Skip to main content

Questions tagged [discrete-signals]

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

Filter by
Sorted by
Tagged with
1 vote
1 answer
37 views

does extension to reals of an arbitrary signal with a zero tail eventually cross a threshold

Suppose I have a sampled signal $S(x) :=\space [ \space ..., X_{-2}, \space X_{-1}, \space 0, \space 0, \space 0, \space 0, \space ... \space ]$ where $\{X\}_{n}$ is bounded by $\pm1$ when n is a ...
micsthepick's user avatar
3 votes
1 answer
113 views

Best Methods for Interpolating Short Non-Periodic Bandlimited Signals

I need advice on interpolating a very short (N < 10) discrete, bandlimited signal that is sampled above the Nyquist rate. I understand that technically finite length signals have infinite bandwidth,...
Gillespie's user avatar
  • 1,906
0 votes
1 answer
23 views

Problem observing the correctness of a Fourier transform property

I'm studying "Signals & Systems" by Oppenheim et al. On page 391, for a real-valued $x[n]$ whose Fourier transform is $X(e^{j\omega})$: $$x[n] \leftrightarrow X(e^{j\omega})$$ $$\...
Robert's user avatar
  • 3
0 votes
1 answer
55 views

Energy as mean of absolutes of data samples

Normally, we find the energy of a given signal as $\sum{{x_n}^2}$. But, what if I compute, energy as $\sum{|x_n|}$. In the latter case, if I want energy in dB, which formula should I use - $10\log_{10}...
JHKKHJ's user avatar
  • 11
0 votes
0 answers
40 views

Generating a whitening filter using MATLAB cceps() function

I have a few thousand realisations of a discrete stochastic process. I am trying to generate a whitening filter from these realisations. I am expected to use the MATLAB cceps() function to generate ...
SumDood's user avatar
3 votes
2 answers
189 views

Create a minimum phase filter from an elliptic digital filter

I have the numerator and denominator of a lowpass digital elliptic filter. I know how to create a minimum-phase filter with the same magnitude response using cepstrum technique. But I came across this ...
AHT's user avatar
  • 469
0 votes
1 answer
59 views

Why is $y(n)=Ax(n)+B$ not relaxed if $B\neq 0$?

I'm wondering why $y(n)=Ax(n)+B$ not relaxed if $B\neq 0$? The definition of a relaxed system as I've understood is that $y(n)$ does not depend on any $y$-values. So what is the definition of a ...
per persson's user avatar
0 votes
1 answer
69 views

Inverse of a causal and stable system

Consider a discrete-time causal and stable LTI system $S_1$​. The inverse system $S_2$​ is defined as the system that takes the output of $S_1$​ as its input and provides the input of $S_1$​ as its ...
Nyquist-er's user avatar
1 vote
0 answers
29 views

What is the analogy of frequency sampling of a 1D signal in a 2D signal (image)?

I made model to remove noise using deep learning for 1D ECG signal (time-amplitude domain). The model was trained on 360 Hz frequency sampling ECG data on millivolts unit. I stated to my professor ...
Muhammad Ikhwan Perwira's user avatar
0 votes
1 answer
47 views

Amplitude scaling for the FFT of a logarithmic frequency sweep

I have performed a logarithmic frequency sweep on a system from 1 Hz - 5000 Hz at constant amplitude and acquired the data at a linear acquisition rate of 10000 Hz. The frequency sweep reference ...
Nuno's user avatar
  • 3
0 votes
0 answers
24 views

Interpolation Control for doing Timing Recovery in FPGAs

I intend to make a timing recovery circuit on an FPGA and for that I have to make synthesizable models of Xilinx Blocks for Interpolation Control (Module-1 Counter based) in Simulink. I have made ...
Iron Bat's user avatar
1 vote
1 answer
57 views

finding the coefficients of the following difference equation so that it holds true

I'm having trouble solving the following problem: Find the coefficients $a_1,a_2,a_3$ so that the signal $x[n] = Ar^n \sin(\Omega_0 n)u[n]$, $|r|<1$, satisfies the following difference equation for ...
Nyquist-er's user avatar
3 votes
1 answer
121 views

Z-transform of the Unit Step and DTFT

In class we showed the the z transform of the unit step only exists for |z|>1 but we also calculated the DTFT of the unit step. Does convergence on the unit circle imply the DTFT exists but not the ...
Amur's user avatar
  • 33
0 votes
0 answers
24 views

Spectral Theory: A Key to Unlocking Efficient Insights in Network Datasets

In the context of directed or undirected graphs, matrices such as adjacency and Laplacian matrices are commonly used. The eigenbasis of these matrices addresses some practical implications, such as ...
ABB's user avatar
  • 387
0 votes
1 answer
28 views

What is the correct interpretation of the capacity formula with modulation?

Someone sent me the image below, and I think I'm confused as well. Is the second formula (modulation) correct? What does it mean? From the symbol, I think it represents capacity, but it doesn't make ...
internet's user avatar
  • 131
2 votes
1 answer
71 views

Frequency components in graph signal processing

As a mathematics researcher, I've delved into the intriguing realm of graph signal processing, yet I often find myself tangled in mental conflicts about certain aspects of this field. Any insights you ...
ABB's user avatar
  • 387
0 votes
1 answer
65 views

algorithm for second order butterworth filter

I want to implement an algorithm for a second order butterworth filter on the form $ H(s) = \dfrac{Y(s)}{U(s)}= \dfrac{1}{\left(\frac{s}{w_0}\right)^2+2\zeta\frac{s}{w_0}+1} $ I want to get it on the ...
pjoltergeist's user avatar
0 votes
0 answers
21 views

Unsupervised Real-Time Pattern Counting in Time Signal Data Without Prior Knowledge

I'm facing a problem and it seems I can't find a working solution since a few years. TLDR : Is there a well-known algorithm or NN-model that is able to autodetect and count patterns in a time signal ...
SamoloH's user avatar
0 votes
0 answers
31 views

DT System with input initially at rest

This is the very basics of Signals but my lecturer has provided barely any notes and I cannot find answers online (not just to this, but most of signals for some reason) Dealing with DT system: y[n]=y[...
Lucy's user avatar
  • 1
0 votes
1 answer
72 views

How do i find the fast and slow changing discrete time signals? [closed]

Here are some examples: 1.) Which of these discrete time signals have the fastest changing values: a) $\cos\big(\tfrac{99}{100} \pi n \big)$ b) $\cos\big(\tfrac{49}{100} \pi n \big)$ c) $\cos\big(\...
Nonono's user avatar
  • 11
0 votes
1 answer
41 views

How to find response of DT system to an input

This year I have fallen behind in my Signals module due to poor mental health and insomnia. I have a homework due in 9 hours and dont understand anything, while also not having the time to learn ...
Lucy's user avatar
  • 1
0 votes
1 answer
66 views

Why the Discrete time fourier series coefficients of a real discrete time periodic signal are not symmetric about y axis?

If the signal is something like cos(πn/3) , we get the two DTFS coefficients that are symmetric about y axis and the resulting frequency spectrum is an even function . Now take the example given in ...
amoghfyi's user avatar
0 votes
1 answer
18 views

How to compute the 2D coordinate in the s-domain?

I am not sure if my question is a right question to ask or not since I am still learning about Laplace Transform and S-Domain. If we have 2D coordinates (x,y) in the spatial domain (i.e., Euclidean ...
S.EB's user avatar
  • 163
0 votes
1 answer
87 views

Is the magnitude spectrum of the Discrete Time Fourier Series of a Discrete Time periodic Signal , an even Function?

We know that the magnitude spectrum of a continuous time fourier series representation of a real periodic signal is an even function (i.e. symmetric about y axis). Does this hold true for discrete ...
amoghfyi's user avatar
1 vote
0 answers
125 views

Proof that the order of a linear prediction model cannot be reduced by analysing non-adjacent points

I have a signal, for which a linear prediction model of order $M$ can be constructed. This means, that a system of the shape $$ \begin{bmatrix} s_0 & s_1 & \cdots & s_M \\ s_1 & s_2 &...
Tigozawr's user avatar
0 votes
0 answers
15 views

Real-world examples of unweighted directed graphs

Social Networks, Internet Traffic, Citation Networks, Transportation Networks, and Biological Networks exemplify real-world instances of unweighted directed graphs. Within these domains, the Graph ...
ABB's user avatar
  • 387
0 votes
0 answers
39 views

Related to SNR in wireless communication

I am working on a research paper related to wireless communication, wherein I am facing some doubt while writing expression of SNR (which is a ratio of Signal variance in numerator to Noise variance ...
Pranu's user avatar
  • 3
0 votes
1 answer
51 views

Looking for an online course

I work for a company with expertise in electromagnetics physics, specifically dealing with time domain-based simulation software. We routinely need to transform our results into frequency domain, ...
DrEarlGray's user avatar
0 votes
0 answers
42 views

Smoothing sensor signal with discontinuities on DSP for obtaining signal derivative

I am trying to implement PID control on a sensor signal that has many discontinuities in it. Due to these discontinuities, the differentiated signal does not provide a meaningful or useful signal I ...
Mr Phase Locked Loop's user avatar
0 votes
0 answers
30 views

Why are MFCCs of different signals equal?

What I am trying to do: I am trying to extract features based on the difference between a reference signal (white noise in my case, let's call it ref) and different processed versions of it (let's ...
benczejrobert's user avatar
1 vote
1 answer
128 views

If the input of the system depends on the future outputs then is the system non-causal?

While I'm aware of the fact that causality implies that the present output is only dependent on present and past inputs, something that is bugging me is what if the input is dependent on future ...
Ahan Shetty's user avatar
0 votes
1 answer
44 views

Signal level from its FFT

Suppose I have the FFT of an arbitrary real audio signal z samples long. Is there a way to discover the signal level (intended as the largest absolute value of its samples) from the FFT without ...
elena's user avatar
  • 351
0 votes
0 answers
50 views

Laplace Transform and Inverse laplace Transform for 2D images python code available?

I am wondering if there is any implementation of Laplace Transform and Inverse Laplace Transform available for 2D data (i.e., images). For example, a batch of N ...
S.EB's user avatar
  • 163
0 votes
1 answer
58 views

Lowpass Filter to Average sinusoid signal

How to get an average of a sinusoidal signal? The frequency of a signal is 50 Hz and could have harmonics, i.e. high THD. I tried to use exponential moving average with low cut-off frequency (about 1....
Rafael Santos's user avatar
0 votes
0 answers
23 views

Fusing multiple IMUs in EKF framework

What is the approach to fuse multiple IMUs in EKF framework? Normally you take the IMU as the motion model and the sense step to consist of other sensors but when have multiple IMUs operating, what is ...
FourierFlux's user avatar
4 votes
1 answer
53 views

Show that the similarity between a signal at an analysis frequency with a phase offset with a reference signal is $\frac{N}{2}\text{cos}(\phi)$

I'm reading Brian McFee's excellent book Digital Signals Theory. He presents the DFT as a measure of similarity $S$ between a digital signal $x[n]$ with $N$ samples and a set of reference signals $y_m[...
NickleDave's user avatar
0 votes
0 answers
24 views

Filter coefficients hamming window for low-complexity Welch PSD computation

I am trying to implement the proposed method from this paper 1, to eventually have a more efficient PSD computation for feature extraction on a microcontroller. The method is suitable since I am using ...
michael's user avatar
0 votes
1 answer
68 views

Correlation between two signals

I am having an input signal x[n]=[1 2 3 4 5 6] and another signal y[n]=[2 3 4]. In order to check whether y[n] is present in the signal x[n],I did cross correlation and the result obtained was [ 0 0 0 ...
Aami's user avatar
  • 315
2 votes
2 answers
146 views

insights into making AR Burg extrapolate finite periodic signals

Following a past question, I'd like to extrapolate a periodic signal using AR Burg, but when doing so, it seems that I need to sample "enough" for that to work. For example, if I use the ...
bla's user avatar
  • 588
0 votes
2 answers
93 views

Influence of phase discontinuity on power spectrum density

I was wondering about the influence of phase discontinuities on a power spectrum density calculated with f.e. Welch's method. I know you shouldn't have any phase discontinuities in your signal, but I'...
Stijn's user avatar
  • 3
1 vote
0 answers
51 views

Is there something wrong with MATLAB's pwelch function?

The normalized factor for windowing, is it $(\sum w[n])^2$ or $\sum w^2[n]$? I try to reproduce the pwelch function, if I set the normalized factor to $(\sum w[n])^2$, I get the same result as MATLAB ...
Devin's user avatar
  • 11
2 votes
2 answers
112 views

How can I denoise this signal?

I have data captured by a wireless sensor that is noisy. It randomly jumps in value frequently, and I want to know what this signal will look like without these jumps. I am looking for an elegant ...
stochasticlover1's user avatar
2 votes
2 answers
146 views

What is the difference between the DFS (Discrete Fourier Series) and DTFS (Discrete-Time Fourier Series)

I'm looking at two different books written by Oppenheim. In Discrete-Time Signal Processing (source 1) he defines the DFS to be: where, $W_N=e^{-j(2\pi/N)kn}$ , while in Signals and Systems (source 2)...
eball's user avatar
  • 131
1 vote
0 answers
51 views

FFT analysis of signals that were combined

I have a dataset with ECG artefacts, noise and EMG activations. Now I want to analyse the EMG activation using Welch's and Burg's method. The EMG realizations are approximately 0.25 s long, resulting ...
Stijn's user avatar
  • 11
2 votes
0 answers
125 views

The Discrete Fourier Transform (DFT) decomposes any signal into four orthogonal signal components

Let $F=\frac{1}{\sqrt{n}}(w^{kl})_{k,l=0}^{n-1}$ be the discrete Fourier matrix of size $n$ where $w=\exp^{-\frac{2\pi i}{n}}$. It is a well-known that $F_n^4 = I_n$ where $I_n$ represents the ...
ABB's user avatar
  • 387
0 votes
1 answer
41 views

Quasi-static-detector operation principle

Im currently working on a project to get navigation information of a robot from Data-Fusion through different IMUs. First step is to make a calibration and I picked a method where I need to detect ...
Orthos's user avatar
  • 1
0 votes
0 answers
24 views

I need help finding the PSF and characterizations of the following

My professor explained this to me in a super convoluted way, so hopefully someone can explain this to me better. I'm trying to find the PSF of the following signals. I also need to check if it's FIR ...
FafaDog's user avatar
  • 149
3 votes
1 answer
72 views

Discrete time serie online derivative

I'm looking for an algorithm to compute the numeric derivative $\dot x_i$ of a discrete time serie $(x_i, t_i)$. It should runs as the data is generated, hence $\dot x_i$ can only depend on $x_{j<=...
piwicode's user avatar
0 votes
0 answers
25 views

Understanding Fresnel reflection coefficient formula

In textbook "Wireless Communications Principles and Practice" by Theodore S. Rappaport, the expression of Fresnel reflection coefficient ($\Gamma$) for parallel polarization is given as $\...
Heretolearn's user avatar
4 votes
1 answer
134 views

Relation between DTFT and DFT

Let $X \left( e^{j \omega} \right)$ be the DTFT of a discrete-time signal $x \left[ n \right]$ given as $$ x \left[ n \right] = \left( \frac{1}{3} \right)^{n} u \left[ n \right] \tag{1} $$ Determine a ...
Harsha's user avatar
  • 53

1
2 3 4 5
51