MATLAB (MATrix LABoratory) is a numerical computing environment and a fourth-generation programming language. Use this tag with care.. see excerpt.

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14 views

Demodulation low-pass filter [on hold]

I want to know what is the suitable value of low-pass filter frequency to recover the message signal? The second question is: does the sampled signal take the frequency of the sampling frequency or ...
0
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6 views

Research help on BM3D

I am working on BM3D (Block-matching and 3D filtering). I extract all reference patches and target patches and find out distances between them. But now how to group them according to reference patch ...
0
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0answers
12 views

How one can perform a noise free first order derivation in discrete domain?

I need to have a noise-free first order derivation. Now I am using a simple (x(n)-x(n-1))/Ts. It is super-sensitive to noises. Do we have a noise-free or noise-reduced first order differentiation ...
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2answers
36 views

How is the sound converted to matrix in Matlab?

I am using the audioread(filename,y,Fs) function of Matlab and it converts an audio file to a matrix. I want to know how is each value of that matrix generated. Is ...
3
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0answers
37 views

How to create a guitar waveform using Arduino DAC

I'm using Arduino DUE (Cortex-M3 based board). I want to make a guitar sound using DAC (digital to analog converter). For instance, the note A2's fundamental frequency is 110 Hz (using A4 440 Hz as ...
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2answers
55 views

Why Fourier Transform doesn't show obvious periodicity?

I have a clearly 4Hz periodic signal (see image below). However when I apply a fourier transform, there is no peak at 4Hz. Also, when I do a power spectrum density (using Matlab's pwelch algorithm), ...
3
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1answer
27 views

What does MATLAB display when plotting a sound signal?

When you load the speech file 'mtlb' in MATLAB (which is by the way the voice of a woman saying the word 'MATLAB'), and plot the data, you get the following plot: My question is this: what does the ...
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13 views

Depth estimation from live video stream [duplicate]

I have two calibrated cameras and webcam support package and image acquisition toolbox. in this post depth is estimated from two recorded videos but my application is real-time and I want to estimate ...
0
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0answers
11 views

What are the correct way to calculate the SNR with these images in MATLAB?

Currently I am trying to figure out the Signal to Noise Ratio of a set of images as a way of gauging the performance of my deconvolution (filtering algorithms). I Have a set of images like the one ...
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0answers
8 views

How to remove roots at z=1 by using pdiv function in scilab?

I'm trying to write a code for line spectral frequencies from prediction filter coefficient and I have two polynomials P1 and Q1 as arrays from which I have to remove the known roots at z=1 and ...
1
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1answer
28 views

Depth estimation from live video stream in matlab

I want to estimate depth from live video stream with two calibrated webcams in matlab but has no results. In this post depth is estimated with two recorded video files. how can I estimate depth in ...
0
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0answers
43 views

2D Convolution Along Only One Axis and MATLAB Implementation

I'm trying to implement a Depth Map algorithm for Light Field images and I stumbled in a 2D convolution of an image and a kernel, but I think that the convolution is only preformed along the x axis. ...
0
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1answer
37 views

Gaussian wavelet generation of a given frequency

How can I generate a Gaussian wavelet (time domain) with a given central frequency. I mean, if I take the Fourier Transform then its spectrum should be around that given central frequency. For ...
1
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1answer
33 views

IQ imbalance amplitude

I have to fix the amplitude of measured IQ receiver data. According to my information about the data, I can estimate that one signal needs to be corrected to the other in amplitude. The phase ...
0
votes
1answer
22 views

Matlab Adaptive Filters

In the audio domain, I am currently attempting to use Matlab to distil: 1) 'signal' from noise+signal 2) 'noise' from noise+signal using two adaptive filters --> two results. I get the first ...
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0answers
34 views

Magnitude Squared Coherence C/C++

I have two questions about the mscohere function in matlab. The first is, is it a requirement for length(N*M) of the image you are trying to find be equal to the length of a column in the image you ...
0
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1answer
25 views

MATLAB fvtool: Setting the passband ripple below 0dB for a FIR Filter

I'm new to using filter tools in MATLAB and I'm having a bit of difficulty. I'm designing a lowpass FIR filter and I'm trying to keep the passband ripple below 0dB in the magnitude response. So far, ...
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0answers
15 views

Multidimensional EMD - Problem Plotting Spectogram

I'm having difficulty plotting the famous Time vs Frequency plot of the Amplitude. What I did so far is  1. Simulated a three dimensional signal using ...
0
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2answers
36 views

how do i calsulate SNR of a noisy signal without having the noise?

i want to calculate the SNR value of a speech signal in matlab having only the clean and the noisy one and not the noise.what should i do?
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0answers
36 views

Delay by “$z$” in matlab simulink

I have a simple question How could one implement the $z$ or $z^2$ in simulink? The $z^{-2}$ could be implemented by Variable Integer Delay block, but what about $z^2$?
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20 views

Basics of signal simulation in MATLAB

I'm trying to get my head around signal simulation in MATLAB/octave and generation of AWGN using 1: n = sqrt(1/EbN0)*randn(1,N); vs 2: ...
0
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1answer
34 views

Finding parameters of exponentially decaying sinusoids (Matrix Pencil Method)

The matrix pencil method is an algorithm which can be used to find the individual exponential decaying sinusoids' parameters (frequency, amplitude, decay factor and initial phase) in a signal ...
0
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0answers
24 views

Cohen-Daubechies-Fauraue 7/9 wavelet in Matlab

I just want to ask what the wavelet filter name used for Cohen-Daubechies-Fauraue 7/9. what name should I used in 'wname' when I want to use this type of wavelet in Matlab. some say that it is ...
0
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0answers
28 views

Help DFT Filter Bank

I'm implementing maximally decimated FB on matlab and it's happening a strange thing. If i implement parallel filters, the output is near reconstructed, without aliasing in other channels, while if i ...
0
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0answers
11 views

Amorphous X-Ray Diffraction Pattern

I have a pattern of an amorphous material from x-ray diffraction and I need to clean it up a bit. A paper I am following mentioned that they reported the data as "the results of deconvoluting the ...
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0answers
23 views

How to calculate output from non-uniformly sampled transfer function data?

I have non-uniformly sampled transfer function data (magnitude only) in the range of 100kHz and 200MHz. Using this transfer function, I would like to calculate output from specific input. Question : ...
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0answers
18 views

Problem with DFT Filter Banks and MATLAB

I'm posting the results of dft FB on matlab, and I would discuss about them. To generate the analysis and synthesis prototype i used a simple method for pseudo-QMF, published by Mitra in his ...
0
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2answers
53 views

Matlab fast fourier transform (FFT) function and time in hours frequency : hertz or millihertz?

I have a function of type $$C(t)=0.31 \left(e^{-0.267t}-e^{-1.72t}\right)$$ Where $t$ is in hours The function represents the evolution in a window of 24 hours of a drug blood concentration, after ...
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0answers
19 views

Excite AR-Model with white noise to reconstruct a signal

The following Matlab code creates an AR process and then calls aryule to find the AR Model. Now, as far as I've read, you can excite this model with white noise and ...
0
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1answer
58 views

how to design LPH and HPF from APF

I came across a concept that says we can design LPH and HPF from APF when the transfer function of the two APFs given as $$\begin{align}A_0(z)&=1\\ A_1(z)&=\frac{-a+z^{-1}}{1-az^{-1}}\\\\ ...
0
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1answer
31 views

how to find breakpoints of a signal based on the frequency of the signal

There are 4 cos signals with 10,20,30 and 100 Hz each. The main signal is the sum of those 4 and I have to create a low pass filter, on the main signal for the frequency's > 50 Hz. ...
0
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1answer
44 views

Code generation for `sum` function in MATLAB

In cross correlation we use the below command to calculate the sum after elementary multiplication of the vectors. But when we try to convert this Matlab code to vhdl using HDL coder, this command is ...
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33 views

AWGN channel matrix in MATLAB

I need to create an AWGN, Rayleigh and Rician channel in MATLAB to reduce the transmission power in real time. So that I have to generate a 2*2 and 4*4 channel matrix. For Rayleigh and Rician I ...
2
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1answer
65 views

Why Butterworth filter always starts my signal from from zero mark (amplitude)?

I am trying to filter my force signal using Butterworth low pass filter. so this is the signal, I have to filter (noise frequency is around 33 Hz). So when I use Butterworth filter with following ...
0
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0answers
42 views

FFT and Power Spectrum from Time series using MATLAB

I'm trying to better understand some things about FFT so I've asked for a small assignment, in MATLAB, in which I'll make some signal analysis on existing data. All I have is a time series which is a ...
0
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0answers
26 views

how to write the mathematical equation for the concatenation of RGB channels into one image

I have the following RGB channels for a given image (x): R=x(:,:,1); G=x(:,:,2); B=x(:,:,3); I concatenated them using the ...
0
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2answers
35 views

Eigenvalues of a vector

I'm trying to calculate (with Matlab) the minimal and maximal Eigenvalues $\lambda_{min}$ and $\lambda_{max}$ of the autocorrelationmatrix $R$ to adjust the stepsize of an adaptive filter. My input ...
0
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1answer
31 views

How can I reconstruct a Time series using it AR coefficients in MATLAB?

I have estimated AR coefficients of a time series using "aryule" function in MATLAB. Now I want to obtain the error of the estimated model. I think at first I must reconstruct it. so How can I ...
3
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1answer
22 views

How to merge transitions?

I need to represent my signal as a set of transitions from one level to another, and I am interested in transitions that have relatively big amplitude 2000+. I applied median filter to get rid of the ...
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0answers
26 views

Filtering an audio file using IIR filter on Matlab

First of all, sorry for my English. I'm quite lost with Matlab, I'm not comfortable at all and I have to create an IIR filter using Matlab. The thing is I'd like to remove background noise from an ...
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2answers
30 views

Regarding BIQUAD IIR implementation in MATLAB

I want to implement a high pass filter (order 4) in MATLAB using cascade form. ...
0
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0answers
25 views

Vein extraction from this image

I have this image: What methods should I use to extract the veins from this image. Thank you.
1
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1answer
42 views

Choosing low-pass filter parameters

I have position of objects from recording sampled at 30 fps. I wish to remove high frequencies from position with the help of low-pass filter. I am confused as to how to choose the filter parameters ...
0
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0answers
24 views

Undersampling with Simulink

i'm modeling an ADC with Fs = 40 MHz with a signal sine at Fc=130MHz, sampled at 520 MHz. I'm expected to see this at 10 MHz after to be sampled, thanks to undersampling. The problem is the sample ...
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2answers
80 views

FFT, padding, IFFT and plot in time domain

I performed an FFT with some zero padding and would like to transform it back to time domain. When I plot the signal it looks wrong. Is it because of the padding used in the FFT? How can I make it ...
0
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1answer
44 views

what is happening when i run this code line? [closed]

I have the following MATLAB code: x=[1 2 3; 4 5 6; 7 8 9;]; u=(0:255)/(255-1).^1.05; x2=u(x+1) when I run this code I get the following as a result in ...
0
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1answer
63 views

Simulate packet loss in internet video streaming

i have encoded H.264 video using ffmpeg . I want to apply packet loss model like Gilbert Eliot model to depict video transmission over unreliable network. Like in this thread TV noise is simulated. ...
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3answers
53 views

Logaritmic amplitude squarewave

This morning i was experimenting with GNU Octave. I created several signals(Sine, Saw tooth, square wave and noise). After this i used the periodogram. in the periodogram the square wave weren't ...
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0answers
19 views

Calculation of snr at output of Adaptive Filter

I am working on Spectram Digital DSK having Texas Instruments c6713 DSP Processor. I have run the sample code of adaptive filter. I have to calculate the SNR ratio at the output in MATLAB. I can get ...
0
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0answers
19 views

How to choose a wavelet order

I'd like to perform the DWT on a signal in order to find the time-frequency information. I've read from a textbook that the coiflet performs best on this type of signal (ECG), I guess due to the shape ...