interesting ways to form insights on discrete Laplace ...
Georg Essl's user avatar

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