Questions tagged [spectrum]
The spectrum tag has no usage guidance.
13
questions with no upvoted or accepted answers
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1answer
149 views
Two details about phase noise have been confusing me for a long time. Hope to be resolved
Just like FLOYD M. GARDNER said in the PhaseLock Techniques, 3rd Edition: "In light of that success in spectrum analyzers, a practitioner’s answer to the question above is: The spectrum of phase noise ...
1
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1answer
44 views
Power Spectral Density units
I am trying to compare power spectral density values (obtained from dsp.SpectrumAnalyzer) with PSD values obtained from hardware which has a VSA.
MATLAB's documentation says that " The power spectral ...
1
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1answer
44 views
Noise Floor of ADC using PWELCH
While using MATLAB's Pwelch function, I am not able to match the noise floor of the "Modelled" ADC to (Delta)^2/6 {1 sided Spectrum}.
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27 views
How does spectral density of a power signal change when it is multiplied by \$cos(2\pi f_ct)\$?
Suppose we have a power signal \$n(t)\$ whose power- auto-correlation function is: \$R_{n}(\tau)\$ . Now we multiply the signal by a cosine as: \$cos(2\pi f_ct) \cdot n(t)\$, whose auto-correlation is ...
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128 views
Speaker designed for ultrasound operation
I've created a transmission protocol in order to transmit information bits between a PC speaker and a smartphone, or between 2 smartphones using ultrasounds. I've implemented a QFSK system which uses ...
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69 views
DAC “aliasing” of harmonics
While reading articles and application notes regarding DACs and their output spectrum, I stumbled across aliasing of higher harmonics to the first Nyquist band. For example, when generating a single ...
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20 views
Elastic optical network
I am starting to study elastic optical network and I'm confused about the correlation between bandwidth channels supper channels does any one have a pdf file or slide of this subject? thank you so ...
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42 views
From noise spectral density to equivalent short circuit input RMS noise
I have an acquisition system that is supposed to be low noise. It acquires from an ADC into a wav file. I read this file and process it with Matlab. Then, being "x" the array with time signal, Fs the ...
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33 views
Doppler spectral power density
In layman terms, why doppler spectral power density has U shape?
Does this mean that frequency components with maximum doppler shift have maximum power?
I am confused with the interpretation of the ...
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0answers
30 views
non-negative FFT spectrum, subtlety
definations
\$x(t)\$ is a function of time. Physically, it can be voltage, displacement, magnetization and so on. It can be real, complex, vectors or more fancy numbers.
\$C(t)\$ is the auto ...
0
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1answer
72 views
Analog Led Audio Spectrum Analyzer Simulation
I am having a bit of trouble trying to simulate a variation(different frequency ranges/gain for the BP filters) of this project: https://makezine.com/projects/audio-spectrum-analyzer/
I am not too ...
0
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1answer
47 views
Why averaging in Spectral magnitude domain not in complex domain to estimate spectrum of a process
Consider we need the magnitude spectrum of the signal. Signal is recorded in \$N\$ trials to a certain stimuli. Signal varies from each trial because of noise. So, to estimate the actual magnitude ...
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148 views
License free frequency spectrum in Australia
What is the license free frequency spectrum in Australia? Is it 433Mhz or 915Mhz Or 868Mhz? I am trying to do some IOT Project using RF (LORA/ZigBee) modules. I thought it was 433Mhz. But some online ...
