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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2answers
22 views

Using Matlab xcorr to find a signal hidden behind noise

I am trying to develop some code to find a transient signal in a data set I have. Before I get there however I am trying to write code using simulated data. I first am creating a signal with a ...
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0answers
22 views

Which method overcome false edge problem [on hold]

I have one problem that is false edge problem. Given a image with real edge and false edge. How to detect where is real edge? Which method?
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0answers
16 views

Amplitude and frequency plot for an input image.

This is my original image: First I have plotted scale vs frequency then transformed scale to frequency and got frequency-time plot: I have plotted highest power of coefficients (indicated by ...
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2answers
29 views

separate signal values from noise

let us consider following graph of singular values i want to make some kind of clustering of these data,namely to seperate main components from non main components,let say signal components ...
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2answers
36 views

will always periodogram produce correct frequencies?

let say we have some data,some signal written in this form $x(t)=s(t)+\epsilon(t)$ where $s(t)$ is pure signal and $\epsilon(t)$ is white noise with mean zero and some variance ,question is ...
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0answers
20 views

How to use pseudo frequencies with wavelet transforms

I'm slowly getting my head around the use of wavelet transforms (CWT & DWT) with my data, but I'm interested in how the wavelet transforms correspond to certain bands of frequencies. I'm using ...
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0answers
12 views

Algorithm Switch in Simulink

I am currently working on a control mechanism which looks as in the following figure: In general, I'd like the input1 (the one where only gain and integrator are present), if and only when input2 ...
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1answer
39 views

reconstruction of time series in SSA

i am trying to reconstruct time series from SSA ,because according to this link http://en.wikipedia.org/wiki/Singular_spectrum_analysis there is procedure ...
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0answers
30 views

Matlab : Reconstructing signal from cosinusoïdes : DC offset question [code + picture]

i'm trying to reconstruct a signal from amplitude and phase of cosinusoides to understand totally how DCT works. So far i've managed to get the signal very close, only by a DC offset that i don't get. ...
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1answer
40 views

EEG signal processing

I have an EEG data set downloaded from physionet. I want to play that data into a brain monitoring device like for example BIS monitor or Narcotrend or any other similar brain monitoring device.I use ...
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0answers
29 views

MATLAB QPSK MMSE plot is not working [closed]

Error in r=s+w;. How can this be fixed? ...
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1answer
46 views

matlab's FFT is wrong? don't think so

i'm trying to get an FFT of a signal my FFT has 1024 samples i added two sin functions one of freq 86,13Hz (2*44100/1024) and one of freq 129,19Hz (3*44100/1024) the WAV looks like that (for 1 ...
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1answer
32 views

Log energy calculation

I have some code here that I don't quite understand. It calculates the energy for a given frame the following way: En=log(1+energy(32767*frame)) The energy ...
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1answer
55 views

use wavelet for improving spectral resolution

let us consider following code ...
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0answers
43 views

CWT for filtering / feature extraction

I had asked a question last night in regards to how to process my data (Noise rejection / feature extraction) but I have a more specific question now that I hope someone can answer. As mentioned in ...
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0answers
21 views

error calculation and ber

I have this NRZ-L model: where the subsystem contains the following: . What is exactly the operation of this error calculation subsystem?
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0answers
39 views

Signal-to-Quantization Noise ratio

What is the formula of the signal-to-Quantization Noise ratio for a quantizer as shown in the figure below (input being the top and output being the bottom figure) Do different quantizer types have ...
0
votes
1answer
77 views

Calculation of cosine in frequency domain instead of calculatin in time-domain followed by a FFT

I got an $N$, in my case 512, point FFT of a real-valued signal. Based on some calculation in my application I determine the parameters $k \in [1, N-1]$, the number of oscillations per period, $\phi ...
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0answers
42 views

The order analysis in MATLAB [duplicate]

Can anybody tell me how to calculate the order analysis / spectrum of a signal? I've been searching in vain. I want to use MATLAB to analyse the signal / sound of a motor. For more information about ...
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1answer
64 views

How to analyse the sound of Motor

I have a motor, that I want to analyse, using its sound, so I can its 'character' I was using the the simple fft, and figured out, that it wouldn't help, so I tried the order analysis, at least I ...
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0answers
22 views

Matlab:Sampling Curve into Frames and Plotting

I have a Output Curve of following characteristics http://i.imgur.com/hABfsiC.jpg Following is the data which represents the output curve cited above ...
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0answers
10 views

Help in simulink for detecting specific parts of the signals

I am modeling some real-time ECG signals in simulink, and as I detect the zero-crossings or the peak of the pulse for this signal, I want to display the samples at which this occurs in the scope. This ...
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0answers
33 views

IIR filter SOS and Direct Forms doubt

I have below doubts, so confusing! As I don't want to assume from what I read, I am asking for help here! Are Second Order Sections another name for biQuads ? If I have 2 single pole transfer ...
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1answer
55 views

Time duration of a signal to determine the peak frequency

I have two questions regarding signal processing: 1) In my analysis I generate a signal in the time domain with a frequency of 0.1 Hz. I apply the FFT and then determine the peak frequency of the ...
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1answer
59 views

use prony method for damped exponentials

let us consider represented of damping exponential model by prony method,there is source code ...
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2answers
69 views

generating pilot sub-carriers in matlab

I wanted to simulate OFDM system in MATLAB. I'm using Fixed WiMAX OFDM parameters in my simulation, where the number of data sub-carriers are 192, number of Pilot sub-carriers are 8, number Null ...
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0answers
11 views

how to chose independent sample from a non linear regression problem

I would have a question concerning the first part of my assignment here below: (in bold) In this problem, the objective is to approximate a nonlinear function using a feedforward artificial neural ...
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1answer
43 views

Polyphase decimation matlab

I am new to DSP, and currently trying to implement a simple polyphase decimation program in matlab. M is decimation factor, x is input (for now it is a square wave 8096 samples), y_polyDec is result ...
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1answer
63 views

Problem with Kalman filtering accelerometer data

I'm having some trouble implementing a Kalman filter in MATLAB. I have an Android phone connected sending data from accelerometer for 10 seconds. After i have the data I take out the x-axis vector. ...
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0answers
19 views

Hough Transform - sign of rho and theta- Matlab

I understood that origin of the picture space (x,y) will be upper left corner. Origin of the parameter space (rho, theta) will be center point. I understood basic idea of the hough transform. I am ...
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1answer
43 views

snr relation with modulation index and noise power

What is the relation between the AM modulation index and the SNR?(I plotted this and it came as the shape of the exponential graph) Also what is the relation between the channel noise power and the ...
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2answers
41 views

1.0e-03 * 0.9734 numerical representation in Matlab [duplicate]

Is 1.0e-03 * 0.9734 equivalent to 0.9734 * 10^-3 = 0.0009734 ? Because I am not sure
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0answers
43 views
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2answers
62 views

Design Filter Banks for every 100 Hz

I need to study a wave file for every 100 Hz. However, I dont know how can I design filer for each 100 Hz. Let's say 0-100 Hz, 100-200 Hz, ... , ((fs/2)-100) _ (fs/2) Hz. Is it any MATLAB code for ...
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2answers
57 views

2D Deconvolution in matlab

I am trying to solve the following equation for h (an [MxM matrix]): $$ k[\tau_1,\tau_2]=\sum_{i_1=0}^M \sum_{i_2=0}^M h[i_1,i_2]x[\tau_1-i_1]x[\tau_2-i_2] $$ I have k, which is a 2D [MxM] symmetric ...
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1answer
56 views

ARMA models for non stationary signals

let us suppose that we have non stationary signal,whose value is given by ...
-1
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1answer
36 views

999e3 numerical representation in Matlab [closed]

Is 999e3 in matlab = 0.999? Because I am not sure whether e mean exponential or you move the decimal point by 3decimal places
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1answer
43 views

Simulink for Amplitude Modulation

I am using Matlab Simulink to analyse Amplitude Modulation in Noise. I attached my system below. My problems: 1)In the mixer I am using a bandpass filter and another one after the envelope ...
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0answers
20 views

get similar picture from wavelet transform

my today's question is related to previous question about wavelet, ...
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1answer
41 views

use chirp z transform for spectral resolution

let us suppose that we some signal $x(t)$,which consist of sinusoidal components and white noise,i would like to know how to use chirp z transform for improving spectral resolution?i found this ...
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votes
3answers
71 views

What is benefit when convert signed 16 bit to unsigned 8 bit in medical image?

I have an image with its type is 16 bit signed. I see some paper, the author often convert it to unsigned 8 bit. But they did not explain why they do it. Could you explain what is benefit of this ...
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0answers
36 views

How to Prevent overflow/saturation in fixed point implementation of Fast Data Projection Algorithm

I am trying to implement an algorithm in real-time on a Fixed point DSP (The Blackfin from Analog Devices). The algorithm does a lot of stuff, but in the middle it performs an algorithm called "Fast ...
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1answer
26 views

Convert normalized frequency to real frequency in AR model

Let us suppose that we have modeled signal using AR model, and suppose we have following model: I used spectral estimation function from MATLAB pyulear Now ...
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0answers
29 views

Help implementing biquad iir filters

i have a matlab simulink model, which consist of three blocks From Wav file two IIR filter block Save to wave file IIR filter transfer function is ...
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3answers
97 views

use wavelet transform to extract frequencies from given signal

let us suppose that we have following signal values,which consists by deterministic components and random noise(white noise) ...
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0answers
28 views

Online FFT of simulated signal

it is a couple of weeks that I am thinking about the following: I have a tool which is able to simulate the dynamic behavior a steel tower exhibites due to the coupled action of wind and waves. ...
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0answers
31 views

AMARI ERROR in Matlab ( FASTICA Comparison)

I am now doing a project comparing non-linearities in FASTICA and the best way to compare them is by using AMARI error. Could I ask how to perform Amari Error after fastICA in Matlab?I tried to search ...
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2answers
61 views

Approximate the magnitude response of an analog filter with a digital filter, starting from its gain expression

I have an analog filter with its frequency response curve in dB described by the following expression: $$ N_{dB}=20log_{10}\omega t_1 \sqrt{\frac{1+(\omega t_2)^2}{1+(\omega t_1)^2}} $$ This ...
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1answer
53 views

Removing empty/low amplitude part from signal

I have a signal of length 'N' which looks like this ...
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vote
2answers
103 views

can't find out the period of my signal

I've a noisy signal, which is the sound of motor with a constant speed, so the sound "should" be periodic, I know that there is a way to use the autocorrelation function to get the period,I did it, ...