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

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65 views

How to extract IF (instantaneous frequency) from Discrete Hilbert Transform?

The continuous time Hilbert transform is $$\hat x(t) := x(t) + j\left( p.v. \left\{\frac{1}{t\pi} \ast x \right\} (t)\right)$$ where $$ \theta(t) = \tan^{-1}\left( \frac{ p.v. \left\{\frac{1}{t\pi} ...
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0answers
28 views

Size obtained by applying Linear convolution

We know that applying a filter on an image is called correlation or convolution depending on the filter angle. In Gonzalez I have read that we can apply linear convolution on an image. Here I have a ...
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0answers
11 views

Estimation of dominating frequencies of pseudorandom signal

I have generated a gaussian distributed pseudorandom signal using command randn(). Then I plotted its frequency response with FFT. Now how I will come to know what ...
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0answers
43 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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2answers
59 views

Purpose of Phase Information

I am learning Fourier Transform from many days but till now I am not able to understand what does phase angle image show us or tell us? They say that MAGNITUDE tells "how much" of a certain frequency ...
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1answer
41 views

Computer Vision / Speech Recognition

I am not sure if the question is off topic but I need some input before I can finalize anything. Actually to do my higher studies (in research) I wanted to make sure that I land my career in Digital ...
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2answers
40 views

Pole/Zero existence at infinity

How can poles and zeros exist at infinity?Can anybody explain using a system function?
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1answer
42 views

Frequency Spectrum of an image

I have been studying about Frequency Domain from many days but still i am not able to clear one of the confusion. We say that in frequency domain an image is represented as waves. What I am able to ...
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0answers
18 views

Roll pitch and yaw Accelerometer

I have some accelerometer data and I am trying to reallign it. The method I am using is applying the following equations which are basically from a rotation matrix ...
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1answer
31 views

how to detect signal noise

I have data from a power transformer that has a frequency of 60 hz. Sometimes there are faults in the system and causes a large spike in the reading of the transformer. What I want to do is run the ...
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1answer
39 views

Can all pass filers have a pole/zero at the origin of the root locus

I came across this root locus diagram in my DSP class. It has a pole at the origin, another pole within the unit circle and a zero just outside the unit circle. I understand that the poles and zeros ...
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1answer
71 views

How to learn MUSIC algorithm?

I was actually preparing for my semester project and decided to take up Frequecncy estimation.I ll directly come to the point that I want to know how should I learn MUSIC algorithm. How do I start it? ...
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18 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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1answer
32 views

Implementing discrete time systems

Discrete time systems work on sampled continuous time signals. We need samples only at discrete time to be fed as input to a discrete time system. Does this mean discrete time systems are clocked so ...
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3answers
122 views

Study Signal Processing

I'd Like to ask two questions : What is the difference between studying Signal processing (both Deterministic and statistical) in Department of Electrical Engineering versus Department of Mathematics ...
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0answers
16 views

Stationary wavelet transfrom: diagonal detail response

I am using the PyWavelets library to take the stationary wavelet transform of some images. By looking at the documentation for the stationary wavelet transform, I notice that for each scale level it ...
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1answer
34 views

How increasing the Signal to Quantization noise increases the resolution of ADC

Inside ADC we have a quantizer, when the sampled signal is passed through it, the signal values get discretized. The number of discrete levels in which the signal is discretized is called the ...
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1answer
34 views

Discrete Time to Frequency Response

I'm learning (trying to learn) how to find a frequency response. I have a discrete time equation and want to understand the process for finding a frequency response. Ex: $$f(n) = ...
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2answers
34 views

Spectral Content of two waveforms

I have found this interesting question here: Which of these two waveforms has a richer spectral content, and why? Intuitively speaking, I think that the first one is richer, but I cant really ...
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2answers
93 views

Checking linearity/time-invariance etc. for recursive system

I'm familiar with the general methodology for checking if a system is linear: Define output $y_1[n]$ for input $x_1[n]$, define output $y_2[n]$ for input $x_2[n]$ Define $x_3[n] = ax_1[n] + bx_2[n]$ ...
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27 views

Error tolerance for MUSIC (Multiple Signal Classification)

I would like to know if there is rule about how much can a matrix X-hat deviate from original matrix X $$\epsilon \le ||X -\hat{X}||_2$$ for MUSIC algorithm to still work. $$\hat{X} = X + Noise$$ I ...
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0answers
57 views

Extracting the phase of a jittering sine wave using python

The background: I conducted an experiment where I rotated an object (with three-fold symmetry) many times and recorded the projection of the object. I should be able to tomographically reconstruct ...
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1answer
35 views

converting block diagrams with delays to equations

given this block diagram: can someone please clarify how to interpret the second delay (the one prior to $Y$)? to convert this block diagram into a simple equation, I interpret the diagram as: ...
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2answers
72 views

Thoretically, what makes multi-pitch detection so difficult?

For multi-pitch detection, I mean for example pressing several piano keys at the same time. For signal pitch detection (pressing one key at a time), after FFT, mostly the frequency with the largest ...
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1answer
53 views

understanding discrete-time convolution in LTI systems

I'm trying to understand the discrete-time convolution for LTIs and its graphical representation. standard explanations (like: this one) start with the idea of decomposing an input signal $x[t]$ into ...
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2answers
72 views

Best method to do piano key pitch detection?

For example, when playing piano, at the same time, print out the key notes by analyzing the signal of piano sound. How to do some pre-processing to remove the noise? When calculate with FFT, noise ...
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0answers
21 views

Variation in Signal Power in Mimo system

I am exploring methods for reducing computations required by MUSIC (Multiple Signal Classification) Algorithm. Most of the computational power is spent on calculating SVD. My approach is to take ...
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1answer
24 views

float image to integer type image

I have a multispectral satellite image and I would like to "transform" each of the image bands into one with integer values. For example to stretch? the image between 0 and 255. Not sure how to ...
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1answer
43 views

How to obtain mean Power Spectrum from two audio channels?

I have a source of noise in a duct, on either side of the noise source I have a microphone, which register the pressure, so that I get two pressure signals: $p_1$ and $p_2$. I want to get the acoustic ...
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1answer
46 views

Difference Equation - Time Response analysis of Discrete Systems

We know that that the difference equation formula for computing an output sample at time $ n$ is based upon its past/present input samples and past output samples in time domain: $\displaystyle ...
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1answer
51 views

Natural, Forced and Total System Response - Time domain Analysis of DT

I am a self-learner of DSP by reading related books. While reading Time domain Analysis of DT (Discrete Time) system, I suddenly got introduced to difference equation representing a system. It then ...
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5answers
145 views

Why does the DFT assume the transformed signal is periodic?

In many signal processing books, it is claimed that the DFT assumes the transformed signal to be periodic (and that this is the reason why spectral leakage for example may occur). Now, if you look at ...
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1answer
49 views

Autocorrelation of a signal comprised of only the same number

In MATLAB I generated a signal and its autocorrealtion function using: signal = ones(1,500).*5; % a vector of the number 5 acf = autocorr(signal,numel(signal)-1)); To my suprise the ...
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1answer
35 views

minimum frequency in periodic components

Suppose we have the following signal model $y(t) = A_1\sin(\omega_1 t+\phi_1) + A_2\sin(\omega_2 t+\phi_2) + ... + A_p\sin(\omega_p t+\phi_p) + z(t)$ When we are sampling at sampling frequency ...
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36 views

Estimate the Discrete Fourier Series of a Signal with Missing Samples

Assuming we have a discrete signal $ { \left\{ x \left[ n \right] \right\}}_{n = 1}^{N} $. Which has a Discrete Fourier Series. Now, assume I'd like to estimate its Discrete Fourier Series ...
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0answers
44 views

How To Generate a Band Limited Sawtooth Wave Using Additive Synthesis using C++

I am trying to generate a continuous Band Limited Sawtooth wave using Additive Synthesis in C++. I understand that the harmonic structure of a sawtooth wave can be generated in this manor: ...
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1answer
50 views

Properties of Discrete-time Sinusoidal Signal

I was reading in a book that below stated are the Properties of Discrete-time Sinusoidal Signal: Property 1. The discrete time sinusoids whose frequency are separated by an integer multiple of ...
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1answer
52 views

Basics of waveform, how to define the zero point

Audio is a sequence of waveforms which have peaks, troughs, 0, just like below. How to define the x axis (y = 0) in the picture, how to choose the 0 point in the waveform since there are so many ...
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3answers
480 views

disadvantages of FFT, it can not extract enough frequencies without enough samples

Let's say sampling rate is $Fs = 44\mathtt{kHz}$, now I have $N = 2048$ samples, then I can get $N/2 + 1 = 1025$ frequencies. I'm confused by Matlab's FFT documentation that says the frequencies are ...
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0answers
31 views

DC offset removal from tetra signal

Hey I want to remove DC offset from tetra signal captured as inphase and quadrature phase samples(I and Q samples). I and and Q samples are 16 bit signed values. I tried averaging 2000 I and Q samples ...
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1answer
85 views

Understanding the windowing method in PSD calculation

I have some issues understanding the use of a window (it doesn't matter which one) to calculate the Power Spectral Density of a signal. For example say I want to use the hann window, with $N = ...
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0answers
32 views

Clustering of overlapping windows (K Means)

I'm attempting the clustering of some of my data using a K-means Euclidean square method. I've broken the data down into small windows, 200 samples in size, but with a 50% overlap. I've chosen to use ...
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2answers
89 views

Generating a high SNR sinusoide with lut on a DSP

I'm generating a sinus by using a lut method on a DSPic33f. My sample rate is 48 kHz, so I saved 12000 of the first value (unsigned int, 16 bits) and use trigonometric formulas to calculate the other ...
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1answer
190 views

Determine whether a signal is periodic or not and get fundamental period

Here is my signal Cos(n/2)*cos(pi*n/4) cos(n/2) has period 4pi and cos(pi*n/4) has period 8 Now, the question is will the signal be periodic for fundamental ...
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0answers
32 views

Time delay analysis in different binary sequences

I am extracting a property of a signal which I represent with either a 0 for absent or 1 for present. This property is extracted for each data point in a time series and in the end I am left with a ...
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3answers
74 views

Decimate/downsample a signal from 1920.93Hz to 1920Hz. Possible? [duplicate]

I've just learned that the A/D converter I am using is not sampling at my desired sampling rate. I request 20 seconds of data at 1920Hz and I receive 38400 points of data that were actually sampled ...
4
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1answer
69 views

Intertial navigation on android phone with Kalman filter

Ok, so suppose I've got a phone with gyroscope, compass and 3-d accelerometer. I wanted to track position of the moving phone for about 1 minute with let's say 50 mm accuracy. Actually let's say that ...
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2answers
211 views

Negative dB signal to noise ratio

Is it common to find systems having signal to noise ratio (SNR) less than 1 i.e. noise is more than signal? I am currently working with SNR of -5db to -20db. And how useful is it to work with sensor ...
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2answers
80 views

What is 'energy compaction' in simple terms?

This is my understanding of 'energy compaction' and want to know if it is right. Take a vector. The energy of the vector is the sum of the squares of its elements. If A is the transformation matrix ...
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2answers
133 views

shifting sequences using Matlab

I'm reading this book and I came across a function to shift sequences. Mathematically, $$ y(n) = \{x(n-k) \} $$ if $m = n-k$, then $$ y(m+k) = \{ x(m) \} $$ ...