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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4 views

Dirty Paper Coding Precoding MU-MIMO BC Channel

I'm on my final paper work and I have a lot question to ask since I'm a newbie. so here it is, I'm working on Precoding Dirty paper coding MU-MIMO in broadcast channel with selective frequency fading. ...
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23 views

How to remove modulation frequency and its harmonics

I have amplitude modulated sound file signal and after demodulation using FFT I got fundamental frequency and its harmonics and of course noise. How to remove that fundamental modulation frequency ...
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21 views

Enhancement Of Ecg Signal

Load, display and manipulating of ECG signals Design notch filters both in FIR and IIR for 50 Hz and 100 Hz respectively. Design a band pass filter to eliminate muscle noise. Plot the spectrum of ...
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11 views

Anyone know about 2D S transform [on hold]

Please provide how to convert 4D to 2D S transform. Implementing 2D stransform
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1answer
15 views

A question about image compression with SVD - MATLAB

I have to compress an image by using svd. I did a few things but all of them produced gray image. However, Output must be rgb. How can i compress an image without changing its original format?
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17 views

uniformly distributed random signal

i need to generate an uniformly distributed random signal.... i was seeing in the internet that "The uniform distribution (also called the rectangular distribution) " and " A uniform distribution has ...
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0answers
17 views

computing peak to peak ratio in matlab

i need to compute a signal's peak to peak ratio..... i have a doubt... do we calculate a signal's Peak to peak ratio in time or freq domain.... and ok say for a sine wave i can understand how to ...
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15 views

generation of frequency with magnitude 1

hi i need to generate F=[F0,F1,........Fn-1] wer n=16 such that lFnl=1..... so i understand i need 16 freq samples whose magnitude sums upto 1..... now i need to generate it in matlab...... can anyone ...
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2answers
46 views

ecg signal analysis

I'm a newbie and I have a few questions regarding ecg signal. Here is my plot of raw ecg signal with a sampling frequency 200Hz in Matlab. Does it look good to you? Why is it flipped?
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1answer
38 views

Comparing the FFT to numerical integration in Matlab

The result of calculating the fourier transform using numerical integration is: the result of using Matlab's FFT is: So where did I go wrong here? I know the FT of a Gaussian should be ...
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9 views

kalman filter for accelerometer of mobile device.can it measure exact displacement?

Matlab code for implementation of accelerometer data and kalman filter required.ASAP Any help is welcome.
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1answer
87 views

Cooley-Tukey Implementation of FFT in Matlab

For my course I need to implement a 30 point Cooley-Tukey DFT by transforming it into a 5x6 matrix. I have tried to implement using the following Matlab code: ...
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42 views

DFE for QPSK in matlab

I need to do a DFE for QPSK simulation in matlab. The system, consist in QPSK signal transmitted with power = 1. Then pulse shapping with a square raised-cosine filter. Add AWGN and a filter receptor ...
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20 views

wavelet analysis for signal when frequencies are known in advance

i would like to ask one question, generally wavelet analysis helps us to identify which frequencies at which time interval was occurred, but the point is that both frequencies and time intervals ...
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2answers
47 views

how to detect corner in a digital image using MATLAB?

I am designing an algorithm for image processing. I am using MATLAB for the processing of the images(video). How I can detect the position of the corners in the image?
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1answer
24 views

What is the best Algorithm to estimate the frequency for Almost-Periodic Data or complex periodic data?

I’ve got what it looks like a periodic signal but the periods seem not equally repeated, I want to estimate the PSD, particularly I need to obtain the dominant frequency of this data. I’ve estimated ...
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0answers
25 views

Is speech stationary ? How do I test it in matlab?

I'm taking a "Random Signals" class in school and I've got an simple assignment about speech in matlab. I have been asked to record two files: A single word or sentence. A couple of syllables each ...
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9 views

License manager error-4

How to resolve this error? Whenever i am using 'syms' it shows this error:- "Error using sym License checkout failed. License Manager Error -4 Maximum number of users for Symbolic_Toolbox reached. ...
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22 views

How to smooth out a noisy signal?

I've been waiting for an answer to my question here therfore I decided to ask the question in a different way. Could anyone please help me to smooth out the signal below!!. I've no experience of ...
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0answers
14 views

Time invariance and time variance

How can I write a MATLAB program that takes the given system described in terms input x(t) and output y(t) relations is input and finds out whether it is time-invariant or not?
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1answer
61 views

Discrete algorithm for low pass filter

I am working on a position controller for a marine vessel. I have an measurement signal containing the y-position of the vessel that consists of both low frequency (<.1 rad/s) and high frequency ...
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25 views

Getting error in PSNR calculation using Matlab

I want to find out PSNR and SNR values of two images A and B of same dimension in Matlab.I used the following code [peaksnr, snr] = psnr(A,B) and getting an ...
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1answer
34 views

Get a power spectral density from real random data

I am using real data of wind, which is a random one to get the power spectral density of these values. How can I do to get this PSD in matlab, and Can I get an analytical expression for this psd. ...
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1answer
29 views

Image getting completely white on downsampling

I performed an image downsampling with averaging operation(The image is divided into 2 by 2 blocks,then it is downsampled by 4 times.New pixel values od downsampled image is replaced with the mean of ...
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0answers
11 views

Meaning of events in EEGlab

I'm reletively new to the EEG signal processing domain and EEGlab and I'm trying to figure out the meaning and the following terms used in EEGlab and in general context in EEG.It will be helpful if ...
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1answer
15 views

Different results for seperable filtering v/s direct filtering on 2-D image in MATLAB

I compared the difference between seperable and direct filtering for MATLAB's cameraman image. The difference is huge. I would like to understand the reason for this. Code below. ...
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1answer
35 views

cross power spectral density explanation in matlab

let us consider following code ...
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1answer
44 views

fft of a complex signal

I am new to dsp and just have a vague understanding of fft process. i know fft is used to convert time to freq domain.... i need to generate a sequence of frequencies such that F=[F1,F2,.....Fn-1] ...
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2answers
27 views

Implementing image chroma keying with FIR filter in MATLAB

Is there any way I can apply the concept of FIR filters in chroma key composition, where I will remove a green background to focus on a subject and replace a different image on the removed part, sort ...
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1answer
44 views

Learning fundamentals of OFDM (Theory & Simulation)

Will you please suggest me some basic fundamental reference to learn OFDM techniques. I am looking for underneath theory with some basic mathematical explanations of CP, Subcarrier, FFT Size, Pilot ...
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1answer
34 views

Characterising a system from its input and output

I have 2 data sets sampled at regular intervals which represent the input and the output of a system. A quick analysis of the plots shows the following: There is a proportional factor between the ...
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12 views

.ptw Video conversion

On Video recording with IR camera, a file in .ptw is obtained. I want to analyze the file using standard software, like MATLAB. However, video processing in MATLAB requires the file to be converted to ...
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17 views

How to add bandpass filter to recorded sound in matlab

I have a sound that is being recorded but I am trying to apply bandpass filtering to the sound so that it filters out anything above and below a selected frequency range. I have tried the tool in ...
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46 views

Radon Transform Implementation In Matlab

I know MATLAB has a built in Radon function, but I am working on implementing the radon transform in order to perform filtered back projection. As I started, my idea was multiple nested for loops for ...
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34 views

Removal of skull stripe from MR image

How to remove the skull stripe from an MR image and to get the csf part from the image clearly? ...
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28 views

How to display images with log axes?

I'm trying to plot few points on existing log-log graph, for comparison. I've saved the existing graph as .png image then I plotted the points on the image!. The difficulty I'm having is how to ...
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9 views

Inverse Distance Weighting Filter

I am trying to use “inverse distance weighting” to improve on some 2D map (called B1-map in MRI field). I am generating this map on voxelwise basis. My algorithm returns the value right most of the ...
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61 views

What is the best method to estimate the frequency(PSD) for noise signal

I’ve been trying to estimate the frequency of a signal I obtained at 1000Hz sampling frequency. The dominant frequency is expected to be not more than 4 or 5 Hz. I’ve estimated the PSD using ...
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1answer
84 views

Bicubic Interpolation

I'm trying to do bicubic interpolation on an 8*8 matrix(image) shown below. ...
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0answers
27 views

Linear time-invariant time response kernel, MATLAB vs Octave

I am trying to get some MATLAB scripts to run in Octave, but have a problem with the following line of code: x = ltitr( a, b, u, x0 ) ; which throws an error in ...
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1answer
87 views

Solution to Cross-correlation problem of 2 audio signals

There are 2 audio signals, X & Y. X is of 15 second duration. The duration of Y is not given. Y is a part of signal X (ie a small part of audio X is extracted & made into audio Y) I have to ...
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3answers
66 views

Appying a Filter Several Times on Data

I have data from an experiment and apply a lowpass filter (digital Butterworth filter, in Matlab). My question ist what happens if I apply the same filter e. g. 2 times on the data? What is ...
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14 views

Process Noise “Q” covarience matrix in a kalman filter

I am trying to implement a Kalman filter on a Phasor Measurement Unit (PMU) values. I meaured the signal from PMU and give those meaurement as input to Kalman filter to get best estimate. I do not ...
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28 views

Detecting white noise signal and narrowing the frequency in matlab

I created a white noise that is played in 2 channels. While the left channel is active the right is silent and vice versa. I am trying to detect the signal arrival time after it has run through the ...
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1answer
83 views

Compare Overlapping FFTs to a longer FFT

How would you compare the SNR gain from a longer FFT (more samples) to overlapping FFTs? Given the choice, which one would you pick and why? Update: Suppose you have 2048 samples of a signal. ...
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1answer
20 views

Determining effect of powers of DFT matrix conjugate on input without multiplying

Suppose I have a DFT matrix $F$ of dimensions $N \times N$ where $N$ is a power of $2$. I convert it into a unitary matrix $\displaystyle U = \frac{F}{\sqrt{N}}$ and compute $S = U^* U^* $. $S$ ...
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1answer
32 views

The error between the theoretical value and the simulation value of imaginary part of the FFT results

As we know, a complex analytic signal can be obtained through Fourier transformation of a real value function, and the imaginary part can be reconstructed by Hilbert transform of real part. But I have ...
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11 views

choose correct variant of signal/noise ratio calculation

let us consider following sinusoidal model ...
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1answer
121 views

Check for time invariance of a _system_ using MATLAB?

I am having difficulty in developing an algorithm for checking if a given system is time invariant or not. For example, let there be 2 systems with input output relation given as: $$y(t)=x(t-2)$$ ...
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1answer
136 views

Calculating power and energy of a signal in matlab

I am a little new to matlab and would like to get some help on how to write a program or a function that can calculate the energy/power of a signal depending on whether the signal is an energy or a ...