A discrete signal or discrete-time signal is a time series consisting of a sequence of quantities.

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Multivariate Wavelet

I am new in Digital Signal Processing.I am working with wavelet but I do not have source code for multivariate wavelet decomposition for 1D data.plz any body help me on this.
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Determining if an unknown signal has “converged” or become quasi-steady

Relevant background: I am trying to simulate unsteady flow in a converging-diverging nozzle, and trying to see how the flow shedding downstream of the nozzle affects the wall shear stress ...
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18 views

Sub-clock FPGA delays on output line

I am trying to include the ability to have sub-clock delays on an FPGA system's data bus without the need of fractional delay filters. I am using a Xilinx V6 part, and could utilize its IODELAYE1 ...
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integrate/ differentiation of discrete signal in Matlab

if I have a sinusoidal signal constructed using Matlab (discrete signal constructed from samples) fs=1000; t=0:1/fs:1-1/fs; x=5*sin(2*pi*40*t); plot(x) what ...
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23 views

Is it possible to calculate the variance of signal in real time implementation?

In communication system, when we received some signal which contain our message of known variance sigma_s which is corrupted in noise of unknown variance. If I need the variance of the signal in ...
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22 views

What is the preferred method of aggregating audio FFT data given variable-size frequency bins?

I am coding a program which uses a FFT to process audio data. I need to aggregate the FFT output into three bins ("bass", "mid", and "treb") determined by two arbitrary frequency values. The end-goal ...
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1answer
43 views

my Butterworth lowpass formulas do not agree with Fisher webpage

I want to implement Butterworth low-pass filter. Thanks to this question, I have found out that the filter coefficients can be generated using Tony Fisher web-site or using his code. But the problem ...
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22 views

How to normalize pwelch output and calculate band power using it ? . In matlab

I am using , [pxx,f] = pwelch(x,window,noverlap,f,fs) , to compute power spectrum of a EEG signal . I have to calculate band power in 1Hz frequency bands in 4-30Hz , using Hamming window , with 50% ...
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34 views

Relationship between values of frequency magnitude and values of time amplitude in an audio signal

I have an audio signal in wave format, with its time amplitude values located between -1 and 1. When I compute its fft (in respect to the whole signal) and then extract its absolute value to plot the ...
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43 views

Generate time-domain random signal from PSD

Given an analytical description of the PSD, for example (MATLAB "pseudocode"): ...
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5answers
75 views

Looking for an algorithm that computes “Similarity” between two signals

I'm new in this forum! ... and I'm not an expert in signal processing! ... So I hope to find help here:-) I was wondering if someone could point me to an algorithm/technique that is used to compare ...
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4 views

Noise modeling and reduction in Video when we have just noisy video

We would like to send a video (sequence of images), we have limit bandwidth. If there is a lot of noise, the required bandwidth (bitrate) is needed to send the video+noise becomes high that is not ...
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2answers
48 views

Discrete Fourier series for a sum of deltas

so Im given a discrete sum $$x[n] = \sum\limits_{r=\infty}^{+\infty}\delta[n-rN]$$ how do I calculate its discrete Fourier series coefficients? Thank you. edit: this is what i've come to up to now:
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1answer
33 views

Initial value Problem with difference equation

How to solve the initial value problem with x(n + 1) + x(n) = n^2; x(0) = 1 I do know how to solve for initial value theorem in differential equation, but not in ...
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2answers
72 views

Transfer function block diagram

Can any one help with the $y[n]$ and $x[n]$ relationship in this block diagram, I just keep have a $t[n]$ in my answer that I can't get rid off. On my best try I got to $y[n] = ...
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44 views

Periodicity of discrete time signal: $ x\left [ n \right ] = \cos (\frac{\pi n^{2}}{8}) $

I need to find the periodicity of the following signal: $$ x\left [ n \right ] = \cos (\frac{\pi n^{2}}{8}) $$ Now I understand that the basic procedure to determine the periodicity is to find a $ N $ ...
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sampling frequency of a bandpass modulated signal

If the input signal is 3khz and the carrier signal is 10khz what will be sampling frequency of the modulated signal if the modulation is bandpass modulation?
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33 views

The channel capacity with additive Gaussian noise with changing variance?

As we all know the capacity for a AWGN channel with constant noise variance is just given by $\frac{1}{2}\log(1+SNR)$. What if the variance of the noise changes with the type (assuming the variance ...
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45 views

How to define cyclic frequency for cyclostationary signal in terms of signal parametrs?

I am trying to detect cyclostationary signal. For that it is required to know its cyclic frequency. But I am unable to figure out how it can be related to signal parameter. Is it possible to define ...
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1answer
259 views

What is the theoretical upperbound of information that could be transmitted by a device per second?

Suppose I would like to stream data from a device in a single second. What would be the theoretical upperbound of the amount of information (in bits, bytes, pixels...) that could be sent during this ...
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1answer
23 views

Resource request: CRLB for system identification

On the Computation of the Cramer-Rao Bound for ARMA Parameter Estimation by Benjamin Friedlander, provides the CRLB for AR model driven by a white Gaussian noise. ...
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2answers
62 views

Computing main lobe width of Hamming window in Matlab by plotting

I wanted to verify the fact that main lobe width of a Hann/Hamming window is twice that of a rectangular window, using Matlab. I computed the analytical expressions for the respective frequency ...
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1answer
38 views

Z Transform problem

I have a class exercise of an inverse Z transform and I have some trouble. I will render an example to make my point. Let's asume the Z transform pairs: $$a^n \cdot u[n] \Leftrightarrow ...
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1answer
37 views

The two types of stability and “Why exponential”

When I was learning about LTI systems, I noticed that LTI system is said to be BIBO stable if and only if its square sum of impulse response is finite. This expression is found on many textbook of ...
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1answer
28 views

How would I go about designing a difference equation for a given type of filter?

I have experience using design tools such as Xilinx's CoreGen and MatLab's DSP tool kit, but I have not really had much experience designing filters from the ground up. Reinventing the filter as it ...
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1answer
28 views

What is the difference between a sampled time system and a discrete time system?

I am trying to evaluate whether I should control a system in simulink using sampled data system or discrete time system. The discrete model is as follows: The sampled time system is as follows ...
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39 views

Why is my bode plot showing periodic behavior?

I found something very interersting when I was trying to simulate a discrete time system. So first I discretized the continuous system $G(s)$ using "c2d" function and "dbode". The resulting bode ...
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143 views

How to estimate for an exponential in WGN

Question: $y_0= \min {\mathbf{P}}$ where each and $\mathbf{P} = \{p_1,p_2,\ldots,p_k\}$ where each $p_i = z^d$. Each $p_i$ is computed from the sum of some recordings by a sensor. Let, there be ...
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Transposing pitch profile of one audio on another

I have one audio file with rap music and one audio with sound record of my friend's reading some text. I want to transpose pitch profile of rap music on sound recording, is that possible? I can ...
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1answer
37 views

System Identification: smoothing in E-step of EM algorithm

My question is, do the smoothed values affect the estimates obtained from the Maximization Step? If not then we could eliminate the smoothing. Once the estimates are obtained, they do not change apart ...
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3answers
216 views

A question about the sampling theorem

Let's say I have a signal, containing frequencies up to $30$ kHZ. I am sampling this signal at $40$ kHz with infinite bit depth (just for theory). Will I be able to recover exactly all the ...
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52 views

How compute frequency of signal from zero crossing? [duplicate]

I need to compute frequency of a signal from zero crossing.It's possible to compute to frequency from zero crossing of a signal. Plz anybody help me about this with matlab .
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43 views

Help in formulating the log-likelihood expression for AR model

An IIR system is excited by a signal $x_n$ described as follows: $x_n$ is the binary input to the system. This is how I proceeded : The original data $y_t$ is a noisy version of a time series ...
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Yule walker equation limited matrix size

Definitions For an ARMA model $$x_n=-\sum_{p=1}^P a_px_{n-p}+\sum_{q=0}^Qb_qw_{n-q}$$ where $w_n$ is zero mean stationary white noise with unit variance. It is straightforward to show that the ...
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Wavelet packet transform (WPT) features dimensionality

Just a question that could be trivial for someone but I'm doubtful. Let's say that I have a signal, e.g. electromyography signal, of length $300$. If I apply a WPT, how can I define the dimensionality ...
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1answer
54 views

Doubt in state space representation

$y$ is scalar observations and so C will be a 1x2 matrix. I want to represent the following model as a state space representation so as to estimate the hidden states from the noisy observations $y$ ...
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How does we choose parameter in SPECTROGRAM(X,WINDOW,NOVERLAP,NFFT,Fs)

I am facing problem in SPECTROGRAM(X,WINDOW,NOVERLAP,NFFT,Fs) How would i choose Window, Noverlap,nfft parameter for spectrogram of children voices sampled at ...
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2answers
140 views

Recognition of markes in long audio recording

I am about to do a lot of a recordings when performing tests. The thing is that there are some parts I would like to extract easily from my recording. Is there a way to play some special sequence of ...
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3answers
49 views

Is there a algorithm for detecting bursts in signal?

Suppose we have a signal like that and we want to know when a burst have happened. Rigth now our approach is pretty straightforward. We measure std of signal at some time window and then with each new ...
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1answer
60 views

Why are MFCCs of two equivalent signals completely different?

I have an audio file, of which I calculate 16 (actually 15 because I omit the first one) MFCCs in R. When I stream this file via VLC-Player and Icecast2-Server, receive it in Java (with the Player of ...
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2answers
67 views

Resample an array in real-time (application: pitch-bend)

I'm working on a sampler software (that plays .WAV files, when notes are played on a MIDI keyboard). In order to implement pitch-bend feature (i.e. you have a "pitch bend wheel" on the synth and you ...
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1answer
43 views

Preprocessing signal before LPC

I have a signal that contains the speaking of three vowels. The signal is contaminated with dc offset and an interference at 60 Hz. I want to perform LPC for the synthesis of the spoken vowels. Do I ...
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54 views

What is the best codec for streaming of audio in this case?

I am trying to stream audio from device. I can't use the PCM audio because it is not compact enough, and I don't have so much bandwidth. What is the option to substitute wave PCM with some codec? I ...
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1answer
47 views

Resampling signal in MATLAB

I read a wav file in MATLAB and it has a sampling rate of 16kHz. I want to pass it through a filter I designed which has a sampling rate of 44.1 kHz. So, I thought I would use ...
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1answer
85 views

Calculation frequency response of digital filter with known structure

Short question What are main stages (steps) of calculation frequency response of digital filter by their structure? Detailed question Let suppose that there is discrete FIR filter with known ...
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90 views

DFT vs FFT: does odd number works for DFT only?

I am always confused between FFT and DFT. In both algorithm, it has been assumed that the signal is periodic (so my understanding is that, if you have a 20 sample point signal, and you do DFT or FFT, ...
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I saw this question on one of the sites related to DFT

The analog signal x(t) is band-limited to 40 Hz. Suppose the signal is sampled at the rate of 100 samples per second and that at this rate 200 samples are collected. Then 200 zeros are appended to the ...
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when is a kalman filter different from a moving average?

this thread asks when a discrete-time Kalman filter is better/different from a simple moving average of the observations: ...
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kalman filter with time-varying noise?

in regular discrete-time (1 dimensional) kalman filter, it is assumed that we have white gaussian noise affecting the transitions and the observations: $x(t+1) = Ax + w$ $y(t) = Cx(t) + v$ ...
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68 views

Time frequency domain analyis of signals

In the time frequency domain I have used the following denoising methods Thresholding or schwirnking - Soft,Hard,Median and with methods (minimax, adaptative and sure). However if recomposing the ...