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
0
votes
1answer
14 views

Highest frequency component in 2D Fourier transform

I was trying to understand the 2d dft(discrete Fourier transform) and discrete spatial Fourier transform (dsft) of images. But while understanding the graph i didn't understand that how come ($\pi,\pi$...
1
vote
0answers
17 views

Best way to measure effectiveness of discrete wavelet denoising?

I am using matlab wavelet toolbox to denoise physiological signals, I am plotting the denoised signal on top of the original noisy signal and making sure spikes were not removed as a measure of ...
0
votes
0answers
25 views

How to quantize filter coefficients to certain number of bits?

I am designing an lowpass filter in Matlab. I used designfilt function to design a filter. After designing my coefficients are 9x6 double. Now I want to quantize this to 16 bits. How can I quantize, ...
1
vote
0answers
28 views

Change FFT frequency domain values range

So, I`m currently working on program for computing spectrogram in real-time, using signal from a microphone. And now I want to add "scaling" feature, that allows to look at the spectrum more ...
1
vote
1answer
31 views

3 dB bandwidth of a filter

I am solving one of the question from signal processing about calculating the 3dB bandwidth of the filter. But I am stuck once I got the magnitude response of the filter. Can someone help me with this?...
1
vote
2answers
30 views

Partitioning the energy of a signal between its components

In physics, the total energy of a system is the summed energy of its component subsystems, and energy must be conserved, ie, adding the energy of the components gives the total energy. In signal ...
2
votes
1answer
29 views

Is my solution to the DTFT of a delta function correct?

I am newer to signal processing math and just figured out something cool (hopefully). I was trying to see how the DTFT of the delta function is 1, because thats what my book says. I could only find ...
0
votes
0answers
16 views

How to I obtain the real part of a an Analytic Signal when the real and imaginary parts have been delayed by different amounts

A real audio signal (0-3 KHz) is processed by a Hilbert filter to obtain the Imaginary component. Both the real signal and the imaginary are delayed but by different amounts. I want to obtain the real ...
1
vote
0answers
15 views

Is my implementation of Generlized Pencil-of-Function correct?

I have a time-series data that should be of the form $$ f(t) = \sum_nA_n(e^{\alpha_n t}+e^{-\alpha_n(T-t)});\;\alpha_n=\eta_n+i\omega_n;\;i=\sqrt{-1} $$ and I want to find parameters $A_n$, $\eta_n$, ...
0
votes
1answer
43 views

Drawing conclusions from impulse response of a discrete LTI system

I have an impulse response of an LTI system which is h(n)= n*u(n)-u(n-2) where n=[0,3] (1) Now regarding the stability and causality of this system, i've drawn the ...
3
votes
1answer
53 views

Understanding Parseval's Theorem with Discrete Wavelet Transform

I have difficulty to understand the results I get with implementing Parseval's Theorem in Python to DWT. I have the good results getting the Energy with Fourier transform and the time series in python:...
0
votes
0answers
30 views

Can largest-triangle-three-buckets downsampling method used with fourier transformed signal?

I've been reading on the largest-triangle-three-buckets downsampling method for downsampling. Though it was originally published in the thesis "Downsampling Time Series for Visual Representation&...
0
votes
0answers
12 views

How does the band pass wavelet act as a high pass filter in DWT

I am understanding that wavelets have a bandpass filter response due to their compact support, and when doing decomposition they are used as a high pass filter along with the scaling function as a low ...
1
vote
1answer
53 views

Fourier transform of the sampled signal

I want to calculate Fourier transform of the sampled signal in two ways. Let $$s(t) = \sum_{k = -\infty}^{\infty}\delta(t - kT)$$And $z(t) = x(t)s(t)$. So we have $$z(t) = \sum_{k = -\infty}^{\infty}x(...
1
vote
1answer
31 views

Some questions about the intuition of the DWT

Assuming a DWT of a signal of length 8 with Haar filter taps. At the lowest level, I end up with a3 and d3 both of length 1, d2 of length 2 and d1 of length 4 which is the same number of coefficients ...
0
votes
1answer
25 views

Matlab: xcorr: Having trouble when I try to calculate delay between two sinusoids

I have a problem when I try to use Matlab built-in function for cross-correlation 'xcorr'. Background: I created two sinusoids, one of them delayed in time. I choose center frequencies of these ...
-1
votes
0answers
12 views

Output of LTI diagram with this question and is it stable [closed]

the input δ(t) and output of a LTI signal is shown below. 1- is this system casual? 2- is it stable? why? 3- draw the output of the system. Tnx in advance
1
vote
2answers
98 views

Ideal Lowpass Filters [closed]

I am a beginner to Digital Signal Processing. I took this course of DSP from Coursera in which I am stuck with this question. Since, I am new, please be descriptive. Any help will be appreciated. ...
0
votes
1answer
42 views

Calculating IIR Filter gain at given frequency

Let's consider an IIR filter with transfer function: $H(z)$. Given the sampling frequency $F_s$ how can I calculate gain at say $F$ ? When I was dealing with analog systems when I wanted to calculate ...
0
votes
1answer
31 views

How to convert ofdm symbol to signal?

Hello may I know how to convert ofdm symbol generated from ifft block to an OFDM signal for the purpose of transmitting it?
1
vote
3answers
62 views

How to improve the Kalman filter for tracking the periodic motion of a car?

I have a quite typical Kalman filter to design. I really read a lot of articles about the design of this filter but the performances of my filter are still quite bad. Here is my situation. I have a ...
1
vote
1answer
30 views

How to construct Neyman Pearson statistic to detect discrete signal in AWGN with unknown location?

I have a discrete datastream of length $10^5$ samples. Somewhere embedded in it is a rectangular pulse of unknown amplitude (prior probability of data containing signal is 0.5) and width 100 samples. ...
1
vote
1answer
49 views

Can time-invariance be determined from a given a transfer function?

I've the following function. $$ G(z) = 2 + \frac{-1+5z^{-1}}{(1-0.5z^{-1})(1-z^{-1})}$$ Calculating it's inverse using $\mathcal Z$-Transform, I get the following function: $$g[n] = 2\delta[n] + 8u[n] ...
1
vote
0answers
41 views

Detecting complex signal within complex AWGN using Neyman Pearson statistic

I need to construct a Neyman Pearson statistic for detecting a complex signal with known amplitude and unknown phase in additive complex Gaussian noise. My hypotheses are: \begin{align} \mathcal{H}_0 &...
2
votes
2answers
68 views

1D DCT matlab code

I was writing MATLAB code to compute 1D DCT of sample y. On computing DCT for y=[0,1,2], code generates coefficient ...
1
vote
3answers
73 views

Meaning of sampling frequency?

Say there is a communication system, which can manage sampling frequency up to 4 MHz (given by software). Can the system be able to process signals with maximum frequency more than 2 MHz? Because ...
1
vote
1answer
41 views

Deriving of magnitude, phase response and impulse response of transfer function

I have a transfer function as $$H(z) = \frac{-0.0625z^4 + 0.25z^3 + 0.625z^2 + 0.25z - 0.0625}{z^4}$$ I want to derive magnitude and phase response of this equation. can someone help me from here I ...
0
votes
2answers
30 views

How to plot poles, zeros and impulse response of a transfer function

I want to plot poles and zeros as well as impulse response of a transfer function that is given below: $$H(z) = -0.0625z^4 + 0.25z^3 + 0.625z^2 + 0.25z -\frac{0.0625}{z^4}$$ For poles and zeros, I ...
-1
votes
0answers
39 views

When are MLSE (with Viterbi algorithm) equalizer used in real life (only for equalization)? [closed]

The complexity of a MLSE decoder (with Viterbi Algorithm) is in the order of $M^L$, where $L$ is the length of the channel and $M$ is the order of modulation. My question is in what circonstances, it ...
1
vote
0answers
68 views

Separating/recovering base signal from two mixed signals, given phase information

I have collected two signals, $B_1(x)$ and $B_2(x)$. The signals start and end at the same $x$-values. Each signal $B_i(x)$ contains: a base signal $b(x)$, which is the same for both, and a signal, ...
12
votes
5answers
1k views

Are there any real world applications for complex-valued signals or impulse responses?

I was just curious... $$x[n] {\longrightarrow} \boxed{h[n]} {\longrightarrow} y[n]$$ I've never seen a real world filter where the coefficient of $h[n]$ were complex, or where $x[n]$ was a complex ...
0
votes
1answer
20 views

Having Problem about DownConversion

I hope, you are doing well. I want to ask question about baseband conversion. Background: I generated two AM signals in MATLAB, which one of them is shifted in time. I multiply the signals with $\cos(...
1
vote
1answer
26 views

what is the relationship between the reliability of a monte carlo test and the length of the samples tested and the number of errors found?

Considering this setup, single tone transmission over a channel impaired by AWGN, doppler spread, and inter symbols interference. We are to compute the BER as a function of the SNR. We want to find ...
1
vote
1answer
18 views

deconvolving a 1d signal using a lookup table of “PSFs”?

assuming I measure a signal that has different PSFs per position in time. for example: ...
1
vote
1answer
43 views

What the disadvantages of up-sampling

Let's say we have a signal $x[n]$ upsampled at the transmitter by $4$ and then downsampled at the receiver by $4$ too. As known, the performance will be much better compared with transmitting the ...
1
vote
2answers
62 views

Showing error energy goes to zero

Let $$\hat{x}[k] = \frac{1}{2\pi}\int_{-W}^{W}X(e^{j\omega})e^{j\omega k}d\omega,\label{ift}\tag1$$ where $$X(e^{j\omega}) = \sum_{n=-\infty}^{+\infty} x[n]e^{-j\omega n}\label{dft}\tag2$$ Also, $$d[k]...
0
votes
2answers
59 views

Coefficient Scaling of IIR filter to obtain unity gain response

I am designing a 2nd order IIR digital filter : My tf equation with coefficients is ...
1
vote
1answer
30 views

How to apply band-pass filter and get the filtered back from frequency to time domain in python?

I know this is basic for signal processing, but, I am not sure what is wrong about my approach. I have a signal that behaves as damped sine signal with a sampling frequency of 5076Hz and 15,000 number ...
1
vote
1answer
73 views

Duality in the discrete-time Fourier series

Suppose $g[n]$ is periodic with fundamental period $N$ and $f[k]$ being its Fourier coefficients i.e. $$ f[k] = \frac{1}{N}\sum_{n=<N>}g[n]e^{-j\frac{2\pi}{N}nk}$$ In more convenient notation $$...
0
votes
1answer
39 views

Confusion regarding notation/symbol?

I was reading circular convolution topic from Digital Signal Processing Using Matlab 3rd Ed,by Proakis. I came across a strange term/symbol; I have highlighted it in attached snapshot I have also ...
0
votes
0answers
23 views

Filtering out symmetric noise from an oscilloscope reading

I have a signal that looks like this: The data is readings from two oscilloscope channels, one color coded blue, the other color coded orange. I would like to filter out the supply noise (all the ...
0
votes
1answer
32 views

Conjugate symmetry of the DFT of real-valued sequences

I have read about Fourier transformation that real signals are "mirrored" in the real and negative halves of the Fourier transform because of the nature of the Fourier transform. For ...
0
votes
1answer
30 views

Understanding index transformation in derivation of Fourier transform for sampling rate reduction

Was going over some notes regarding deriving fourier transform equation for Sampling Rate Reduction. Reference to Notes from below link https://ocw.mit.edu/courses/electrical-engineering-and-computer-...
2
votes
1answer
27 views

How are these two discrete time signals equal?

How are these two signals equal? What I have tried: $ x[n] = (-3)(-2)(-2)^{n-1}u[n] + (-2)^{n-1}u[n] $ I am not sure how this leads to the answer.
0
votes
1answer
37 views

Convolution that outputs a unit impulse

Im thinking whether any convolutional operation can output a unit impulse, an example to further explain: where a convolution between system $h[n]$ and unknown system $g[n]$ would output $\delta[n]$. ...
0
votes
0answers
14 views

scipy.signal.deconvolve not working, Blind deconvolution in python

I am trying to deconvolve my original signal with a given wavelet (Ricker wavelet). But scipy.signal.deconvolve is not giving any output to the signal. Impulse signal can be generated by below code. ...
2
votes
2answers
58 views

Z transform of finite signals

I was trying to solve the Z-transform for u[n] - u[n-N], where u[n] means discrete unit step function, and N is some finite integer. I solved this using 2 methods. ...
0
votes
1answer
13 views

A question about the Commutativity Property in discrete signals block diagrams

According to the Commutativity Property of block diagrams, we can place b0 at the entrance or at the exit of the block diagram, it wouldn't matter. My question is, if we placed it at the entrance, we ...
0
votes
0answers
28 views

How to make noise power estimation on a single tone transmission?

Suppose we have a single tone transmission over a Single Input, Single Output (SISO) channel impaired by Inter-symbol Interference and Additive White Gaussian Noise (AWGN). How to compute the noise ...
0
votes
1answer
14 views

Frequency response of discrete PT1 in MATLAB

I want to calculate the frequency response of a discrete PT1 system with T=T1 and K=1. (the code is at the bottom of the question) To validate the magnitude response, I want to use an sinusoidal input ...

1
2 3 4 5
35