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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Why oversample data before using raised cosine filter?

In the process of creating a baseband signal, the complex symbols are filtered using a raised cosine filter to perform pulse shaping (I'm following some literature as a guide). The pulse shaping is ...
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8 views

SRAD code in matlab it doesn't work [on hold]

i just applied the SRAD code in matlab and i get error in line 430 ...
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21 views

Choosing the frequency for a comb filter

I have an audio sample. From doing FFT on it it looks as if I need to use a comb filter to remove resonant frequencies. This is what I generate: I honestly have no clue where to start ...
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22 views

work on paper useing matlab dsp

I'm going on a research paper on the cardiac signal processing methods, the implementation and practice. Downloads In: http://s5.picofile.com/file/8153336292/DSP_Project_1393_1_.pdf.html In this ...
3
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1answer
40 views

Implementing overlap add method for convolution with a slice of the filter

In overlap add method for convolution a filter $x$ of length $M$ will get convolved with a signal $y$ of length $N$ where $M << N$, i.e., $z = x * y $. Here the signal $y$ is sliced into ...
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0answers
36 views

Understanding the use of remainder after division in circular convolution [help] [on hold]

I've always hated the remainder after division concept, because I never understood it. In the context of circular convolution... Like when we use the function 'rem' in matlab, or modulo operations ...
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1answer
53 views

Get data ready for IFFT

I am having troubles applying the IFFT function to some data I have. I already had a look here Complex conjugate and IFFT and here What assumptions should be used to invert spectrum into time domain ...
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1answer
18 views

coded filter vs fdatool : inconsistency in the results for same parameters

I tried creating a filter in 2 different ways in Matlab and I obtain different results: one filter is stable, whereas the other one is unstable. Coded filter ...
1
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1answer
57 views

Filters performance analysis

I am working on some experimental data which, at some point, need to be time-integrated and then high-pass filtered (to remove low frequency disturbancies introduced by integration and unwanted DC ...
1
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1answer
60 views

I can't make sense of the amplitude spectrum of a signal. Help please

I have a sinusoidal signal namely: signal = sin(2*pi*0.08*t) + sin(2*pi*0.2*t) + sin(2*pi*0.32*t) + sin(2*pi*0.4*t); so the segment of the code becomes: ...
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0answers
32 views

How to find the corner of a whale fin?

I have got the images of whales and I extract the fin from the whale and then apply an edge detection algorithm which gives me a 2 dimensional vector with the edge values. I can plot this vector to ...
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3answers
53 views

Filter order and cut off frequency

How can I know exactly what frequencies are not influenced by the filter? I mean, I have a signal in the range of frequencies $5-100 Hz$ and I apply a high-pass, $4^{th}$ order Butterworth filter ...
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23 views

Writing spectogram code to analyze discrete signal [duplicate]

i am new here and i have a trouble about matlab and analyzing a signal.I need to write a code to display the spectrogram of a discrete-time signal but of course without using ...
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0answers
21 views

similarity between two songs using in matlab using matched filter [duplicate]

I am a student who works on a project similarity between two songs in matlab using matched filter. I am asking if anybody has something about this to help me solve the problem? I dont know what to ...
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0answers
20 views

Implementing a Sum of Sincs filter in Matlab

I am trying to implement a filter that looks like: $$G(\omega)=\dfrac{\tau}{\sqrt{2\pi}}\sum_{k\in\mathcal{K}}b_k\mathrm{sinc}\left(\dfrac{\omega}{\frac{2\pi}{\tau}}-k \right)$$ in Matlab. I have: ...
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49 views

How to compute transfer function (Frequency Response Function) from experimental data

I have a set of data, in the freqeuncy domain, corresponding to a structural test. I have amplitude, phase and frequency for both the measured output and the input signal (accelerations are measured ...
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1answer
22 views

Image processing to detect water diseases

Is there any way to detect water diseases using image processing ? and is there any way to develop it in android or in matlab thank you ?
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1answer
27 views

How to convert Third Octave data into single SPL quantity

I have a data vector which consists of calibrated pressure at each sampled point in time. I have also taken this signal, applied a filter bank to it using a butterworth filter with passbands according ...
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2answers
62 views

Removing 'high-frequency' components from an array?

I am new to the stream of digital signal processing, and hence my doubt may seem extremely stupid, but: In tools such as matlab, signals are stored in a single array. If i convolute it with an LPF ...
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3answers
81 views

Why does an 8 point DFT behave differently from a 16 point?

I have a 50 Hz sine wave sampled at 1600 Samples/second.I'm computing the 16 point DFT.So my fundamental frequency is 100 Hz. I then decimated the 1600 samples to 400 samples.I then computed the 8 ...
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23 views

Filtering of accelerometers data for double integration

This question in strictly related to this one http://scicomp.stackexchange.com/questions/16057/numerical-integration-and-filtering-of-acceleration-experimental-data but in this case I would like to ...
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0answers
14 views

Bit Error Rate High Values

I am using this code to find the bit error rate for the Kmeans clustering algorithm for receving a QPSK modulated data. Running the code high BER values are obtained (something more than 80). Can ...
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2answers
56 views

Why is this MATLAB butterworth filter giving me wrong results

Given a 128 Hz signal, in MATLAB I entered the following command ...
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1answer
17 views

One representative time series signal from multiple time series data

I came across this basic problem in DSP which is not my area owf expertise but I consider this problem to be a common problem which others might be addressing. I have multiple time series data and I ...
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2answers
44 views

Singal processing for undersampled signal

I have got a set of pressure data from a boiler which has been sampled at 45Hz and I need to extract a frequency component of 250Hz from the signal. Using a standard FFT method doesn't display ...
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0answers
14 views

Confusion in the spectrum of FSK modulated signal by using matlab fskmod module

I want to do a comparison of power spectral density of BFSK, 4FSK and 8FSK by using matlab baseband module "fskmod".Following is ...
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2answers
33 views

Understanding Arrangement of second order sections

When splitting higher order recursive filters into more convenient 2nd order sections (biquads), in matlab, we usually use zp2sos to convert. In document, there's a ...
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1answer
70 views

Complex numbers in ifft of an MMSE amplitude estimator

I am trying to reconstruct a signal from a noisy speech using an MMSE algorithm proposed long time ago by Ephraim and Malah (1984). After going through the algorithm, I got a matrix A which represents ...
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19 views

Matlab: Conceptual issues on correlation and its analytical expression

Let x = [1 0.9 0.1 -0.3]'. The formula for Autocorrelation is E[x*x'] which should give a vector of mean values. The ...
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12 views

Matlab: Issue time lagged time series

My data $Y$ is the output of an autoregressive model of order $p = 2$ excited by Gaussian white noise of zero mean. $y_t$ is a vector output of the AR process: $y_t = 0.195y_{t-1} - 0.95y_{t-2}$ $t$ ...
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1answer
41 views

What is the rms value of a signal and how to use it

In some papers/books I found infos about a signal given as RMS value. What is the RMS value and what information does it contain? How can I compute it? Moreover, if they say that the signal is a ...
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0answers
33 views

How to, efficiently, identify telephone number from the key pressed data audio file?

A very common homework question. You are given an audio file(.wav) which has the recording of the keys pressed during a telephone call. You have to identify the telephone number from this audio file ...
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2answers
95 views

Is magnitude information enough to reconstruct an audio signal

I have used an MMSE STSA estimator to obtain the magnitude of an audio signal. The original signal is combined with white noise and I used an algorithm given in an old research paper by Ephraim and ...
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28 views

Mind helping me understand what this matlab code is doing? is this a PSD? or FFT?

I'm trying to learn how to get a useful frequency response of a single plucked string on a guitar. I have some old code that I'm working off of... It works in that i get a spectral response, but i ...
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1answer
35 views

modified Bessel function for Speech enhancement Using MMSE in matlab

I am trying to implement an algorithm proposed in an old research paper by Ephraim and Malah for my DSP course project. I hope someone can help me with this difficult question. For the clean signal ...
0
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1answer
37 views

Matlab: How do I implement the Expectation operator for time series

I have the output of a time series y(t) which is a vector for t = 1,2,...m denoting the number of data points. Q1: If ...
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1answer
28 views

Calculate properties of a given Modulated Signal

I'm having a hard time trying to understand signal modulation graphics and how can I calculate/find the properties of the signal. The properties I'm talking are: Max. amplitude Carrier frequency ...
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1answer
41 views

digital butterworth filter design error

I am trying to design a digital butterworth filter for the given specifications.. code is posted below.. rp=3; rs=15; FS=1; wp=0.5*pi; ws=0.75*pi; pwp=2*FS*tan(wp/2); pws=2*FS*tan(ws/2); ...
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25 views

how to code fir filter in matlab using discrete equation?

I want to design a fir filter in matlab using the discrete equation. I won't be using any built in functions. For doing so what will be the coefficient? How can i compute it?
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1answer
167 views

Is it necessary to downsample data for filtering of low frequencies?

My data is sampled at $f_s = 32kHz$, and for a particular analysis I'm only interested in signals with certain frequencies from $f_{highpass} = \text{0.1Hz}$ to $f_{lowpass} = \text{300 Hz}$. When I ...
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1answer
87 views

Question on Chebyshev filter

What does the output signal look like when you insert $2000 Hz$ square pulses to chebyshev filter with parameters: (Matlab syntax). I tried to do it like this but I don't understand where it goes ...
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2answers
62 views

How to design a filter with custom group delay — why is it an IIR?

Say I have an FIR filter with desired magnitude characteristics. I could imagine using an allpass IIR in series with the FIR to alter the group delay characteristic to provide both a 'magnitude ...
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31 views

Wave-time trace to Amplitude and PSD spectrum

For a project I’m currently working on, I composed a irregular ocean wave (function of time) by the summation of n regular waves. For the validation and further processing I’d like to produce the ...
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35 views

Generate band limited white noise to be used as excitation in ODE

I am trying to repeat an example I found in a paper. I have to solve this ODE: $25 \ddot{x} + 15 \dot{x} + 330000 x = p(t)$ where $p(t)$ is a white noise sequence band-limited into the 10-25 Hz ...
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46 views

Problem in Implementing Cyclostationary Feature Detector in Matlab

I have Implemented this detector in AWGN channel in Matlab but I am getting vague result. As it performance doesn't vary with change in SNR. Its very strange result for me. I don't know what mistake I ...
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2answers
93 views

Head detection using HOG and SVM

I am currently trying to detect heads in a sequence of real-footage images and am using HOG feature descriptor and SVM as classifier. Currently I am using Dalal's HOG implementation code in MATLAB ...
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1answer
51 views

what method for thresholding?

I want to do one threshold method on high pass components of a wavelet frame decomposition approch,for edge detection in image. I have 14 high pass components. for thresholding, I need keep the ...
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2answers
41 views

Why is my discretized transfer function unstable when my discretized state-space model is stable?

I am working with a 30-state, 14-input linear model that is described by a state-space model: model_state_space = ss(A, B, C, D); The model is extremely slow (it ...
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14 views

Taking a special image derivative using convolution

Could someone help me with the question posted here, which I posted in stackoverflow. I should have posted the question here in the signal processing.
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33 views

Basic Fourier Transform filtering and LTI frequency response using Matlab

Not sure if this is the right place to ask... I'm new to Matlab for LTI signal processing and wondering if anyone can help with something that I'm sure is meant to be basic. I've spent hours and hours ...