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41 views

PSD from autocorrelation in MATLAB

I am trying to simulate a simple stochastic process defined by the equation: \begin{equation} \frac{1}{v}\frac{db}{dt} +\Gamma_0 b= \sqrt{\sigma}R(t), \end{equation} where $R(t)$ is a zero-mean white ...
0
votes
0answers
16 views

splitting real voice based on words using python or other program

Recently, I have a research project that need me to cut a large number of wav files containing the voice from movies, youtube videos or songs based on words for statistical analysis. The sounds are ...
0
votes
0answers
22 views

Autocorrelation of an AR model

When I plot the autocorrelation function of an autoregressive signal, I get this instead of a damping sinusoid. I am having trouble understanding why this is happening. My signal is an generated ...
0
votes
1answer
42 views

Estimation / Reconstruction of an Image from Its Missing Data 2D DFT

Given the 2D DFT of an image i.e. a NxM matrix of complex numbers, with some missing lines (or even partial lines), considering we have zeros in the missing positions. Any suggestions for an ...
0
votes
1answer
27 views

What factors affect the propagation delay at wireless communication?

Generally, the signal propagation delay is d/c. d is a distance between a transmitting antenna and a receiving antenna. c is light speed. However in NS-3, there is Random Propagation Delay Model ...
0
votes
2answers
46 views

Ripples in filter

What are the uses of ripples in the filter design. We try to design a filter with least ripples but sometimes we design a filter to have 2 or 3 ripples. Why is it so?
0
votes
2answers
37 views

Correlation between a signal segment and its stretched replica

In my application the measurements are affected by temperature and the signal is stretched over time, though preserving relatively similar structure. I want to find incremental stretching between ...
0
votes
1answer
20 views

How to calculate this energy for a given signal?

So the question Im asking can be seen in the picture below.The d at the end of the question stands for the minimum euclidian distance. Mostly I just want to know how to calculate the energy for each ...
2
votes
2answers
125 views

How would you interpret the pattern in this picture? (generated by re-sorting pixels based on their RGB value)

Was playing with some pictures and ran the ruby code below. The code reads an input image using the ImageMagick library, gets an array of pixels, re-sorts the pixels and then writes out an image with ...
1
vote
2answers
85 views

Old style signal processing?

I am wondering if "an array of overlapping band-pass filters" it is 'mostly' equivalent to a Short-Time Fourier transform. See this (figure down), where $s(t)$ is the signal; LPF a second-order low-...
1
vote
3answers
87 views

Reverse engineering a digital filter

I have 2 simultaneous signals that both are designed to measure eye movements. They are sampled at 250 Hz. We have 12 subject recordings. For 3 stable periods in each subject, we choose 256 points and ...
-1
votes
1answer
29 views

Simulating polar pattern for custom radiator (custom speaker design)

I'm interested in performing a speaker simulation to extract an approximate polar pattern for two custom speaker designs. First design: A half wave pipe (transmission line) subwoofer 24 hz to 56 hz ...
-1
votes
0answers
14 views

How can I analyse, recognise some part of audio files?

I have 1000+ programmes recorded from a radio channel. There are about 6 kind of programmes among them. I would like to discard one of the six types of programmes: about 1/6 of the programmes, ~...
-4
votes
0answers
14 views

how to calculate rmse and mse using codes in matlab?

i am new to matlab. for predicting energy data in ann tool, im little bit confused about calculating rmse and mse in matlab. i had tried many codes for calculating rmse but errors are arriving. can ...
1
vote
1answer
32 views

Implementing MVDR beamformer in the STFT domain

I am trying to implement an MVDR beamformer for the first time. I was reading a couple of papers and books with many different notations and I am a bit confused. In my case, without loss of ...
1
vote
2answers
55 views

Finding impulse response of an RC circuit from its step response

I have to find the impulse response of an RC circuit (c up ). I have to find it from the step response $g(t)$. I found that $V_i - V_c - V_r = 0$ , with $V_r = V_u$ So $V_u = V_r = R I_r$ , with ...
0
votes
1answer
18 views

Linear prediction and filter stability

I am currently trying to implement an iterative block-wise algorithm in which AR coefficients are computed for each block. There is a issue with my code where values get too large, and I was ...
1
vote
0answers
11 views

Convolutional coding that payload length does not change

This is the question about Sigfox radio specification. The stack: Specifically, in Section 3.10 of the specification, we have a convolutional coding (after CRC) with three possible polynominals. I ...
1
vote
3answers
60 views

Is spectral leakage normal for FFT?

I record a sample of 2000 data points, with a sampling rate of 40khz, so freq. resolution is 20hz. I multiplied the chunk of data with a Hanning window prior to doing the FFT. I recorded a 1khz test ...
2
votes
1answer
27 views

Stereo triangulation similar triangle derivation

I understand that the similar triangles are the red and blue triangles. I'm trying to understand where $T + x_r - x_l$ comes from. I understand we are trying to compute the length of the base of the ...
0
votes
1answer
13 views

Computing differences between dynamic power spectrums to identify transient features

I have a few minutes of magnetic field data with a lot of noise and unwanted frequencies, and I'd like to be able to identify any transient waves that may appear in my data. To do this, I'm dividing ...
0
votes
1answer
32 views

The frequency-domain spectrum obtained using MATLAB's FFT function seems inaccurate

I am using MATLAB R2018b on a Windows 10 PC. In order to obtain the frequency domain information of a signal, I'm applying MATLAB's FFT function. The signal of interest is obtained from an experiment ...
0
votes
0answers
76 views

Help me understand this filter

I'm a trader, so I'm interested in filtering data with minimum lag. I found a post on Forexfactory of a user who posted 3 pictures of a filter he got and participated to create at TSD (an old trading ...
0
votes
0answers
29 views

Is the whole data needed for the fast fourier transform with an ongoing signal?

I sample an signal with around 840k values a second, to check the spectrum around <400kHz. But i can't save the whole data as it is just to much for my microcontroller. I know that for the ...
0
votes
2answers
89 views

Intermittent Harmonics, Is there a physical explanation?

I am doing some frequency analysis of a vibration signal from a spinning rotor, I am expecting to see peaks corresponding to the rotational frequency of the rotor. So the fundamental frequency ...
1
vote
3answers
129 views

How can I know if these two signal are orthogonal to each other

So the question is to determine if this statement is true or false. The question can be seen below. I know that two signals are orthogonal if their inner product is equal to 0. I know how this ...
3
votes
1answer
85 views

Which Noise Reduction Algorithms Are Used in Commercial RAW Image Processors?

I'm trying to guess what noise reduction algorithms are used in commercial processors for raw images from digital cameras. I find this fairly easy to do for the sharpening algorithms (most use unsharp ...
-1
votes
0answers
20 views

If a AM modulation have large carrier is a asincronous modulation? and if that is correct why?

When I use DSB-LC (Double Side Band-Large Carrier) trasmission the receiver just use a envelope detector instead a mixer that fact means a asincronuos trasmission? Because I understand that in DSC-...
1
vote
0answers
26 views

Granular synthesis of a periodic waveform - How to derive grain start and end point

I understand to find the length of the grain I need to perform an FFT over the source to find the fundamental harmonic, I can do that and find an accurate grain length, but now I need to find a start ...
0
votes
2answers
44 views

Second Order Transfer Function : Imaginary component in $R$?

I have been looking at the following transfer function: $$ H(z) = \tfrac12 - \tfrac12 z^{-2} $$ Given the usual method for finding $\theta$ and $R$ in the complex plane, I calculate that $\theta = \...
0
votes
2answers
45 views

Is it valid to calculate the magnitude, power, and phase of a real time-domain signal without converting it to the frequency-domain?

I would assume you perform the calculations the same way, but since there would be no imaginary component because the signal is not complex it would be simpler: ...
-1
votes
1answer
27 views

Correct way of viewing negative voltages in units of dB for noise analysis

I have a voltage signal, on top of which there is some noise. I am interested in the noise components so the way I am trying to do this is to fit the known signal to the data and look at the residuals....
1
vote
1answer
38 views

Impulse Response Function-Green's Function

Assuming a input-output system $$u(t) = c \cdot \big(h(t)\circledast m(t) \big)$$ where its impulse response function is: $$ h(t) = \begin{cases} \frac{A}{\tau}te^{-\frac{t}{\tau}}, &...
0
votes
0answers
24 views

Spectral correlation zero modulation frequency $S_x(\alpha, 0)$

I got a simple modulating signal $x(t)=\sin(2\pi\alpha t)\sin(2 \pi \beta t)$ with carrier frequency $\alpha$ and modulation frequency $\beta$. The spectral correlation will obviously have components ...
0
votes
1answer
25 views

Get FIR Hilbert coefficients from Matlabs envelope() function

How can I get the used Hilbert filter coefficients from the Matlab function envelope()? ...
0
votes
0answers
27 views

How do I find the peak frequency of a wav file in python?

I am fairly new to python and signal processing and I was given a task to record audio for 'x' seconds and then find the peak frequency in the audio file. So far I have successfully implemented the ...
2
votes
1answer
72 views

What Is the Correct Way to Apply Richarson Lucy Deconvolution to Luminance Data?

My question concerns the Richardson–Lucy deconvolution algorithm, which is described in Richardson's original paper. I am interested in applying it in the context of a raw image converter for digital ...
1
vote
1answer
35 views

Multi Resolution STFT for audio

I am looking at trying to achieve a multi resolution STFT analysis on a log sine sweep audio measurement. I have an impulse, and I would like to perform two different windowed length FFTs on the ...
1
vote
1answer
51 views

Why would FFT interpolation using zero-padding undershoot the true frequency of a single tone sinusoid?

Why would FFT interpolation by zero-padding or using the Chirp Z-Transform produce a maximum at a bin that corresponds to a frequency less than the input frequency of a single tone sinusoid? I am ...
1
vote
0answers
24 views

Calculate the tension of a triad of notes

I'm trying to implement and calculate the tonal tension of a triad (and its harmonics) following the definition given here: https://pdfs.semanticscholar.org/f05e/56c9548fa18c64efeed248742e3a6afb0c02....
1
vote
1answer
39 views

How to adjust receiver gains to avoid saturation and quantization noise to optimise post digital processing?

I am using a Hack RF One as SDR and the software GNU Radio to receive and process signals emitted from a drone. Given that the drone is moving and is emitting signals from a wide zone, received signal ...
1
vote
3answers
80 views

Reduce the number of intensity levels of a grayscale image in Matlab

I have written a Matlab script to reduce the number of intensity levels of each pixel of a grayscale image from 256 to some power of 2. ...
0
votes
0answers
9 views

How to get NMF sparse component factors

In the NMF framework, whenever I want to get a sparse component, I set the rank to 1 (lowest possible) and get the W and H matrices of the low-rank component by doing a multiplication of the resulting ...
1
vote
0answers
40 views

CIC compensation filter and total response

UPDATE: New plot with properly scaled CIC comp response. I'm studying about CIC filters for interpolation/decimation and I'm reading about CIC compensation filters due to CIC filters not having a ...
-2
votes
0answers
16 views

What is the difference between zero state and zero input response in a recursive system?

From Proakis' Digital Signal processing: What does relaxed signify here? What is the meaning of zero state? Why is zero input response called "free response"? Why is zero state called forced response?...
0
votes
1answer
26 views

Fourier transform in Matlab and hermitian symmetry

According to the conjugate symmetry property of Fourier transform, shouldn't the following command not return 1 (=true): ...
0
votes
0answers
13 views

Normalizing FFT after recording with Pyaudio

I have a USB microphone that has a 24 bit ADC, however, Pyaudio doesn't allow for 24 bit encoding so I used 16 bit. I hope this is not an issue. Having said that, I hope to make sure I'm applying the ...
0
votes
1answer
29 views

Contributions to a DFT frequency bin

So, a frequency bin is centered around an interesting frequency $f_0$. Assume the spectrum is such that there is no spectral leakage from other frequencies to that specific frequency $f_0$. Now. I ...
1
vote
1answer
49 views

What measurement errors occur in an inteferogram?

This question is bordering on physics, but it is the signal side that I am interested in so I hope this is the correct forum. I am very familiar with instrumental noise sources in CCD based ...

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