Questions tagged [signal-processing]
The subfield of electrical engineering that focusses on analysing, modifying, and synthesizing signals such as sound, images, and scientific measurements.
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Existence of monochromatic pulses?
Why there can not be a monochromatic pulse? My physics professor told us that we can't generate a monochromatic light pulse and I was wondering what are the physical limitations causing this.
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Reconstruction of "wavefunction" phases from $|\psi(x)|$ and $|\tilde \psi(p)|$
Consider a "wavefunction" $\psi(x)$, which has a Fourier transform $\tilde \psi(p)$
Suppose that we know, for each $x$, $|\psi(x)|^2$, and that we know, for each $p$, $|\tilde \psi(p)|^2$.
Have we ...
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Why can't you hear music well over a telephone line?
Why can't you hear music well well over a telephone line?
I was asked this question in an interview for a university study placement and I unfortunately had no idea.
I was given the hint that the ...
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Can the Kramers–Kronig relation be used to correct transfer function measurements?
In experimental physics, we often make measurements of linear transfer functions; these are complex-valued functions of frequency. If the underlying system is causal, then the transfer function must ...
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Why are cosine and sine functions used when representing a signal or a wave? [closed]
Actually, in the mathematics sine and cosine functions are defined based on right angled triangles. But how will the representation of a wave or signal say based on these trigonometric functions (we ...
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Why is bandwidth, range of frequencies, important when sending wave signals, such as in radio?
So in wired/wireless networking and radio, signals are sent in form of wave. Then the concept of bandwidth comes in, which is the difference between highest frequency and lowest frequency in a signal. ...
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Use of negative frequency for the sake of simplifying mathematics?
How can we use the idea of negative frequency for the sake of simplifying mathematics if negative frequency does not exist (to my knowledge) in nature ? For example, when plotting the spectra of a ...
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Convolutions in Physics
At a high-level Wikipedia states: "A convolution between two functions produces a third expressing how the shape of one is modified by the other."
But there are clearly many ways of combining ...
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Frequency shift without affecting signal length
Non-physicist here.
From what I've learned in university and what common sense says, a shift in frequency of a signal results in a change in its length in time. For example, if a sinusoid signal of ...
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Products of Gaussian stochastic process variables
In the classic experimental physics text "Statistical Theory of Signal Detection" by Carl. W. Helstrom, Chapter II, section 4 concerns Gaussian Stochastic Processes. Such a process is observed at ...
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How is energy conserved for discrete Fourier transforms of different bin size?
I have gotten myself into a muddle regarding the discrete Fourier transform (DST) and would appreciate if someone could help me become unstuck.
I noticed that the fft of the following are the same:
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Fractional Fourier Transform and Fresnel Propagation
I am currently trying to wrap my head around Fresnel propagation, and I understand it is mathematically linked to the Fractional Fourier Transform, but I'm having a hard time with the units and the ...
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What is a Nyquist edge?
I've come to this sentence and I don't understand the term Nyquist edge.
Because observing in the FM band is not feasible, a sampling frequency of 200 MHz has been chosen for most of the receiver ...
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Why does audio signal amplitude always fall off at higher frequencies?
In the frequency spectrum of every real audio sample that I've ever seen, the amplitude of the frequency components is always higher at low frequencies, then rapidly falls off at higher frequencies.
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Can human ear distinguish between sounds of different phase?
A noise cancelling headphone produces a sound that's out of phase with ambient noise, mixes them and hence cancels them.
But I wonder if we were to hear the 2 sounds which are out of phase to each ...
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