Tagged Questions

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

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0answers
17 views

Shifting of a Signal and then Subtracting

I would like to know how an digital unit impluse is formed when we subtract a digital unit signal shifted one to the right from the unshifted unit digital step signal?
0
votes
1answer
28 views

Mixing two signals creates power at dc?

I have a signal with components at 1200 and 1800 Hz. When I mix this signal with a 1500 Hz signal to create components at -300 and +300 Hz (then LPF) a DC offset presents itself when the input signal ...
0
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0answers
9 views

Nth Order Differentiated Parabolic Wave Synthesis

I am working on a sound synthesis software project. At the moment I am working on an implementation of the "Differentiated Parabolic Wave" or DPW algorithm in C++, specifically a sawtooth ...
-1
votes
1answer
18 views

Confusion when applying Hamming window to signal

I am writing some code which takes a signal of length $n$, and processes it in 20 ms chunks with 5 ms of overlap... So basically I have a buffer of 20 ms worth of sampled data, and I am trying to ...
0
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0answers
26 views

How to choose sampling rate?

I am working on a FMCW radar and I want to sample the I/Q signals from the 2 receiving antenna (total 4 channels) simultaneoulsy and send the digital data to computer to extract range and velocity ...
0
votes
0answers
24 views

Why do we use Hilbert Transform in discrete time domain?

I have few questions regarding hilbert transform, Questions are as follows: 1)What are the benifits of using hilbert transform hardware and software point of view? 2)Cannot we use any other digital ...
0
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0answers
18 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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votes
0answers
13 views

Structured light 3D imaging

i am currently working on structured light 3-D imaging, i have read no of journal papers but still i am not getting practical approach of the subject. Especially how to use triangulation principle, I ...
0
votes
2answers
28 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 ...
1
vote
1answer
29 views

What is the use of the Welch lower bound when k > 1?

The Welch lower bound on the maximum cross-correlation (inner product) of $m$ vectors, each of $n$ elements, is given by $c_{max} = f(m, n, k)$ (eg, see Wikipedia Welch bounds). It is always assumed ...
0
votes
1answer
73 views

How to show that y[n] = x[n] * h[n] turns into the Y(z) = X(z).H(z)?

I'm trying to show that $y[n]=x[n]*h[n]$ turns into $Y(z) = X(z)H(z)$ in Z-domain by first applying convolution then by taking the inverse Z-transform of the $Y(z)$, stating that it's the same ...
0
votes
1answer
29 views

DFT independent variable as fraction of sampling rate

When the frequency domain's independent variable is labeled as a fraction of the sampling rate, the values along the horizontal axis always run between $0$ and $0.5$, since discrete data can only ...
0
votes
0answers
31 views

Different methods of periodicity detection of irregular signal

I'm going to describe the situation and the solutions I've tried and then ask some questions. The data The data I'm working with is sampled once per second and there either was an event (1) or not ...
0
votes
1answer
47 views

Is it possible that adding noise to a signal can increase detection possibility?

I am simulating a feature detector in noisy environment which consist of AWGN Noise and Impulsive Noise. But I am getting a strange result as Signal with Impulsive+AWGN noise has better detection ...
1
vote
1answer
20 views

How to apply “Substitution Method” in Difference Equations?

How to get the value of $y_p(n)$ using substitution method? What exactly do we need to substitute to get the value?
0
votes
0answers
43 views

Image super resolution algorithm in Matlab

I'm trying to implement a simple Image super resolution algorithm (DWT-Based Resolution Enhancement ) in the following paper http://www.ripublication.com/aeee/52_pp%20%20%20405-412.pdf I tried to ...
0
votes
1answer
27 views

Deriving time-scaling property for Fourier Series

thanks for taking the time to help with this problem! I have to prove the time-scaling property: $$ x_{(m)}[n] = \begin{cases} x[n/m], & n=0,\pm m, \pm 2m,...\\ 0, & otherwise \end{cases} $$ ...
0
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0answers
36 views

For discrete signals, why does phase change not correspond to time shift?

I'm going through a Signal Processing lecture where the professor mentions this fact and the argument given is: Suppose you have a sinusoidal signal: $Acos(\omega t)$ Now if you change the phase of ...
0
votes
1answer
31 views

Extending a waveform

Apologies if this makes no sense or seems rather simple, I'm a Matlab newbie. Basically, I've got a .wav audio waveform which I am resampling to various different frequencies and then trimming the ...
0
votes
1answer
18 views

Estimating signal strength from PCM-encoded signal

I am processing rtl_fm output (in time domain), extracting Manchester encoded bits. I can detect preamble and, therefore, decode the message which follows the preamble. This is how my signal looks ...
1
vote
1answer
65 views

Removing frequency using FFT

So if I were to have an $n$ length sample of a given sample rate and were to run it through an FFT, resulting in $n$ complex elements. How would I obtain the frequency bins, such that if I know the ...
0
votes
0answers
33 views

generating a waveform in matlab for rohde and schwarz signal generator

We are doing a test which consists in sending a waveform from Matlab to the signal generator SMB100A and sending it through a cable to the r&s spectrum analyzer just to have a channel. We set the ...
1
vote
1answer
85 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} ...
1
vote
0answers
29 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 ...
0
votes
0answers
14 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 ...
0
votes
0answers
57 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 ...
0
votes
2answers
60 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 ...
0
votes
1answer
46 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 ...
0
votes
2answers
41 views

Pole/Zero existence at infinity

How can poles and zeros exist at infinity?Can anybody explain using a system function?
1
vote
1answer
43 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 ...
0
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0answers
19 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 ...
-1
votes
1answer
33 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 ...
-1
votes
1answer
44 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 ...
1
vote
1answer
76 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? ...
0
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0answers
31 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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
0answers
18 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 ...
1
vote
1answer
57 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 ...
-1
votes
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) = ...
0
votes
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 ...
0
votes
2answers
102 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 $x_3[n] = ax_1[n] + bx_2[n]$ ...
0
votes
0answers
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 ...
2
votes
0answers
62 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 ...
0
votes
1answer
38 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: ...
2
votes
2answers
82 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 ...
-1
votes
1answer
60 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 ...
0
votes
2answers
73 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 ...
1
vote
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 ...
0
votes
1answer
31 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 ...