# All Questions

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### Hanning Window Formula - Matlab didnt work

Im trying to do the Hanning Window manually but didnt work, what Im doing wrong? t=[0:.1:10]; x=.5-.5*cos(2*pi*t/102); plot(x); Not sure why I cant obtain the full hanning window..
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### 0 accuracy on test data with MFCCs

I have designed a classifier for "bols"(strokes) of the tabla, using the MFCC coefficients 2-13 (ignoring the first coefficient.) at the onsets. When I do a cross validation, I get approximately 46% ...
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### how could i fill missing data?

i tried a forecasting method and i want to check if it is correct or not and why? my study is about evaluating mutual funds for two kind of them it is a comparative study and i wan to use gcc index ...
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### Best segmentation method

This is part of my samples ...
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### What's $\omega _n$ difference between Matlab and Mathematica?

I want to plot this Butterworth filter's TransferFunction: ...
8 views

### Symmetry of Walsh matrix

Walsh matrix is abtained by sorting the rows of Hadamard matrix by number of sign changes (1st row had 0 changes, 2nd has 1 change of sign etc). Walsh matrix is symmetric. Meaning the sorting the ...
8 views

For those who have either used Picasa/Photoshop, they would see different image enhancement options such as: Change exposure Change shadow Change highlights Change vibrance I have searched online ...
25 views

### Feature vector for MFCCs

I am working on a project, for which I am finding the onset times of an audio and then extracting the MFCC coefficients for all the times. Thus if I have n onset times, I would have n feature ...
15 views

### Effect of Sampling frequency on RMS estimation

I have a simple, but interesting question for you. I have to compute the RMS (root mean square or standard deviation) value of a time signal which represents in my case a velocity mesasurement over ...
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### Relationship between Difference equation and Impulse response

I'm having some difficulties understanding the relationship between the impulse response and the difference equation for IIR filters
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### How to extract unknown packet from collision between said packet and another, known packet?

I need to apply successive interference cancellation (SIC) to an RF signal which is the result of collisions between 2 or more unsynchronised packets. For this question let's just assume that the ...
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### calculate signal power for windowed sine like signal while ignoring phase shift

What is the best way to calculate the signal power of a sine like signal, recorded into a small buffer (32 samples), in such a way that phase shifts of a few samples will not have an influence on the ...
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### Normalized cut segmentation output correct or not?

I have implemented "normalized cut" segmentation. The change here is that, instead of giving an image as input, I have given an matrix of image. As my output looks odd to me. I need to know whether my ...
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### What is the Roll-Off factor of a Root Raised Cosine Filter?

When designing a root raised cosine filter on Matlab, there is an option to set its "roll-off factor". What does this mean? I have been looking around for a while but I can't seem to find a clear ...
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### PSNR of two images of different size in matlab

I performed bicubic interpolation on a 256*256 image(img) dest = interp2(img,'bicubic') and i got a 511 * 511 image.I want to compute PSNR of a 512 * 512 ...
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### Inverse fourier transform normalization - Filtering in frequency domain

After the multiplication of two signals in frequency domain, I have applied inverse FFT to get filtered signal. What could be the multiplication factor to be used after applying inverse FFT to get ...
21 views

### FIR filter design using windowing

I am a newbee in DSP. I am using an FIR low pass and high pass filter with rectangular window in C++. I have calculated the filter coefficients using Low pass filter kernel: High pass filter ...
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### comparing different signals

I have some noise measurements and 4 different models that can generate a similar noises using estimated parameters from the real measurements. To compare the estimated noises I calculated the PDF, ...
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### How to improve an FFT AM demodulator for NOAA APT satellite imagery?

My question involves proper FFT Technique for AM demodulation, in the special case where the modulation rate exceeds the carrier frequency. This question has a specific hobbyist application, the ...
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### How does I calculate and plot equalized cdf?

I want to know how to get equalized histogram like this Figure 10 in here http://cache.freescale.com/files/dsp/doc/app_note/AN4318.pdf Especially, If you don't mind please let me know as Matlab code. ...
18 views

### 2D FFT vs 2 Pass 1D FTT

We know that the 2D FFT can be performed by taking the FT along the rows and then taking the FT along the columns. I'm wondering how theoretical performance compares to the direct 2D FT case, which ...
23 views

### Why doesn't JPEG use 1D DCT for image compression?

I know that JPEG uses 2D dct and splits the images in 8x8 blocks. Why doesn't it simply split the image in one-dimensional vectors in $\mathbb{R}^{64}$? Wouldn't it simplify the math? My guess is that ...
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### Does anyone know how to overlay a equalized CDF plot with equalized histogram in matlab?

I am willing to overlay a equalized cdf with equalized histogram in matlab. But it's really hard to find any recommends. so if you can, would you please let me know about that?
37 views

### How does taking the absolute value of a complex signal reflect in the frequency domain?

I have a frequency-domain representation $F[n]$ of the complex discrete one-dimensional signal $x[n]$: $F=\mathcal{F}(x)$. Is there a frequency-domain transformation of $F$ into $F'=\mathcal{F}(|x|)$? ...
35 views

### Realization of IIR resonator

The measure of a given frequency $\omega$ in a signal $x(t)$ is: $\frac{1}{N}\sum\limits^N_{t=0}x\left(t\right)e^{^{-i \omega t}}$ This is basically an average of the correlation between the signal ...
51 views

### Find a sinusoidal fit from data with fft

I have a vector with raw data (120 samples). From the frequency spectrum I can tell there is one dominant frequency component. Now I am supposed to use the fft data (magnitude and phase) to find a ...
45 views

### Find the frequency response of the system

How can I find the frequency response of the following linear system
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### Developing a classifier for a periodic music

I am trying to develop a classifier for Indian Taals, for which I would be focusing only on the Tabla. Now once a extract a period of the Tala(a repetitive pattern), I want to develop some feature ...
53 views

### Plotting DFT in dB

I'm having a little trouble plotting the DFT of a signal in dB. I can get the picture up nicely when using the magnitude but when I try converting the magnitude to decibels it all goes south. I've ...
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### comparing statistical destributions and non-gaussian noise measeruments

I have some non Gaussian noise measurements and I want to find a statistical model that best represents those measurements. The statistical models that I used for comparison are Middleton Class A , ...
60 views

### Choosing the best measure for machine learning on a Spectrogram

I am working on an application to classify Talas(a piece of music with onsets). For that, I have the spectrogram of a Tala, which I want to compare with the test Tala, or compare 2 Talas. For this I ...
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### Audio Recognition and Learning

I'm a beginner with absolutely no experience in signal processing, but it has been a long-term goal of mine to do something that mixes music (a hobby of mine) and computer science (my "expertise"). ...
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### Separating 'signal' from periodic 'noise'

I have data in which the signal we want is a few gaussian peaks superposed on a noisy background in which some of the 'noise' is periodic. Simply suppressing the associated fourier modes is effective ...
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### When does Nyquist criteria apply for signal analysis?

I have a transmitter that sends 128 samples/second to my laptop. I want to do a frequency domain analysis of such signal. Can someone remind me if I need to resample this already sampled signal at ...
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### moving average filter vs up sampled low pass filter

I'm experimenting on different low pass filters in matlab. I've considered a vector x=[1 0 1 0] ; an up sampled low pass filter by a factor of two. And the frequency response turned out to be And in ...
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### Is this expression true? [closed]

Is this expression true? In Non fractional and Non radical systems,if condition of homogeneous is satisfied,the system is linear.
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### DS-BPSK UWB modulation

I'm trying to calculate the BER of DS-BPSK UWB modulation but I don't find references with accurate demonstration it's urgent please I need your helps and I'll be grateful. THX.
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### DFT of a pressure signal from space domain to wavenumber domain

When I do the DFT of the following signal: I get the following DFT which doesn't capture any peaks at all: Why is this? I'm not really able to identify what the error is?
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### What does “real time” signal processing mean?

I thought this was supposed to be an obvious question, until I finally set up my real time system. So basically I have a transmitter that sends 128 samples/second to a receiver. The transmitted ...
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### up sample and down sample

Let's say that I have a sampled signal x[n], it is being, in this exact order, up sampled by 2, down sampled by4, up sampled by 4 and down sampled by 2 to produce y[n]. It seems to me that it should ...