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1500 questions
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votes
3 answers

How to pick coefficients for Fractional Delay Filters?

I have a Virtex 6 FPGA running at 200MHz with ADC/DACs on it. I have been converting a WiFi signal (2462MHz) down to a more reasonable IF of 25MHz, sampling, running the signal through taps, tweaking them, and mixing back up. This all works…
toozie21
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2 answers

How to know if a continuous function can be represented by a finite sum of sinusoids?

I have a lack of mathematical knowledge, and notably in mathematical vocabulary, so maybe a similar question exists but with a different wording. What I want to know, is actually how to know if a function, given its properties (for example, a…
endyx
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1 answer

Bandwidth of an entire song

My question has to do with the difference between the frequencies of a single note, and the frequencies of an entire song. If I have a 5 second signal of the form: $x(t)=\sin(8\pi t)$, here is the frequency response with zero-padding: For a signal…
Levi
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1 answer

'Best fit' motion curve for an unachievable profile

I have a discrete function that represents a 1d position in space over time. I have a motion system that would like to achieve this curve, but, due to constraints on jerk (3rd derivative) and acceleration (2nd derivative), it cannot actually…
Dan Bryant
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6
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1 answer

Deblurring algorithm to precede thresholding - speed over accuracy

I'm writing an app that recognizes Sudoku puzzles from a camera input. I'd like to remove camera blur from the images to improve recognition. Here is an example image: Since I'm processing a continuous camera feed, I'm concerned about speed,…
1''
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6
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2 answers

Modelling MEMS accelerometer noise

I am trying to compare two MEMS accelerometers in terms of their noise for ground motion monitoring applications. I would like to take some "clean" data (recorded by good quality instrumentation), add white noise to it so I can bring it to the noise…
marco890
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2 answers

Discrete Fourier Transform of the Gaussian

Cross-posted from here I encountered the following question in a Digital Image Processing examination: Find the 2D DFT of $\frac{1}{2 \pi \sigma^2} e^{-\frac{(x - x_0)^2 + (y - y_0)^2}{2 \sigma^2}}$ where $x_0, y_0$ are integers and $x_0, y_0 \in…
kaddy
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6
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3 answers

Does analytic signal have positive instantaneous frequency?

The Analytic representation of a signal has no negative frequencies. Does this mean that everywhere, it's instantaneous frequency is positive?
Sebastian Præsius
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Implementing logarithmic AGC (automatic gain control)

I'd like to implement the Log(arithmic) AGC from Understanding Digital Signal Processing But with import numpy as np import matplotlib.pyplot as plt def signal(): cycles = 15 resolution = cycles * 20 length = 2 * np.pi * cycles x…
ge45mue
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1 answer

Is there an intuitive explanation for how adaptive beamformers work?

Recently I've been learning about and implementing some adaptive beamforming schemes (particularly the SMI/Capon beamformer, and the Robust Capon Beamformer). I understand the mathematical derivations for them, but I'm struggling with the intuition…
Dan Pollard
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4 answers

What is the audible level for digital audio dB units?

What is the audible level for digital audio dB units? I was looking at a soundwave from an mp3 file. I am using the "Sonic Visualizer" app available on Linux. The amplitude is between ~ -0.1,0.1 in my file. I have already learned the amplitude is on…
user2183336
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1 answer

Any good image blind deconvolution algorithm for removing camera shake?

I am working in the field of digital image restoration. I have images that are degraded by camera shake. My images are similar to this blurry photo from camera shake. Can anyone please suggest a better non-blind deconvolution algorithm? I have…
Mayank Tiwari
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6
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1 answer

Discrete Fourier Transform a dummy approach

I'm trying to understand how DFT works exactly. However, when experimenting around, I compared both Matlab generated FFT result with a dummy approach result and I get similar result. However, the Imaginary part of both results are negated. The code…
NcJie
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Cross Power Spectral Density of Unevenly Sampled Data

Here's my problem. The input signals $x$ and $y$ will be having the time value aligned with each other. However, the data are not evenly sampled. I would like to calculate CPSD of both signals. The solution comes to my mind is as follow $R_{xy}$ =…
SeeJay
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6
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2 answers

Does PSD (dBm/Hz) of white noise depend on sampling rate?

I am confused about signal processing broadband noise like white noise and single-tone noise (sine wave) using FFT. As a starter, I am trying to understand how to normalize white noise properly after FFT. My understanding is that once properly…
anikap
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