Questions tagged [signal-analysis]
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1,820
questions
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8 views
Optimal Combination of received signals from two antenna
I really appreciate an answer or any hint how to approach this problem:
Problem:
A receiver has two antennas. The first antenna receives $Y_1=hx+n_1$, where $x\in\{-A,+A\}$, $h$ estimated channel, and ...
0
votes
1answer
26 views
Does the RMS value of a signal yields its root-power?
I'm relatively new to the field of signal processing and might be a bit confused about terminology here. I'm trying to understand what determines whether I deal with a root-power or simple power ...
1
vote
1answer
42 views
How to calculate the instantaneous frequency for one specfic signal?
I have a signal which like this:
I want to calculate this signal's instantaneous frequency.I have tried hht and so on which method I can find but can not get the result.
So does somebody can give me ...
0
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1answer
40 views
Why is z (and not ω) the variable of interest for discrete time systems?
A continuous time domain system is well described by the Laplace transform. It allows to express any continuous signal x(t) as the integral sum of weighted complex and exponentially growing/decaying ...
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0answers
12 views
What are some good references that define images from a statistical point of view?
I know that images can be studied and understood as 2 dimensional signals. However, I hope you can point me towards references that define and present images rigorously in terms of realisations of a ...
0
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2answers
47 views
Working out EIRP
There is a debate about the proper way of how to calculate the EIRP, so I need your help on which method is wrong and why please!
Let's suppose we have the following:
Output power: 165 W
Reflected ...
0
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1answer
30 views
Belt tension measurement (36 Hz): What should my FFT size be?
These are my setting that I can adjust and I need to measure 36 Hz. +- 1 Hz.
What settings do you recommend?
1
vote
1answer
26 views
How to Combine white gaussian random noises from different Seeds?
I have generated two different white gaussian random noises in MATLAB using two different seeds. For example:
...
1
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1answer
51 views
How to compute convolution using the Discrete Hartley Transform
It's easy to compute the Discrete Hartley Transform of a 1D signal:
...
1
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1answer
52 views
Compare two Fourier transforms of two signals by calculating the coherence
My overall aim is to compare the edges of two images by comparing their Fourier Transforms (FFT) and to calculate one number as a key performance indicator that describes how much they are similar to ...
0
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0answers
28 views
fft result with the number of integer multiples of fs
With the cosine signal fc=3Hz and the fs=13Hz as below,
fc=3;
fs=13;
Ts=1/fs;
N=101*13; % 101 times of fs
n=0:N-1;
x=cos(2*pi*fc*n*Ts);
and then fft with the ...
0
votes
1answer
24 views
Finding transfer function from bode plot
Given a bode diagram
From the figure, I see that when $\omega = 100 \text{ rad/s}$ the magnitude response starting to go down and when $\omega = 1000 \text{ rad/s}$ the slope become higher. Then
$$H(...
0
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1answer
23 views
Transmitting an approximate CW with an FM modulator
Imagine we had an FM modulator with carrier frecuency $f_c$. My doubt is about the optimal approach to use it for transmitting a tone (CW) of a frequency $f_c+\Delta f$.
Let $x(t)$ a and $y(t)$ be the ...
0
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0answers
18 views
$Z$-transform of a multilinear function/ consecutive multplication of $k$ signals $y_1(n), \ldots, y_k(n)$
How should one go about calculating the $Z$-transform of a signal that is the multiplication of $k$ signals (i.e. a multilinear function with regards to signals $y_1(n) \ldots y_k(n)$ ? Namely, $\...
1
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0answers
52 views
Plotting amplitude and phase spectrum in MATLAB [closed]
We are supposed to write a code that will help us plot the following signal and their amplitude and phase spectrum.
unit step
exponential
unit ramp
sinc
rectangular
I believe I can scrap the code ...
2
votes
2answers
54 views
Meaning of Rect and Train of Rect Spectra
The Fourier transform of $x(t)=\operatorname{rect}(t)$ is $X(f)=\operatorname{sinc}(f)$
The Fourier transform of a periodic train of rectangular pulses $x(t)=\sum\limits_{n=-\infty}^{\infty}\...
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0answers
17 views
Trying to do frequency analysis of an accelerometer output
I am new to signal processing. I have a 3 axis MEMS accelerometer. I have read its output into $\mbox{Matlab}^{\tt TM}$.
My problem is that the signal I am trying to isolate has a frequency of about 0....
0
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1answer
13 views
I want to perform aec on a wav file and calculate erle
I am trying to evaluate the performance of an AEC by comparing the i/p and output wav file. I want to calculate echo return loss enhancement to predict how much(db) echo has been attenuated but i am ...
0
votes
1answer
24 views
Where can I get the file l1eq_pd.m?
To recover the original signal when compressive sensing is used, we get an error, to avoid the error, we need to modify the l1eq_pd.m file. How to go about it? Where can I get this file in Matlab?
4
votes
1answer
115 views
Is there mathematical relationship between the FFT and DCT transforms
I need to model the relationship between the DCT and DFT transforms (If it exists). I mean real signal $x \to y = \textrm{DCT}(x) \to z = \textrm{DFT}(y)$, so I need to get the relationship between ...
0
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0answers
17 views
Speaker Walkaround
Does anyone know what Speaker Walkaround means in context of a digital amplifier?
Also how is this test performed?
Lastly, how is it different from Load Diagnostics in Amplifiers?
1
vote
1answer
22 views
Is there a difference measure that is insensitive to shifts?
I'm trying to figure out a difference measure that is relatively insensitive to time shifts.
I have tried DTW (dynamic time warping.)
This is the result:
The signals on the left are clearly more ...
0
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0answers
21 views
How to determine STFT parameters as a function of desired resolution
None of the Q&As I've seen thus far have given a clear answer to what seems like a simple question: assuming I know the CenterFrequency, ...
0
votes
0answers
23 views
Coherence of a signal with itself to assess the PSD increase due to device turning on
I have a sensor that acquires data in the form of a time series, which I can model as a (mostly Gaussian) stationary stochastic process. I can study it in the frequency domain through its Power ...
-1
votes
1answer
22 views
Phase in FIR filters [closed]
Does anyone have any idea what is Clear Phase technology ? How is it implemented ? And which audio channels whether left ,right center , sub woofer should have this technology implemented and why ?
0
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1answer
27 views
RMS Amplitudes of voltage
I am looking here at the course of current fluctuations and have calculated the RMS values, but somehow it seems strange to me: with the black line there are small fluctuations, but the RMS value is ...
2
votes
3answers
103 views
Why would a time shifted signal have a higher maximum frequency than an unshifted one?
I´m reading the book Numerical Simulation of Optical Wave Propagation by Jason Schmidt.
In section 2.1-2.2, the author performs the FFT of a centered and a shifted Gaussian pulse and makes the ...
0
votes
2answers
45 views
What's the point of defining the signal over the whole time domain?
This question is classic for anyone starting with some signal processing course, suppose $y(t)=x(t/2)$ then the system is noncausal because we have that the output at t=-6 depends on the input at t=-3 ...
3
votes
1answer
85 views
Error probability for orthogonal signaling with unequal symbol probabilities
I'm trying to derive the equation of error probability in orthogonal signaling. Here what I've tried:
Let $\vec{s_1} = (\sqrt{E_b} , 0)$ and $\vec{s_2} = (0, \sqrt{E_b} )$ be vector representation of $...
0
votes
1answer
26 views
Confusion understanding phase shift/delay?
I am reading proakis, as shown highlighted in attached snap shot,there is '-'sign along with j,but still it is written (underlined red) implies shift in positive n direction,why and how positive?when ...
0
votes
0answers
14 views
Two lock in amplifiers, almost identical setup, different AC Gain?
I am measuring a voltage output of around ~110 uV for two thermometers. Other than the placement of the thermometers on the sample and the frequency of the lock ins, everything else is kept the same ...
0
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0answers
15 views
Log in MFCC vectors incorrect according to Source-Filter Theory
In the MFCC vectors computation given many in places and here we apply log after we average with the mel bands. However, the source-filter theory says that the source frequency is modified by the ...
0
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0answers
35 views
I think the number of possibile value(s) of variable $\omega$ is 1 however actually it takes 2 values of angular frequency
Sampling is done by $~F_{s}=4[\text{Hz}]$ against$~x(t)=\cos(2\pi t)+1$ and the below function is given.
$$y[n]=\frac{1}{2} \left\{ x\left[n \right] +x\left[n -1\right] \right\} $$
And it is said ...
0
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0answers
14 views
Please explain the following Linear Prediction estimate graph
I am reading this doc https://librosa.org/doc/latest/generated/librosa.lpc.html#librosa.lpc?
I can't understand the graph for linear prediction coefficients. Please help explain it as I a new to this ...
0
votes
1answer
44 views
What does frequency weighting an acceleration signal mean? And How do I frequency weight the raw acceleration data collected?
Disclaimer: I have very little knowledge in signal processing.
I'm trying to calculate a Whole Body Vibration(WBV) measure called Vibration Dose value(VDV).
$$VDV = \left(\int_{0}^{T}a(t)^4\,dt\right)^...
1
vote
1answer
43 views
Help with literature pointers for improving estimation of underlying mean for signal with periodic noise
I am in the starting phase of a master thesis and are having some trouble finding a good starting point in the literature for my thesis.
The aim of my thesis is to provide as good of an estimate as ...
0
votes
1answer
29 views
Bio-signal discontinuity after FIR filtering
I'm filtering respiration signal. I have a signal of duration equal to 10 minutes, so I decided to divided it into period of 10 s. I filtered each epoch with FIR filter, but I have discontinuities ...
0
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0answers
30 views
Python library for audio filtering, gating, and sound/silence detection
Is there a Python library that can do all of the following?:
Band-pass filter;
Noise gate, with different parameters set for different segments of audio file;
Detect and count the number of discrete ...
-1
votes
1answer
28 views
Equalization in CAR- Automotive Audio
Can someone tell me what is the purpose of CAR Equalization in audio and why before CAR Equalization ,gain adjustments are necessary ?
Also why would someone use FIR filters during CAR Equalization ...
0
votes
2answers
32 views
Digital Signal Quantized Processor Complexity
In “traditional” digital signal processing, the complexity is computed as a number of multiplication the operation requires, e.g. the computation of the N-point DFT via the decimation-in-frequency FFT ...
1
vote
1answer
43 views
Balance Fader in Digital Amplifiers
What is the purpose of Balance / Fader in a digital Audio amplifier?
In a signal flow what is the most apt position to place balance and fader(for example after before a compressor unit or at the ...
0
votes
3answers
153 views
There is an implant in me, is there a way to identify the frequency it is receiving signals on?
There is an implant in me, is there a way to identify the frequency it is receiving signals on?
I don't want to share the evidence and my reasoning for believing there is an implant in me, you can ...
1
vote
2answers
59 views
Best temperature compensation equation?
I'm looking for the correct temperature compensation equation to use on our project.
We are measuring the output of a detector who's signal is very sensitive to temperature drift.
Any external ...
5
votes
2answers
98 views
What are the restrictions on DFT input sequences in order to produce valid spectral results
In a recent comment (as I understand it) our colleague OverLordGoldDragon’s stated that the only restrictions on DFT input sequences, to produce valid DFT spectral results, are that (1) the input ...
1
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0answers
41 views
Why we only can transmit a real signal? [duplicate]
i just wondering, why we always transmit a real signal but when we deal with a baseband signal we use a complex signal ? are this is related to up and down conversion of the signal (Because complex ...
10
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5answers
591 views
A DFT “periodic inputs” question
Why do people say that the fast Fourier transform (FFT) “views”, or “interprets”, or “assumes” its input sequence is periodic? I ask this question because the activities of viewing, interpreting, and ...
0
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2answers
35 views
Centre channel derivation using correlation
I would like to know the algorithm for how centre channel is derived from rejecting left and right channel in audio upmixing process.
Can someone explain intuitively rather than hard hitting ...
4
votes
2answers
289 views
Geometric representation of a signal using basis functions
I'm trying to solve the following problem where I need to express $x(t)$ in terms of the given $φ_i(t)$ functions. (It is proven that the $φ_i(t)$ functions are orthonormal).:
Here's what I tried:
In ...
0
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0answers
28 views
Current fluctuations with reduced capacity
I simulate a neuron by compartments, where each compartment is represented by an electrical circuit. Myelinated nerves have reduced capacitance - so for example, if $n$ denotes the membrane layers, ...
1
vote
1answer
98 views
Envelop detection using matlab hilbert function
I am trying to detect the envelope of a high-frequency signal (similar to below) using Matlab Hilbert function
This is my output
It generally follows the envelope, but there is a high-frequency ...
