Questions tagged [frequency-spectrum]

The frequency spectrum of a time-domain signal is a representation of that signal in the frequency domain.

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Filter characteristic frequencies of one time series signal dataset and paste/add them into another

I have two categories of a time series signal dataset in the time domain - one "good" and one "bad" category. My goal is to create "fake" bad data by filtering out the ...
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How important or interesting to increase the spatial resolution of linear array for narrow band or broadband radar for SONAR or other areas?

May I request your comments, please? Consider we have a linear array (radar) to detect some targets. The system may be narrowband or broadband. Using broadband we may get better time resolution but ...
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Why is taking the inverse Fourier transform the same as taking the Fourier transform when computing the cepstrum?

Usually, the cepstrum of a signal is introduced as the result of taking the logarithm of its power spectrum, then applying the inverse Fourier transform: $$C_p = |F^{-1}\{\log(|F\{f(t)\}|^2)\}|^2$$ It ...
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Telecommunication with same frequencies

If signal is transmitted with same frequencies they interfers, but why can't we use the technique of encryption and decryption to stop from interfering signals with same frequencies?
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What is the result of taking the real part and imaginary part of a complex signal in the frequency domain?

Suppose that $g(t)$ is a lowpass complex signal with magnitude (solid line) and phase (dashed line) To modulate $g(t)$ into a bandpass equivalent signal $f(t)$ with center frequency $f_c$, we compute ...
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Get Hilbert marginal spectrum with emd package in python

I want to get the Marginal Hilbert Spectrum in Python using the emd package. You can estimate the Marginal Hilbert Spectrum as where, and A(ω,t) is the time-dependent amplitude modulation and ω ...
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Why does adding a high-pass or low-pass EQ increase volume?

The following three screenshots show the max volume levels (indicated above the VU meter) of Cuckoo by Tipper if played with: No EQ: -0.5db Headroom High Pass EQ: +2.5dB over Low Pass EQ: +0.4dB ...
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how make an equation of a procedure?

Good day to everyone, i have frequency spectrum i selected top 10 peaks of that spectrum i give weightage from 1 to 10 to top 10 frequencies by multiplying the corresponding amplitude by weightage ...
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Units of a Fourier Transform (FFT) and Spectrogram [closed]

I am very interested in analyzing signals in the frequency domain. Units of a Fourier Transform (FFT) when doing Spectral Analysis of a Signal 1.In the previous question, answer the unit for the ...
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Mapping STFT magnitude to sound intensity level

I have a signal for which I have computed my STFT magnitude spectrum in dB. The plot is the following: This is my magnitude spectrum in dB computed with ...
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Power spectrum of a signal in negative frequency domain

I have a signal with fc = 308 kHz and B = 30 kHz and some white noise added. The signal is sampled at samplFreq = 4fc. ...
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Phase Noise and Multi-carrier Frequency conversion

I have a oscillator with a phase noise mask that was represented in dBc at specific offsets from a carrier. Two options for a multicarrier signal going into a converter, apply the phase noise mask (...
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Limiting Bandwidth for QAM and OFDM signal in MATLAB Simulink

currently im creating an application capable of generating QAM and OFDM signal to be transmitted using SDR. The whole application is implemented in MATLAB Simulink using only code generateable ...
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I have two signals, recorded from the same device. How do I standardize/normalise them?

I essentially have two signals X and Y, recorded with PPG devices. These have been filtered already. I want to standardize(z-score) or min-max scale them but I don't know if I should do this on each ...
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Problem with the output self implemented “ Iterative FFT DIT Radix2 ” algorithm matlab

I´m trying to implement my own FFT with the iterative Radix2 algorithm (I even thought about using the recursive one but it seems Simulink doesn´t allow me to). I tried all of the possible variations ...
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Extract signals with certain frequenceis from a data sample using python

I did not major in signal processing, and I do not know a lot about some possibly very basic facts, so although SE has some questions related to this, I still have some confusion. I am given a data ...
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dB octave band spectrum

When I was at the University I did some courses about Acoustic. I always seen the dB octave band spectra, as the Fourier Transform of the dB in time. Now looking at some reference in Matlab, I noticed ...
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How to Frequency Modulate an Audio Signal

I've started to learn about FM and I followed this guide to FM a sine wave. I have managed to do it and here is the result: And the code: ...