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16,591 questions
8 views

Intercepting a Bluetooth Signal

Hello fellow Stack exchange doods. I am but a humble teen who is currently suffering cause at lunch these "gangsters" blast their rap music really loudly in the cafeteria and I get mucho annoyed. So ...
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Spectrogram power/magnitude normalization in analogy with image intensity normalization

In analogy with the 8-bit grayscale image color depth, in which the intensity of a sample pixel is normalized to a value between 0 and 255 by taking into account the minimum and maximum intensities ...
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How to find the filter coefficient of matched filter to detect the pulse of a signal?

I would to understand how to find the coefficient of a matched filter. Let's consider we have a signal and the signal is buried in the following noise. we want to find the coefficient of a matched ...
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Given N samples point from y =original_signal+noise, how can I recover the original signal from N samples points

The distribution of noise can be seen as known.
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Calculating N for DFT

We want to compute an N-point DFT of a one-second duration compact disc (CD) audio signal x[n], whose sample rate is $f_s = 44.1Khz$ with a DFT sampling of 1 Hz. (a) What is the number of necessary x[...
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PLL carrier recovery: intermediate versus baseband

When looking at carrier recovery, a PLL is often applied to correct the frequency offset between the local oscillator and the transmitter after down conversion. I'm wondering what happens to the PLL ...
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How to match resolution of two or more signals

I have received the following 4 time-series signals and wanted to do some data analytics using these. Although the sampling is the same for all of these signals, 2 samples per second, problem is that ...
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Calculating noise floor of digitization system using FFT

I am trying to calculate self noise of a digitization system with differential inputs.For this purpose, i select a differential channel, set input range to +/-5 V, short both differential inputs and ...
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Do Fourier frequencies actually exist in real life in form of “instantaneous frequency”?

For me, this is a very awkward question to be asked, as at this point in my studies I'm supposed to be quite expert with elementary mathematical tools like Fourier transforms, but this has always ...
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MATLAB & Power Spectral Density - Error - Getting the same range of values regardless of sound type?

I wrote code [attached at end of question] to take .wav files of child vocalizations and tried to see if there are valid ranges for the formants F1:F2:F3 for the 5 ...
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Mscohere in Matlab-why would the coherence tends to 1 as nfft increases?

Does anyone have a clue as to why -using mscohere- the coherence becomes exactly one for all frequencies if nfft is set to about 190-200. I know it's standard practice to set it to a number that is a ...
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rate 1/128 channel code for 5 bits of information

I need to construct channel code for 5 bits of information for a wireless channel. Possible code rate could be as low as 1/128 (very reliable). At decoder I assume to use channel LLRs as decoder input ...
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Getting SNR of reconstructed signal in MATLAB

I am trying to run code to compare the efficiency of various basic sampling methods such as ideal sampling, natural sampling and so on. I want to then use average power to see how accurate the ...
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What is the precise definition of a nonlinear signal?

I tried to find the the precise definition of a nonlinear signal. However it is not easy. How can we define a nonlinear signal?
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Tetrahedral microphone array beamforming in MATLAB

I have a microphone array of 4 channels taken as channels [6,10,22,26] from Eigenmike spherical microphone array. I wish to do 3D beamforming and create $8\times 4$ beams, 4-elevations with 8 ...
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Odd-order Butterworth filter gain at cutoff frequency

Wikipedia gives the gain of an n-order Butterworth filter as $$G^2(\omega)=\left |H(j\omega)\right|^2 = \frac {{G_0}^2}{1+\left(\frac{j\omega}{\omega_c}\right)^{2n}}$$ here. If you look at the gain ...
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IFFT, negative frequencies and noncausal impulse

When using the IFFT to compute an approximation to the IDTFT, frequency range is 0 to 2$\pi$ versus $-\pi$ to $\pi$. This produces a different impulse sequence(causal I think). How do you calculate ...
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Taking FFT of a signal with lots of “holes”

I have a time series that is spotty (more 'no sample' than 'sample' at each second, which is the sample rate). There are obvious trends when viewed visually. However since there are holes, the FFT ...