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3 views

How do we find the SNRseg if I have a block with 2D in time domain

I always get the answer -.0017 and it suppose to have some negative number around 30. I get the average for the plane voice then the average for the difference between plain and the encrypted voice ...
-2
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1answer
31 views

System Properties; Linear, Causal, Time-Invariant, Stable?

I know the answers of the below question but I dont know why, except linear, could you explain the rest? Small tick: correct, small tick with dash incorrect answer.
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1answer
17 views

How convert scal to frequency when use cwt in matlab

I am new in DSP.I have the flowing code t = linspace(0,1,1000); x = cos(2*pi*60*t); CWTcoeffs = cwt(x,1:64,'sym8','plot'); colormap jet; and my output is: ...
5
votes
1answer
68 views

Duration of unknown rectangular pulse with additive white Gaussian noise

Problem. There is a discrete signal $f[i]$ (example below). It is known, that $f[i]$ have a form of rectangular pulse with additive white Gaussian noise. $f[i] = s[i] + n[i]$, $s[i] = ...
3
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2answers
75 views

OFDM transmitter bandwidth

Theory Suppose an OFDM transmitter with four subcarriers is implemented using the structure shown below. If the serial data input rate is 40 bps, each parallel stream will run at 10 bps. ...
1
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1answer
42 views

Sampling orthogonal signals

Suppose I have two signals $f,g$ which are orthogonal in the sense of the usual inner product on $\mathbb R^d$. Then if I'm not mistaken these signals have disjoint spectral support, i.e their fourier ...
0
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2answers
40 views

Fundamental frequency

Can someone help me: I have a signal which consist of three frequencies; for example, $f_1=800\,\text{Hz}$, $f_2=1050\,\text{Hz}$, $f_3=1600\,\text{Hz}$. How can i compute the fundamental frequency? ...
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1answer
14 views

how do you compute the channel gain from path loss index in wireless communication?

how do you compute the channel gain from path loss index in wireless communication?
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1answer
21 views

How to detect time-domain ringing in real valued signals?

Is there a way of quantifying overshoot and ringing in a real-valued signal?
1
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1answer
14 views

Is a negative Es/No for an SCPC RF signal possible, and what would such a value signify?

I apologize if this isn't the correct Stack on which to ask this question, but it seemed like the best fit. I've tried to Google an answer, but I haven't been able to find anything that applies ...
0
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2answers
67 views

What is a 'time-variant' signal?

I have found in the literature a "time-variant signal" term , but I could not understand what that's mean. I know that there is "time-variant systems", but this is the first time, which I see a ...
0
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0answers
26 views

Using bilinear method while filtering a signal - Matlab

i have to current signal in matlab: Fs = 8000; T = 1/Fs; N=512; t = (0:N-1)*T; ...
0
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0answers
21 views

USB-connectable ECG machine

I would like to buy some kind of ECG (electrocardiogram) machine for developing signal processing and machine learning applications. I am looking for something that is not overly expensive, can be ...
2
votes
2answers
50 views

Periodicity of the output of causal time-invariant systems when the input is periodic

For time-invariant systems, if the input is periodic, the we can argue that the output is periodic: If we shift the input signal one period, we come up with the same signal as before, and since the ...
0
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0answers
21 views

Applying Bilinear filter to a signal -MATLAB

I have the following code: ...
1
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3answers
57 views

Normalization purpose in signal processing

What is the purpose of normalizing the signal? If we have two signals on hand, how is it used when comparing these two signals?
0
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0answers
22 views

To determine dominating frequency from pressure time plot

I have pressure data over time. I need to find the dominating frequency of this data. I tried fft in fluent and also in matlab. Both gives me the same plot which is having too much of peaks. I need to ...
1
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1answer
63 views

Beat Detection with Arduino

I'm trying to make a robot dance on several songs using Arduino. I need to understand how to get the rhythm from the songs, something like detecting the beats, calculating the bpm.. I'm not expert but ...
0
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0answers
30 views

Feature extraction and Variance

I see there is a relationship between the Variance of a signal (i.e EEG signal) and features extraction of that signal. for example PCA tend to take almost of the variance of the original signal , but ...
2
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2answers
67 views

Effects of DC offset on a signal

What are some of the reasons why DC offset is considered undesirable for a timeseries signal other than wastage of power during transmission ? Specifically, How does it cause spectral leakage and out ...
0
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0answers
11 views

weak sense stationarity sufficient for multitaper spectrum analysis?

This is a general question on multitaper spectral analysis of signals and stationarity I work with time series which are non stationary. In this regard I have two questions Is weak sense ...
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1answer
15 views

Expected value of coupled signals is zero

Suppose there are two vector signals, $u$ and $v$, which are functions of time. Given, $E[uv^T]=0$, what is the physical significance of this statement. For clarity, assume $u$ and $v$ are noises in a ...
0
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1answer
52 views

Additive but not homogeneous continuous system?

I am trying to find an example of a continuous system that is homogeneous, but not additive. So far, the only example I could find was an example from this page, which describes system as $y(t) = ...
-2
votes
1answer
33 views

What happens to the fourier transform of sample result of $30kHz$ sinusoidal signal when sampled with sample frequency $44.1KHz$?

As the title says,w hat happens to the fourier transform of the sample output of $30KHz$ when sampled with sample frequency $44.1KHz$? I do not get how alias can appear, because fourier transform of ...
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1answer
37 views

What is the distance metric in dynamic time warping?

I am reading the lecture slides from this site http://luthuli.cs.uiuc.edu/~daf/courses/CS-498-DAF-P/Lecture%2018%20-%20Time%20series,%20DTW.pdf In slide 24, the lecture suggest using metric of the ...
0
votes
1answer
42 views

Why do we need to normalize a WAV file before calculating the FFT?

I am trying to calculate the FFT of a signal stored in a WAV file using SciPy. I found a solution here, but it seems like we need to perform this step before the FFT: ...
1
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1answer
64 views

Unsupervised learning algorithms to detect anomaly in waves

I have a sample of graphs (more than 10000...). that look like in the image below: I am searching for an unsupervised learning algorithms that can help me to detect anomalous observations. Here ...
1
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1answer
71 views

dominant eigenvectors of an unknown matrix

Do you have any idea about how we can find the principle eigenvectors of an unknown matrix ${H}$? The elements of $H$ are unknown in general. If you are familiar with channel estimation procedure in ...
0
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1answer
50 views

What is the rms value of a signal and how to use it

In some papers/books I found infos about a signal given as RMS value. What is the RMS value and what information does it contain? How can I compute it? Moreover, if they say that the signal is a ...
0
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0answers
34 views

Trying to understand the gold-rabiner pitch detection algorithm

I am currently in the process of taking on implementing the Gold-Rabiner pitch tracking algorithm, and I came across what seemed like a good explanation of it in David Meehan's "A Code Excited Linear ...
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0answers
44 views

How to, efficiently, identify telephone number from the key pressed data audio file?

A very common homework question. You are given an audio file(.wav) which has the recording of the keys pressed during a telephone call. You have to identify the telephone number from this audio file ...
-1
votes
1answer
49 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 ...
1
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1answer
96 views

Question on Chebyshev filter

What does the output signal look like when you insert $2000 Hz$ square pulses to chebyshev filter with parameters: (Matlab syntax). I tried to do it like this but I don't understand where it goes ...
0
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0answers
29 views

algorithm for low frequency filter and analysis

i have a number of analog signals being monitored and then compared. My issue is that the signals are not synchronized (potentially 4-5 seconds out of phase) and my target "trouble" frequency is much ...
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0answers
28 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 ...
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0answers
42 views

Removing the mean in finding PSD

Does removing the mean value of the signal effect the estimation of power spectral density(PSD)? If it effects, how? What is the advantage we can get by removing the mean of the signal in estimating ...
0
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0answers
69 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 ...
1
vote
1answer
31 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 ...
2
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1answer
106 views

Regarding Bode plots; $H(s)$ and $H(j\omega)$

In circuit analysis, I understand the use of Laplace Transforms to obtain the impedance of a linear RLC circuit, ie transforming from the time domain to the frequency domain. In most texts I have seen ...
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0answers
13 views

Suppose we have the following data. How can we calculate the channel capacity and R?

A channel has a bandwith of 5MHz. If signal strength to spectral noise density S/N0 is 107 Hz, calculate the channel capacity C and R. The problem is that I can use Shannon-Hartley theorem because ...
0
votes
2answers
62 views

“Perfect waveform” for cross-correlations?

I am well versed in cross-correlations, as my masters thesis heavily relied on them for music classification and beat detection. So this question focuses more on the signals that I am running an ...
1
vote
1answer
23 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?
1
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2answers
206 views

Simple and efficient algorithm to detect frequency and phase of a sine signal

I need an algorithm to detect frequency and phase of a pure sine signal. The frequency of the input signal changes between 0 and 100 Hz. The value of the signal gets captured with a frequency of 20 ...
1
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1answer
67 views

range and motion in received signals by radar

I've got two signals which are consecutive received signals by a radar system. the signals values are complex (in form x+iy). I have generated a trasmitted signal using the info available. Now, I ...
0
votes
2answers
94 views

Butterworth filter in python

I'm trying to use a Butterworth filter in Python as described in this thread with these functions: ...
1
vote
1answer
59 views

why upsampling contracts the spectrum?

I'm trying to understand why Matlab function upsample causes contraction in the spectrum, like the following figure shows. Also showed in mathwork online document. enter link description here ...
0
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0answers
28 views

Adaptive filtering for detection of a known-frequency periodic signal

Given a very noisy signal (EEG recording), to identify which periodic component is stronger, out of $N$ (e.g. $4$) known frequencies. For the sake of completion, the application is an SSVEP-based ...
0
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0answers
16 views

Big sharp spikes with maximal negativity

I am wondering if anyone knows how can I detect a big sharp spikes with maximal negativity as shown in the figure below in the red box. Many thanks.
0
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0answers
21 views

Calculating the modulation based on the coordinates in the constellation diagram

A constellation diagram has points at the following coordinates: (2,2), (2,-2), (-2,2), ...
1
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1answer
85 views

Detecting a frequency swept sinusoid and its parameters?

Given a (FFT-sized) frame of data, and detection of a spectral component statistically above the noise floor in the FFT of this window, what characteristics or signal analysis could be used to ...