# All Questions

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7 views

### Reconstruct signal from imprecise sampling?

I'm trying to digitize a VGA signal with a low-power consumer computer running a consumer OS and am having issues with the stability of the sampling rate. What I did so far: grabbing the green ...
4 views

### What are the differences between the DWT and the MODWT?

What are the differences between the DWT (Discrete Wavelet Transform), which is the most classical algorithm and the Maximum Overlap Discrete Wavelet Trasnform (MODWT)? Both these algorithm are ...
11 views

### Pre envelope of an FM signal $s(t) = 8.6\cos[2{\pi}40000t + 0.1\sin(2{\pi}53.9t)]$

I want to ask a question about pre-envelope of an FM wave: $$s(t) = 8.6\cos[2{\pi}40000t + 0.1\sin(2{\pi}53.9t)]$$ Can someone explain briefly how we calculate the pre-envelope of this signal?
17 views

### Confusion regarding DFT calculation?

I am studying Richard lyon chap3 , article "Understanding the DFT equation " But i am bit confused how x(n) is calculated specially x(0) and x(1) because apparently x(n) is calculated by plugging ...
21 views

### Taking inverse Fourier transform in column-wise and solve it in row-wise

$\DeclareMathOperator{\FFT}{FFT}\DeclareMathOperator{\IFFT}{IFFT}$Assuming I have a matrix $X$ of size $64\times16$. Taking the $\IFFT$ for it in column-wise, I means that $Y = \IFFT(X)$; Is it ...
20 views

### why there is no 0 on the right side? (matlab, low pass filter)

I took even number of sample (in this case 6) from sinc, hamming window, and multiple of those two. then after fourier transform, frequency-domain variables have zero only left side, in this case its ...
11 views

### Stability of a signal

I would like to know when I can determine that a system is stable. I've seen Stability of a system but this is very theoretically. My background is that I've set up a measurement system to detect the ...
12 views

### Noise level estimation using Hildebrand & Sekhon method

I have some data from a radar to process in order to find the moments and in turn the wind speeds. I have no prior knowledge in signal processing so it's giving me a hard time to estimate the noise ...
14 views

### Matched filter for “amplitude SNR” vs power SNR

I am working on an application for which a matched filter seems like the right concept. In the derivation for the matched filter which I went through (here), they define the SNR as the ratio of ...
9 views

### Phase difference between two wave files

I am doing comparison between two wave files, How to calculate phase difference between those files?
8 views

### What does it mean to rotate an image by 0.1 degrees?

In the old Tangent Prop paper (you don't need to know this paper), the tangent vector of the rotation transformation (think of this as a vector-valued function) at some input image is approximated by (...
4 views

### How to select states for a Kalman Filter

I'm a bit rusted on Kalman filters. I read about them about 10 years ago. So here it goes I have this equation which I'm aware is non-linear. This a simplified equation a DC-link capacitor with ...
10 views

### Applications for the Maximum Phase Filter

A maximum phase digital filter has all zeros outside the unit circle, and has the maximum phase and therefore longest delay for a given magnitude response. Besides the possibility of needing a ...
10 views

### what is the DNL of flash converter

i have a flash ADC converter with 1V vref and idial ressistors but in the comparator i have standart deviation of 3mV. how do i calculate from the the standart deviation of the whole device(DNL INL)? ...
21 views

### What helped you in reading and implementing papers and coming up with original ideas in computer vision/graphics?

I'm trying to get into academic research at the intersection of vision and graphics, and was wondering how researchers in the field went about this: Was it useful to do a lot of fundamental math ...
10 views

### Smoothing jagged lines in an image?

I have an image like this - I would like to smoothen the lines in this (as you can see they lines are a little jaggy.) How can I do this? I obtained the lines by isolating them from another image ...
22 views

### How can I detect the presence of echo in an audio?

The presence of echo during a phone call can be extremely irritating. Echo consists typically of the speakers sound being picked up by the microphone with a certain delay (10-200ms). One of the causes ...
20 views

### Is Differentiation as a system, is an invertible system?

is the following system invertible? as I understand it, invertible means finding an inverse function which should return back the original input from an output of the given system. if so I ...
23 views

### Control of a nonlinear static MIMO System

I am currently writing my master thesis and trying to design a controller for my system. However, the system is somewhat unconventional. It has a large number of inputs and outputs, is static, non-...
23 views

### Image Processing [closed]

I have an image and I am trying to find its rows and columns. A = imread('lena.jpg'); nrows = size(A,1) ncols = size(A,2) This is 3 dimensional matrix. Output ...
12 views

### Justification for squared L2 data and smoothness term as an error bound

Often in variational methods (and not only) we have an energy that is of the form: $$E(u) = \frac{1}{2}\|f-u\|^2_2 + \frac{\alpha}{2}\|\psi(u)\|^2_2,$$ where the first term is referred to as the data ...
12 views

### Remove a signal that is known to repeat every 4 samples at a known phase i.e. exactly 500 Hz signal in 2000 Hz data

I have a situation that the measurement device is generating a known signal in the data at 1/4 of the rate. In this case that is a 500 Hz signal when sampling at 2000 Hz. Now, I can already measure ...
11 views

### Can someone explain the Walsh modulation sequence of “0” and “4”? [closed]

can someone explain the tribit sequence generation please ? and the meaning of "0" and "4" ?
22 views

### denoising floor function

Suppose that $y(t) = \lfloor x(t) + \epsilon(t) \rfloor$, where $\epsilon(t)$ is zero mean, independent noise. Is there any techniques on recovering $x(t)$ from $y(t)$?
8 views

### Matlab implementation a correlated channel model

I am looking for a mistake in my implementation a correlated Rayleigh fading. Before I asked here how correlation affects the BER. To implement the correlated Rayleigh channel coefficients I used an ...
22 views

### How to choose pilot symbols count in OFDM?

I am from an Instrumentation background and recently have been working on an OFDM project. With my research, I was unable to find the solution to the below question. How to choose the Pilot Carriers/...
5 views

### how to use robot framework to launch unit tests on matlab?

I Know the syntax of rfw and and I want to make some unit test, for some kernels and functions in matlab and I need some help to begin with
14 views

### name the RF Impairments That Distort a Signal before it is converted to baseband form? [closed]

let's suppose we have a HF signal for instance what are the impairment or all the processing we need to do before we can get into matching filtering and equalizer: Phase/Frequency Offset , I/Q ...
30 views

### Pitch shifting with bins creating large feedback

I am attempting to create a pitch correction algorithm. I started by performing a test. The test goes as such: Get WAV file Split it into bins of size n (512 in my case) Shift each bin by 2 semitones ...
18 views

### phase offset extraction using matched filter

I'm looking for an application of detecting the drift of a received signal carrier frequency from ADC clock of the receiver (in case of no drift, ADC clock should be optimally an integer multiple of ...
16 views

### How to identify the frequencies of periodic peak signals in a noisy time series?

Suppose to have two time series with peak signals at different frequencies, like these two: ...
19 views

### Discrete Wavelet Transform output: coefficients or FIR-filtered signals?

I have a theoretical question about the calculation of the Discrete Wavelet Transform, using MATLAB specifically. According to this video-tutorial on the MATLAB lagorithm: https://it.mathworks.com/...
27 views

### Size (bytes) of a sampled signal

I am a beginner and maybe I have the false idea but I will thank your understanding, my background is not so on the DSP side. I have a KX134-1211 accelerometer that delivers a digital output. It is ...
11 views

### Projection Onto Convex Set (POCS) algorithms [closed]

Hi, we are asked to construct POCS algorithm in matlab but I couldn't find any sources to implement this. The true_input.mat file is an array sequence whose length is 128 and when I plot it, it is ...
10 views

### Mutual information smaller on data subsets compared to entire data set

I am estimating the mutual information for a continuous data set using the kNN-based mutual information estimator proposed by Kraskov et al [1]. Lets consider two features $X$ and $Y$, and the ...
10 views

### how to implement Bark filter bank on the power spectrum for PLP feature extraction?

So the implementations for PLP feature extraction I have seen in python and Matlab, are as follows: suppose the FFT features of an audio signal are of the size 257 (512 point FFT). if we have one ...
11 views

### What channel model to choose while simulating a system in passband with frequencies over GHz range?

I was wondering as to what kind of channel model do we use to test for BER vs SNR in a passband RF system. The system that I designed is basically a wideband frequency hopped OFDM system where I use ...
14 views

### Sinusoid amplitude loss in power spectrum estimation using Pwelch method

I am trying to estimate the amplitude or power spectrum of a sinusoidal signal using Pwelch method. The following is the matlab code I use. ...
56 views

### On the simplification using trigonometric functions

Assume I have a matrix $D$ whose its entries are as below : Where $A$ and $B$ can be written using using the trigonometric functions for (1) as: My question, Is it possible to simplify (1) more? ...
29 views

### Energy of audio signal

From audio file [y,FS]=something.wav So the y is typically N cross 2 matrix I want calculate energy so i.e sum(abs(y.^2)) So when I apply these I end with two answer for each column. So I want ...
24 views

### Filter design with arbitrary response

I would like to design a feedforward filter for a current controller. I could of course run MATLAB to brute force an arbitrary response for me, but I have some ranges "don't cares" in the response ...
22 views

### FFT of a variable-frequency signal

I'm writing a software that read engine rpm during acceleration, using a recorded audio. To do that, I divide the record in small time-steps, and for each one I do an FFT, to know the rpm in that ...
20 views

### fft of a signal in the space at a fixed time

I have to do a fft of a signal in the space at a fixed time. I have always done fft of signals in time, so this is strane for me. In particular I have some difficulties in defining the Nyquist ...
20 views

### Obtaining the Impulse Response (IR) from cross correlation MATLAB

I am trying to obtain the impulse response from the autocorrelation (rxx) of the input signal and the cross-correlation of the input and output signals (rxy) using the following MATLAB code however I ...
20 views

### Where does the “Desired Response” come from in a Wiener filter?

I'm confused right off the bat in the introduction to Wiener filters, because how can you know what the "Desired response" is? Where does it come from? And if you know it already, then why build a ...
19 views

### bandwidth vs. bandwidth range

As known, Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies. OK, what means when saying that bandwidth range is 15 ~ 20 KHz ? Does that mean that ...
25 views

### Why does my I/Q data from radar are not centered?

I am working on the IQ raw data from FMCW radar. I plot the I and Q data, they seem to be strongly shifted from the center. And the amplitude of I and Q also varies. I don't understand why it looks ...
28 views

### Construct IFFT from only the major frequencies of an input signal?

I have data which when plotted looks like the green line in the below image. The data is from the walking-motion of a reinforcement-learning-model in a simulation and therefore the values do not ...