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0
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1answer
13 views

Which solution will work for compressed audio signal problem

I have got an audio recording that they say recorded over time duration 2mins and 46 seconds (what app shown them while recording)but the app did something after 15 seconds record, while saving that ...
0
votes
1answer
23 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
votes
0answers
23 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
votes
2answers
58 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
votes
0answers
10 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 ...
0
votes
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
votes
1answer
33 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) = ...
-1
votes
0answers
32 views

How to find the corner of a whale fin?

I have got the images of whales and I extract the fin from the whale and then apply an edge detection algorithm which gives me a 2 dimensional vector with the edge values. I can plot this vector to ...
-1
votes
0answers
34 views

How would you select the top n frequency of a sample from a noisy audio file?

I am trying to select the top n frequency spectrum from a wav file for my feature vector ...
-2
votes
1answer
28 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 ...
0
votes
1answer
34 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
31 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
vote
1answer
57 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
votes
0answers
40 views

Why do we use sliding window to detect peaks in FFT?

In the sample code below it uses sliding window to detect peaks of a FFT, what I don't understand is that why can't we just pass through once and keep track of the previous value? ...
1
vote
1answer
57 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
votes
1answer
41 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
votes
0answers
27 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 ...
0
votes
0answers
33 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
39 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
vote
1answer
88 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
26 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 ...
0
votes
0answers
27 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 ...
1
vote
0answers
37 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
votes
0answers
46 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
votes
1answer
100 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 ...
0
votes
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
52 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
21 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
vote
2answers
184 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
vote
1answer
45 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
70 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
57 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
votes
0answers
23 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
19 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
vote
1answer
81 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 ...
0
votes
2answers
106 views

Merits of “Zero-Phase” Zero Padding

I understand the reasons for zero-padding a finite signal before FFT. However, I was reading this book (http://www.dsprelated.com/dspbooks/sasp/Zero_Phase_Zero_Padding.html) where the topic is Zero ...
-2
votes
1answer
69 views

FFT on Hamming Window Function [duplicate]

I want to apply Hamming window function the Audio sample then find out its fft.. ...
0
votes
0answers
36 views

Help with IQ Balance Equations?

I have developed a spectrum scope that plots signal vs frequency starting from IQ signals. I currently do not have a way to balance the IQ signals, so am looking at various ways to do so. I have ...
0
votes
1answer
46 views

Extending a waveform

Apologies if this makes no sense or seems rather simple, I'm a Matlab newbie. Basically, I've got a .wav audio waveform which I am resampling to various different frequencies and then trimming the ...
0
votes
1answer
31 views

Bluetooth locating with RSSI and only one receiver

Is there a method to find the relative direction of a Bluetooth device to the receiver? A quick Google search on "Bluetooth positioning" returns several methods using triangulation, but I don't want ...
-1
votes
1answer
26 views

BCI project using EEG signals

I want to make a BCI project, based on EEG signals, to control a robot using the brain's P300 wave. I have read a lot of papers, which give me a wide knowledge on how to deal with those signals, but ...
1
vote
1answer
107 views

Find similarity of sound signal

So I was working on a program to comparing the similarity between the pronunciation of a word, First I got the audio file, and I use FFT on it to get the amplitude over frequency array, then I just ...
1
vote
1answer
95 views

Why these harmonics always present?

I am using Audio Precision 2700 to test some test vectors. I have connected resistor banks as class - d power amp's load, and tap from this resistor using a XLR cable to the AP. When my power amp ...
0
votes
0answers
11 views

how could i fill missing data?

i tried a forecasting method and i want to check if it is correct or not and why? my study is about evaluating mutual funds for two kind of them it is a comparative study and i wan to use gcc index ...
0
votes
1answer
61 views

Feature vector for MFCCs

I am working on a project, for which I am finding the onset times of an audio and then extracting the MFCC coefficients for all the times. Thus if I have n onset times, I would have n feature ...
0
votes
0answers
21 views

calculate signal power for windowed sine like signal while ignoring phase shift

What is the best way to calculate the signal power of a sine like signal, recorded into a small buffer (32 samples), in such a way that phase shifts of a few samples will not have an influence on the ...
0
votes
0answers
35 views

comparing different signals

I have some noise measurements and 4 different models that can generate a similar noises using estimated parameters from the real measurements. To compare the estimated noises I calculated the PDF, ...
-1
votes
5answers
129 views

Call recognition using Digital Signal Processing

We are looking for writing applications which would recognize Bird calls and Frog calls using Sound processing. EDIT: I want to identify the species of bird / frog and do not want to differentiate ...