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Spectral kurtosis on non-stationary signal

I posted a question some weeks ago I still have not found an answer to. I updated the old question and am hoping someone could help. Link: Varying speed of shaft Spectral Kurtosis
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0answers
5 views

Amplitude reduction of Simple Moving Average on sinusoid

When a -causal/non-centered- simple moving average filter (arithmetic mean) with length $n$, is applied to a sinusoidal curve with period $p$, and the resulting curve is compared to the original input ...
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2answers
19 views

Complex exp. Fourier series, finding x(t) when X(jw) is given as magnitude and phase plot

I'm watching Neso Academy series on Signals and Systems, and in one of the videos the problem is to find $x(t)$ when magnitude and phase plot are given. The plot looks like this: When he finishes ...
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0answers
20 views

Rectangular vs Hann windowing

I'm trying to create a basic digital signal processing pipeline, to manipulate a WAV file. Nothing fancy, I'm just looking to apply some filtering. My first attempt was to divide the input signal to ...
1
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0answers
16 views

Is non-causal, non-LTI solution to difference equation correct?

Find a solution to the difference equation $y[n]-\frac{5}{6}y[n-1]+\frac{1}{6}y[n-2]=\frac{1}{3}x[n-1]$ that is neither casual nor LTI, where $y[0]=y[1]=1$ and $x[n]=\delta[n]$ The homogenous ...
-1
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0answers
12 views

Frequency response and corresponding magnitude response

I'm given this frequency response: And I want to find the corresponding magnitude response. My answer is $|H(e^{j\omega})|$ = 1 if $|\omega|$ is within $\frac{\pi}{2}$; 0 otherwise. Is this correct?
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1answer
23 views

Blind Estimation of Signal Parameter and Noise Variance

Let $y[n]= h*x[n] + w[n]$, where $h$ is an unknown but deterministic parameter, $x[n]$ is a BPSK random variable with equal probability of +1 and -1, $w[n]$ are i.i.d. Gaussian with zero mean and ...
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0answers
6 views

Visualization of wavelets coefficients using python

I need to prepare a plot similar to figure below using coefficients of details of a wavelet transform.I am trying for more than 2 weeks to find how I can do it. This plot represents coefficients of ...
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3answers
26 views

Confusion regarding calculation of fundamental period?

I am reading signal processing first and in chapter 3 ex3.8 i came across an example of fundamental period as shown in attached photo It apparently shows that signal $$x(t)=\cos^2(4\pi t)$$ has ...
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1answer
19 views

Why do we use Difference RGB to grayscale function?

I found this function for RGB to Gray scale converter at this kind: RGB to grayscale This example converts an image with RGB channels into an image with a single grayscale channel. The ...
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0answers
20 views

How to find if the signals are in sync or out of sync with each other?

Considering these are two signals over time, black and red.Following are some of the properties Every Second a new data point is added over time . There is no control on the generation of the ...
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0answers
21 views

Harmonic Product Spectrum from FFT output to the fundamental frequency

I'm trying to do the HPS algorithm on my FFT output, but I'm stuck here. My signal is from a bass (cable), 16bits, 48.000Hz. I split in time domain the array of the whole record into multiple arrays ...
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1answer
18 views

How to specify the input data bit width for fixed point implementation in windowed OFDM?

I am implementing a fixed point model of Windowed OFDM and to quantize the input data, I used 16 bits(complex) to encode it. But I am not sure how do we specify the minimum number of bits that should ...
1
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0answers
32 views

Processing Multiple Images to Detect Moving Object in Low SNR Conditions

I am new to this forum and new to the use of Fast Fourier transforms although I can program in Python 3 a bit. I have an unusual question and am seeking some general advice on (a) whether what I am ...
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0answers
12 views

Sampling points on a face of a human body mesh

Is there a known shape analysis technique to sample points of a not necessarily naked human body mesh (more specifically the head part). The goal would be to randomly sample (uniform distribution) ...
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2answers
48 views

How do Anti-Aliasing Filters filter the signal?

I have programmed a anti-aliasing filter that uses the fourier-transformation and makes a perfect cutoff on my desired cutoff frequency for downsampling without aliasing. I have read about other ...
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0answers
35 views

Interest in adapting signal processing for reverse engineering principally from a biogenomic standpoint [closed]

NB: Cross-post to this post on reverseengineering.stackexchange.com. I am seeking any possible help for a problem I have devoted a quite protracted period of time exploring. I am total perm disabled, ...
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0answers
16 views

Estimating Real-Time Vehicle Velocity from low-frequency GPS, accelerometer, gyro and magnetometer in Smartphone

I am trying to write a system that would be able to estimate the velocity of a traveling vehicle (usually a car) using a smartphone. Most smartphones have the next sensors: 1Hz Low-Frequency GPS 10-...
0
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1answer
35 views

Super resolution with aliased signal

SKIP to Questions below if you want : In super resolution I can create a high resolution signal from a low resolution signal. But it is also possible that the low resolution signal contains aliasing. ...
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0answers
19 views

What is meant by“ discontinuous”here?

I am reading signal processing first by Mcclellan In chap 3,last para of article 3.1.2, i came across a term "discontinous" as shown underlined in attached photo What is meant by it in the context ...
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1answer
38 views

OFDM pilot allocation block type and comb type

As known, the pilot insertion in OFDM can be either bock type or comb type, I think comb type is appropriate for double-selective channel while block type is for frequency selective channel: In the ...
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2answers
33 views

Impulse response of an LTI system given the input and output signals

I have been given the input and output signals of an LTI system as: $x[n] = (\frac{1}{2})^nu[n] + 2^nu[-n-1]$ $y[n] = 6(\frac{1}{2})^nu[n] - 6(\frac{3}{4})^nu[n]$ I have found the system function $...
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1answer
17 views

Why does my signal magnitude increase after adaptive filtering?

I am using a series-cascade of multiple NLMS adaptive filters each with step size 0.0040, leakage factor 1.0, and 100 filter taps. My signal gains magnitude at each step of the filtering, say the peak ...
0
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1answer
30 views

Determine reflections from received signal

I have a reference signal $r(t)$ and the correlation between that reference signal and the received signal : $C_{XR}(\tau)$. The signal I receive contains reflections on walls. I have to build a ...
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0answers
23 views

Discretizing my continuous system in Matlab

I was hoping someone could help me with conducting my discretization in MATLAB. I have a linear system with known data: sampling interval $T$, system matrix $\mathbf{A}$, input matrix $\mathbf{B}$, ...
1
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0answers
53 views

Nyquist-Shannon sampling theorem: implications on matching data records?

I have two data records $R_1$ and $R_2$ with sampling periods $T_1$ and $T_2$, where $T_1$ < $T_2$. These records arise from sampling and filtering two signals to remove any noise (including ...
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2answers
24 views

OFDM time vs. frequency domain channel estimation/equalization

In OFDM, the majority of Equalizers are used in frequency domain. I mean the signal is transmitted in time domain (after performing iFFT), then to estimate the channel we should perform FFt to use ...
0
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1answer
30 views

How does a shift in time domain result in phase shift in frequency spectrum?

I am aware of the fact that a time shift of say $t_0$, results in a phase shift in the frequency spectrum. What confuses me is how this scales the rotational part of the transform by $t_0$ and doesn’t ...
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0answers
66 views

How do i calculate the accuracy of an algoruthm?

I'm doing research on an machine learning image processing algorithm (segmentation algorihtm)i.e. computer vision performs when an image takes as an input and objects in an image are segmented and ...
0
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1answer
23 views

Do all systems in z domain are filters?

Normally a system transfer function is represented by H(z) I want to know wether all those system transfer functions are only representing a digital filter? Or their any other thing/entity in z ...
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0answers
18 views

Do we need a transmit and a receive filter in a OFDM transceiver system?

can anyone specify in brief what are the filters that can be used as a transmit and receive filter in OFDM. Any material to start with will be very much appreciated. Thank you!
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5answers
110 views

Does negative frequency actually exist or it is just theoretical?

This below questions gives good explanation regarding negative frequency What is the physical significance of negative frequencies? But I have one query Does negative frequency only exist ...
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1answer
30 views

The use of FDM for a single message signal

Suppose I have a single message signal, m(t), that is subjected to AWGN upon transmission. Is there any way that FDM (or any multiplexing strategy) can be used to ultimately improve the SNR of the ...
0
votes
1answer
27 views

Programmatically (e.g. in Python) adding clipping to an audio file? [closed]

I am trying to replicate the audio artifact exemplified here to a set of 1000 audio files. In particular, I would like to be able to 'clip' the louder parts of each sound clip so they become distorted ...
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0answers
18 views

How do you determine the power required for a phase shift keying modulation scheme?

This wiki article has a diagram : which shows how the message "11000110" is conveyed as a waveform. I'm trying to understand how the power to transmit this message can be determined. Do I need ...
1
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0answers
64 views

Division in the Fourier Domain (Deconvolution) - How to Handle Lengths of the Signals

In order to avoid circular convolution $y(t)$ of two functions say $u(t)$ and $v(t)$ in Fourier transforms, the data length must be at least ($u(t)$)+length($v(t)$)$-$1. If we are interested in ...
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2answers
60 views

Rectify signal basic question

When rectifying a signal by squaring it, is it necessary to upsample by a factor of 2? Why is this?
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0answers
8 views

Computation of Bispectrum for feature extraction

I'm working on vibration analyis and trying to extract features from the frequency domain. I came across a relevant paper where the Bispectrum is computed. However, I do not understand how it is done. ...
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0answers
33 views

Spatial wavelength

I was reading a paper on motion magnification, Eulerian Video Magnification for Revealing Subtle Changes in the World by MIT CSAIL researchers, where the equation (14) of the paper uses spatial ...
0
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1answer
41 views

Different amplitude in time-domain vs frequency-domain

Reading the book Understanding Digital Signal Processing I am confused with the following picture: First figure is the input signal ($x_1(n) = \sin(2\pi f_0nt_s)$, $f_0$ frequency, $t_s$ being the ...
0
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1answer
54 views

QPSK vs BPSK bandwidth efficiency

Id like if someone could confirm my logic here ... So I have two scenarios In the first scenario I have an analogue signal (100s long), which I sample 300 times, at 8 discrete quantization levels. ...
2
votes
2answers
74 views

Show Equivalence Between Multiplication in Time Domain to Convolution in Frequency Domain

My goal is to compute the Fourier of the product between two discrete time signals, y1 and y2. This can be done by computing the convolution between the fourier transform of y1, f1 and the fourier ...
1
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2answers
77 views

I am having some hard time in understanding the difference between MAP criteria and ML?

There are a number of possible criteria to use in making decisions. Can someone elaborate on the difference between ML and MAP for a sequence of BPSK symbols impaired by gaussian noise ?
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0answers
8 views

Removing background from video of actors in front of stage

I have a live video of actors on a stage. I can assume, that the stage is not to 'noisy', but it is not a greenscreen (it's not a professional stage) and may have multiple colors. But it does not ...
0
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1answer
17 views

Frequency-specific Delay?

So an equalizer manipulates the gain of certain frequencies by use of a variety of filters, as we all know. But is there a way to manipulate delay in a frequency-specific manner? A parametric ...
3
votes
1answer
38 views

Proof for the solution of homogenous difference equation

Suppose the output $y_h[n]$ of a linear, time-invariant system is described by by the following equation for input $x[n]=0$, $$\sum_{k=0}^{N}a_k y_h[n-k] = 0$$ My book states the $y_h[n]$ is in fact ...
1
vote
1answer
49 views

Analytic solution for non-flat filter design

I'm trying to write an accelerometer calibration script that uses filters to convert from volts into $m/s^2$. As accelerometers tend to have non-flat response curves, this means I have to design a ...
0
votes
1answer
35 views

What is the formula for the frequency spectrum?

A signal $f[n]$ is given, the corresponding DTFT as $F(e^{j\omega})$ and a plot of the frequency spectrum $f(t)$. Unfortunately I can't find a formula for the frequency spectrum in my documents. When ...
-1
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1answer
38 views

How to generate Hilbert Filter FIR coefficients for a given specification in MATLAB? [closed]

Order = 27, stop and pass band variable. Is there any built in function to get the coefficients?
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0answers
43 views

Lowpass Butterworth filter equation

I am using a 5th order lowpass Butterworth filter with a varying cutoff frequency, $f_c$, to smoothen some data coming from a spectrometer. An example of a spectrum, plotted with the filtered data, ...

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